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Application of graphene in analytical sample preparation
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Qian Liu, Jianbo Shi, Guibin Jiang
As a new member of the carbon family, graphene has fascinated the scientific community since its discovery. Recently, graphene also exhibited great potential to be an adsorbent in analytical sample preparation due to its exceptional properties (e.g., large surface area, π-electron-rich structure, and good thermal and chemical stability). In this article, we review the recent applications of graphene and graphene-based materials in solid-phase extraction and solid-phase microextraction, and other sample-preparation techniques. We also cover the use of graphene as extractor and matrix in matrix-assisted laser desorption/ionization mass spectrometry. Finally, we discuss possible challenges and future perspectives in this rapidly developing field.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Qian Liu, Jianbo Shi, Guibin Jiang
As a new member of the carbon family, graphene has fascinated the scientific community since its discovery. Recently, graphene also exhibited great potential to be an adsorbent in analytical sample preparation due to its exceptional properties (e.g., large surface area, π-electron-rich structure, and good thermal and chemical stability). In this article, we review the recent applications of graphene and graphene-based materials in solid-phase extraction and solid-phase microextraction, and other sample-preparation techniques. We also cover the use of graphene as extractor and matrix in matrix-assisted laser desorption/ionization mass spectrometry. Finally, we discuss possible challenges and future perspectives in this rapidly developing field.
Highlights
► We review recent applications of graphene-based materials in SPE and SPME. ► We review recent applications of graphene-based materials in MALDI-MS. ► We discuss challenges and perspectives of graphene-based sample preparation.Graphene for impedimetric biosensing
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Alessandra Bonanni, Adeline Huiling Loo, Martin Pumera
Graphene displays promising features for biosensing applications. Electrochemical impedance spectroscopy (EIS) is a very sensitive, label-free technique that is ideally suited to be coupled with a graphene platform. We discuss recent advances of graphene-based platforms for impedimetric genosensors and immunosensors. We also provide an overview on EIS and the preparation of graphene by different methods, which exhibit strong influence upon the function of the biosensor.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Alessandra Bonanni, Adeline Huiling Loo, Martin Pumera
Graphene displays promising features for biosensing applications. Electrochemical impedance spectroscopy (EIS) is a very sensitive, label-free technique that is ideally suited to be coupled with a graphene platform. We discuss recent advances of graphene-based platforms for impedimetric genosensors and immunosensors. We also provide an overview on EIS and the preparation of graphene by different methods, which exhibit strong influence upon the function of the biosensor.
Highlights
► Impedance spectroscopy is a powerful technique when combined with graphene surfaces. ► A biorecognition layer can attach to graphene surfaces covalently or non-covalently. ► Single-stranded DNA oligomer can be used for DNA sequence sensing or aptasensing.Modification of carbon nanotubes for preconcentration, separation and determination of trace-metal ions
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Rafal Sitko, Beata Zawisza, Ewa Malicka
Carbon nanotubes (CNTs) have received much attention for their many potential applications in analytical chemistry due to their adsorptive properties. Unmodified CNTs can be used as sorbents in solid-phase extraction (SPE), especially if metal ions are complexed with an appropriate chelating agent. However, raw CNTs are insoluble and hardly dispersible in solvents due to strong van der Waals interactions that hamper sorption of metal ions. Proper surface treatment of CNTs not only enhances dispersibility but also improves metal sorption and selectivity in SPE. This review focuses on chemical modification of CNTs. We discuss functionalization of CNTs through oxidation and further modification via creation of amide or ester bonds. We also review radical addition with aryl-diazonium salts and the N2-plasma technique as effective methods of grafting functional groups onto CNT surfaces. Moreover, we present CNT-based composites, including magnetic composites. We show that modified CNTs and their composites can be very attractive as sorbents due to their high adsorption capacity. The review includes several applications of modified CNTs in preconcentration and determination of trace-metal ions in water, food, environmental and biological samples.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Rafal Sitko, Beata Zawisza, Ewa Malicka
Carbon nanotubes (CNTs) have received much attention for their many potential applications in analytical chemistry due to their adsorptive properties. Unmodified CNTs can be used as sorbents in solid-phase extraction (SPE), especially if metal ions are complexed with an appropriate chelating agent. However, raw CNTs are insoluble and hardly dispersible in solvents due to strong van der Waals interactions that hamper sorption of metal ions. Proper surface treatment of CNTs not only enhances dispersibility but also improves metal sorption and selectivity in SPE. This review focuses on chemical modification of CNTs. We discuss functionalization of CNTs through oxidation and further modification via creation of amide or ester bonds. We also review radical addition with aryl-diazonium salts and the N2-plasma technique as effective methods of grafting functional groups onto CNT surfaces. Moreover, we present CNT-based composites, including magnetic composites. We show that modified CNTs and their composites can be very attractive as sorbents due to their high adsorption capacity. The review includes several applications of modified CNTs in preconcentration and determination of trace-metal ions in water, food, environmental and biological samples.
Highlights
► This review focuses on chemical modification of carbon nanotubes (CNTs). ► We discuss different methods of chemical functionalization. ► We present several applications of modified CNTs in determining trace-metal ions. ► We discuss the adsorption capacity of modified carbon nanotubes (CNTs).The surface-plasmon-resonance effect of nanogold/silver and its analytical applications
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Aihui Liang, Qingye Liu, Guiqing Wen, Zhiliang Jiang
Gold and silver nanoparticles (Au/AgNPs) are widely used in analytical chemistry, and their intense colors have inspired artists and fascinated scientists. This review describes the absorption and Rayleigh-scattering effects of the surface-plasmon resonance (SPR) of Au/AgNPs. Specifically, the color associated with Au/AgNPs is utilized for immunoassay and aptamer assays. SPR-Rayleigh scattering is used for nanoanalysis, when combined with immune, aptamer and nanocatalysis reactions.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Aihui Liang, Qingye Liu, Guiqing Wen, Zhiliang Jiang
Gold and silver nanoparticles (Au/AgNPs) are widely used in analytical chemistry, and their intense colors have inspired artists and fascinated scientists. This review describes the absorption and Rayleigh-scattering effects of the surface-plasmon resonance (SPR) of Au/AgNPs. Specifically, the color associated with Au/AgNPs is utilized for immunoassay and aptamer assays. SPR-Rayleigh scattering is used for nanoanalysis, when combined with immune, aptamer and nanocatalysis reactions.
Highlights
► We review gold/silver-SPR absorption and SPR-Rayleigh-scattering effects. ► SPR absorption has been utilized for immunoassay and aptamer assay. ► SPR-Rayleigh scattering has been used for immune, aptamer and nanocatalytic analysis.Hydrophilic interaction chromatography
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Mariana Roberto Gama, Raquel Gomes da Costa Silva, Carol H. Collins, Carla B.G. Bottoli
In the early 1990s, hydrophilic interaction (liquid) chromatography (HILIC) emerged as a new separation method. HILIC is becoming increasingly popular for the separation of polar compounds in aqueous-organic mobile phases rich in organic solvents (usually acetonitrile). It has become important for the separation of pharmaceuticals, neurotransmitters, nucleosides, nucleotides and other compounds. This review presents an overview of HILIC separation systems, comparing it to several other recently described modes.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Mariana Roberto Gama, Raquel Gomes da Costa Silva, Carol H. Collins, Carla B.G. Bottoli
In the early 1990s, hydrophilic interaction (liquid) chromatography (HILIC) emerged as a new separation method. HILIC is becoming increasingly popular for the separation of polar compounds in aqueous-organic mobile phases rich in organic solvents (usually acetonitrile). It has become important for the separation of pharmaceuticals, neurotransmitters, nucleosides, nucleotides and other compounds. This review presents an overview of HILIC separation systems, comparing it to several other recently described modes.
Highlights
► Hydrophilic interaction (liquid) chromatography (HILIC) separation systems. ► HILIC has great potential applications for separations of polar compounds. ► HILIC is an interesting alternative for separations that are problematic.Analytical Eco-Scale for assessing the greenness of analytical procedures
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Agnieszka Gałuszka, Zdzisław M. Migaszewski, Piotr Konieczka, Jacek Namieśnik
We propose the analytical Eco-Scale as a novel comprehensive approach to evaluating the greenness of analytical methodology. It is based on assigning penalty points to parameters of an analytical process that are not in agreement with the ideal green analysis. This approach compares different parameters and different steps of the analytical process. Traditional green chemistry metrics (e.g., Atom Economy, E-factor and Reaction Mass Efficiency), which were introduced for organic preparations, do not usually fit the purposes of green analytical chemistry. Existing databases for evaluation of green analytical methods refer to known procedures and instruments, and do not encourage new, more environmentally-friendly equivalents. As an alternative to traditional green chemistry metrics, the analytical Eco-Scale can be a good, semi-quantitative tool.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Agnieszka Gałuszka, Zdzisław M. Migaszewski, Piotr Konieczka, Jacek Namieśnik
We propose the analytical Eco-Scale as a novel comprehensive approach to evaluating the greenness of analytical methodology. It is based on assigning penalty points to parameters of an analytical process that are not in agreement with the ideal green analysis. This approach compares different parameters and different steps of the analytical process. Traditional green chemistry metrics (e.g., Atom Economy, E-factor and Reaction Mass Efficiency), which were introduced for organic preparations, do not usually fit the purposes of green analytical chemistry. Existing databases for evaluation of green analytical methods refer to known procedures and instruments, and do not encourage new, more environmentally-friendly equivalents. As an alternative to traditional green chemistry metrics, the analytical Eco-Scale can be a good, semi-quantitative tool.
Highlights
► An analytical Eco-Scale is proposed as a tool for green analysis evaluation. ► Limitations of existing green analytical metrics are presented. ► The greenness of every step of a multi-stage analytical process is discussed. ► A method of analytical Eco-Scale calculation is explained. ► Examples of the Eco-Scale values for several laboratory procedures are given.Sample-preparation techniques for the analysis of chemical-warfare agents and related degradation products
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Deme Pragney, U.V.R. Vijaya Saradhi
Chemical-warfare agents (CWAs) are toxic chemicals intended for use in mass destruction and terrorist attacks. Their presence in the environment is of great concern due to their rapid distribution and toxicity. The Organization for the Prohibition of Chemical Weapons conducts proficiency tests for the offsite analysis of samples contaminated with CWAs and their degradation or oxidation products. In this article, we review recent trends in the development of sample-preparation techniques for efficient extraction of Chemical Weapons Convention-related chemicals from environmental and industrial samples. We discuss extraction methodologies (e.g., solvent extraction, solid-phase microextraction, solid-phase extraction, and gas-phase and headspace analysis) and their advances.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Deme Pragney, U.V.R. Vijaya Saradhi
Chemical-warfare agents (CWAs) are toxic chemicals intended for use in mass destruction and terrorist attacks. Their presence in the environment is of great concern due to their rapid distribution and toxicity. The Organization for the Prohibition of Chemical Weapons conducts proficiency tests for the offsite analysis of samples contaminated with CWAs and their degradation or oxidation products. In this article, we review recent trends in the development of sample-preparation techniques for efficient extraction of Chemical Weapons Convention-related chemicals from environmental and industrial samples. We discuss extraction methodologies (e.g., solvent extraction, solid-phase microextraction, solid-phase extraction, and gas-phase and headspace analysis) and their advances.
Highlights
► Sample-preparation methods for chemical analysis for the Chemical Weapons Convention. ► Stir-bar sorptive extraction, and single-drop and solid-phase microextraction. ► Headspace methods and other gas-sampling techniques are discussed in detail. ► We set out the advantages of new methods, which were incorporated in a table.Recent advances in pharmaceutical separations with supercritical fluid chromatography using chiral stationary phases
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Wang Ren-Qi, Ong Teng-Teng, Ng Siu-Choon, Tang Weihua
Supercritical fluid chromatography (SFC) has developed rapidly in recent years, particularly in the area of enantioseparations. The merits of SFC (e.g., fast analysis speed, wide polarity compatibility, lower cost of the mobile phase and higher column efficiency) would in many cases make it a better choice than high-performance liquid chromatography in drug discovery for the pharmaceutical industry. Packed-column SFC meets the gradual rise in demand for simultaneous chiral and achiral separations, impurity quantitation and direct scaling up from the pharmaceutical purifications achieved in the laboratory, especially for chiral drugs. This review focuses mainly on the latest examples of pharmaceutical separations with chiral stationary phases in SFC for efficient analyses and preparative-scale purifications.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Wang Ren-Qi, Ong Teng-Teng, Ng Siu-Choon, Tang Weihua
Supercritical fluid chromatography (SFC) has developed rapidly in recent years, particularly in the area of enantioseparations. The merits of SFC (e.g., fast analysis speed, wide polarity compatibility, lower cost of the mobile phase and higher column efficiency) would in many cases make it a better choice than high-performance liquid chromatography in drug discovery for the pharmaceutical industry. Packed-column SFC meets the gradual rise in demand for simultaneous chiral and achiral separations, impurity quantitation and direct scaling up from the pharmaceutical purifications achieved in the laboratory, especially for chiral drugs. This review focuses mainly on the latest examples of pharmaceutical separations with chiral stationary phases in SFC for efficient analyses and preparative-scale purifications.
Highlights
► We overview SFC applications for analytical and preparative chiral separation. ► We summarize the implementation of CSPs with packed-column SFC. ► We overview the SFC conditions for optimization of enantioseparation. ► We summarize tandem SFC for chiral separation.Development of electrochemical DNA biosensors
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Ailin Liu, Kun Wang, Shaohuang Weng, Yun Lei, Liqing Lin, Wei Chen, Xinhua Lin, Yuanzhong Chen
Due to the rapid response, the high sensitivity, the good selectivity and the experimental convenience of the electrochemical DNA biosensor, its applications have attracted broad interest. This article reviews electrochemical DNA biosensors and different methods proposed for their construction to overcome their limitations in selectivity and sensitivity. We also discuss their performance and future prospects.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Ailin Liu, Kun Wang, Shaohuang Weng, Yun Lei, Liqing Lin, Wei Chen, Xinhua Lin, Yuanzhong Chen
Due to the rapid response, the high sensitivity, the good selectivity and the experimental convenience of the electrochemical DNA biosensor, its applications have attracted broad interest. This article reviews electrochemical DNA biosensors and different methods proposed for their construction to overcome their limitations in selectivity and sensitivity. We also discuss their performance and future prospects.
Highlights
► Electrochemical DNA biosensors offer many advantages for DNA-sequence detection. ► We reviewed the development of electrochemical DNA biosensors. ► Immobilization and configuration were important factors influencing performance. ► We showed how electrochemical transductions produce sensitive assays.Analytical chemistry and metrological issues related to nonylphenols in environmental health
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
S. Rabouan, A. Dupuis, A. Cariot, M. Albouy-Llaty, V. Migeot, A. Cariot, A. Dupuis, M. Albouy-Llaty, V. Migeot, B. Legube
In recent decades, the development of environmental risks and their repercussions on health has led to environmental health being a field of scientific research in which interdisciplinarity is intrinsic. This article on nonylphenols (NP) shows how exchanges and knowledge transfer involving chemists, biologists, pharmacists and physicians underscore the need to further the development of analytical methodologies. We spell out the difficulties encountered when selecting a reference material for the analysis of NP (i.e. multiplicity of isomers, and variability in the composition of batches for the same CAS Registry Number). As a result, we propose 353NP (CAS 186825-36-5) as the reference material (because of its high proportion in the industrial mixture and its pronounced estrogenic power).
Source:TrAC Trends in Analytical Chemistry, Volume 37
S. Rabouan, A. Dupuis, A. Cariot, M. Albouy-Llaty, V. Migeot, A. Cariot, A. Dupuis, M. Albouy-Llaty, V. Migeot, B. Legube
In recent decades, the development of environmental risks and their repercussions on health has led to environmental health being a field of scientific research in which interdisciplinarity is intrinsic. This article on nonylphenols (NP) shows how exchanges and knowledge transfer involving chemists, biologists, pharmacists and physicians underscore the need to further the development of analytical methodologies. We spell out the difficulties encountered when selecting a reference material for the analysis of NP (i.e. multiplicity of isomers, and variability in the composition of batches for the same CAS Registry Number). As a result, we propose 353NP (CAS 186825-36-5) as the reference material (because of its high proportion in the industrial mixture and its pronounced estrogenic power).
Highlights
► Review of naming of nonylphenols (NP) and standards applied in NP determinations. ► 353NP as a reference material in analysis of environmental and drinking waters. ► Argued choice of 353NP as the standard in studiesfor evaluating public health risk.Sample-extraction methods for ion-mobility spectrometry in water analysis
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Sanna Holopainen, Marjaana Nousiainen, Mika E.T. Sillanpää, Osmo Anttalainen
The requirement to monitor the chemical quality of water has become one of the major issues in environmental analytics. Ion-mobility spectrometry (IMS), a fast, sensitive method traditionally used in security and military applications, is also suitable for environmental analysis and detection of organic pollutants from aqueous matrices, when combined with advantageous methods to isolate analytes from the water phase. This article reviews the current literature on the sample-extraction methods most feasible for aqueous samples prior to ion-mobility analysis, and highlights their principles and trends in IMS applications. These partition-based methods include solid-phase microextraction, stir-bar sorptive extraction, single-drop microextraction, hollow-fiber liquid-phase microextraction, pervaporation-membrane extraction and paper spray. We also discuss comparisons of method characteristics and relative performance, and conclude that IMS is a potential method for both on-line and on-site determination of organic pollutants in aqueous matrices.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Sanna Holopainen, Marjaana Nousiainen, Mika E.T. Sillanpää, Osmo Anttalainen
The requirement to monitor the chemical quality of water has become one of the major issues in environmental analytics. Ion-mobility spectrometry (IMS), a fast, sensitive method traditionally used in security and military applications, is also suitable for environmental analysis and detection of organic pollutants from aqueous matrices, when combined with advantageous methods to isolate analytes from the water phase. This article reviews the current literature on the sample-extraction methods most feasible for aqueous samples prior to ion-mobility analysis, and highlights their principles and trends in IMS applications. These partition-based methods include solid-phase microextraction, stir-bar sorptive extraction, single-drop microextraction, hollow-fiber liquid-phase microextraction, pervaporation-membrane extraction and paper spray. We also discuss comparisons of method characteristics and relative performance, and conclude that IMS is a potential method for both on-line and on-site determination of organic pollutants in aqueous matrices.
Highlights
► Ion-mobility spectrometry can determine organic pollutants in aqueous matrices. ► We described promising sample-extraction methods for ion-mobility spectrometry. ► IMS methods differ in the number of sample-preparation steps and ease of use. ► Extracting materials are available for different sample types. ► Paper spray is the most novel method to combine with ion-mobility spectrometry.Analytical methods for determination of cork-taint compounds in wine
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Ariel R. Fontana
Cork taint is considered a major organoleptic defect in wine, producing a moldy aroma. Haloanisoles are the main compounds responsible, although there are other analytes that cause the same problem. Occurrence of cork taint deteriorates the quality and the acceptability of wines, causing significant financial loss to the wine industry. The taste and odor thresholds of taint compounds in wine are very low, but the concentration causing a problem depends on the characteristics and the composition of the wine. Many efforts have been made to provide a highly-sensitive, selective analytical method for the determination of cork-taint compounds. Since the concentration of these analytes in wine is usually low, it is necessary to count on highly efficient preconcentration procedures for their estimation by instrumental techniques. This review summarizes the most recent analytical developments in sample-preparation techniques for the determination of cork-taint compounds in wine, including different modes of liquid-phase microextraction, Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS), solid-phase microextraction, stir-bar sorptive extraction and microextraction in packed syringe. Furthermore, we explain instrumental techniques used for separating and identifying cork-taint compounds. Recovery rates, detection limits, matrix effects and specific parameters of each method have all been considered and discussed.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Ariel R. Fontana
Cork taint is considered a major organoleptic defect in wine, producing a moldy aroma. Haloanisoles are the main compounds responsible, although there are other analytes that cause the same problem. Occurrence of cork taint deteriorates the quality and the acceptability of wines, causing significant financial loss to the wine industry. The taste and odor thresholds of taint compounds in wine are very low, but the concentration causing a problem depends on the characteristics and the composition of the wine. Many efforts have been made to provide a highly-sensitive, selective analytical method for the determination of cork-taint compounds. Since the concentration of these analytes in wine is usually low, it is necessary to count on highly efficient preconcentration procedures for their estimation by instrumental techniques. This review summarizes the most recent analytical developments in sample-preparation techniques for the determination of cork-taint compounds in wine, including different modes of liquid-phase microextraction, Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS), solid-phase microextraction, stir-bar sorptive extraction and microextraction in packed syringe. Furthermore, we explain instrumental techniques used for separating and identifying cork-taint compounds. Recovery rates, detection limits, matrix effects and specific parameters of each method have all been considered and discussed.
Highlights
► A review of analytical methods for cork-taint determination in wines is presented. ► Miniaturized and green liquid-phase microextraction approaches are emphasized. ► Sorptive microextraction techniques are discussed. ► Instrumental techniques for identification and quantification are explained.Recent advances in monolithic column-based boronate-affinity chromatography
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 37
Hengye Li, Zhen Liu
Cis-diol-containing biomolecules are an important class of compounds, including carbohydrates, glycoproteins, RNA, and nucleosides. Many are the main analytes at the frontiers of life science studies (e.g., proteomics, metabolomics and glycomics). As many cis-diol molecules of biological importance are present in very low abundance in samples while interfering substances are usually present in high abundance, specific capture and effective enrichment of target cis-diol biomolecules become key, challenging steps in the -omics analyses. Boronate-affinity chromatography (BAC) is a tool for specific isolation and enrichment of cis-diol compounds. In recent years, monolithic column-based BAC has attracted increasing attention. A variety of BAC monolithic columns have been developed and impressive applications in selective enrichment of glycopeptides and nucleosides have been demonstrated. We review recent advances in monolithic column-based BAC. We mainly focus on the common issues encountered during the development and application of monolithic columns for BAC. We suggest a set of strategies to guide how to select appropriate binding-buffer composition and how to design new BAC columns with the desired properties. We highlight progress and discuss trends in lowering the binding pH.
Source:TrAC Trends in Analytical Chemistry, Volume 37
Hengye Li, Zhen Liu
Cis-diol-containing biomolecules are an important class of compounds, including carbohydrates, glycoproteins, RNA, and nucleosides. Many are the main analytes at the frontiers of life science studies (e.g., proteomics, metabolomics and glycomics). As many cis-diol molecules of biological importance are present in very low abundance in samples while interfering substances are usually present in high abundance, specific capture and effective enrichment of target cis-diol biomolecules become key, challenging steps in the -omics analyses. Boronate-affinity chromatography (BAC) is a tool for specific isolation and enrichment of cis-diol compounds. In recent years, monolithic column-based BAC has attracted increasing attention. A variety of BAC monolithic columns have been developed and impressive applications in selective enrichment of glycopeptides and nucleosides have been demonstrated. We review recent advances in monolithic column-based BAC. We mainly focus on the common issues encountered during the development and application of monolithic columns for BAC. We suggest a set of strategies to guide how to select appropriate binding-buffer composition and how to design new BAC columns with the desired properties. We highlight progress and discuss trends in lowering the binding pH.
Highlights
► Development of monolithic column-based boronate-affinity chromatography. ► The mechanism of separation of boronate-affinity chromatography. ► Strategies for selectivity manipulation in boronate-affinity chromatography. ► Recent progress in lowering binding pH. ► Prospects for monolithic column-based boronate-affinity chromatography.Electrocatalysis, sensors and biosensors in analytical chemistry based on ordered mesoporous and macroporous carbon-modified electrodes
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry
Alain Walcarius
The past few years have seen an explosion in the use of ordered mesoporous carbon and, to lesser extent, templated macroporous carbon, as novel materials to design nanostructured electrodes devoted to sensing and biosensing. These materials offer attractive features that can be exploited in electrochemistry [e.g., good electronic conductivity, great porosity (high specific surface area, large pore volume and size) and widely open ordered structure]. After a brief presentation of these materials (template synthesis, characterization, properties and uses) and the ways to attach them to electrode surfaces (including their basic electrochemical behavior), we review their interest for electroanalytical purposes. We pay particular attention to applications in the fields of preconcentration electroanalysis, electrocatalysis, potentiometry and electrochemical biosensing, and to discussing the advantages of such templated porous carbons over other related nanostructured carbon materials.
Source:TrAC Trends in Analytical Chemistry
Alain Walcarius
The past few years have seen an explosion in the use of ordered mesoporous carbon and, to lesser extent, templated macroporous carbon, as novel materials to design nanostructured electrodes devoted to sensing and biosensing. These materials offer attractive features that can be exploited in electrochemistry [e.g., good electronic conductivity, great porosity (high specific surface area, large pore volume and size) and widely open ordered structure]. After a brief presentation of these materials (template synthesis, characterization, properties and uses) and the ways to attach them to electrode surfaces (including their basic electrochemical behavior), we review their interest for electroanalytical purposes. We pay particular attention to applications in the fields of preconcentration electroanalysis, electrocatalysis, potentiometry and electrochemical biosensing, and to discussing the advantages of such templated porous carbons over other related nanostructured carbon materials.
Highlights
► Templated macro- and mesoporous carbon materials are attractive for electrochemistry. ► They offer good conductivity, great porosity, and widely open regular structure. ► They exhibit intrinsic adsorption and electrocatalytic properties. ► They have applications in chemical sensors and electrochemical biosensors. ► Possible advantages over related nanostructured carbons are discussed.Methods for the determination of biomarkers of exposure to emerging pollutants in human specimens
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry
Vicent Yusa, Xiaoyun Ye, Antonia M. Calafat
Biomonitoring is a very useful tool for assessing human exposure to environmental pollutants. This review discusses recent methods for the quantitative measurement of biomarkers of exposure to different classes of chemicals used in personal-care products (e.g., musk fragrances, preservatives, UV filters, and insect repellents) and consumer products (e.g., organophosphate flame retardants, phthalate esters, perfluorinated compounds, and industrial phenols). The measurements are mainly taken in urine, blood, and breast milk. We also discuss the different procedures commonly used for sample-pretreatment, extraction, and clean up, and chromatographic techniques currently used to determine these compounds. Finally, we present data on the main biomarkers occurring in different human specimens.
Source:TrAC Trends in Analytical Chemistry
Vicent Yusa, Xiaoyun Ye, Antonia M. Calafat
Biomonitoring is a very useful tool for assessing human exposure to environmental pollutants. This review discusses recent methods for the quantitative measurement of biomarkers of exposure to different classes of chemicals used in personal-care products (e.g., musk fragrances, preservatives, UV filters, and insect repellents) and consumer products (e.g., organophosphate flame retardants, phthalate esters, perfluorinated compounds, and industrial phenols). The measurements are mainly taken in urine, blood, and breast milk. We also discuss the different procedures commonly used for sample-pretreatment, extraction, and clean up, and chromatographic techniques currently used to determine these compounds. Finally, we present data on the main biomarkers occurring in different human specimens.
Highlights
► Biomonitoring is a useful tool for assessing human exposure to emerging pollutants. ► We report the methods for analysis of biomarkers of exposure to emerging pollutants. ► LC-MS/MS is the prevailing technique in determining biomarkers of emerging pollutants. ► We present data on the main biomarkers occurring in different human specimens.Electrospun nanofiber-based solid-phase extraction
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry
Samuel Chigome, Nelson Torto
The article discusses theoretical and experimental aspects of fabricating devices and developing methods for electrospun nanofiber-based solid-phase extraction (SPE). It seeks to encourage better understanding of the use of electrospun nanofibers as a chromatographic sorbent bed. We base discussion on fabricating six electrospun nanofiber-based SPE devices and evaluating their performance. We also categorize electrospun polymer nanofibers that are applicable as SPE sorbents are presented as polystyrene type (relatively low mechanical strength) and nylon type (relatively high mechanical strength). We propose that the formats and the configurations of future electrospun nanofiber-based SPE devices may be guided by the mechanical strength of the polymer.
Source:TrAC Trends in Analytical Chemistry
Samuel Chigome, Nelson Torto
The article discusses theoretical and experimental aspects of fabricating devices and developing methods for electrospun nanofiber-based solid-phase extraction (SPE). It seeks to encourage better understanding of the use of electrospun nanofibers as a chromatographic sorbent bed. We base discussion on fabricating six electrospun nanofiber-based SPE devices and evaluating their performance. We also categorize electrospun polymer nanofibers that are applicable as SPE sorbents are presented as polystyrene type (relatively low mechanical strength) and nylon type (relatively high mechanical strength). We propose that the formats and the configurations of future electrospun nanofiber-based SPE devices may be guided by the mechanical strength of the polymer.
Highlights
► Electrospun nanofiber-based sorbents. ► Electrospun nanofiber-based solid-phase extraction (SPE) devices. ► Theoretical and experimental aspects of electrospun nanofiber-based SPE devices.Sample-preparation methods for pesticide-residue analysis in cereals and derivatives
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry
Miguel Ángel González-Curbelo, Antonio V. Herrera-Herrera, Lidia M. Ravelo-Pérez, Javier Hernández-Borges
Since the Neolithic Age, cereals have constituted an important part of the human diet, and they are now one of the foods most produced and consumed in the world. As a result, and because of the large population involved, food-safety issues are an important matter of concern and appropriate action is required. Pesticide-residue analysis, including method optimization, method development and monitoring programs are becoming increasingly important. The aim of this review article is to provide a general overview of the different sample-preparation methods published in the period 2006–11 covering the analysis of pesticides in cereal samples, including some of their derivatives, such as flour or cereal-based baby foods.
Source:TrAC Trends in Analytical Chemistry
Miguel Ángel González-Curbelo, Antonio V. Herrera-Herrera, Lidia M. Ravelo-Pérez, Javier Hernández-Borges
Since the Neolithic Age, cereals have constituted an important part of the human diet, and they are now one of the foods most produced and consumed in the world. As a result, and because of the large population involved, food-safety issues are an important matter of concern and appropriate action is required. Pesticide-residue analysis, including method optimization, method development and monitoring programs are becoming increasingly important. The aim of this review article is to provide a general overview of the different sample-preparation methods published in the period 2006–11 covering the analysis of pesticides in cereal samples, including some of their derivatives, such as flour or cereal-based baby foods.
Highlights
► Analytical methods used in the analysis of pesticide residues in cereals. ► Sample-pretreatment methods for the analysis of pesticide residues in cereals. ► Publications in 2006–11 for the analysis of pesticide residues in cereals.Analytical and unconventional methods of cancer detection using odor
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry
Bogusław Buszewski, Joanna Rudnicka, Tomasz Ligor, Marta Walczak, Tadeusz Jezierski, Anton Amann
Finding a non-invasive, painless and simple screening method for early detection of cancer is a desirable goal. There is evidence that volatile organic compounds (VOCs) detectable in exhaled air and producing specific breath odor could be taken into consideration as possible cancer markers. Chemical analysis of VOCs in the breath that utilizes gas chromatography-mass spectrometry or an array of specific sensors (an electronic nose) could be useful for cancer screening. Preliminary reports show that canines, due to their extraordinary sense of smell and ability to perform well with operant conditioning, could also be used in the future as biological screeners for different forms of cancer. However, the question remains open whether specific VOCs or breath odors appear at very early (sub-clinical) stages of cancer disease or only at advanced stages of the disease during tumor decomposition.
Source:TrAC Trends in Analytical Chemistry
Bogusław Buszewski, Joanna Rudnicka, Tomasz Ligor, Marta Walczak, Tadeusz Jezierski, Anton Amann
Finding a non-invasive, painless and simple screening method for early detection of cancer is a desirable goal. There is evidence that volatile organic compounds (VOCs) detectable in exhaled air and producing specific breath odor could be taken into consideration as possible cancer markers. Chemical analysis of VOCs in the breath that utilizes gas chromatography-mass spectrometry or an array of specific sensors (an electronic nose) could be useful for cancer screening. Preliminary reports show that canines, due to their extraordinary sense of smell and ability to perform well with operant conditioning, could also be used in the future as biological screeners for different forms of cancer. However, the question remains open whether specific VOCs or breath odors appear at very early (sub-clinical) stages of cancer disease or only at advanced stages of the disease during tumor decomposition.
Highlights
► Carcinomas are a human health problem. ► Analytical methods for detecting potential markers for cancer in biological samples. ► Unconventional methods for detecting carcinoma, such as dogs’ sense of smell. ► Cancer detection using odor.Advances in the determination of β-lactam antibiotics by liquid chromatography
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry
Francisco J. Lara, Monsalud del Olmo-Iruela, Carmen Cruces-Blanco, Carolina Quesada-Molina, Ana M. García-Campaña
β-lactam antibiotics have been the most widely used antimicrobial drugs for more than 80 years and still constitute the most important group of antibiotics. Their extensive use in veterinary medicine practices as growth promoters, and chemotherapeutic and/or prophylactic agents causes numerous residues in foodstuffs which present a serious health hazard. For this reason, sensitive and specific methods for the quantification of these compounds in numerous matrices have been published. This article reviews the current status of the application of liquid-chromatography-based analytical methods in the analysis of β-lactam antibiotics. These methods are classified according to the different detection systems used: UV-visible spectrophotometry, mass spectrometry and other detection techniques such as fluorescence or chemiluminescence. We include applications in different fields (e.g., food, environmental, clinical and pharmaceutical).
Source:TrAC Trends in Analytical Chemistry
Francisco J. Lara, Monsalud del Olmo-Iruela, Carmen Cruces-Blanco, Carolina Quesada-Molina, Ana M. García-Campaña
β-lactam antibiotics have been the most widely used antimicrobial drugs for more than 80 years and still constitute the most important group of antibiotics. Their extensive use in veterinary medicine practices as growth promoters, and chemotherapeutic and/or prophylactic agents causes numerous residues in foodstuffs which present a serious health hazard. For this reason, sensitive and specific methods for the quantification of these compounds in numerous matrices have been published. This article reviews the current status of the application of liquid-chromatography-based analytical methods in the analysis of β-lactam antibiotics. These methods are classified according to the different detection systems used: UV-visible spectrophotometry, mass spectrometry and other detection techniques such as fluorescence or chemiluminescence. We include applications in different fields (e.g., food, environmental, clinical and pharmaceutical).
Highlights
► Critical review of analysis of β-lactam antibiotics by liquid chromatography. ► Detection modes and analytical applications of LC methods for β-lactam antibiotics. ► Advantages and drawbacks of sample preparation for LC of β-lactam antibiotics.Analytical methods based on exhaled breath for early detection of lung cancer
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry
M.D. Luque de Castro, M.A. Fernández-Peralbo
Lung cancer is among the most common malignancies and among the most difficult to treat, mainly due to the lack of symptoms, which means that the vast majority of tumors to be diagnosed are at an advanced stage. After reviewing the literature on this subject, with special emphasis on both canine smell and the potential of omics biomarkers for detecting lung cancer, we discuss the role of analytical chemists in the new steps to be taken for early detection. We also comment on the steps to be developed (from sampling to full validation of the biomarkers found).
Source:TrAC Trends in Analytical Chemistry
M.D. Luque de Castro, M.A. Fernández-Peralbo
Lung cancer is among the most common malignancies and among the most difficult to treat, mainly due to the lack of symptoms, which means that the vast majority of tumors to be diagnosed are at an advanced stage. After reviewing the literature on this subject, with special emphasis on both canine smell and the potential of omics biomarkers for detecting lung cancer, we discuss the role of analytical chemists in the new steps to be taken for early detection. We also comment on the steps to be developed (from sampling to full validation of the biomarkers found).
Highlights
► Canine scent for lung-cancer detection should involve analytical chemists. ► Biomarkers detect lung cancer in patients’ breath at very low concentrations. ► Proteomics and metabolomics are key to lung-cancer detection through breath.Isotopic methods give clues about the origins of trace metals and organic pollutants in the environment
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry
Philippe Négrel, Michaela Blessing, Romain Millot, Emmanuelle Petelet-Giraud, Christophe Innocent
Recent advances in techniques and methodologies in analytical chemistry help to address problems of environmental contamination. This is particularly true for isotope determinations of metals using multi-collector inductively coupled plasma mass spectrometry (MS) and on-line coupling of capillary gas chromatography and isotope-ratio MS, or compound-specific stable isotope analysis. We explore the methodologies and applications using the isotope signatures of inorganic or organic contaminants, which offer good potential for distinguishing potential sources within contamination plumes and possibly even estimating different source inputs at the catchment scale. Moreover, for organic pollutants, such methods provide unique information for deciphering their origin and studying degradation processes.
Source:TrAC Trends in Analytical Chemistry
Philippe Négrel, Michaela Blessing, Romain Millot, Emmanuelle Petelet-Giraud, Christophe Innocent
Recent advances in techniques and methodologies in analytical chemistry help to address problems of environmental contamination. This is particularly true for isotope determinations of metals using multi-collector inductively coupled plasma mass spectrometry (MS) and on-line coupling of capillary gas chromatography and isotope-ratio MS, or compound-specific stable isotope analysis. We explore the methodologies and applications using the isotope signatures of inorganic or organic contaminants, which offer good potential for distinguishing potential sources within contamination plumes and possibly even estimating different source inputs at the catchment scale. Moreover, for organic pollutants, such methods provide unique information for deciphering their origin and studying degradation processes.
Highlights
► Advances in analytical chemistry methodologies address pollution. ► Isotope signatures provide valuable information to decipher the origin of pollutants. ► Isotope signatures provide valuable information to study degradation processes. ► We review of isotope methodologies and applications for studying pollution.
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Andrea Jaquins Gerstl, I. Mitch Taylor, Zhan Shu, Hong Zhang, Stephen G. Weber
Source:TrAC Trends in Analytical Chemistry, Volume 36
Andrea Jaquins Gerstl, I. Mitch Taylor, Zhan Shu, Hong Zhang, Stephen G. Weber
Chemical monitoring activity for the implementation of the Water Framework Directive
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Philippe Quevauviller, Mario Carere, Stefano Polesello
Source:TrAC Trends in Analytical Chemistry, Volume 36
Philippe Quevauviller, Mario Carere, Stefano Polesello
Chemical monitoring and emerging pollutants in the Common Implementation Strategy of the Water Framework Directive
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Mario Carere, Stefano Polesello, Caterina Sollazzo, Bernd Manfred Gawlik
This Foreword gives an overview on the last two mandates on Chemical Monitoring under the Common Implementation Strategy of the Water Framework Directive. It describes the development from 2005 until today, highlighting the various topics being addressed by the expert group. It sets the work into the relationship of the policy-making process as regards chemical-monitoring aspects for priority substances and emerging contaminants.
Source:TrAC Trends in Analytical Chemistry, Volume 36
Mario Carere, Stefano Polesello, Caterina Sollazzo, Bernd Manfred Gawlik
This Foreword gives an overview on the last two mandates on Chemical Monitoring under the Common Implementation Strategy of the Water Framework Directive. It describes the development from 2005 until today, highlighting the various topics being addressed by the expert group. It sets the work into the relationship of the policy-making process as regards chemical-monitoring aspects for priority substances and emerging contaminants.
Guidance for sediment and biota monitoring under the Common Implementation Strategy for the Water Framework Directive
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Mario Carere, Valeria Dulio, Georg Hanke, Stefano Polesello
The Environmental Quality Standards Directive 2008/105/EC (EQSD) marks an important step in the use of sediments and biota as matrices for chemical-status assessment under the Water Framework Directive 2000/60/EC (WFD). Analysis of contaminants in sediments and biota is indeed widely recognized as a cost-effective approach in water-quality monitoring to describe the general contamination level, to supply reference values for local and regional monitoring and to identify areas of concern where additional monitoring effort is needed. Because of the explicit reference in the EQSD to the use of sediments and biota as preferred matrices for the monitoring of substances with accumulation potential – especially for the assessment of long-term trends, but also for compliance checking, wherever appropriate – Member States of the European Union (EU) asked the European Commission to publish a guidance document to enhance the degree of harmonization among EU countries in chemical monitoring of sediments and biota, taking into account best available techniques, standard procedures and common practices. This article presents the key features of that guidance document, its main recommendations for chemical monitoring of sediments and biota and the scope for further improvement in current monitoring practices.
Source:TrAC Trends in Analytical Chemistry, Volume 36
Mario Carere, Valeria Dulio, Georg Hanke, Stefano Polesello
The Environmental Quality Standards Directive 2008/105/EC (EQSD) marks an important step in the use of sediments and biota as matrices for chemical-status assessment under the Water Framework Directive 2000/60/EC (WFD). Analysis of contaminants in sediments and biota is indeed widely recognized as a cost-effective approach in water-quality monitoring to describe the general contamination level, to supply reference values for local and regional monitoring and to identify areas of concern where additional monitoring effort is needed. Because of the explicit reference in the EQSD to the use of sediments and biota as preferred matrices for the monitoring of substances with accumulation potential – especially for the assessment of long-term trends, but also for compliance checking, wherever appropriate – Member States of the European Union (EU) asked the European Commission to publish a guidance document to enhance the degree of harmonization among EU countries in chemical monitoring of sediments and biota, taking into account best available techniques, standard procedures and common practices. This article presents the key features of that guidance document, its main recommendations for chemical monitoring of sediments and biota and the scope for further improvement in current monitoring practices.
Highlights
► The European Commission developed Guidance on monitoring of sediment and biota. ► The Guidance addresses harmonization on monitoring sediment and biota in EU countries. ► Practically applying Water Framework and Environmental Quality Standards Directives.Chemical-monitoring on-site exercises to harmonize analytical methods for priority substances in the European Union
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Georg Hanke, Giulio Mariani, Sara Comero, Robert Loos, Giovanni Bidoglio, Stefano Polesello, Sara Valsecchi, Marianna Rusconi, Jan Wollgast, Javier Castro-Jiménez, Luisa Patrolecco, Nicoletta Ademollo
In support of the implementation of the Water Framework Directive (WFD, 2000/60/EC), three intercomparison exercises were carried out on European rivers (Po, Danube and Meuse) in order to assess the current state of monitoring methodologies. Laboratories from European Union (EU) Member States (MSs) were invited to gather at the selected EU river and sample together, each laboratory with its own method. Participants simultaneously sampled the river water and analyzed according to their protocols. A selection of priority substances (PSs) [i.e. polybromodiphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs) and alkyl phenols (APs)] included in Directive 2008/105/EC were analyzed in standard solutions, extracts from river waters and river-water samples in order to investigate variabilities in different steps of the analytical process. Concentrations measured in river samples using WFD-monitoring protocols showed that even some of the most challenging WFD PSs (e.g., PAHs, PBDEs and APs) can be measured at WFD-relevant concentrations with methods currently applied in MSs, but variability is still too great and not all laboratories meet required limits of quantification. Hindrance to the implementation of the monitoring requirements is therefore not the technical feasibility of analysis at these concentration levels, but rather communication, knowledge exchange and harmonization among the laboratories involved.
Source:TrAC Trends in Analytical Chemistry, Volume 36
Georg Hanke, Giulio Mariani, Sara Comero, Robert Loos, Giovanni Bidoglio, Stefano Polesello, Sara Valsecchi, Marianna Rusconi, Jan Wollgast, Javier Castro-Jiménez, Luisa Patrolecco, Nicoletta Ademollo
In support of the implementation of the Water Framework Directive (WFD, 2000/60/EC), three intercomparison exercises were carried out on European rivers (Po, Danube and Meuse) in order to assess the current state of monitoring methodologies. Laboratories from European Union (EU) Member States (MSs) were invited to gather at the selected EU river and sample together, each laboratory with its own method. Participants simultaneously sampled the river water and analyzed according to their protocols. A selection of priority substances (PSs) [i.e. polybromodiphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs) and alkyl phenols (APs)] included in Directive 2008/105/EC were analyzed in standard solutions, extracts from river waters and river-water samples in order to investigate variabilities in different steps of the analytical process. Concentrations measured in river samples using WFD-monitoring protocols showed that even some of the most challenging WFD PSs (e.g., PAHs, PBDEs and APs) can be measured at WFD-relevant concentrations with methods currently applied in MSs, but variability is still too great and not all laboratories meet required limits of quantification. Hindrance to the implementation of the monitoring requirements is therefore not the technical feasibility of analysis at these concentration levels, but rather communication, knowledge exchange and harmonization among the laboratories involved.
Highlights
► European intercomparison for implementation of the Water Framework Directive. ► Current state of monitoring methods for PAHs, PDBEs and alkyl phenols in EU rivers. ► Harmonization of monitoring procedures among laboratories is needed.Testing sample stability in short-term isochronous stability studies for EU-wide monitoring surveys of polar organic contaminants in water
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Bernd Manfred Gawlik, Robert Loos, Giovanni Bidoglio, Gisela Fauler, Xinghua Guo, Ernst Lankmayr, Thomas Linsinger
The article introduces the European Union (EU)-wide monitoring concept as run by the European Commission’s Joint Research Centre (JRC) and specifically addresses the issue of stability tests for environmental specimen and samples using the so-called isochronous stability-test design. We briefly describe the underlying statistical concept and apply it to water samples being collected in the context of the JRC’s EU-wide environmental monitoring activities. The stability of spiked tap-water and river-water samples and their containers was assessed at 4°C, 20°C and 40°C using ibuprofen, gemfibrozil, ketoprofen, diclofenac, bezafibrate, naproxen, perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), carbamzepine, sulfamethoxazole, terbutylazine and triclosan as test substances in two different stability-testing schemes. The stability of the samples decreased as expected with an increase in the storage temperature. Uncertainty contributions were calculated and it was concluded that this type of sample remains stable for ca. 6weeks if stored at 4°C.
Source:TrAC Trends in Analytical Chemistry, Volume 36
Bernd Manfred Gawlik, Robert Loos, Giovanni Bidoglio, Gisela Fauler, Xinghua Guo, Ernst Lankmayr, Thomas Linsinger
The article introduces the European Union (EU)-wide monitoring concept as run by the European Commission’s Joint Research Centre (JRC) and specifically addresses the issue of stability tests for environmental specimen and samples using the so-called isochronous stability-test design. We briefly describe the underlying statistical concept and apply it to water samples being collected in the context of the JRC’s EU-wide environmental monitoring activities. The stability of spiked tap-water and river-water samples and their containers was assessed at 4°C, 20°C and 40°C using ibuprofen, gemfibrozil, ketoprofen, diclofenac, bezafibrate, naproxen, perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), carbamzepine, sulfamethoxazole, terbutylazine and triclosan as test substances in two different stability-testing schemes. The stability of the samples decreased as expected with an increase in the storage temperature. Uncertainty contributions were calculated and it was concluded that this type of sample remains stable for ca. 6weeks if stored at 4°C.
Highlights
► We developed a non-probabilistic, pan-European snapshot mechanism for water samples. ► It is used to derive benchmarks and links to regional chemical-monitoring programs. ► We addressed the issue of analyte stability in water samples. ► We applied the isochronous stability test used for reference materials. ► We used data directly to feed into policy implementation.Chemical water monitoring under the Water Framework Directive with Certified Reference Materials
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Marina Ricci, Ivan Kourtchev, Hendrik Emons
In the field of environment protection, a series of European Directives with special emphasis on the water bodies has been approved as a cascade after the milestone Water Framework Directive (WFD) of the year 2000. The most recent piece of legislation, Directive 2009/90/EC, points out the necessity of ensuring the quality of the analytical data and prescribes that the laboratories appointed by the Member States as responsible for the chemical water monitoring shall “demonstrate their competences…by…analysis of available reference materials…”. Certified Reference Materials (CRMs) are the anchor points for comparability of measurement results, in both space and time, ensuring their traceability to a common reference. In this article, we present a critical overview of existing matrix CRMs, related to WFD monitoring needs. Our survey concerns available water, biota and sediment matrix CRMs for the 33 Priority Substances (PSs) (and the eight “other certain pollutants”) listed in the WFD, together with a reference to discontinued CRMs. Tables providing a more synoptic view are available on-line as supplementary information. For the four priority metals (Cd, Pb, Hg and Ni), there are sufficient CRMs for all matrices considered to cover the needs of the monitoring laboratories, but there is a serious lack of matrix CRMs for most of the organic PSs. Also, for the matrix water, there are no materials available for organic pollutants that could be classified as CRMs as commonly understood. We also briefly discuss pure compounds and solution CRMs for calibration purposes. In the final section, we show how a CRM could be used in the estimation of measurement uncertainty for checking compliance at the Environmental Quality Standard level, according to the technical specifications given in Directive 2009/90/EC.
Source:TrAC Trends in Analytical Chemistry, Volume 36
Marina Ricci, Ivan Kourtchev, Hendrik Emons
In the field of environment protection, a series of European Directives with special emphasis on the water bodies has been approved as a cascade after the milestone Water Framework Directive (WFD) of the year 2000. The most recent piece of legislation, Directive 2009/90/EC, points out the necessity of ensuring the quality of the analytical data and prescribes that the laboratories appointed by the Member States as responsible for the chemical water monitoring shall “demonstrate their competences…by…analysis of available reference materials…”. Certified Reference Materials (CRMs) are the anchor points for comparability of measurement results, in both space and time, ensuring their traceability to a common reference. In this article, we present a critical overview of existing matrix CRMs, related to WFD monitoring needs. Our survey concerns available water, biota and sediment matrix CRMs for the 33 Priority Substances (PSs) (and the eight “other certain pollutants”) listed in the WFD, together with a reference to discontinued CRMs. Tables providing a more synoptic view are available on-line as supplementary information. For the four priority metals (Cd, Pb, Hg and Ni), there are sufficient CRMs for all matrices considered to cover the needs of the monitoring laboratories, but there is a serious lack of matrix CRMs for most of the organic PSs. Also, for the matrix water, there are no materials available for organic pollutants that could be classified as CRMs as commonly understood. We also briefly discuss pure compounds and solution CRMs for calibration purposes. In the final section, we show how a CRM could be used in the estimation of measurement uncertainty for checking compliance at the Environmental Quality Standard level, according to the technical specifications given in Directive 2009/90/EC.
Highlights
► Quality and comparability of water chemical monitoring results should be ensured. ► CRMs are necessary for quality assurance and quality control of measurement results. ► Water, biota and sediment matrix CRMs for Cd, Pb, Hg and Ni are generally available. ► There are no water-matrix CRMs for organic priority substances under the WFD. ► Biota and sediment CRMs exist only for some organic priority substances under the WFD.Monitoring of contaminants in suspended particulate matter as an alternative to sediments
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Birgit Schubert, Peter Heininger, Martin Keller, Evelyn Claus, Mathias Ricking
The Water Framework Directive (WFD) requires Member States of the European Union to achieve good status of all waters in 2015. The survey of chemical status focuses on checking compliance of the quality of water systems against environmental quality standards and temporal trend monitoring of contaminants in sediments and/or biota. As sediments appropriate for monitoring contaminants may not always be available, we discuss the use of suspended particulate matter (SPM) as an alternative. We describe and discuss differences in quality and quantity of sediments and SPM collected by different sampling techniques with regard to the respective advantages and drawbacks for various monitoring purposes. Often, both contaminant concentrations in sediments and in SPM may give the required information. However, selection of the technique applied for collecting SPM should take into consideration, inter alia, the purpose of the monitoring, as well as the hydrodynamic and morphological conditions of the area monitored. We illustrate general conclusions with field applications from the European rivers Rhine and Elbe.
Source:TrAC Trends in Analytical Chemistry, Volume 36
Birgit Schubert, Peter Heininger, Martin Keller, Evelyn Claus, Mathias Ricking
The Water Framework Directive (WFD) requires Member States of the European Union to achieve good status of all waters in 2015. The survey of chemical status focuses on checking compliance of the quality of water systems against environmental quality standards and temporal trend monitoring of contaminants in sediments and/or biota. As sediments appropriate for monitoring contaminants may not always be available, we discuss the use of suspended particulate matter (SPM) as an alternative. We describe and discuss differences in quality and quantity of sediments and SPM collected by different sampling techniques with regard to the respective advantages and drawbacks for various monitoring purposes. Often, both contaminant concentrations in sediments and in SPM may give the required information. However, selection of the technique applied for collecting SPM should take into consideration, inter alia, the purpose of the monitoring, as well as the hydrodynamic and morphological conditions of the area monitored. We illustrate general conclusions with field applications from the European rivers Rhine and Elbe.
Highlights
► Suspended particulate matter (SPM) and sediments accumulate hydrophobic contaminants. ► The WFD requires trend monitoring of contaminants in sediments and/or biota. ► We compare the use of SPM and sediments for contaminant monitoring. ► Contaminant monitoring may be carried out for various purposes. ► The techniques described are applicable to rivers, estuaries and coastal systems.The analytical problem of measuring total concentrations of organic pollutants in whole water
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
N. Ademollo, L. Patrolecco, S. Polesello, S. Valsecchi, J. Wollgast, G. Mariani, G. Hanke
The Water Framework Directive (WFD) (2000/60/EC) of the European Union provides protection from chemical pollutants through the Environmental Quality Standards (EQS) Directive (2008/105/EC), which sets EQSs for priority substances (PSs) and certain other pollutants, according to the requirements set out in Article 16(8) of the WFD. For organic PSs, these EQSs are expressed as total concentrations in the whole-water sample. Total concentrations can be obtained by direct analysis of the whole-water sample or by separate determinations on filterable and solid phases. Both solutions have their advantages and drawbacks, which we critically discuss in the present review. Analysis of data in the literature and experience from standardization activities show that it is possible to find a simple extraction method for analyzing whole water without time-consuming separation steps. The solid-phase extraction disk is now subject to standardization efforts as the most promising technique to achieve this goal. We discuss limitations of this approach in the light of the consequences for chemical-status assessment.
Source:TrAC Trends in Analytical Chemistry, Volume 36
N. Ademollo, L. Patrolecco, S. Polesello, S. Valsecchi, J. Wollgast, G. Mariani, G. Hanke
The Water Framework Directive (WFD) (2000/60/EC) of the European Union provides protection from chemical pollutants through the Environmental Quality Standards (EQS) Directive (2008/105/EC), which sets EQSs for priority substances (PSs) and certain other pollutants, according to the requirements set out in Article 16(8) of the WFD. For organic PSs, these EQSs are expressed as total concentrations in the whole-water sample. Total concentrations can be obtained by direct analysis of the whole-water sample or by separate determinations on filterable and solid phases. Both solutions have their advantages and drawbacks, which we critically discuss in the present review. Analysis of data in the literature and experience from standardization activities show that it is possible to find a simple extraction method for analyzing whole water without time-consuming separation steps. The solid-phase extraction disk is now subject to standardization efforts as the most promising technique to achieve this goal. We discuss limitations of this approach in the light of the consequences for chemical-status assessment.
Highlights
► Whole-water analysis is carried out by direct analysis or separate determinations. ► We discuss the ways to analyze organics in whole water without separation. ► It is possible to use membrane-disk extraction for whole-water analysis. ► For whole-water analysis, membrane disks are validated in standardization activities. ► Limitations in whole-water analysis in the light of chemical-status assessment.Sediment and biota in trend monitoring of contaminants in transitional waters
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
C. Maggi, A. Ausili, R. Boscolo, F. Cacciatore, A. Bonometto, M. Cornello, D. Berto
According to Directive 2008/105/EC, the Italian Parliament issued in 2010 the Legislative Decree 219, which determined the environmental quality standard (EQS) for sediment of marine coastal areas, lagoons and coastal ponds. For the purpose of trend monitoring, sediment and biota are the most suitable matrices for many substances. Directive 2008/105/EC gives an indication of the substances that should be taken into consideration for trend monitoring and sets an integrated water-management plan, which has to be prepared for each river-basin district. This article illustrates the criteria that were applied to draw the plan with the aim of assessing the trends of several substances in sediment and biota of the Lagoon of Venice, taking into account the recommendations of Directive 2000/60/EC and the daughter Directives. For this purpose, contaminant concentrations coming from a survey conducted in 2005 were compared with the Italian EQS. Results allowed for the evaluation of spatial and temporal trends of several contaminants in sediments and mollusks of the Lagoon of Venice. They allowed us to focus on which compounds need further monitoring and, most of all, which pollutants require measures to reduce inputs.
Source:TrAC Trends in Analytical Chemistry, Volume 36
C. Maggi, A. Ausili, R. Boscolo, F. Cacciatore, A. Bonometto, M. Cornello, D. Berto
According to Directive 2008/105/EC, the Italian Parliament issued in 2010 the Legislative Decree 219, which determined the environmental quality standard (EQS) for sediment of marine coastal areas, lagoons and coastal ponds. For the purpose of trend monitoring, sediment and biota are the most suitable matrices for many substances. Directive 2008/105/EC gives an indication of the substances that should be taken into consideration for trend monitoring and sets an integrated water-management plan, which has to be prepared for each river-basin district. This article illustrates the criteria that were applied to draw the plan with the aim of assessing the trends of several substances in sediment and biota of the Lagoon of Venice, taking into account the recommendations of Directive 2000/60/EC and the daughter Directives. For this purpose, contaminant concentrations coming from a survey conducted in 2005 were compared with the Italian EQS. Results allowed for the evaluation of spatial and temporal trends of several contaminants in sediments and mollusks of the Lagoon of Venice. They allowed us to focus on which compounds need further monitoring and, most of all, which pollutants require measures to reduce inputs.
Highlights
► We assessed the trend monitoring of contaminants in the Lagoon of Venice. ► For the purpose of trend monitoring, we investigated sediment and biota. ► Directive 2008/105/EC states Member States must set Integrated Water Management Plans. ► Results used for the Sediment Monitoring Plan (2010–2012) for the Lagoon of Venice.Biomonitoring of lake sediments using benthic macroinvertebrates
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
R. Bettinetti, B. Ponti, L. Marziali, B. Rossaro
The Water Framework Directive (2000/60/EC) is an innovative piece of legislation aimed at protecting the quality of all continental and coastal waters in Europe through an ecological evaluation of the ecosystems. Since it is widely acknowledged that the greater the ecological realism the greater the difficulty of its definition, we describe the different uses of benthic organisms as a tool for assessing the quality of sediment in lakes. We review the responses from single species to the community. We focus on studies in the laboratory and in the field, and we also critically consider the use of predictive models for these evaluations. Our discussion of the information collected underlines the importance of the relation between sensitivity of single species and contaminants. Moreover, the recent approach in developing mechanistic models to predict the response of natural communities seems to be particularly powerful for community ecology, and we strongly recommend more effort along these lines.
Source:TrAC Trends in Analytical Chemistry, Volume 36
R. Bettinetti, B. Ponti, L. Marziali, B. Rossaro
The Water Framework Directive (2000/60/EC) is an innovative piece of legislation aimed at protecting the quality of all continental and coastal waters in Europe through an ecological evaluation of the ecosystems. Since it is widely acknowledged that the greater the ecological realism the greater the difficulty of its definition, we describe the different uses of benthic organisms as a tool for assessing the quality of sediment in lakes. We review the responses from single species to the community. We focus on studies in the laboratory and in the field, and we also critically consider the use of predictive models for these evaluations. Our discussion of the information collected underlines the importance of the relation between sensitivity of single species and contaminants. Moreover, the recent approach in developing mechanistic models to predict the response of natural communities seems to be particularly powerful for community ecology, and we strongly recommend more effort along these lines.
Highlights
► Macroinvertebrates are used as indicators of lake sediment toxicity in laboratory and field tests. ► Biomarkers provide early warning of contamination of lake sediments in the field. ► Mesocosms can assist study of the response of a community to toxic contamination. ► Biotic indices and species traits can measure community structure and functioning as response to toxic contamination.Importance of dietary uptake of trace elements in the benthic deposit-feeding Lumbriculus variegatus
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Marina Camusso, Stefano Polesello, Sara Valsecchi, Davide A.L. Vignati
The Water Framework Directive and daughter Directives of the European Union state that a risk-assessment approach should be used to set Environmental Quality Standards (EQSs) for different environmental compartments, including sediments. The derivation of sediment QSs is particularly relevant for substances that accumulate in sediment and could pose a risk through direct toxicity to benthic invertebrates, or to benthic predators through the food chain (secondary poisoning). For metals, total concentrations in sediment are not usually directly related to ecotoxicological effects because of variable natural background levels, and many abiotic and biotic factors can modify their bioaccessibility and bioavailability. The most common methods for incorporating bioavailability correction in QSsediment refer to the medium in which organisms live and determine only the chemical availability (bioaccessibility sensu) of elements, assuming that the available fraction is independent of the organisms to protect. However, there is significant evidence that the bioavailable fraction also depends on the feeding behavior and the ecology of biota, especially when the diet (sediment intake) is the main route of uptake. In the present work, we apply the Biodynamic Model to literature and original unpublished data of trace-element bioaccumulation in the sediment-dwelling oligochaete Lumbriculus variegatus to assess the main factors that affect the bioaccumulation and hence the bioavailable fraction in sediments. Results highlighted that, for L. variegatus, there is not a single, predominant route of uptake for all the elements considered. Ni is accumulated mainly from pore water. Sediment ingestion is the main uptake route for As, Cd, Cu and Zn. Pb body burden seems to depend on both the freely dissolved concentration in pore water and the dietary uptake. When diet is the main route of uptake, trace-element bioaccumulation is strongly controlled by the sediment-ingestion rate, which is itself a function of organic carbon (OC) content. We discuss the implications of these findings for the derivation of QSsediment and explore avenues for future research.
Source:TrAC Trends in Analytical Chemistry, Volume 36
Marina Camusso, Stefano Polesello, Sara Valsecchi, Davide A.L. Vignati
The Water Framework Directive and daughter Directives of the European Union state that a risk-assessment approach should be used to set Environmental Quality Standards (EQSs) for different environmental compartments, including sediments. The derivation of sediment QSs is particularly relevant for substances that accumulate in sediment and could pose a risk through direct toxicity to benthic invertebrates, or to benthic predators through the food chain (secondary poisoning). For metals, total concentrations in sediment are not usually directly related to ecotoxicological effects because of variable natural background levels, and many abiotic and biotic factors can modify their bioaccessibility and bioavailability. The most common methods for incorporating bioavailability correction in QSsediment refer to the medium in which organisms live and determine only the chemical availability (bioaccessibility sensu) of elements, assuming that the available fraction is independent of the organisms to protect. However, there is significant evidence that the bioavailable fraction also depends on the feeding behavior and the ecology of biota, especially when the diet (sediment intake) is the main route of uptake. In the present work, we apply the Biodynamic Model to literature and original unpublished data of trace-element bioaccumulation in the sediment-dwelling oligochaete Lumbriculus variegatus to assess the main factors that affect the bioaccumulation and hence the bioavailable fraction in sediments. Results highlighted that, for L. variegatus, there is not a single, predominant route of uptake for all the elements considered. Ni is accumulated mainly from pore water. Sediment ingestion is the main uptake route for As, Cd, Cu and Zn. Pb body burden seems to depend on both the freely dissolved concentration in pore water and the dietary uptake. When diet is the main route of uptake, trace-element bioaccumulation is strongly controlled by the sediment-ingestion rate, which is itself a function of organic carbon (OC) content. We discuss the implications of these findings for the derivation of QSsediment and explore avenues for future research.
Highlights
► Deposit-feeding Lumbriculus variegatus accumulate trace elements mainly via diet. ► Ingestion rate is a key factor in forecasting trace-element accumulation by diet. ► Organic carbon in sediment influences trace-element intake by changing ingestion rate. ► Dietary uptake of elements must be considered in deriving sediment Quality Standards.Relevance and applicability of active biomonitoring in continental waters under the Water Framework Directive
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Jean-Philippe Besse, Olivier Geffard, Marina Coquery
In order to achieve the objectives of the European Union’s Water Framework Directive (WFD) for assessing chemical contamination of water bodies [i.e. checking compliance with Environmental Quality Standards (EQSs) for priority substances (PSs), and monitoring trends of contamination], it is necessary to propose reliable methodologies for monitoring micropollutants. For hydrophobic substances, this involves the use of integrative matrices (e.g., biota or sediment). We discuss here the implementation and the feasibility of a large-scale chemical biomonitoring approach for continental waters, considering the benefits and the limitations of existing biomonitoring strategies, the factors that can affect data interpretation, and the choice of species with regard to the WFD. Current scientific knowledge shows that, unlike the marine environment, continental waters have only a few established and standardized biomonitoring methodologies. From the literature reviewed, active approaches to biomonitoring (using transplanted organisms) appear to be more suitable than passive approaches (based on sampling of indigenous species), as they implement reproducible strategies, control biotic confounding factors and provide robust, comparable results. If fishes are organisms of choice for checking compliance with biota EQSs, they have several characteristics that limit their use for active biomonitoring, while macroinvertebrates represent a good compromise in terms of feasibility and fulfilling the objectives of the WFD.
Source:TrAC Trends in Analytical Chemistry, Volume 36
Jean-Philippe Besse, Olivier Geffard, Marina Coquery
In order to achieve the objectives of the European Union’s Water Framework Directive (WFD) for assessing chemical contamination of water bodies [i.e. checking compliance with Environmental Quality Standards (EQSs) for priority substances (PSs), and monitoring trends of contamination], it is necessary to propose reliable methodologies for monitoring micropollutants. For hydrophobic substances, this involves the use of integrative matrices (e.g., biota or sediment). We discuss here the implementation and the feasibility of a large-scale chemical biomonitoring approach for continental waters, considering the benefits and the limitations of existing biomonitoring strategies, the factors that can affect data interpretation, and the choice of species with regard to the WFD. Current scientific knowledge shows that, unlike the marine environment, continental waters have only a few established and standardized biomonitoring methodologies. From the literature reviewed, active approaches to biomonitoring (using transplanted organisms) appear to be more suitable than passive approaches (based on sampling of indigenous species), as they implement reproducible strategies, control biotic confounding factors and provide robust, comparable results. If fishes are organisms of choice for checking compliance with biota EQSs, they have several characteristics that limit their use for active biomonitoring, while macroinvertebrates represent a good compromise in terms of feasibility and fulfilling the objectives of the WFD.
Highlights
► Using biota is essential for chemical monitoring under the Water Framework Directive. ► Active biomonitoring approaches (caging) appear more suitable than passive ones. ► Caging allows control of confounding factors and provides comparable results. ► For continental waters, only caging enables use of a single standardized protocol. ► Macroinvertebrates are suitable for large-scale, active, chemical biomonitoring.An in situ intercomparison exercise on passive samplers for monitoring metals, polycyclic aromatic hydrocarbons and pesticides in surface waters
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
C. Miège, S. Schiavone, A. Dabrin, M. Coquery, N. Mazzella, C. Berho, J.-P. Ghestem, A. Togola, C. Gonzalez, J.-L. Gonzalez, B. Lalere, S. Lardy-Fontan, B. Lepot, D. Munaron, C. Tixier
An intercomparison exercise on passive samplers (PSs) was organized in summer 2010 to measure selected metals, polycyclic aromatic hydrocarbons (PAHs) and pesticides in surface waters. Various PSs were used and compared at two river sites and one marine lagoon. A total of 24 laboratories participated. We present selected significant results from this exercise, including discussion on quality assurance and quality control for PSs, the interlaboratory variability of field blanks, time weighted average water concentrations and their uncertainties, the representativity of samples from Diffusive Gradient in Thin film, the ability of PSs to achieve lower limits of detection, PAH fingerprints in various PSs compared with spot samples, and the relevance of the permeability reference compound approach to the Polar Organic Chemical Integrative Sampler with pesticides. These in situ intercomparison exercises should enable progress on the harmonization of practices for use of passive sampling, especially for priority chemical monitoring and regulatory programs in compliance with the European Union’s Water Framework Directive and the Marine Strategy Framework Directive.
Source:TrAC Trends in Analytical Chemistry, Volume 36
C. Miège, S. Schiavone, A. Dabrin, M. Coquery, N. Mazzella, C. Berho, J.-P. Ghestem, A. Togola, C. Gonzalez, J.-L. Gonzalez, B. Lalere, S. Lardy-Fontan, B. Lepot, D. Munaron, C. Tixier
An intercomparison exercise on passive samplers (PSs) was organized in summer 2010 to measure selected metals, polycyclic aromatic hydrocarbons (PAHs) and pesticides in surface waters. Various PSs were used and compared at two river sites and one marine lagoon. A total of 24 laboratories participated. We present selected significant results from this exercise, including discussion on quality assurance and quality control for PSs, the interlaboratory variability of field blanks, time weighted average water concentrations and their uncertainties, the representativity of samples from Diffusive Gradient in Thin film, the ability of PSs to achieve lower limits of detection, PAH fingerprints in various PSs compared with spot samples, and the relevance of the permeability reference compound approach to the Polar Organic Chemical Integrative Sampler with pesticides. These in situ intercomparison exercises should enable progress on the harmonization of practices for use of passive sampling, especially for priority chemical monitoring and regulatory programs in compliance with the European Union’s Water Framework Directive and the Marine Strategy Framework Directive.
Highlights
► We present the first results from an intercomparison exercise on passive samplers. ► We discuss quality control and quality assurance strategy. ► We discuss the interlaboratory time weighted average (TWA) water concentrations. ► Through examples, we present the scope of some passive samplers (DGT, POCIS and SPMD). ► We discuss the permeability reference compounds approach to POCIS and pesticides.Chemical calibration, performance, validation and applications of the polar organic chemical integrative sampler (POCIS) in aquatic environments
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Nicolas Morin, Cécile Miège, Marina Coquery, Jérôme Randon
The polar organic chemical integrative sampler (POCIS) was relatively recently developed to trap hydrophilic organic micropollutants in aquatic environments. The aim of this article is to compile information from numerous references involving the POCIS in order to discuss the evaluation of time-weighted average concentrations (e.g., calibration methods, sampling rates, performance and reference compounds) and to review critically the different in situ applications (e.g., screening or quantifying micropollutants, and coupling to toxicity tests), application domains (e.g., molecules analyzed, and sampling media) and analytical protocols (e.g., processing, analysis, and exposure duration).
Source:TrAC Trends in Analytical Chemistry, Volume 36
Nicolas Morin, Cécile Miège, Marina Coquery, Jérôme Randon
The polar organic chemical integrative sampler (POCIS) was relatively recently developed to trap hydrophilic organic micropollutants in aquatic environments. The aim of this article is to compile information from numerous references involving the POCIS in order to discuss the evaluation of time-weighted average concentrations (e.g., calibration methods, sampling rates, performance and reference compounds) and to review critically the different in situ applications (e.g., screening or quantifying micropollutants, and coupling to toxicity tests), application domains (e.g., molecules analyzed, and sampling media) and analytical protocols (e.g., processing, analysis, and exposure duration).
Highlights
► We discuss on the evaluation of time-weighted average concentrations with POCIS. ► We review the different applications and analytical protocols for POCIS. ► POCIS is a very useful tool for screening and identifying sources of pollutants. ► POCIS can evaluate toxicological effects in aquatic environments. ► We conclude with aspects of POCIS requiring more research.Estimation of sampling uncertainty in lake-water monitoring in a collaborative field trial
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 36
Fabrizio Botta, Bénédicte Lepot, Eva Leoz-Garziandia, Anne Morin
A collaborative sampling trial was performed by AQUAREF (French national reference laboratory for water and the aquatic environment) at Paladru Lake, Isere, France. This trial was the first national test aiming at improving knowledge of the effect, in lake water, of sampling on global uncertainty. Ten sampling teams regularly involved in Water Framework Directive monitoring of lake water were asked to participate, in agreement with the Regional Water Agencies. All the samples were collected and analyzed by INERIS in order to minimize the analytical impact on global uncertainty. The data treatment was performed according to standard NF ISO 5725-5. Overall results for a few metals (cobalt and nickel) showed predominance (>90%) of sampling uncertainty compared to analytical uncertainty. For other metals, the initial blank tests showed possible contamination of sampling systems, and really pointed to the importance of blank sampling. Finally, this trial highlighted the need for general guidelines for sampling that could minimize the risk of misclassification of lake-water status.
Source:TrAC Trends in Analytical Chemistry, Volume 36
Fabrizio Botta, Bénédicte Lepot, Eva Leoz-Garziandia, Anne Morin
A collaborative sampling trial was performed by AQUAREF (French national reference laboratory for water and the aquatic environment) at Paladru Lake, Isere, France. This trial was the first national test aiming at improving knowledge of the effect, in lake water, of sampling on global uncertainty. Ten sampling teams regularly involved in Water Framework Directive monitoring of lake water were asked to participate, in agreement with the Regional Water Agencies. All the samples were collected and analyzed by INERIS in order to minimize the analytical impact on global uncertainty. The data treatment was performed according to standard NF ISO 5725-5. Overall results for a few metals (cobalt and nickel) showed predominance (>90%) of sampling uncertainty compared to analytical uncertainty. For other metals, the initial blank tests showed possible contamination of sampling systems, and really pointed to the importance of blank sampling. Finally, this trial highlighted the need for general guidelines for sampling that could minimize the risk of misclassification of lake-water status.
Highlights
► We evaluated sampling practices on lakes and impact of sampling on total uncertainty. ► We studied metals usually measured in monitoring programs. ► Blank samples already displayed contamination, particularly by Zn and Pb. ► For some metals, sampling uncertainty was greater than analytical uncertainty. ► We offer practical guidance on how uncertainty can be reduced in sampling lake water.
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 35
Jiri Barek, Reiner Salzer, Paul Worsfold, Jens Andersen
Source:TrAC Trends in Analytical Chemistry, Volume 35
Jiri Barek, Reiner Salzer, Paul Worsfold, Jens Andersen
Quantitative 1H NMR spectroscopy
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 35
Santosh Kumar Bharti, Raja Roy
This review illustrates the need to use nuclear magnetic resonance (NMR) spectroscopy for the quantitative analysis of small molecules in their crude forms and in mixtures. We provide the basic concepts of quantitative NMR (qNMR), a brief description of important acquisition and processing parameters responsible for obtaining high-quality, reproducible NMR spectra in order to maximize accuracy, and the latest referencing techniques used for quantitative analysis. We also describe methods that are used for quantitative analysis including calibration-curve and standard-addition methods. Further, we briefly address validation of qNMR spectroscopy and its major applications in various scientific disciplines.
Source:TrAC Trends in Analytical Chemistry, Volume 35
Santosh Kumar Bharti, Raja Roy
This review illustrates the need to use nuclear magnetic resonance (NMR) spectroscopy for the quantitative analysis of small molecules in their crude forms and in mixtures. We provide the basic concepts of quantitative NMR (qNMR), a brief description of important acquisition and processing parameters responsible for obtaining high-quality, reproducible NMR spectra in order to maximize accuracy, and the latest referencing techniques used for quantitative analysis. We also describe methods that are used for quantitative analysis including calibration-curve and standard-addition methods. Further, we briefly address validation of qNMR spectroscopy and its major applications in various scientific disciplines.
Highlights
► We discuss quantitative analysis using NMR (qNMR) spectroscopy. ► We examine and optimize parameters affecting the quantitative accuracy of qNMR. ► We discuss internal, external and electronic referencing in qNMR spectroscopy. ► We discuss qNMR spectroscopy using calibration-curve and standard-addition methods. ► We present applications and advantages of qNMR spectroscopy in various disciplines.Synthesis and analytical potential of silica nanotubes
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 35
J.A. García-Calzón, M.E. Díaz-García
Silica nanotubes (SiO2NTs) have unique physico-chemical properties, which make them attractive building blocks in the field of nanotechnology. We review here some general methods to synthesize SiO2NTs and different approaches to functionalize them. Finally, we use some selected examples to illustrate the analytical applications and the potential of these nanomaterials.
Source:TrAC Trends in Analytical Chemistry, Volume 35
J.A. García-Calzón, M.E. Díaz-García
Silica nanotubes (SiO2NTs) have unique physico-chemical properties, which make them attractive building blocks in the field of nanotechnology. We review here some general methods to synthesize SiO2NTs and different approaches to functionalize them. Finally, we use some selected examples to illustrate the analytical applications and the potential of these nanomaterials.
Highlights
► Different methods for synthesis of silica nanotubes. ► Procedures for functionalization of silica nanotubes. ► Analytical applications of silica nanotubes in sensing and separations. ► Applications of silica nanotubes in drug/gene delivery and catalysis.Flow-batch analysis
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 35
Paulo Henrique Gonçalves Dias Diniz, Luciano Farias de Almeida, David Peter Harding, Mário César Ugulino de Araújo
Since its inception, flow-based analysis has dramatically transformed the way that sample analysis is handled. What used to be manual, slow and prone to error has become automated, rapid and precise. Though many improvements and modifications have already been explored, a most promising development has been the flow-batch analyzer. Through use of an instantaneous stop-mixing chamber and computer-controlled, flow-based sampling, it achieves extraordinarily high sampling rates. We review its historical evolution, components, features and operation, and analytical applications.
Source:TrAC Trends in Analytical Chemistry, Volume 35
Paulo Henrique Gonçalves Dias Diniz, Luciano Farias de Almeida, David Peter Harding, Mário César Ugulino de Araújo
Since its inception, flow-based analysis has dramatically transformed the way that sample analysis is handled. What used to be manual, slow and prone to error has become automated, rapid and precise. Though many improvements and modifications have already been explored, a most promising development has been the flow-batch analyzer. Through use of an instantaneous stop-mixing chamber and computer-controlled, flow-based sampling, it achieves extraordinarily high sampling rates. We review its historical evolution, components, features and operation, and analytical applications.
Highlights
► We review flow-batch analysis (FBA), a new in-flow analysis automation system. ► Flow-batch analysis (FBA) unifies techniques to achieve great practical flexibility. ► The instantaneous stop chamber allows discrete sampling and complete process control. ► Computerized analytical approach controls reagent/analyte valve timing commutation.An instrumentation perspective on reaction monitoring by ambient mass spectrometry
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 35
Xiaoxiao Ma, Sichun Zhang, Xinrong Zhang
The elucidation of reaction mechanisms in inorganic and organic chemistry, and more recently in supramolecular chemistry, has attracted great interest. Better understanding of these mechanisms would enable people to work more wisely and innovatively in designing new reactions and synthesizing novel chemicals and materials. In addition, monitoring both substrates and reaction products during the reaction process aids the study of reaction dynamics, which will be helpful in optimizing reaction conditions. In comparison with other reaction-monitoring techniques [e.g., electron-spin resonance spectroscopy, ultraviolet spectroscopy and chemically-induced dynamic nuclear polarization], mass spectrometry is widely used due to its high sensitivity, specificity and scanning speed. In this review, we focus on ambient ion sources that have undergone rapid development in the past decade and greatly facilitate direct, rapid analysis of samples with little or no sample preparation. These ion sources, including but not limited to desorption electrospray ionization, extractive electrospray ionization, low-temperature plasma probe, electrospray-assisted laser desorption/ionization, and desorption/ionization on porous silicon, offer varied reaction times (several milliseconds to several minutes) and are controlled by corresponding experimental parameters. We discuss examples of different ion sources coupled with MS for reaction monitoring and highlight some of their unique applications in bioorganic and organic chemical reactions. We believe that, with this abundant toolbox of ion sources as sampling methods, we can be more confident in choosing the most effective technique to address problems of interest in reaction monitoring.
Source:TrAC Trends in Analytical Chemistry, Volume 35
Xiaoxiao Ma, Sichun Zhang, Xinrong Zhang
The elucidation of reaction mechanisms in inorganic and organic chemistry, and more recently in supramolecular chemistry, has attracted great interest. Better understanding of these mechanisms would enable people to work more wisely and innovatively in designing new reactions and synthesizing novel chemicals and materials. In addition, monitoring both substrates and reaction products during the reaction process aids the study of reaction dynamics, which will be helpful in optimizing reaction conditions. In comparison with other reaction-monitoring techniques [e.g., electron-spin resonance spectroscopy, ultraviolet spectroscopy and chemically-induced dynamic nuclear polarization], mass spectrometry is widely used due to its high sensitivity, specificity and scanning speed. In this review, we focus on ambient ion sources that have undergone rapid development in the past decade and greatly facilitate direct, rapid analysis of samples with little or no sample preparation. These ion sources, including but not limited to desorption electrospray ionization, extractive electrospray ionization, low-temperature plasma probe, electrospray-assisted laser desorption/ionization, and desorption/ionization on porous silicon, offer varied reaction times (several milliseconds to several minutes) and are controlled by corresponding experimental parameters. We discuss examples of different ion sources coupled with MS for reaction monitoring and highlight some of their unique applications in bioorganic and organic chemical reactions. We believe that, with this abundant toolbox of ion sources as sampling methods, we can be more confident in choosing the most effective technique to address problems of interest in reaction monitoring.
Highlights
► Characteristics of ambient mass spectrometry. ► On-line and off-line methods for reaction monitoring by ambient mass spectrometry. ► Particular applications of ambient mass spectrometry.Direct chromatographic methods in the context of green analytical chemistry
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 35
Marek Tobiszewski, Jacek Namieśnik
We review analytical protocols based on gas and liquid chromatography (GC and LC), but involving no sample preparation. Green analytical chemistry seeks to minimize negative impacts of analytical chemistry. Direct analytical methods ideally fulfill this requirement, as they preclude sample preparation – the most polluting step of the analytical procedure. We describe examples of GC methodologies for environmental and food analysis using on-column, programmed temperature vaporizers and injectors with sorbent-packed liners. Although LC methods are less amenable to eliminating sample pretreatment, we also present some successful applications of direct LC methods in environmental and food analysis, and bioanalysis.
Source:TrAC Trends in Analytical Chemistry, Volume 35
Marek Tobiszewski, Jacek Namieśnik
We review analytical protocols based on gas and liquid chromatography (GC and LC), but involving no sample preparation. Green analytical chemistry seeks to minimize negative impacts of analytical chemistry. Direct analytical methods ideally fulfill this requirement, as they preclude sample preparation – the most polluting step of the analytical procedure. We describe examples of GC methodologies for environmental and food analysis using on-column, programmed temperature vaporizers and injectors with sorbent-packed liners. Although LC methods are less amenable to eliminating sample pretreatment, we also present some successful applications of direct LC methods in environmental and food analysis, and bioanalysis.
Highlights
► Direct chromatographic techniques meet the standards of green analytical chemistry. ► Direct chromatographic techniques can be applied in environmental and food analysis. ► Direct and indirect chromatographic methods have similar analytical performance.Multivariate class modeling for the verification of food-authenticity claims
04 July 2012,
11:45:35
Publication year: 2012
Source:TrAC Trends in Analytical Chemistry, Volume 35
Paolo Oliveri, Gerard Downey
Food authenticity is a challenging analytical problem normally addressed using sophisticated laboratory methods that produce large data sets. Multivariate mathematical methods are required to process such data sets, typically to answer a question such as “Is sample X, which claims to be of type A, compatible with type-A samples on the basis of its analytical measurements?”. We recommend class-modeling methods to answer this type of question and discuss the principles, the practice and the results of several types of such methods. We also compare them, in terms of advantages and short-comings, with the discriminant-classification approach.
Source:TrAC Trends in Analytical Chemistry, Volume 35
Paolo Oliveri, Gerard Downey
Food authenticity is a challenging analytical problem normally addressed using sophisticated laboratory methods that produce large data sets. Multivariate mathematical methods are required to process such data sets, typically to answer a question such as “Is sample X, which claims to be of type A, compatible with type-A samples on the basis of its analytical measurements?”. We recommend class-modeling methods to answer this type of question and discuss the principles, the practice and the results of several types of such methods. We also compare them, in terms of advantages and short-comings, with the discriminant-classification approach.
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