UPLC-MS/MS同时检测婴幼儿配方乳粉中氯酸盐和高氯酸盐残留

该实验建立了超高效液相色谱-串联质谱法（UPLC-MS/MS）同时测定婴幼儿配方乳粉中氯酸盐和高氯酸盐残留量的方法。样品经甲酸水提取，乙腈沉淀蛋白，乙腈饱和正己烷除去脂肪，采用Anionic Polar Pesticide色谱柱（2.1 mm×150 mm，5 μm）分离，以0.9%甲酸+50 mmol/L甲酸铵水溶液和乙腈为流动相梯度洗脱，在电喷雾离子源负离子（ESI-）多反应监测模式条件下，对氯酸盐和高氯酸盐进行定性和定量分析。结果表明，高氯酸盐和氯酸盐分别在0.5～50.0 μg/L和1.0～100.0 μg/L范围内线性关系良好，高氯酸盐和氯酸盐的定量限（LOQ）分别为7.5 μg/kg和15.0 μg/kg。高氯酸盐和氯酸盐的加标回收率为82.5%～98.5%，精密度试验结果的相对标准偏差（RSD）为2.0%～8.7%；该方法稳定、准确、灵敏度高，可用于婴幼儿配方乳粉中氯酸盐和高氯酸盐残留量检测。

Simultaneous determination of chlorate and perchlorate residues in infant milk powder by UPLC-MS/MS

In this experiment, an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for simultaneously quantitative determination of chlorate and perchlorate in infant milk powder. The samples were extracted by formic acid water and protein was precipitated by acetonitrile. Using acetonitrile saturated n-hexane to remove fat, and the analytes were separated by Anionic Polar Pesticide column (2.1 mm×150 mm, 5 μm), eluted by gradient with 0.9% formic acid solution + 50 mmol/L ammonium formate aqueous solution and acetonitrile. Mass spectrometry conditions were scanned by electron spray ionization (ESI-) multiple reaction monitoring (MRM) mode to conduct qualitative and quantitative analysis of the chlorate and perchlorate residues. The results showed that perchlorate and chlorate demonstrated good linearity at 0.5-50.0 μg/L and 1.0-100.0 μg/L, respectively. The limit of quantitation (LOQ) of perchlorate and chlorate were 7.5 μg/kg and 15.0 μg/kg, respectively. The recoveries of perchlorate and chlorate were 82.5%-98.5%, respectively. The relative standard deviation (RSD) of precision tests result were 2.0%-8.7%. The method was stable, accurate and with high sensitivity, which could be used for the chlorate and perchlorate determination in infant milk powder.