毛细管气相色谱法检测水皂角等中药提取物有机氯农药残留

Capillary Gas Chromatograph Determination of Organochlorine Pesticides in Chinese Medicinal Extracts

目的:建立水皂角等中药提取物中六六六及滴滴涕异构体含量的气相色谱分析方法。方法:样品采用改进了的微量化学法进行提取,浓硫酸净化,以不分流方式进样,用HP-5弹性石英毛细管柱分离样品,微电子捕获检测器检测,载气为高纯氮气,流速为1.5 mL·min-1,尾吹速度为40 mL·min-1,进样口温度250℃,检测器温度300℃。柱初始温度为100℃,以20℃·min-1升至160℃后,保持2 min,以10℃·min-1升至250℃,保持6 min。结果:最小检测量为1.4×10-14-1.2×10-12g,加样平均回收率为93.2%-101.6%;被测样品中均含有不同程度的有机氯农药残留。结论:该法快速、灵敏、准确,各项技术指标均满足农药残留检测的要求。

Objective: A capillary gas chromatographic method was reported for determination of organochlorine pesticide residues in extracts from Cassia nomame L., Vaccinium vitisidaea L., Epimedium brevicornum L., Rhodiola rosea L., Carthamus tinctorius L., and Pueraria lobata L. Methods: The organochlorine pesticides were extracted from samples by modified micro - chemical technique. Then,the extracts were cleaned up by concentrated H2S04, and separated by HP - 5 capillary column with micro - electron capture detector. Highly pure nitrogen was used as carrier gas, and the flow rate was 1. 5 mL·min-1, with the make up gas rate 40 mL·min -1, injector temperature 250 ℃, detector temperature 300 ℃. The initial temperature was set at 100℃ ,then it was raised to 160 ℃at the rate of 20℃·min-1 ,and subsequently sustained for 2 min. After that,the temperature was raised to 250 ℃ at the rate of 10 ℃·?min-1 ,and subsequently sustained for 6 min. Results: The average recoveries were within 93. 2% -101. 6%. The limits of detection were 1. 4×10 -14 - 1. 2×10 -12 g. All the samples showed orgranochlorine pesticide residues. Conclusion: This method is rapid, sensitive, accurate and suitable for analysis of pesticide residues.