A new method for the determination of arecoline in Semen Arecae decoction pieces by microchip capillary electrophoresis with contactless conductivity detection （MCE-CCD） was proposed. The effects of various electrop...A new method for the determination of arecoline in Semen Arecae decoction pieces by microchip capillary electrophoresis with contactless conductivity detection （MCE-CCD） was proposed. The effects of various electrophoretic operating parameters on the analysis of arecoline were studied. Under the optimal conditions, arecoline was rapidly separated and detected in 1 rain with good linearity over the concentration range of 20 1500 uM （r2=0.9991） and the detection limit of 5 uM （S/N=3）. The method was used for the analysis of arecoline satisfactorily with a recovery of 96.8 -104%.展开更多
A simple, economical, and sensitive capillary electrophoresis (CE) method integrated with capacitively coupled contactless conductivity detection was developed for the determination of metal ions such as K<sup>+...A simple, economical, and sensitive capillary electrophoresis (CE) method integrated with capacitively coupled contactless conductivity detection was developed for the determination of metal ions such as K<sup>+</sup>, Na<sup>+</sup>, Mg<sup>2+</sup>, Sr<sup>2+</sup>, Ca<sup>2+</sup> in drinking water. 18-Crown-6 ether and Hexadecyltrimethylammonium Bromide (CTAB) were employed as complexing reagents. The effects of electrolyte additives, citric acid buffer solution, and other separation conditions of CE were comprehensively investigated and carefully optimized. The best results were obtained in a running buffer solution composed of citric acid (12 mM), 18-crown-6 ether (0.2 mM), and CTAB (0.015 mM) at pH 3.5. Under these conditions, a complete separation of five metal ions was successfully achieved in less than 12 min. The limits of detection for the optimal procedure were determined to be in the range of 0.02 - 0.2 mg·L<sup>-1</sup>. The repeatability with respect to migration times and peak areas, expressed as relative standard deviations, was better than 2.3% and 5.1%, respectively. Evaluation of the efficiency of the methodology indicated that it was reliable for the determination of metal ions in six different brands of drinking water samples.展开更多
A method for sensitive determination of five priority haloacetic acids in drinking water has been developed for the first time based on electromembrane extraction(EME)prior to CZE with capacitively coupled contactless...A method for sensitive determination of five priority haloacetic acids in drinking water has been developed for the first time based on electromembrane extraction(EME)prior to CZE with capacitively coupled contactless conductivity detection(CZE-C^(4)D).The target analytes were extracted from 10 mL of the sample solution(donor phase),through the supported liquid membrane(using a polypropylene membrane supporting 1-octanol),and into 10μL of 50 mmol/L NaAc solution(acceptor phase).The extracted solution was directly analyzed by CZE-C^(4)D without de-rivatization.Several factors that affect separation,detection and extraction efficiency were investigated.Under the optimum conditions,five haloacetic acids(monochloroacetic acid,dichloroacetic acid,trichloroacetic acid,mono-bromoacetic acid,and dibromoacetic acid)could be well separated from other components coexisting in water samples within 23 min,exhibiting a linear calibration over two orders of magnitude(r≥0.9943);the enrichment factors at 430-671 were obtained in a 30 min of extraction,and the limits of detection were in the range of 0.17-0.61 ng/mL.The intraday relative standard deviations for peak areas investigated at 10 ng/mL were between 1.2%and 9.7%for the combined EME-CZE-C^(4)D procedure.This approach offers an attractive alternative to the officially proposed method for purified drinking water analysis,which requires derivatization procedure prior to gas chromatography analysis.展开更多
基金support from the National Natural Science Foundation of China (Nos. 20727006,21075139)Guangdong Provincial Science and Technology Project (2008A030102009)the Medical Scientific Research Foundation of Guangdong Province(A2012155)
文摘A new method for the determination of arecoline in Semen Arecae decoction pieces by microchip capillary electrophoresis with contactless conductivity detection （MCE-CCD） was proposed. The effects of various electrophoretic operating parameters on the analysis of arecoline were studied. Under the optimal conditions, arecoline was rapidly separated and detected in 1 rain with good linearity over the concentration range of 20 1500 uM （r2=0.9991） and the detection limit of 5 uM （S/N=3）. The method was used for the analysis of arecoline satisfactorily with a recovery of 96.8 -104%.
文摘A simple, economical, and sensitive capillary electrophoresis (CE) method integrated with capacitively coupled contactless conductivity detection was developed for the determination of metal ions such as K<sup>+</sup>, Na<sup>+</sup>, Mg<sup>2+</sup>, Sr<sup>2+</sup>, Ca<sup>2+</sup> in drinking water. 18-Crown-6 ether and Hexadecyltrimethylammonium Bromide (CTAB) were employed as complexing reagents. The effects of electrolyte additives, citric acid buffer solution, and other separation conditions of CE were comprehensively investigated and carefully optimized. The best results were obtained in a running buffer solution composed of citric acid (12 mM), 18-crown-6 ether (0.2 mM), and CTAB (0.015 mM) at pH 3.5. Under these conditions, a complete separation of five metal ions was successfully achieved in less than 12 min. The limits of detection for the optimal procedure were determined to be in the range of 0.02 - 0.2 mg·L<sup>-1</sup>. The repeatability with respect to migration times and peak areas, expressed as relative standard deviations, was better than 2.3% and 5.1%, respectively. Evaluation of the efficiency of the methodology indicated that it was reliable for the determination of metal ions in six different brands of drinking water samples.
基金supported by the National Natural Science Foundation of China(No.21205042)the Open Funds of the State Key Laboratory of Electroanalytical Chemistry(No.SKLEAC201508)the Special Funds for the Development of Major Scientific Instruments and Equipment(No.2011YQ15007205).
文摘A method for sensitive determination of five priority haloacetic acids in drinking water has been developed for the first time based on electromembrane extraction(EME)prior to CZE with capacitively coupled contactless conductivity detection(CZE-C^(4)D).The target analytes were extracted from 10 mL of the sample solution(donor phase),through the supported liquid membrane(using a polypropylene membrane supporting 1-octanol),and into 10μL of 50 mmol/L NaAc solution(acceptor phase).The extracted solution was directly analyzed by CZE-C^(4)D without de-rivatization.Several factors that affect separation,detection and extraction efficiency were investigated.Under the optimum conditions,five haloacetic acids(monochloroacetic acid,dichloroacetic acid,trichloroacetic acid,mono-bromoacetic acid,and dibromoacetic acid)could be well separated from other components coexisting in water samples within 23 min,exhibiting a linear calibration over two orders of magnitude(r≥0.9943);the enrichment factors at 430-671 were obtained in a 30 min of extraction,and the limits of detection were in the range of 0.17-0.61 ng/mL.The intraday relative standard deviations for peak areas investigated at 10 ng/mL were between 1.2%and 9.7%for the combined EME-CZE-C^(4)D procedure.This approach offers an attractive alternative to the officially proposed method for purified drinking water analysis,which requires derivatization procedure prior to gas chromatography analysis.
