超高效液相色谱-串联质谱法测定水果中乙撑硫脲残留

Determination of Ethylenethiourea Residues in Fruits Using Ultra Performance Liquid Chromatography- Tandem Mass Spectrometry

建立了水果中乙撑硫脲（Ethylenethiourea,ETU）的超高效液相色谱-串联质谱（UPLC-MS/MS）检测方法。样品经碱性乙腈（1.5%氨水乙腈）振荡提取,弗罗里硅土净化后,以乙腈-0.2%甲酸为流动相,0.4m L/min流速下梯度洗脱,经HSS T3色谱柱分离,在正离子模式下采用多反应监测（MRM）扫描测定,外标法定量。研究表明,ETU在5~200μg/L质量浓度范围内线性关系良好,相关系数均大于0.999;5,20,50μg/L 3个加标水平下,苹果、桃、葡萄、柑橘和香蕉5种基质中乙撑硫脲的加标回收率分别为93.6%~101.4%,91.2%~98.4%,84.6%~95.1%,86.8%~97.9%和79.5%~96.3%;检出限分别为0.08,0.13,0.11,0.23,0.26μg/L;定量下限分别为0.28,0.42,0.37,0.75,0.86μg/L。该方法简便、准确、经济、环保,能够满足水果中乙撑硫脲残留的快速检测要求。

A rapid method was developed for the determination of ethylenethiourea（ ETU） residues in fruits by ultra performance liquid chromatography- tandem mass spectrometry（ UPLC- MS / MS） under multiple reaction monitoring mode. The samples were extracted with alkaline acetonitrile containing1. 5% NH3·H2O,cleaned-up by adding Florisil,separated on an HSS T3 column using acetonitrile-0. 2% formic acid as mobile phase by gradient elution at a flow rate of 0. 4 m L / min,and confirmed by positive electrospray ionization tandem mass spectrometry under multiple reaction monitoring（ MRM）mode. The detection was quantified by the external standard method. The results indicated that the calibration curves of ETU were linear in the range of 5- 200 μg / L with correlation coefficients more than 0. 999. The average recoveries of ETU in five fruit samples at three spiked levels of 5,20,50μg /L were in the ranges of 93. 6%- 101. 4%（ apple）,91. 2%- 98. 4%（ peach）,84. 6%-95. 1%（ grape）,86. 8%- 97. 9%（ citrus）,and 79. 5%- 96. 3%（ banana）,respectively. The limits of detection（ LOD） for these five fruits were 0. 08,0. 13,0. 11,0. 23,0. 26 μg / L,and the limits of quantitation（ LOQ） were 0. 28,0. 42,0. 37,0. 75,0. 86 μg / L,respectively. The method is simple,accurate,economic and friendly to the environment,and could meet the requirements for rapid determination of ETU residues in fruits.