A new issue of this journal has just been published. To see abstracts of the papers it contains (with links through to the full papers) click here:
Selected papers from the latest issue:
Investigation of gamma radiation effect on the anion exchange resin Amberlite IRA-400 in hydroxide form by FTIR andC NMR spectroscopy
05 January 2012, 03:05:04
Publication year: 2012
Source: Analytica Chimica Acta, Available online 3 January 2012
A. Traboulsi, N. Dupuy, C. Rebufa, M. Sergent, V. Labed
Radiation-induced decomposition of the anion exchange resin Amberlite IRA-400 in hydroxide form by gamma radiolysis has been studied under different irradiation doses and irradiation atmospheres. In this work, we focused on the degradation of the solid part of the resin by Fourier Transformed Infra-Red (FTIR) andC Nuclear Magnetic Resonance (NMR) spectroscopies associated with chemometric treatments. FTIR andC NMR techniques showed that only −CH2N(CH3)3groups were detached from the resin whereas the polystyrene divinylbenzene backbone remains intact. The quaternary ammonium groups were replaced by amine or carbonyl groups according to the irradiation atmosphere (with or without water or oxygen). Principal Components Analysis (PCA) was used to classify the degraded resins according to their irradiation conditions by separating the effect of the dose or the environment. The PCA loadings have shown spectral regions which discriminate the irradiated resins whereas SIMPLe-to-use Interactive Self-modeling Mixture Analysis (SIMPLISMA) allows to identify families of component characterizing the chemical structure of resins and estimate their relative contributions according to the irradiation atmospheres.
Source: Analytica Chimica Acta, Available online 3 January 2012
A. Traboulsi, N. Dupuy, C. Rebufa, M. Sergent, V. Labed
Radiation-induced decomposition of the anion exchange resin Amberlite IRA-400 in hydroxide form by gamma radiolysis has been studied under different irradiation doses and irradiation atmospheres. In this work, we focused on the degradation of the solid part of the resin by Fourier Transformed Infra-Red (FTIR) andC Nuclear Magnetic Resonance (NMR) spectroscopies associated with chemometric treatments. FTIR andC NMR techniques showed that only −CH2N(CH3)3groups were detached from the resin whereas the polystyrene divinylbenzene backbone remains intact. The quaternary ammonium groups were replaced by amine or carbonyl groups according to the irradiation atmosphere (with or without water or oxygen). Principal Components Analysis (PCA) was used to classify the degraded resins according to their irradiation conditions by separating the effect of the dose or the environment. The PCA loadings have shown spectral regions which discriminate the irradiated resins whereas SIMPLe-to-use Interactive Self-modeling Mixture Analysis (SIMPLISMA) allows to identify families of component characterizing the chemical structure of resins and estimate their relative contributions according to the irradiation atmospheres.
Highlights
► Your works complete the existing studies on the γ-radiation impact on the Amberlite IR400 in OH form ► The irradiation effect under different conditions was determined from an experimental design ► Its structure was characterized by resolving FTIR andC NMR concatenated data from chemometric tools.►Principal Components Analysis discriminated influencing factors as doses and conditions ► SIMPLISMA allowed to identify the new chemical functional groups and their relative proportion.Determination of oxytetracycline in milk samples by polymer inclusion membrane separation coupled to high performance liquid chromatography
04 January 2012, 01:59:45
Publication year: 2012
Source: Analytica Chimica Acta, Available online 2 January 2012
Irma Pérez-Silva, José A. Rodríguez, Ma. Teresa Ramírez-Silva, Ma. Elena Páez-Hernández
The determination of oxytetracycline in milk samples using a polymer inclusion membrane concept with HPLC was studied. The membranes developed are composed by cellulose acetate as polymer base, Cyanex 923 as carrier and o-nitrophenyl octyl ether as plasticizer. In the optimal conditions, the method exhibits good linearity in the range 0.03-0.20 mg Lwith a limit of detection and quantification of 8.2 and 27.3 μg Lrespectively. The method was successfully applied to the analysis of milk samples with high selectivity.
Source: Analytica Chimica Acta, Available online 2 January 2012
Irma Pérez-Silva, José A. Rodríguez, Ma. Teresa Ramírez-Silva, Ma. Elena Páez-Hernández
The determination of oxytetracycline in milk samples using a polymer inclusion membrane concept with HPLC was studied. The membranes developed are composed by cellulose acetate as polymer base, Cyanex 923 as carrier and o-nitrophenyl octyl ether as plasticizer. In the optimal conditions, the method exhibits good linearity in the range 0.03-0.20 mg Lwith a limit of detection and quantification of 8.2 and 27.3 μg Lrespectively. The method was successfully applied to the analysis of milk samples with high selectivity.
Highlights
► Selective extraction and HPLC analysis of oxytetracycline OTC in milk samples. ► Preparation and characterization of a polymer inclusion membrane PIM. ► Optimization of PIM-HPLC method using a Plackett-Burman experimental design. ► The OTC was isolated and the matrix interferences were eliminated. ► Limit of detection useful for OTC residues analysis in real milk samples (8 ng mL).“Multi-way partial least-squares and residual bi-linearization for the direct determination of monohydroxy-polycyclic aromatic hydrocarbons on octadecyl membranes via room-temperature fluorescence excitation emission matrices
04 January 2012, 01:59:45
Publication year: 2012
Source: Analytica Chimica Acta, Available online 2 January 2012
Hector C. Goicoechea, Korina Calimag-Williams, Andres D. Campiglia
Multi-way partial least-squares (N-PLS) is combined to the residual bi-linearization procedure (RBL) for the direct analysis of metabolites of polycyclic aromatic hydrocarbons in urine samples. Metabolite analysis is carried out via a two-step experimental procedure based on solid-phase extraction and room temperature fluorescence spectroscopy. Excitation-emission matrices are recorded from octadecyl (C18) membranes that serve as solid substrates for sample extraction and spectroscopic measurements. Excellent metabolite recoveries were obtained in all cases, which varied from 96.2 ± 1.35% (9-hydroxyphenanthrene) to 99.7 ± 0.49% (3-hydroxybenzo[a]pyrene). Background correction of extraction membranes is carried out with a new alternating least-squares (ALS) procedure adapted to second order data. The performance of N-PLS/RBL is compared to the well-established multivariate curve resolution-alternating least-squares (MCR-ALS) algorithm. Both algorithms provided similar analytical figures of merit, including their ability to handle unknown interference in urine samples. With only 10 mL of sample, the limits of detection varied between 0.06-0.08 ng mL(1-hydroxypyrene) to 0.016–0.018 ng mL(2-hydroxyfluorene). When compared to previously reported univariate calibration data, the limits of detection via N-PLS/RBL and MCR-ALS are approximately one order of magnitude higher. This was somehow expected due to the effect of unexpected components in multivariate figures of merit, i.e. a more realistic approach to the analysis of metabolites in human urine samples
Source: Analytica Chimica Acta, Available online 2 January 2012
Hector C. Goicoechea, Korina Calimag-Williams, Andres D. Campiglia
Multi-way partial least-squares (N-PLS) is combined to the residual bi-linearization procedure (RBL) for the direct analysis of metabolites of polycyclic aromatic hydrocarbons in urine samples. Metabolite analysis is carried out via a two-step experimental procedure based on solid-phase extraction and room temperature fluorescence spectroscopy. Excitation-emission matrices are recorded from octadecyl (C18) membranes that serve as solid substrates for sample extraction and spectroscopic measurements. Excellent metabolite recoveries were obtained in all cases, which varied from 96.2 ± 1.35% (9-hydroxyphenanthrene) to 99.7 ± 0.49% (3-hydroxybenzo[a]pyrene). Background correction of extraction membranes is carried out with a new alternating least-squares (ALS) procedure adapted to second order data. The performance of N-PLS/RBL is compared to the well-established multivariate curve resolution-alternating least-squares (MCR-ALS) algorithm. Both algorithms provided similar analytical figures of merit, including their ability to handle unknown interference in urine samples. With only 10 mL of sample, the limits of detection varied between 0.06-0.08 ng mL(1-hydroxypyrene) to 0.016–0.018 ng mL(2-hydroxyfluorene). When compared to previously reported univariate calibration data, the limits of detection via N-PLS/RBL and MCR-ALS are approximately one order of magnitude higher. This was somehow expected due to the effect of unexpected components in multivariate figures of merit, i.e. a more realistic approach to the analysis of metabolites in human urine samples
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