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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。
OBJECTIVE To establish an analytical method for the determination of 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid in three kinds of oilseed crops including peanut, soybean and sesame by using automatic solid phase extraction-gas chromatography-mass spectrometry. Methods The samples were extracted by dichloromethane, derivatized, purified by automatic SPE, separated by DB-5MS capillary column, selected by ion scan mode and quantified by external standard method. Results The results showed that the two pesticides had a good linear relationship in the linear range with the correlation coefficient r≥0.999, the limit of quantification below 0.010 mg / kg, the average recoveries between 73.6% and 100.8% and the relative standard deviations between 3.31% ~ 7.68% between. Conclusion The established method of sample pretreatment is simple, the purification process has realized the automation operation, greatly enhanced the work efficiency. The method has high sensitivity and good recovery and is suitable for the simultaneous detection of two pesticides in oil crops.