超高效液相色谱串联质谱法测定豆芽中4－氯苯氧乙酸的含量

目的]采用超高效液相色谱串联质谱法建立豆芽中4-氯苯氧乙酸的定性定量分析方法。方法]样品经0.01 mol/L氢氧化钠溶液提取,Oasis HLB固相萃取小柱净化,C18色谱柱分离,乙腈-0.1%甲酸水溶液为流动相,采用电喷雾离子源多反应监测模式下液相色谱串联质谱法检测,基质曲线外标法定量。结果]在最佳检测条件下,4-氯苯氧乙酸在20~500μg/L线性关系良好,相关系数为0.998 1,检出限(S/N=3)为20μg/kg。在加标水平为20、60、100μg/kg时的平均加标回收率分别为87.62%、102.10%和100.00%,其相对标准偏差(RSD)分别为3.48%、4.92%和6.59%。结论]该方法具有灵敏度高、准确度和稳定性良好、操作简捷等的特点,能够满足残留分析的要求。

Determination of 4-Chlorophenoxyacetic Acid in Bean Sprout by UPLC-MS/MS

Objective] To establish a qualitative and quantitative analysis method for 4-chlorophenoxyacetic acid in bean sprout by ultra per-formance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).Method] The sample was extracted with 0.01 mol/L sodium hydroxide solution, and cleaned up with Oasis HLB.The separations were performed on a C18 column, with a mobile phase of 0.1% formic acid aqueous solution-acetonitrile and detected by positive-ion electrospray ionization mode and multi-reaction monitoring ( MRM) mode. Re-sult] Under the optimal test condition, 4-chlorophenoxyacetic acid showed good linear relationship within the range of 20 -500 μg/L, with correlation coefficient of 0.998 1.The limit of detection(S/N=3) was 20.0 μg/kg.The average recovery rates at three spiked levels of 20, 60, 100 μg/kg were 87.62%, 102.10% and 100.00%, respectively.The relative standard deviations (RSD) were 3.48%、4.92%and 6. 59%, respectively. Conclusion] This method had the characteristics of high sensitivity and accuracy, which can meet the requirement of re-tention analysis.