UPLC-MS/MS法测定柑橘中喹啉铜残留量

Determination of Oxine-Copper Residue in Citrus by UPLC-MS/MS

该研究使用超高效液相色谱-串联质谱法(UPLC-MS/MS)检测柑橘中喹啉铜的残留量,对样品处理方法、色谱条件和质谱条件进行了优化。结果表明:样品经含0.1%甲酸的乙腈-水(体积比1∶1)溶液涡旋提取,果肉样品使用20 mg PSA净化,全果样品使用20 mg C18净化;采用Mixed-Mode HILIC-1色谱柱分离,以0.1%甲酸水-0.1%甲酸乙腈溶液作流动相进行梯度洗脱,洗脱流速为0.3 mL/min,柱温为35℃;在选择反应检测扫描(SRM)模式下进行测定,喹啉铜在0.01~2 mg/L范围内性关系良好,决定系数均≥0.9982,喹啉铜在柑橘果肉和全果中的最低检测浓度均为0.05 mg/kg,添加回收试验中喹啉铜在柑橘果肉和全果中的平均回收率范围为91%~103%,相对标准偏差范围为1.9%~8.4%。该方法操作简便、快速,准确度和精密度高,适用于柑橘中喹啉铜残留量的检测。

In our study,the ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)was used to determine oxine-copper residue in citrus.Meanwhile,sample treatment methods,mass spectrometry conditions and chromatographic conditions were optimized:the samples underwent vortexed extraction in acetonitrile aqueous solution(1∶1,v∶v;containing 0.1%formic acid);the p ulp samples were purified by 20 mg N-propylethylenediamine(PSA);the whole-fruit samples were cleaned up by 20 mg C18;a Mixed-Mode HILIC-1 column(150 mm×2.1 mm,3μm)was used for separation,0.1%formic acid aqueous solution and 0.1%formic acid-acetonitrile aqueous solution were used as mobile phase for gradient elution,the elutionflow rate was 0.3 mL/min,and the column temperature was 35℃;the determination was performed in SRM mode.The result showed that axine-copper exhibited a good linear relatonship in the range of 0.01-2 mg/L(coefficients of determination≥0.9982).The limits of detection of axine-copper were 0.05 mg/kg for both citrus pulp and whole fruit.The average recoveries of oxine-copper at diferent spiked levels in citrus pulp and whole fruit were 91%-103%with relative standard deviations of 1.9%–8.4%.This method is characterized by simple and rapid sample processing,high accuracy and precision,which is suitable for the detection of oxine-copper residues in citrus.