目的实现牛奶中农药残留快速、准确的分析检测，更好地监督牛奶的食品安全问题．方法采用分散液液微萃取技术（ DLLME）作为前处理方法，气相色谱－质谱联用（ GC-MS）作为色谱分析仪器，建立了牛奶中4种酰胺类除草剂（甲草胺、乙草胺、丙草胺和异丙甲草胺）的残留分析方法．结果和结论对影响萃取效率的因素进行了分析和优化，最终选取40μL四氯化碳作为萃取剂，1000μL甲醇作为分散剂，提取时间设置为1．0 min．在最优的试验条件下，4种酰胺类除草剂质量浓度在0．05～5．00 mg· L－1范围内均具有良好的线性相关，相关系数≥0.9978．该方法灵敏度高，检出限在0．8～1．4μg· L－1（S／N＝3）范围内．该方法应用于实际牛奶样品的检测，4种目标物的平均添加回收率为67．0％～105．7％，相对标准偏差（RSD）为1．6％～8．3％．%Objective]To supervise the food safety problem in milk and achieve a rapid and accurate de-termination of pesticide residues in milk .[Method]In this paper , a simple , sensitive and environment friendly dispersive liquid-liquid microextraction ( DLLME ) technique coupled with gas chromatography-mass spectrometry ( GC-MS) was established for the extraction and determination of four amide herbicides (alachlor, acetochlor, pretilachlor, and metolachlor ) in milk samples.[Result and conclusion]The factors that affected extraction efficiency were studied and optimized .Eventually , 40μL carbon tetrachlo-ride was used as the extractant , 1 000 μL methanol was chosen as the dispersant and the extraction time was set to 1.0 min.Under the optimum conditions, the good linearity was exhibited from 0.05 to 5.00 mg· L-1 herbicide, with the correlation coefficient being more than 0.997 8.The method had a high sensitivity, and the limits of detection (S/N=3) of the four amide herbicides ranged from 0.8 to 1.4μg· L-1 .The recoveries of the target analytes from milk samples were found between 67.0% and 105.7%, and the relative standard deviations (RSD) varied from 1.6%to 8.3%.The method can be successfully applied for the analysis of amide herbicides in real milk samples .
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