中空纤维液相微萃取-气相色谱法测定白芍中20种农药残留

Determination of 20 pesticide residues in Radix paeoniae Alba. by hollow fiber-based liquid phase microextraction coupled with gas chromatography

目的:建立白芍中20种有机氯和拟除虫菊酯类农药的检测方法。方法:采用中空纤维液相微萃取-气相色谱法,色谱柱为HP-5石英毛细管柱(30m×0.25mm×0.25μm);柱温(程序升温):150℃为起始温度,以5℃.min-1的升温速率升至250℃,保持1min,再以2℃.min-1的升温速率升至270℃,保持5min;进样口温度:230℃;ECD检测器温度:280℃;载气为氮气,测定白芍中20种有机氯和拟除虫菊酯类农药残留量。结果:有机氯和拟除虫菊酯类农药分别在0.4～40μg.L-1和0.8～80μg.L-1范围内呈良好线性关系,r值范围为0.9970～0.9998。平均回收率(n=9)为82.5%～109.2%(RSD<10%)。结论:该方法操作简便快速,灵敏度高,准确度好,可作为中药材中有机氯和拟除虫菊酯类农药残留的测定方法。

Objective：To establish a method for detecting the 20 organochlorine and pyrethroid pesticide residues in Radix paeoniae Alba. Methods ： Hollow fiber - based liquid phase mieroextraction GC with HP - 5 column （ 30 m×0.25mm×0.25μm ） was used to determine 20 organochlorine and pyrethroid pesticide residues in Radix paeoniae Alba. ;The column temperature programming was initial temperature 150 ℃ ,with the increasing rate of 5 ℃ ·min^ -1 to 250℃ （ hold 1 min）, then with the increasing rate of 2℃· min ^-1 to 270℃ （ hold 5 rain） ; The injec- tor temperature was 230 ℃ and ECD detector temperature was 280℃ ; The carrier gas was nitrogen. Results：The calibration curves were linear over the concentraction range of 0.4 -40 μg· L^-1 for organochlorine pesticides and 0. 8 - 80 μg · L^- 1 for pyrethroid pesticides （ r was in the range of 0. 9970 - 0. 9998 ）. The average recoveries （ n =9 ） of 20 pesticides were 82.5% - 109.2% （RSD 〈 10% ）. Conclusion：The method is simple,accurate and sensitive. It can be used for the determination of organochlorine and pyrethroid pesticide residues in Chinese herbal medicines.