全自动固相萃取-气相色谱质谱联用测定酿造用水中的20种农药残留

Determination of 20 Pesticide Residues in Liquor-Making Water by Automatic Solid Phase Extraction Gas Chromatography-Mass Spectrometry

本研究建立了全自动固相萃取-气相色谱质谱联用测定酿造用水中的20种农药残留的分析方法。分别考察了C;柱和HLB柱的萃取效果以及不同混合溶剂的洗脱效率,比较了溶剂和基质对目标农残在质谱上的响应差异。水样经0.25μm滤膜过滤后经HLB小柱富集净化,用乙酸乙酯-二氯甲烷(1∶1,V/V)洗脱,洗脱液混合后经无水硫酸钠脱水,再氮吹复溶,用HP-5MS色谱柱分离,外标法定量。在优化的测试条件下,20种农药残留组分在1~200μg/L时,线性关系良好(R;≥0.993),除七氯和艾氏剂外,其他18种农残的平均回收率在81.57%~115.91%,RSD为4%~13%。该方法相比于传统的液液萃取,重现性较好,适合于酿酒用水中20种农药残留的检测。

In this study a method for the determination of 20 pesticide residues in liquor-making water by automatic solid phase extraction gas chromatography-mass spectrometry was established. The extraction effect of C;column and HLB column, and the elution efficiency of different mixed solvents were investigated. The influences of different solvents and matrixes on the response of the target pesticide residue were compared. The water sample was filtered with 0.25 μm membrane, enriched and purified with HLB column, and then eluted with ethyl acetate-dichloromethane(1∶1, V/V). The mixed eluent was dehydrated by anhydrous sodium sulfate,redissolved by nitrogen blowing, separated by HP-5MS chromatographic column, and quantified by external standard method. Under the optimized test conditions, the 20 pesticide residues had good linear relationship in the range of 1 μg/L to 200 μg/L(R;≥0.993).Except for heptachlor and aldrin, the average recovery rates of the other 18 pesticide residues were between 81.57 % and 115.91 %,and the RSD was between 4 % and 13 %. Compared with the traditional liquid-liquid extraction, this method has better reproducibility, and is suitable for the detection of the 20 pesticide residues in liquor-making water.