胶束电动毛细管色谱法对复杂农药体系的分离和测定

Separation and determination of multiple pesticide system by micellar electrokinetic capillary chromatography(MEKC)

用胶束电动毛细管色谱法(MEKC)分离了12种不同的农药,研究了电泳电压、十二烷基硫酸钠(SDS)、电泳缓冲溶液、有机改性剂(甲醇)及pH等对分离的影响,找出了最佳分离条件,使12种农药在最短时间内达到基线分离.此外,对含其中6种农药的试样溶液用C18小柱进行了纯化和富集,富集因子为10;然后用MEKC方法测试,它们的检测限为0.1～0.02 μg·kg-1,回收率范围为70.20%～88.71%,变异系数为1.3%～13%.

A useful method for separation and determination of twelve pesticides by micellar electrokinetic capillary chromatography(MEKC)has been developed.The influence of operation voltage,sodium dodecyl sulfate(SDS)concentration,background electrolyte,pH of buffer and the concentration of organic additives(methanol )has been studied.Experiments were performed with 27 kV power,75 cm×50 μm fused-silica capillary column and the absorption wavelength was at 214 nm.Sample was injected into the capillary by hydrostatic for 40 s and the running buffer was made up of 54 mmol·L -1 SDS and 25 mmol·L -1 borate(pH 8.0).Solid phase extraction with methanol was investigated for the extraction of six pesticides in plant,an enrichment factor of 10 was achieved;detection limit of MEKC was 0.10.02 μg·kg -1 ,and the recoveries of the pesticides were in the range of 70.20%88.71%.Their relative standard deviations(RSD)were between 1.3% and 13%.