固相萃取GC-ECD法同时测定5种中药材中26种农药残留量

目的：采用GC-ECD法建立5种药材中包括21种有机氯和5种拟除虫菊酯类在内的26种农药残留量的同时测定方法。方法：采用弗罗里硅土固相萃取净化样品,GC-ECD测定,HP-5弹性石英毛细管柱程序升温分离,载气为高纯 N2,柱流量1.0 mL·min-1,恒流方式控制气流,进样口温度260 oC, ECD温度330 oC。结果：弗罗里硅土固相萃取能有效净化药材样品中杂质,26种农药检测限为0.386~2.500 ng·g-1,定量限为 0.879~6.250 ng·g-1, 平均回收率为69.61%~112.80% （RSD=2.43%~15.18%,n=9）。结论：所建立的方法能同时测定 5 种药材中 26 种农药残留量, 可被参照应用于其它类似药材中的农药残留量检测。

Simultaneous Determination of 26 Pesticide Residues in 5 Chinese Medicinal Materials Using Solid-phase Extraction and GC-ECD Method

AIM： To develop an analytical method for the simultaneous determination of 26 pesticide residues including 21 organochlorines and 5 pyrethroids in 5 crude Chinese medicinal materials by gas chromatography-electron capture detector （GC-ECD） method. METHODS： Florisil solid-phase extraction （SPE） was used for the clean-up of samples and GC-ECD for the determination. The separation of the target pesticides was carded out on HP-5 quartz capillary column in an optimized oven program with nitrogen as a carder at a constant flow of 1.0 mL.min-land the injection inlet valve was set at 260 ℃ and ECD at 330 ℃. RESULTS： The florisil solid-phase extraction was effective for the clean-up of the samples. For 26 pesticides, LODs and LOQs of the developed method were 0.386-2.500 ng.g-1 and 0.879-6.250 ng.g-1, respectively, and the average recoveries were found to be 69.61%-112.80% （RSD = 2.43%-15.18%, n = 9）. CONCLUSION： The developed method could be used to simultaneously determine the 26 pesticide residues in 5 Chinese medicinal materials, and it could also be potential in the determination of other similar Chinese medicinal materials.