(北京三元食品股份有限公司， 国家母婴乳品健康工程技术研究中心，北京市乳品工程技术研究中心，母婴研究技术创新中心 北京 100163)
(Beijing Sanyuan Foods Co.， Ltd.， National Engineering Research Center of Dairy Health for Maternal and Child，Beijing Engineering Research Center of Dairy， Beijing Technical Innovation Center of Human Milk Research，Beijing 100163)
为建立高效阴离子交换色谱-串联质谱法检测牛乳和婴儿配方粉中高氯酸盐和氯酸盐的方法，通过优化沉淀蛋白试剂和婴儿配方粉的纯化条件，用乙腈沉淀蛋白，离子色谱前处理柱净化上清液，使用Dionex IonPac AS19高效阴离子色谱柱分离，以氢氧化钾淋洗液进行梯度洗脱，流速0.35 mL/min，进样体积50 μL，柱温 30 ℃，采用质谱检测器检测。结果表明:在该试验条件下，高氯酸盐和氯酸盐能够很好地分离，且在较宽的浓度范围与其对应的定量离子峰面积呈良好的线性关系(R2>0.999)。高氯酸盐和氯酸盐的检出限分别为7 ng/L和1.7 ng/L，定量限分别为20 ng/L和5 ng/L。牛乳和婴儿配方粉的加标回收率在 88.95%~102.33%范围，RSD在1.86%~3.21%范围。该方法样品处理简单，具有较低的检出限与定量限，较好的稳定性，良好的重复性与回收率，能广泛用于牛奶及婴幼儿配方奶粉的检测。
A method for the determination of perchlorate and chlorate in bovin milk and infant formula by high performance anion exchange chromatography-tandem mass spectrometry was developed. It was optimized about the protein precipitation reagent and the purification conditions of infant formula. The protein was precipitated by acetonitrile and the supernatant was purified by ion chromatographic pretreatment column. The separation was performed on a Dionex IonPac AS19 high performance anion column with gradient elution using potassium hydroxide eluent at the flow rate of 0.35 mL/min. The injection volume was 50 μL. The column temperature was 30 ℃. The results showed that the perchlorate and chlorate could be separated well under the experimental conditions and showed a good linear relationship with its corresponding quantitative ion peak area in a wide concentration range (R2>0.999). The limits of detection for perchlorate and chlorate were 7 ng/L and 1.7 ng/L， respectively， and the limits of quantification were 20 ng/L and 5 ng/L. The recoveries of milk and infant formula were 88.95%~102.33%， and the RSDs were 1.86%~3.21%. This method has the advantages of simple sample processing， low limit of detection， low limit of quantification， good stability， good repeatability and recovery， and could be widely used in the detection of milk and infant powder.