气相色谱-质谱法测定奶粉中的三聚氰胺

Determination of melamine in milk powder by GC-MS

目的：建立气相色谱-质谱联用测定奶粉中三聚氰胺的方法。方法：奶粉用10％的三氯乙酸提取后经阳离子固相萃取柱富集净化、浓缩、定容后采用EI源在选择离子模式下进行检测。对提取溶剂、气相色谱以及质谱条件进行了考察。结果：确定了10％三氯乙酸作为提取剂，采用DB-1701作为气相色谱分离柱。空白加标的平均回收为82．1％，测定结果相对标准偏差为1．82％，在0．2～2．0μg／ml的范围内具有良好的线形关系，相关系数为0．9996，最低检出限达到0．1mg／kg。结论：该方法简单，快速，灵敏度佳，克服了常规三聚氰胺检测中需要衍生化的缺点。能较好地满足奶粉中三聚氰胺的定性定量检验要求。

Objective：To study a method that extracts and determines melamine in milk powder. Methods：Test sample was extracted with 10% trichloroacetic acid, then cleaned with cation - exchange extraction column. After being extracted and concentrated, serum sample has been monitored by GC - MS. Some factors effecting extracting melamine were considered, including sol vent type and parameters of GC - MS. Results ：10% trichloroacetic acid solution and the DB - 1701 were determined to be the extraction dosage and splitter. Using the blank milk powder spiked with the standards, the average recovery in the range was 82. 1 and the relative standard deviations （RSD） 1.82%. The linear ranges were from 0. 2 μg/ml to 2. 0 μg/ml with correlation coefficient of 0. 9996. The limit of determination was 0. 1 mg/kg. Conclusion： The proposed method has been proved to be satisfactor for qualitative and quantitative need that is required in poisons sample.