脱脂奶粉中N-亚硝基二甲胺的测定：协同研究

Determination of N-nitrosodimethylamine in nonfat dry milk: collaborative study.

作者信息

Sen N P, Seaman S, Karpinsky K

出版信息

J Assoc Off Anal Chem. 1984 Mar-Apr;67(2):232-6.

Abstract

Ten laboratories participated in a collaborative study of a method for the determination of N-nitrosodimethylamine (NDMA) in nonfat dry milk. NDMA is eluted with dichloromethane from a mixture of Celite, acidic sulfamic acid, and nonfat dry milk (all packed in a chromatography column), concentrated in a Kuderna -Danish concentrator, and finally analyzed by a GC-thermal energy analyzer technique. Ten samples were studied: 6 were naturally contaminated (NDMA levels 0.38-3.56 ppb) and 4 were spiked with known levels (0.96 and 3.2 ppb) of NDMA. The coefficients of variation (CV) of the complete data for the naturally contaminated samples (excluding the 2 samples containing the lowest levels) were 8.5% and 22.5% for repeatability and reproducibility, respectively. The corresponding CVs for the spiked samples were 14.4% and 20.4%, respectively. The percent recoveries of the added NDMA in the spiked samples (at the 2 levels indicated above) were 101.6 +/- 3.2 (omitting 1 outlier) and 95 +/- 2.1, respectively. The method has been adopted official first action.

摘要

十个实验室参与了一项关于脱脂奶粉中N-亚硝基二甲胺（NDMA）测定方法的协作研究。NDMA用二氯甲烷从由硅藻土、酸性氨基磺酸和脱脂奶粉组成的混合物（全部装填在一个色谱柱中）中洗脱出来，在库德奈-丹麦浓缩器中浓缩，最后通过气相色谱-热能分析仪技术进行分析。研究了十个样品：6个是天然受污染的（NDMA含量为0.38 - 3.56 ppb），4个添加了已知含量（0.96和3.2 ppb）的NDMA。对于天然受污染样品（不包括含量最低的2个样品），完整数据的重复性和再现性变异系数（CV）分别为8.5%和22.5%。加标样品的相应CV分别为14.4%和20.4%。加标样品中添加的NDMA（在上述两个水平）的回收率分别为101.6±3.2（剔除1个离群值）和95±2.1。该方法已被采用为官方首次行动方法。