饮用水中二级胺的气相色谱快速检测方法研究

以二甲胺、二乙胺、甲乙胺、吗啉和N-甲基苄胺5种二级胺代表物质为例,分别使用气相色谱-氢火焰(GC-FID)技术和气相色谱-质谱(GC-MS)技术检测饮用水中二级胺质量浓度。结果表明,使用优化的预处理方法处理后进样分析,5种代表物质的线性范围在20~2 000μg/L,相对标准偏差(RSD)≤0.46%,最低检出限在3.18~24.19μg/L。FID比MSD具有较强优势。该方法对于直链脂肪类和杂环类的二级胺都有良好的检测效果,可用于对饮用水二级胺类物质的检测。

Application of two detection methods for rapid GC measurement of secondary amines in drinking water

The present paper is aimed at exploring the influential factors for the GC measurement of derivative secondary amines with benzenesulfonyl chloride.As is known,secondary amines can generate carcinogenic N-nitroso compounds with nitrate,nitrite,and amide.The following five secondary amines: dimethylamine,diethylamine,thylmethylamine,morpholine and N-methylbenzylamine which are on behalf of the secondary amines for example were selected as experimental targets.Gas Chromatography-Flame Ionization(FID) and Gas Chromatography-Mass Spectrometry(MS) was used respectively to detect the content of the five secondary amine in the drinking water.Factors which include temperature,time and pH on the GC analyses were studied.The results of our experiments show that,the peak area reached the highest both in FID and in MS when the heating temperature is 80 ℃.As compared with the control group,the peak area is found to reach the highest when the lasting time is 30 min at the room temperature,and 10 min at the heating temperature of FID.While in the MS,the time is 30 min,20 min.When the pH is 5,the peak area reached the highest both in FID and in MS as compared with the control group.The linearity of the five representative substances has kept a good relationship in the range of 20-2 000 μg/L after optimized by sample pretreatment,the standard deviation is in the range of 0.306 8-0.999 2 μg/L.The relative standard deviation is less than or equal to 4.95% and the lowest detection limit is within 3.18-24.19 μg/L.Compared to the MSD,FID has a strong advantage in which it shows a good effect in detecting both straight-chain aliphatic and heterocyclic secondary amines. Through the analyses of environmental water samples,parts of the drinking water in Linzhou,Henan generally contain trace level of N-methyl-benzylamine.We can conclude that he drinking water of the region has been subjected to minor contamination by secondary amines.