超高效液相色谱-串联质谱法测定番茄酱中链霉素和双氢链霉素的残留

Determination of streptomycin and dihydrostreptomycin residues in tomato ketchup by UPLC-MS/MS

目的建立番茄酱中链霉素和双氢链霉素残留的提取净化及超高效液相色谱-质谱检测的方法。方法样品用磷酸提取液（pH2．0）溶解，超声波辅助提取，用正己烷脱色素。样液经离心后，用HLB固相萃取柱净化。采用HILIC色谱柱（2．1mm×100mm，1．7μm）分离，以乙腈和含0．1％甲酸溶液梯度洗脱，多反应监测模式测定，外标法定量。结果链霉素和双氢链霉素在0．005～0．100mg／kg浓度范围内线性关系良好，检出限均为0．005mg／kg，方法的回收率为79．5％～93．9％，相对标准偏差均〈10％。结论该方法简便、准确，适用于番茄酱中链霉素和双氢链霉素残留量的检测要求。

Objective To develop a method for simultaneous determination of streptomycin and dihydrostreptomycin residues in tomato ketchup by ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）. Methods The sample was dissolved with phosphorus solution （pH 2） and extracted by ultrasonic. The pigment was removed with n-hexane. Then, the sample was cleaned up by HLB SPE. The HILIC chromatographic column （ 100 mm Х 2. 1 mm, 1.7 μm） was used to complete the separation under gradient elution. The mixed solution of 0. 1% formic acid solution and acetonitrile was used as mobile phase. The detection of streptomycin and dihydrostreptomycin were carried out by MS/MS under multiple reaction monitoring （MRM） mode. The external standard method was used for quantitative analysis. Results The calibration curves for streptomycin and dihydrostreptomycin were indicated in the range of 0. 005- 0. 100 mg/kg, and the detection limits were both 0. 005 mg/kg. The recoveries of streptomycin and dihydrostreptomycin were ranged from 79.5% to 93.9% with relative standard deviations no more than 10%. Conclusion The method is simple and accurate to meet the requirements for determination of streptomycin and dihydrostreptomycin residues in tomato ketchup.