【摘要】 文章建立了分散固相萃取-气相色谱法分析原料乳中19种有机氯农药残留量的方法。通过比较不同吸附剂对样品提取液的净化效果和对电子捕获检测器(Electron capture detector,ECD)基线的影响,确定净化方法。样品采用正己烷:丙酮(3:1)提取,加入2 g氯化钠,超声萃取,加入200 mg C18粉进行分散固相净化,最后采用DB-35MS UI毛细柱进行分离,外标法定量。结果显示,在1～100μg/kg浓度范围内,线性相关系数均>0.99,方法检出限<0.0375μg/kg;3水平加标回收率试验,回收率为85%～135%,相对标准偏差(n=6)<10%。该方法准确可靠、灵敏度高、操作简便、快速,可满足日常检测工作要求。更多还原

【Abstract】 Raw milk was pretreated by dispersive solid phase extraction(dSPE) for the purification of 19 organochlorine pesticide residues. And different absorbents were used to optimize the clean-up efficiency on the extraction of raw cow milk extract and the baseline stability of electron capture detector(ECD).Briefly, raw milk samples were extracted with hexane and acetone(3:1), and 2 grams of NaCl was added to the extract. Then it was treated by ultrasonic and clean-up by dispersive solid phase extraction with 200 mg C18. Finally, oranochlorine pesticides were separated via DB-35 MS UI capillary column, and quantified by external standard method by GC-ECD. Results showed that the linear range was between 1 μg/kg to100 μg/kg, the correlation coefficient were all above 0.99, and the limit of detection(LOD) were all below0.0375 μg/kg. The spiked recoveries at three levels were in the range of 85%～135%, and the relative standard deviations(RSDs)(n=6) were below 10%. This method bear the advantages of simplified, rapid operation procedure, as well as high sensitivity, accuracy and precision, which is well qualified for the routine analysis.更多还原