A normal phase high performance chromatographic method with evaporative light scattering detector(ELSD) and diode array detector(DAD), using n hexane/methanol/ethyl acetate(volume ratio 6∶3∶2 ) as the mobile phase, ...A normal phase high performance chromatographic method with evaporative light scattering detector(ELSD) and diode array detector(DAD), using n hexane/methanol/ethyl acetate(volume ratio 6∶3∶2 ) as the mobile phase, was established for the direct determination of active constituents gastrodin(GA) in the ethanol extracts of Gastrodia elata Blume . An silica gel column Zorbax RX SIL\[4 6 mm (\{i.d.\})×25 cm, 5 μm\] was employed. Regression equations revealed the linear relationships( r =0 998 and 0 999) between the peak areas of GA measured by ELSD and DAD and its concentration. The recoveries of GA measured by ELSD and DAD are 104 22% and 97 65%, respectively. The contents of GA measured by ELSD and DAD are 13 9 mg/g(2 79% RSD) and 12 1 mg/g(2 99% RSD) respectively in Gastrodia elata Blume . The detection limits of ELSD and DAD( S/N =3) are 3 mg/L and 1 mg/L respectively. This method is simple, selective and sensitive.展开更多
A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） ...A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） coupled with high performance liquid chromatography-diode array detector （HPLC-DAD）. Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL^-1 for all the five carbamate pesticides, with the correlation coefficients （r^2） varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177- fold, depending on the compound. The limits of detection （LODs） （S/N = 3） were ranged from 0.1 to 0.5 ng mL^-1. The method has been successfully applied to the analysis of the pesticide residues in environmental water samples.展开更多
文摘A normal phase high performance chromatographic method with evaporative light scattering detector(ELSD) and diode array detector(DAD), using n hexane/methanol/ethyl acetate(volume ratio 6∶3∶2 ) as the mobile phase, was established for the direct determination of active constituents gastrodin(GA) in the ethanol extracts of Gastrodia elata Blume . An silica gel column Zorbax RX SIL\[4 6 mm (\{i.d.\})×25 cm, 5 μm\] was employed. Regression equations revealed the linear relationships( r =0 998 and 0 999) between the peak areas of GA measured by ELSD and DAD and its concentration. The recoveries of GA measured by ELSD and DAD are 104 22% and 97 65%, respectively. The contents of GA measured by ELSD and DAD are 13 9 mg/g(2 79% RSD) and 12 1 mg/g(2 99% RSD) respectively in Gastrodia elata Blume . The detection limits of ELSD and DAD( S/N =3) are 3 mg/L and 1 mg/L respectively. This method is simple, selective and sensitive.
基金supported both by the Natural Science Foundations of Hebei(No.B2008000210)the Scientific Research Foundation of Agricultural University of Hebei.
文摘A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） coupled with high performance liquid chromatography-diode array detector （HPLC-DAD）. Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL^-1 for all the five carbamate pesticides, with the correlation coefficients （r^2） varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177- fold, depending on the compound. The limits of detection （LODs） （S/N = 3） were ranged from 0.1 to 0.5 ng mL^-1. The method has been successfully applied to the analysis of the pesticide residues in environmental water samples.
