全自动固相萃取-气相色谱-质谱联用法测定油料 作物中2,4-二氯苯氧乙酸和2,4,5-三氯苯氧乙酸的残留量

Determination of 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid residues in oil crops by automatic solid phase extraction combined with gas chromatography-mass spectrometry

中文关键词:  全自动固相萃取  衍生化反应  气相色谱-质谱联用法  2,4-二氯苯氧乙酸  2,4,5-三氯苯氧乙酸

英文关键词:automatic solid phase extraction  derivatization reaction  gas chromatography-mass spectrometry  2,4-dichlorophenoxyacetic acid  2,4,5-trichlorophenoxyacetic acid

中文摘要:

      目的 建立全自动固相萃取-气相色谱-质谱联用法测定花生、大豆和芝麻3种油料作物中2,4-二氯苯氧乙酸和2,4,5-三氯苯氧乙酸的分析方法。方法 样品经过二氯甲烷提取, 衍生化反应, 全自动固相萃取仪净化, DB-5MS毛细管色谱柱分离, 选择离子扫描模式检测, 外标法定量。结果 2种农药在线性范围内具有良好的线性关系, 相关系数r≥0.999, 定量限均低于0.010 mg/kg, 添加的平均回收率在73.6%~100.8%之间, 相对标准偏差在3.31%~7.68%之间。结论 建立的方法样品前处理简单, 净化过程实现了自动化操作, 大大提高了工作效率。该方法灵敏度高、回收率好, 适用于油料作物中2种农药的同时检测。

英文摘要:

      Objective To establish a method for determination of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in oil crops (including peanut, soybean and sesame) by automatic solid phase extraction combined with gas chromatography-mass spectrometry (GC-MS). Methods The homogenized samples were extracted with dichloromethane, then purified by automatic solid phase extraction. After the analytes were separated by DB-5 ms column, the 2 kinds of pesticides were detected under selected ion monitoring mode and quantified by external standard technique. Results The correlation coefficients, which were both higher then 0.999, were obtained within their respective linear ranges. Also, the limits of quantitation (LOQs) for the 2 kinds of pesticides were both less than 0.010 mg/kg. Meanwhile, the average recoveries ranged from 73.6% to 100.8% with relative standard deviations of 3.31%~7.68%. Conclusion The established method with simple sample preparation achieves the automated purification process and considerably improves the work efficiency. It has simple pretreatment, high sensitivity and good recovery, which is suitable for simultaneous determination of the 2 kinds of pesticides in oil crops.