The Experts below are selected from a list of 1215 Experts worldwide ranked by ideXlab platform
Jian-liang Zhao - One of the best experts on this subject based on the ideXlab platform.
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Determination of biocides in different environmental matrices by use of ultra-high-performance liquid chromatography–tandem mass spectrometry
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Zhi-feng Chen, Hao-chang Su, Fu-qiang Peng, Guang-guo Ying, Feng Chen, Jian-liang ZhaoAbstract:A sensitive and robust method using solid-phase extraction and ultrasonic extraction for preconcentration fol- lowed by ultra-high-performance liquid chromatography-tan- dem mass spectrometry (UHPLC-MS-MS) has been developed for determination of 19 biocides: eight azole fun- gicides (climbazole, clotrimazole, ketoconazole, miconazole, fluconazole, itraconazole, thiabendazole, and carbendazim), two insect repellents (N,N-diethyl-3-methylbenzamide (DEET), and icaridin (also known as picaridin)), three iso- thiazolinone antifouling agents (1,2-benzisothiazolinone (BIT), 2-n-octyl-4-isothiazolinone (OIT), and 4,5-dichloro-2- n-octyl-isothiazolinone (DCOIT)), four paraben preservatives (mEthylparaben, Ethylparaben, propylparaben, and butylpara- ben), and two disinfectants (triclosan and triclocarban) in surface water, wastewater, sediment, sludge, and soil. Recov- ery of the target compounds from surface water, influent, effluent, sediment, sludge, and soil was mostly in the range 70-120 %, with corresponding method quantification limits ranging from 0.01 to 0.31 ngL �1 , 0.07 to 7.48 ngL �1 ,0 .01 to
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determination of biocides in different environmental matrices by use of ultra high performance liquid chromatography tandem mass spectrometry
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Zhi-feng Chen, Hao-chang Su, Fu-qiang Peng, Guang-guo Ying, Feng Chen, Jian-liang ZhaoAbstract:A sensitive and robust method using solid-phase extraction and ultrasonic extraction for preconcentration fol- lowed by ultra-high-performance liquid chromatography-tan- dem mass spectrometry (UHPLC-MS-MS) has been developed for determination of 19 biocides: eight azole fun- gicides (climbazole, clotrimazole, ketoconazole, miconazole, fluconazole, itraconazole, thiabendazole, and carbendazim), two insect repellents (N,N-diethyl-3-methylbenzamide (DEET), and icaridin (also known as picaridin)), three iso- thiazolinone antifouling agents (1,2-benzisothiazolinone (BIT), 2-n-octyl-4-isothiazolinone (OIT), and 4,5-dichloro-2- n-octyl-isothiazolinone (DCOIT)), four paraben preservatives (mEthylparaben, Ethylparaben, propylparaben, and butylpara- ben), and two disinfectants (triclosan and triclocarban) in surface water, wastewater, sediment, sludge, and soil. Recov- ery of the target compounds from surface water, influent, effluent, sediment, sludge, and soil was mostly in the range 70-120 %, with corresponding method quantification limits ranging from 0.01 to 0.31 ngL �1 , 0.07 to 7.48 ngL �1 ,0 .01 to
Zuguang Li - One of the best experts on this subject based on the ideXlab platform.
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simultaneous analysis of antioxidants and preservatives in cosmetics by supercritical fluid extraction combined with liquid chromatography mass spectrometry
Journal of Chromatography A, 2006Co-Authors: Zuguang Li, Tzufeng TsaiAbstract:Abstract This study evaluated supercritical fluid extraction (SFE) combined with liquid chromatography–mass spectrometry (LC–MS) to determine trace preservatives and antioxidants including mEthylparaben (MP), Ethylparaben (EP), propylparaben (PP), butylparaben (BP), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol (α-t) and α-tocopherol acetate (α-ta) in cosmetic products. A supercritical fluid extraction procedure was used to isolate four paraben preservatives and four antioxidants from the cosmetic matrix before quantitative analysis. The optimum extraction condition was performed with static extraction for 5 min, then dynamic extraction for 20 min by using carbon dioxide supercritical fluid at 14,000 kPa and 65 °C. Methanol was used as collection solvent and the sea sand was chosen as a filling material. The analytes were separated on a C18 reversed-phase column using methanol–water as mobile phase and quantified by measuring its mass spectrometry. The linearity range is from 10 to 20,000 ng/g with RSD values below 18%. Detection limits are achieved at the level of 4.7–142 ng/g. It was successfully applied to the determination of paraben preservatives and antioxidants in cosmetics without tedious pretreatment.
Tzufeng Tsai - One of the best experts on this subject based on the ideXlab platform.
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simultaneous analysis of antioxidants and preservatives in cosmetics by supercritical fluid extraction combined with liquid chromatography mass spectrometry
Journal of Chromatography A, 2006Co-Authors: Zuguang Li, Tzufeng TsaiAbstract:Abstract This study evaluated supercritical fluid extraction (SFE) combined with liquid chromatography–mass spectrometry (LC–MS) to determine trace preservatives and antioxidants including mEthylparaben (MP), Ethylparaben (EP), propylparaben (PP), butylparaben (BP), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol (α-t) and α-tocopherol acetate (α-ta) in cosmetic products. A supercritical fluid extraction procedure was used to isolate four paraben preservatives and four antioxidants from the cosmetic matrix before quantitative analysis. The optimum extraction condition was performed with static extraction for 5 min, then dynamic extraction for 20 min by using carbon dioxide supercritical fluid at 14,000 kPa and 65 °C. Methanol was used as collection solvent and the sea sand was chosen as a filling material. The analytes were separated on a C18 reversed-phase column using methanol–water as mobile phase and quantified by measuring its mass spectrometry. The linearity range is from 10 to 20,000 ng/g with RSD values below 18%. Detection limits are achieved at the level of 4.7–142 ng/g. It was successfully applied to the determination of paraben preservatives and antioxidants in cosmetics without tedious pretreatment.
Zhi-feng Chen - One of the best experts on this subject based on the ideXlab platform.
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Determination of biocides in different environmental matrices by use of ultra-high-performance liquid chromatography–tandem mass spectrometry
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Zhi-feng Chen, Hao-chang Su, Fu-qiang Peng, Guang-guo Ying, Feng Chen, Jian-liang ZhaoAbstract:A sensitive and robust method using solid-phase extraction and ultrasonic extraction for preconcentration fol- lowed by ultra-high-performance liquid chromatography-tan- dem mass spectrometry (UHPLC-MS-MS) has been developed for determination of 19 biocides: eight azole fun- gicides (climbazole, clotrimazole, ketoconazole, miconazole, fluconazole, itraconazole, thiabendazole, and carbendazim), two insect repellents (N,N-diethyl-3-methylbenzamide (DEET), and icaridin (also known as picaridin)), three iso- thiazolinone antifouling agents (1,2-benzisothiazolinone (BIT), 2-n-octyl-4-isothiazolinone (OIT), and 4,5-dichloro-2- n-octyl-isothiazolinone (DCOIT)), four paraben preservatives (mEthylparaben, Ethylparaben, propylparaben, and butylpara- ben), and two disinfectants (triclosan and triclocarban) in surface water, wastewater, sediment, sludge, and soil. Recov- ery of the target compounds from surface water, influent, effluent, sediment, sludge, and soil was mostly in the range 70-120 %, with corresponding method quantification limits ranging from 0.01 to 0.31 ngL �1 , 0.07 to 7.48 ngL �1 ,0 .01 to
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determination of biocides in different environmental matrices by use of ultra high performance liquid chromatography tandem mass spectrometry
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Zhi-feng Chen, Hao-chang Su, Fu-qiang Peng, Guang-guo Ying, Feng Chen, Jian-liang ZhaoAbstract:A sensitive and robust method using solid-phase extraction and ultrasonic extraction for preconcentration fol- lowed by ultra-high-performance liquid chromatography-tan- dem mass spectrometry (UHPLC-MS-MS) has been developed for determination of 19 biocides: eight azole fun- gicides (climbazole, clotrimazole, ketoconazole, miconazole, fluconazole, itraconazole, thiabendazole, and carbendazim), two insect repellents (N,N-diethyl-3-methylbenzamide (DEET), and icaridin (also known as picaridin)), three iso- thiazolinone antifouling agents (1,2-benzisothiazolinone (BIT), 2-n-octyl-4-isothiazolinone (OIT), and 4,5-dichloro-2- n-octyl-isothiazolinone (DCOIT)), four paraben preservatives (mEthylparaben, Ethylparaben, propylparaben, and butylpara- ben), and two disinfectants (triclosan and triclocarban) in surface water, wastewater, sediment, sludge, and soil. Recov- ery of the target compounds from surface water, influent, effluent, sediment, sludge, and soil was mostly in the range 70-120 %, with corresponding method quantification limits ranging from 0.01 to 0.31 ngL �1 , 0.07 to 7.48 ngL �1 ,0 .01 to
Soledad Cárdenas - One of the best experts on this subject based on the ideXlab platform.
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Recycling polymer residues to synthesize magnetic nanocomposites for dispersive micro-solid phase extraction
Talanta, 2017Co-Authors: Hoda Ghambari, Emilia M. Reyes-gallardo, Mohammad Saraji, Rafael Lucena, Soledad CárdenasAbstract:Abstract The ubiquitous presence of plastics, an obvious consequence of their usefulness and low price, has turned them into a problem of environmental and safety concern. The new plastic economy, an initiative recently launched by the World Economic Forum and Ellen MacArthur Foundation, with analytical support from McKinsey & Company, promotes a change in the use of plastic worldwide around three main pillars: redesign, reusing and recycling. Recycled plastics, with the aim of extending their life spam, can be used to synthesize materials for analytical purposes. In this article polystyrene (PS) trays, previously used for food packaging, are proposed as polymeric source for the synthesis of magnetic nanocomposites. The synthesis plays with the solubility of PS in different solvents in such a way that PS is gelated in the presence of cobalt ferrite nanoparticles which are finally embedded in the polymeric network. The extraction capability of the magnetic PS nanocomposite was evaluated using the determination of four parabens (mEthylparaben, Ethylparaben, propylparaben and butylparaben) in water using liquid chromatography-tandem mass spectrometry as model analytical problem. Under the optimum conditions, limits of detection and quantification were in the range of 0.05–0.15 and 0.15–0.5 ng/mL, respectively. The precisions, expressed as relative standard deviation (RSD), varied between 4.4% and 8.5% and the relative recoveries for analysis of the water samples were in the interval 81.2–104.5%.
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determination of parabens in cosmetic products using multi walled carbon nanotubes as solid phase extraction sorbent and corona charged aerosol detection system
Journal of Chromatography A, 2010Co-Authors: Isabel Marquezsillero, Soledad Cárdenas, Eva Aguileraherrador, Miguel ValcarcelAbstract:Abstract The potential of carbon nanotubes for the solid phase extraction of parabens in cosmetic products and the detection using a corona-charged aerosol detector (C-CAD) is presented in this work. The analytical procedure is based on a conventional solid phase extraction step for which 20 mg of multi-walled carbon nanotubes were packed in a 3-mL commercial SPE cartridge. MEthylparaben, Ethylparaben, propylparaben and butylparaben were thus isolated and preconcentrated from the pre-treated samples and subsequently separated on a RP-C18 column using acetonitrile:water, 50:50 (v/v) as mobile phase. The analytical signals for the individual parabens were obtained using C-CAD. The experimental variables affecting the extraction procedure and the instrumental detection have been deeply studied. Limits of detection were in the range of 0.5–2.1 mg L−1, while the linear range was extended up to 400 mg L−1. The average precision of the method varied between 3.3–3.8% (repeatability) and 4.3–7.6% (reproducibility). Finally, the optimized procedure was applied to the determination of the target preservatives in a variety of cosmetic products with satisfactory results.