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:
Analysis of perphenazine and fluphenazine by capillary electrophoresis coupled with tris (2,2′-bipyridyl) ruthenium (II) electrochemiluminescence detection
29 October 2013,
09:30:12
Publication date: 15 January
2014
Source:Talanta, Volume 118
Author(s): Lei Xu , Libo Li , Jianshe Huang , Tianyan You
The coupling of end-column tris (2,2′-bipyridyl) ruthenium (II) electrochemiluminescence (ECL) detection with capillary electrophoresis (CE) was developed for the analysis of two antipsychotic drugs, perphenazine (PPH) and fluphenazine (FPH). The parameters related to CE separation and ECL detection, including the detection potential, the buffer pH value and concentration, the separation voltage, and Ru(bpy)3 2+ concentration, were investigated in detail. Under optimum conditions, PPH and FPH were well separated and detected within 11min. The linear ranges were 0.1–5μM for PPH, and 0.1–7.5μM for FPH, respectively. The limits of detection of PPH and FPH were 5 and 10nM (S/N=3). The relative standard deviations (n=3) of the ECL intensity and the migration time were less than 2.5 and 0.65% in a day, and less than 3.4 and 1.7% in different three days. The proposed method was successfully applied to determine PPH and FPH in spiked urine samples with satisfactory results.
Source:Talanta, Volume 118
Author(s): Lei Xu , Libo Li , Jianshe Huang , Tianyan You
The coupling of end-column tris (2,2′-bipyridyl) ruthenium (II) electrochemiluminescence (ECL) detection with capillary electrophoresis (CE) was developed for the analysis of two antipsychotic drugs, perphenazine (PPH) and fluphenazine (FPH). The parameters related to CE separation and ECL detection, including the detection potential, the buffer pH value and concentration, the separation voltage, and Ru(bpy)3 2+ concentration, were investigated in detail. Under optimum conditions, PPH and FPH were well separated and detected within 11min. The linear ranges were 0.1–5μM for PPH, and 0.1–7.5μM for FPH, respectively. The limits of detection of PPH and FPH were 5 and 10nM (S/N=3). The relative standard deviations (n=3) of the ECL intensity and the migration time were less than 2.5 and 0.65% in a day, and less than 3.4 and 1.7% in different three days. The proposed method was successfully applied to determine PPH and FPH in spiked urine samples with satisfactory results.
Graphical abstract
Label-free voltammetric detection of MicroRNAs at multi-channel screen printed array of electrodes comparison to graphite sensors
29 October 2013,
09:30:12
Publication date: 15 January
2014
Source:Talanta, Volume 118
Author(s): Arzum Erdem , Gulsah Congur
The multi-channel screen-printed array of electrodes (MUX-SPE16) was used in our study for the first time for electrochemical monitoring of nucleic acid hybridization related to different miRNA sequences (miRNA-16, miRNA-15a and miRNA-660, i.e, the biomarkers for Alzheimer disease). The MUX-SPE16 was also used for the first time herein for the label-free electrochemical detection of nucleic acid hybridization combined magnetic beads (MB) assay in comparison to the disposable pencil graphite electrode (PGE). Under the principle of the magnetic beads assay, the biotinylated inosine substituted DNA probe was firstly immobilized onto streptavidin coated MB, and then, the hybridization process between probe and its complementary miRNA sequence was performed at MB surface. The voltammetric transduction was performed using differential pulse voltammetry (DPV) technique in combination with the single-use graphite sensor technologies; PGE and MUX-SPE16 for miRNA detection by measuring the guanine oxidation signal without using any external indicator. The features of single-use sensor technologies, PGE and MUX-SPE16, were discussed concerning to their reproducibility, detection limit, and selectivity compared to the results in the earlier studies presenting the electrochemical miRNA detection related to different miRNA sequences.
Source:Talanta, Volume 118
Author(s): Arzum Erdem , Gulsah Congur
The multi-channel screen-printed array of electrodes (MUX-SPE16) was used in our study for the first time for electrochemical monitoring of nucleic acid hybridization related to different miRNA sequences (miRNA-16, miRNA-15a and miRNA-660, i.e, the biomarkers for Alzheimer disease). The MUX-SPE16 was also used for the first time herein for the label-free electrochemical detection of nucleic acid hybridization combined magnetic beads (MB) assay in comparison to the disposable pencil graphite electrode (PGE). Under the principle of the magnetic beads assay, the biotinylated inosine substituted DNA probe was firstly immobilized onto streptavidin coated MB, and then, the hybridization process between probe and its complementary miRNA sequence was performed at MB surface. The voltammetric transduction was performed using differential pulse voltammetry (DPV) technique in combination with the single-use graphite sensor technologies; PGE and MUX-SPE16 for miRNA detection by measuring the guanine oxidation signal without using any external indicator. The features of single-use sensor technologies, PGE and MUX-SPE16, were discussed concerning to their reproducibility, detection limit, and selectivity compared to the results in the earlier studies presenting the electrochemical miRNA detection related to different miRNA sequences.
Selective enrichment of phosphopeptides by titania nanoparticles coated magnetic carbon nanotubes
29 October 2013,
09:30:12
Publication date: 15 January
2014
Source:Talanta, Volume 118
Author(s): Yinghua Yan , Zhifang Zheng , Chunhui Deng , Xiangmin Zhang , Pengyuan Yang
Selective enrichment of phosphoproteins or phosphopeptides from complex mixtures is essential for mass spectrometry (MS)-based phosphoproteomics. In this work, for the first time, titania nanoparticles coated magnetic carbon nanotubes (denoted as MagCNTs@TiO2 composites) were synthesized through a facile but effective solvothermal reaction for selective enrichment of phosphopeptides. The MagCNTs@TiO2 material demonstrated low limit of detection (20fmol), along with an exceptional great specificity to capture phosphopeptides from a tryptic digest of the mixture of a nonphosphorylated protein BSA and a phosphorylated protein β-casein with molar ratios of BSA/β-casein up to 200:1. In addition, the high magnetic susceptibility allowed convenient separation of the target peptides by magnetic separation. Experimental results demonstrated that the MagCNTs@TiO2 composites showed excellent potential for the selective enrichment of phosphopeptides for MS analysis.
Source:Talanta, Volume 118
Author(s): Yinghua Yan , Zhifang Zheng , Chunhui Deng , Xiangmin Zhang , Pengyuan Yang
Selective enrichment of phosphoproteins or phosphopeptides from complex mixtures is essential for mass spectrometry (MS)-based phosphoproteomics. In this work, for the first time, titania nanoparticles coated magnetic carbon nanotubes (denoted as MagCNTs@TiO2 composites) were synthesized through a facile but effective solvothermal reaction for selective enrichment of phosphopeptides. The MagCNTs@TiO2 material demonstrated low limit of detection (20fmol), along with an exceptional great specificity to capture phosphopeptides from a tryptic digest of the mixture of a nonphosphorylated protein BSA and a phosphorylated protein β-casein with molar ratios of BSA/β-casein up to 200:1. In addition, the high magnetic susceptibility allowed convenient separation of the target peptides by magnetic separation. Experimental results demonstrated that the MagCNTs@TiO2 composites showed excellent potential for the selective enrichment of phosphopeptides for MS analysis.
Chemical profiling of Wu-tou decoction by UPLC–Q-TOF-MS
29 October 2013,
09:30:12
Publication date: 15 January
2014
Source:Talanta, Volume 118
Author(s): Yao Qi , Shizhe Li , Zifeng Pi , Fengrui Song , Na Lin , Shu Liu , Zhiqiang Liu
Wu-tou decoction (WTD), a traditional Chinese medicine (TCM) formula, is composed of Aconiti Radix Cocta, Ephedrae Herba, Paeoniae Radix Alba, Astragali Radix and Glycyrrhiza Radix Preparata, and it has been used for more than a thousand years to treat rheumatic arthritis, rheumatoid arthritis and pain of joints, while the active constitutions of WTD are unclear. In this research, an ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC–Q-TOF-MS) method in both positive and negative ion mode was established to investigate the major constitutions in WTD. A Waters ACQUITY UPLC BEH C18 column was used to separate the aqueous extract of WTD. Acetonitrile and 0.1% aqueous formic acid (v/v) were used as the mobile phase. 74 components including alkaloids, monoterpene glycosides, triterpene saponins, flavones and flavone glycosides were identified or tentatively characterized in WTD based on the accurate mass within 15ppm error and tandem MS behavior. All the constitutions were also detected in the corresponding individual herbs. These results will provide a basis for further study in vivo of WTD and the information of potential new drug structure for treating rheumatic arthritis and rheumatoid arthritis.
Source:Talanta, Volume 118
Author(s): Yao Qi , Shizhe Li , Zifeng Pi , Fengrui Song , Na Lin , Shu Liu , Zhiqiang Liu
Wu-tou decoction (WTD), a traditional Chinese medicine (TCM) formula, is composed of Aconiti Radix Cocta, Ephedrae Herba, Paeoniae Radix Alba, Astragali Radix and Glycyrrhiza Radix Preparata, and it has been used for more than a thousand years to treat rheumatic arthritis, rheumatoid arthritis and pain of joints, while the active constitutions of WTD are unclear. In this research, an ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC–Q-TOF-MS) method in both positive and negative ion mode was established to investigate the major constitutions in WTD. A Waters ACQUITY UPLC BEH C18 column was used to separate the aqueous extract of WTD. Acetonitrile and 0.1% aqueous formic acid (v/v) were used as the mobile phase. 74 components including alkaloids, monoterpene glycosides, triterpene saponins, flavones and flavone glycosides were identified or tentatively characterized in WTD based on the accurate mass within 15ppm error and tandem MS behavior. All the constitutions were also detected in the corresponding individual herbs. These results will provide a basis for further study in vivo of WTD and the information of potential new drug structure for treating rheumatic arthritis and rheumatoid arthritis.
Stir bar sorptive extraction polar coatings for the determination of chlorophenols and chloroanisoles in wines using gas chromatography and mass spectrometry
29 October 2013,
09:30:12
Publication date: 15 January
2014
Source:Talanta, Volume 118
Author(s): Juan Ignacio Cacho , Natalia Campillo , Pilar Viñas , Manuel Hernández-Córdoba
The simultaneous determination of 14 chlorophenols (CPs) and chloroanisoles (CAs) in wine samples is carried out using stir bar sorptive extraction (SBSE) with thermal desorption and gas chromatography–mass spectrometry (TD–GC–MS), evaluating the preconcentration efficiency of two different polar extracting phases, ethylene glycol–silicone (EG–Silicone) copolymer and polyacrylate, which have recently become commercially marketed. The influence of several extraction variables on the preconcentration capacity of these two novel coatings was tested, as well as the variables affecting the thermal desorption step. The EG–Silicone extraction phase provided the best results, since it allowed the simultaneous preconcentration of both species the non-polar CAs, due to the silicone base, and the polar CPs, because of the ethylene glycol polymer. Consequently, under the finally selected conditions, CPs were determined without any derivatization step, reaching detection limits in the 0.3–1.4ngL−1 range, depending on the compound. For CAs the detection limits ranged from 0.2 to 0.5ngL−1, with good precision and recovery. Five CAs and three CPs were found in several analyzed wines, some of which can be regarded as defective considering their contents in 2,4,6-TCA and 2,6-DCA.
Source:Talanta, Volume 118
Author(s): Juan Ignacio Cacho , Natalia Campillo , Pilar Viñas , Manuel Hernández-Córdoba
The simultaneous determination of 14 chlorophenols (CPs) and chloroanisoles (CAs) in wine samples is carried out using stir bar sorptive extraction (SBSE) with thermal desorption and gas chromatography–mass spectrometry (TD–GC–MS), evaluating the preconcentration efficiency of two different polar extracting phases, ethylene glycol–silicone (EG–Silicone) copolymer and polyacrylate, which have recently become commercially marketed. The influence of several extraction variables on the preconcentration capacity of these two novel coatings was tested, as well as the variables affecting the thermal desorption step. The EG–Silicone extraction phase provided the best results, since it allowed the simultaneous preconcentration of both species the non-polar CAs, due to the silicone base, and the polar CPs, because of the ethylene glycol polymer. Consequently, under the finally selected conditions, CPs were determined without any derivatization step, reaching detection limits in the 0.3–1.4ngL−1 range, depending on the compound. For CAs the detection limits ranged from 0.2 to 0.5ngL−1, with good precision and recovery. Five CAs and three CPs were found in several analyzed wines, some of which can be regarded as defective considering their contents in 2,4,6-TCA and 2,6-DCA.
Sequential extraction of platinum, cisplatin and carboplatin from environmental samples and pre-concentration/separation using vesicular coacervative extraction and determination by continuum source ETAAS
29 October 2013,
09:30:12
Publication date: 15 January
2014
Source:Talanta, Volume 118
Author(s): Noorbasha N. Meeravali , K. Madhavi , R. Manjusha , Sunil Jai Kumar
A sequential extraction procedure is developed for the separation of trace levels of hexachloroplatinate, cisplatin and carboplatin from soil, which are then, pre-concentrated using a vesicular coacervative cloud point extraction method prior to their determination as platinum by continuum source ETAAS. Sequential extraction of carboplatin, cisplatin and hexachloroplatinate from a specific red soil is achieved by using the 20% HCl, aqua regia at room temperature and by combination of aqua regia and HF with microwave digestion, respectively. The pre-concentration of these species from the extracted solutions is based on the formation of extractable hydrophobic complexes of PtCl6 2− anionic species with free cationic head groups solubilizing sites of the Triton X-114 co-surfactant stabilized TOMAC (tri-octyl methyl ammonium chloride) vesicles through electrostatic attraction. This process separates the platinum from bulk aqueous solution into a small vesicular rich phase. The parameters affecting the extraction procedures are optimized. Under the optimized conditions, the achieved pre-concentration factor is 20 and detection limit is 0.5ngg−1 for soil and 0.02ngmL−1 for water samples. The spiked recoveries of hexachloroplatinate, cisplatin and carboplatin in water and soil extracts in the vesicular coacervative extraction are in the range of 96–102% at 0.5–1ngmL−1 with relative standard deviation of 1–3%. The accuracy of the method for platinum determination is evaluated by analyzing CCRMP PTC-1a copper–nickel sulfide concentrate and BCR 723 road dust certified reference materials and the obtained results agreed with the certified values with 95% confidence level of student t-test. The results were also compared to mixed-micelle (MM)-CPE method reported in the literature [22].
Source:Talanta, Volume 118
Author(s): Noorbasha N. Meeravali , K. Madhavi , R. Manjusha , Sunil Jai Kumar
A sequential extraction procedure is developed for the separation of trace levels of hexachloroplatinate, cisplatin and carboplatin from soil, which are then, pre-concentrated using a vesicular coacervative cloud point extraction method prior to their determination as platinum by continuum source ETAAS. Sequential extraction of carboplatin, cisplatin and hexachloroplatinate from a specific red soil is achieved by using the 20% HCl, aqua regia at room temperature and by combination of aqua regia and HF with microwave digestion, respectively. The pre-concentration of these species from the extracted solutions is based on the formation of extractable hydrophobic complexes of PtCl6 2− anionic species with free cationic head groups solubilizing sites of the Triton X-114 co-surfactant stabilized TOMAC (tri-octyl methyl ammonium chloride) vesicles through electrostatic attraction. This process separates the platinum from bulk aqueous solution into a small vesicular rich phase. The parameters affecting the extraction procedures are optimized. Under the optimized conditions, the achieved pre-concentration factor is 20 and detection limit is 0.5ngg−1 for soil and 0.02ngmL−1 for water samples. The spiked recoveries of hexachloroplatinate, cisplatin and carboplatin in water and soil extracts in the vesicular coacervative extraction are in the range of 96–102% at 0.5–1ngmL−1 with relative standard deviation of 1–3%. The accuracy of the method for platinum determination is evaluated by analyzing CCRMP PTC-1a copper–nickel sulfide concentrate and BCR 723 road dust certified reference materials and the obtained results agreed with the certified values with 95% confidence level of student t-test. The results were also compared to mixed-micelle (MM)-CPE method reported in the literature [22].
Ultrahigh resolution mass spectrometry-based metabolic characterization reveals cerebellum as a disturbed region in two animal models
29 October 2013,
09:30:12
Publication date: 15 January
2014
Source:Talanta, Volume 118
Author(s): Shuhai Lin , Basem Kanawati , Liangfeng Liu , Michael Witting , Min Li , Jiandong Huang , Philippe Schmitt-Kopplin , Zongwei Cai
In the previous reports about cognitive dysfunction, cerebellum was thought to be a less affected tissue by genetic or environmental alterations in comparison to other tissues in the brain including hippocampus under the same conditions. In this work, we investigated two types of metabolomic alterations inside the cerebellum tissue. The first one addressed the differences in the metabolomics profiles between Transgenic (Tg) CRND8 of Alzheimer's disease mice and non-transgenic (non-Tg) littermates. The second one addressed the metabolic differences between wild type mice exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and wild type mice which are not exposed to this toxic compound. For these two investigations, ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS) was implemented. As a result, the significant changes of each comparison were tentatively annotated by the high mass accuracy generated from the measurements in the negative ion mode. The biosynthesis of amino acids was also enhanced pronouncedly, and perturbation of purine metabolism was also observed in Tg mice compared to non-Tg littermates. In another animal model, the reduced levels of amino acids were found whereas the intermediate levels in purine metabolism and fatty acids including fatty acid conjugated metabolites were elevated in cerebellar tissues of mice exposed to TCDD compared to control group. Collectively, it was demonstrated that FT-ICR/MS was a powerful tool for interpretation of the elemental compositions of the peaks, revealing that the metabolic perturbations in cerebellar tissues of mice were induced by either genetic manipulation or environmental factor. Therefore, the non-targeted approach, alternatively, provides various metabolic phenotypes for the systems-level mirror of the complex etiology of neurotoxicity in the cerebellum.
Source:Talanta, Volume 118
Author(s): Shuhai Lin , Basem Kanawati , Liangfeng Liu , Michael Witting , Min Li , Jiandong Huang , Philippe Schmitt-Kopplin , Zongwei Cai
In the previous reports about cognitive dysfunction, cerebellum was thought to be a less affected tissue by genetic or environmental alterations in comparison to other tissues in the brain including hippocampus under the same conditions. In this work, we investigated two types of metabolomic alterations inside the cerebellum tissue. The first one addressed the differences in the metabolomics profiles between Transgenic (Tg) CRND8 of Alzheimer's disease mice and non-transgenic (non-Tg) littermates. The second one addressed the metabolic differences between wild type mice exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and wild type mice which are not exposed to this toxic compound. For these two investigations, ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS) was implemented. As a result, the significant changes of each comparison were tentatively annotated by the high mass accuracy generated from the measurements in the negative ion mode. The biosynthesis of amino acids was also enhanced pronouncedly, and perturbation of purine metabolism was also observed in Tg mice compared to non-Tg littermates. In another animal model, the reduced levels of amino acids were found whereas the intermediate levels in purine metabolism and fatty acids including fatty acid conjugated metabolites were elevated in cerebellar tissues of mice exposed to TCDD compared to control group. Collectively, it was demonstrated that FT-ICR/MS was a powerful tool for interpretation of the elemental compositions of the peaks, revealing that the metabolic perturbations in cerebellar tissues of mice were induced by either genetic manipulation or environmental factor. Therefore, the non-targeted approach, alternatively, provides various metabolic phenotypes for the systems-level mirror of the complex etiology of neurotoxicity in the cerebellum.
Multifunctional AS1411-functionalized fluorescent gold nanoparticles for targeted cancer cell imaging and efficient photodynamic therapy
29 October 2013,
09:30:12
Publication date: 15 January
2014
Source:Talanta, Volume 118
Author(s): Jun Ai , Yuanhong Xu , Baohua Lou , Dan Li , Erkang Wang
Herein, one multifunctional AS1411-functionalized fluorescent gold nanoparticles (named NAANPs) is synthesized and successfully applied for both targeted cancer cell imaging and efficient photodynamic therapy (PDT). The NAANPs are obtained by functionalizing the gold nanoparticles with AS1411 aptamer and then bound with one porphyrin derivative N-methylmesoporphyrin IX (NMM). Using HeLa cells over expressing nucleolin as representative cancer cells, the formed NAANPs can target to the cell surface via the specific AS1411-nucleolin interaction, which can discriminate the cancer cells from normal ones (e.g. HEK293) unambiguously. That the fluorescence intensity of NMM increased significantly upon binding to AS1411 G-quadruplex makes the NAANPs appropriate fluorescence reagent for cell imaging. Meanwhile, NMM can also be used as a photosensitizer, thus irradiation of the NAANPs by the white light from a common electric torch can lead to efficient production of cytotoxic reactive oxygen species for establishing a new type of PDT to cancer cells. Gold nanoparticles play the roles of both carrier and enhancer of the functional groups onto the cells. In addition, they not only possess inherently certain cytotoxicity to the cancer cells, but also boost the cellular uptake of the fluorescent groups. As a result, the efficiency of both the targeted cell imaging and PDT could be ensured.
Source:Talanta, Volume 118
Author(s): Jun Ai , Yuanhong Xu , Baohua Lou , Dan Li , Erkang Wang
Herein, one multifunctional AS1411-functionalized fluorescent gold nanoparticles (named NAANPs) is synthesized and successfully applied for both targeted cancer cell imaging and efficient photodynamic therapy (PDT). The NAANPs are obtained by functionalizing the gold nanoparticles with AS1411 aptamer and then bound with one porphyrin derivative N-methylmesoporphyrin IX (NMM). Using HeLa cells over expressing nucleolin as representative cancer cells, the formed NAANPs can target to the cell surface via the specific AS1411-nucleolin interaction, which can discriminate the cancer cells from normal ones (e.g. HEK293) unambiguously. That the fluorescence intensity of NMM increased significantly upon binding to AS1411 G-quadruplex makes the NAANPs appropriate fluorescence reagent for cell imaging. Meanwhile, NMM can also be used as a photosensitizer, thus irradiation of the NAANPs by the white light from a common electric torch can lead to efficient production of cytotoxic reactive oxygen species for establishing a new type of PDT to cancer cells. Gold nanoparticles play the roles of both carrier and enhancer of the functional groups onto the cells. In addition, they not only possess inherently certain cytotoxicity to the cancer cells, but also boost the cellular uptake of the fluorescent groups. As a result, the efficiency of both the targeted cell imaging and PDT could be ensured.
Graphical abstract
No comments:
Post a Comment