高效液相色谱-串联质谱法测定奶粉中氯酸盐和高氯酸盐

Determination of chlorate and perchlorate in milk power by high-performance liquid chromatography-tandem mass spectrometry

建立了一种测定奶粉中氯酸盐和高氯酸盐含量的高效液相色谱-串联质谱方法。样品经0.1%(v/v)甲酸水-乙腈提取, 10 000 r/min 下离心10 min后,上清液经PRiME HLB固相萃取柱净化;采用离子交换色谱分离,色谱柱为Thermo Scientific Acclaim TRINITY P1复合离子交换柱(50 mm×2.1 mm, 3 μ m),以乙腈和20 mmol/L 乙酸铵溶液为流动相进行梯度洗脱,MS/MS检测,内标法定量。结果显示,氯酸盐和高氯酸盐分别在2.0~40.0 μ g/L 和1.0~20.0 μ g/L 范围内线性关系良好,相关系数( r^2)大于0.999,方法的定量限分别为15.0和7.5 μ g/kg 。氯酸盐和高氯酸盐分别在30.0、60.0、120.0 μ g/kg 和15.0、30.0、60.0 μ g/kg 3个水平下的加标回收率为89.24%~107.85%,相对标准偏差为3.15%~10.42%( n =6)。该方法简便快捷、准确可靠,能适用于奶粉样品的测定。

An analytical method based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for detecting chlorate and perchlorate residues in milk power.Chlorate and perchlorate in milk power were extracted using a 0.1%(v/v) formic acid-acetonitrile solution.The extract was centrifuged at 10 000 r/min for 10 min, and the supernatant was cleaned up on a PRiME HLB column.Separation of chlorate and perchlorate was performed on an ion-exchange column (Thermo Scientific Acclaim TRINITY P1, 50 mm×2.1 mm, 3 μ m) by gradient elution using acetonitrile and 20 mmol/L ammonium acetate solution as the mobile phase.The analytes were identified by MS/MS.Quantification was achieved using internal standards.Chlorate and perchlorate demonstrated good linearity in the ranges of 2.0-40.0 and 1.0-20.0 μ g/L , respectively, with correlation coefficients ( r^2) greater than 0.999.The limits of quantification (LOQs) of chlorate and perchlorate were found to be 15.0 and 7.5 μ g/kg , respectively.The recoveries of chlorate and perchlorate ranged from 89.24% to 107.85% at the three spike levels of 30.0, 60.0, and 120.0, and 15.0, 30.0, and 60.0 μ g/kg , respectively, with relative standard deviations (RSDs) ranging from 3.15% to 10.42%( n =6).This method is convenient, rapid, accurate, and efficient, thus demonstrating its suitability for use in the determination of chlorate and perchlorate in milk power.