超高效液相色谱-串联质谱法测定婴幼儿配方奶粉中氯酸盐和高氯酸盐

Determination of chlorate and perchlorate in infant formula by ultra-high performance liquid chromatography-tandem mass spectrometry

目的建立超高效液相色谱-串联质谱法(ultra-high performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)同时测定婴幼儿配方奶粉中氯酸盐和高氯酸盐的分析方法。方法氯酸盐-18O3和高氯酸盐-18O4加入到样品中,通过涡旋混合、提取、离心和过滤,收集滤液,待UPLC-MS/MS分析。流动相为20 mmol/L甲酸铵和乙腈。Waters TorusTM DEA(2.1 mm×100 mm, 1.7μm)色谱柱用来分析高氯酸盐和氯酸盐。采用负电喷雾电离,多反应监测模式,内标法定量。结果氯酸盐和高氯酸盐分别在0.2~200μg/L和0.1~100μg/L范围内线性关系良好(R2>0.999),方法检出限分别为0.35和0.12μg/kg,定量限分别为1.16和0.40μg/kg。在15.0、75.0和150μg/kg加标水平下,氯酸盐回收率为91.9%~102.8%,相对标准偏差为2.5%~4.4%(n=6)。在7.5、37.5和75.0μg/kg加标水平下,高氯酸盐的回收率为91.3%~106.3%,相对标准偏差为2.6%~3.9%(n=6)。结论该方法简便、快速、灵敏度高、准确性好,适用于各类复杂基质中高氯酸盐和氯酸盐的同时分析。

OBJECTIVE To establish a method for determination of perchlorate and chlorate in infant formula by ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). METHODS Chlorate-18O3 and perchlorate-18O4 were added to the samples, and the filtrate was collected and analyzed by UPLC-MS/MS by vortex mixing, extraction, centrifugation and filtration. The mobile phase was 20 mmol/L ammonium formate and acetonitrile. The Waters TorusTM DEA(2.1 mm×100 mm, 1.7 μm)column was used to separate chlorate and perchlorate. The negative spray ionization(ESI-) was used. The multi-response monitoring(MRM) mode was used for monitoring. The internal standard method was used for quantification. RESULTS The linear relationships of chlorate and perchlorate were good in the range of 0.2-200 μg/L and 0.1-100 μg/L(R2>0.999), respectively. The detection limits(LOD, S/N=3) of chlorate and perchlorate were 0.35 μg/kg and 0.12 μg/kg, respectively, and the quantitative limits(LOQ, S/N=10) of chlorate and perchlorate were 1.16 μg/kg and 0.40 μg/kg, respectively. At the addition levels of 15.0, 75.0 and 150 μg/kg, the chlorate recovery was 91.9%-102.8% and the relative standard deviation(RSD, n=6) was 2.5%-4.4%.At the addition levels of 7.5, 37.5 and 75.0 μg/kg, the recovery rate of perchlorate was 91.3%-106.3% and the RSD(n=6) was 2.6%-3.9%. CONCLUSTION The method is simple, rapid, sensitive and accurate, and is suitable for simultaneous analysis of perchlorate and chlorate in various complex substrates.