高效液相色谱-串联质谱法测定草莓中伊维菌素残留

Determination of ivermectin residues in strawberry by high performance liquid chromatography-tandem mass spectrometry

目的建立一种Qu ECHERS-高效液相色谱-串联质谱法(HPLC-MS/MS),测定草莓中伊维菌素的残留。方法样品经含1%乙酸的乙腈溶液提取,Qu ECHERS方法净化后,以Phenomenex XB-C18(100 mm×2.1 mm,2.6μm)为分析色谱柱,甲醇和5 mmol/L乙酸铵-0.1%乙酸缓冲溶液为流动相进行梯度洗脱,采用MRM模式测定,外标法定量。结果样品经Qu ECHERS净化后,基质效应小,伊维菌素质量浓度为0.01 mg/L^2.0 mg/L时,线性关系良好,r=0.999 9,最低检出限为0.000 3 mg/kg,定量限为0.001 mg/kg。草莓中3种添加水平(0.02 mg/kg、0.10 mg/kg、1.00 mg/kg)的回收率为73.6%~105.5%,相对标准偏差(RSD)为1.2%~5.8%。结论将该法用于实际样品检测,结果表明,该方法操作简单,提取效果好,具有良好的灵敏度、回收率和重复性,适用于草莓中伊维菌素残留的分析测定。

Objective To establish a method for the determination of ivermectin residues in strawberry coupled with Qu ECh ERS and high performance liquid chromatography-tandem mass spectrometry（ HPLC-MS / MS）. Methods Ivermectin was extracted with acetonitrile containing 1% acetic acid,and then purified with Qu ECHERS method. The chromatographic analysis was carried out on a Phenomenex XB-C18（ 100 mm × 2. 1 mm,2. 6 μm） column with methanol and 5 mmol/L ammonium acetate solution（ containing 0. 1% acetic acid） as the mobile phases in gradient program. The samples were detected by tandem quadrupole mass spectrometry by multiple reaction monitoring（ MRM）. External standard method was used to calibrate the results. Results The results showed that after Qu ECHERS purification,the matrix effect of this method was small; good linearity was obtained when the concentration of Ivermectin was within 0. 01 mg / L-2. 0 mg / L,and the correlation coefficient（ r） was 0. 999 9;the lowest limit of detection（ LOD） was 0. 000 3 mg / kg,and the limit of quantification（ LOQ） was 0. 001 mg / kg. The recovery rate rang of this method was within 73. 6%-105. 5% at spiked levels of 0. 02 mg / kg,0. 10 mg / kg,1. 00 mg / kg,with the relative standard deviations（ RSD） of 1. 2%-5. 8%. Conclusion The method was applied to real samples detection. The results showed that the method has the advantages of simple operation,good extracting effect,good sensitivity,recovery rate and repeatability,which is suitable for the determination and analysis of Ivermectin residues in strawberry.