对水中痕量二甲胺传统检测方法的改进

对传统的采用苯磺酰氯衍生、气相色谱法检测水中二甲胺的方法进行了改进,以满足快速检测痕量二甲胺的需要。改进后的方法,前处理时间大大缩短,在1.5 h内可同时衍生25个水样,检测所需水样体积减少了95%,溶剂用量减少了90%,同时采用氢火焰检测器(FID)代替了昂贵的质谱检测器并对色谱条件进行了优化。改进后方法检出限为0.5μg/L,二甲胺的线性范围为1.0～50.0μg/L时,标准偏差(SD)为0.048～0.221μg/L,相对标准偏差(RSD)≤4.43%,水样加标回收率为95.0%～104.6%。改进后的方法检测快速,并具有良好的精密度和准确度,可用于快速分析饮用水中的痕量二甲胺及其他简单的一级和二级脂肪胺。

Improved Method for Determining Trace Dimethylamine in Water by Gas Chromatography

The traditional gas chromatography after derivatization with benzenesulfonyl chloride was improved to meet the requirement for quick determination of trace dimethylamine (DMA) in water. After the improvement, the pretreatment time is decreased remarkably, 25 samples can be derived at the same time within 1.5 h, and the sample volume and solvent volume are reduced by 95% and 90% re-spectively. The expensive MS detector was replaced by FID, and the chromatographic condition was opti-mized. The detection limit of the improved method is 0.5μg/L, the linear range of DMA is 1.0 to 50.0 μg/L, the standard deviation is O. 048 to 0.221 μg/L, the relative standard deviation is equal to or less than 4.43%, and the recovery with standard addition is 95.0% to 104.6%. The improved method is quick in determination and has good precision and accuracy. It can be used for quick determination of trace DMA and other primary and secondary aliphatic amines in water.