一种基于气相色谱-质谱检测水中N-亚硝基二甲胺(NDMA)的固相萃取方法

AN SPE METHOD FOR GC-MS ANALYSIS OF N-NITROSODIMETHYLAMINE IN DRINKING WATER

建立了一种适合于气相色谱-质谱(GC-MS)测定水中N-亚硝基二甲胺(NDMA)含量的固相萃取(SPE)方法.研究中比较了几种不同吸附剂为填料的SPE柱对NDMA的吸附效果,最终发现了一种以椰壳质活性炭(activated coconut charcoal)为填料的SPE柱对水中NDMA的萃取有较好的选择性,仪器检出限为1μg.L-1,方法检出限为5 ng.L-1.处理含有15μg.L-1和100μg.L-1NDMA的两种基体水溶液后,平均回收率稳定在88.5%—100.8%.本SPE柱有较宽的pH使用范围,在pH值为2.5—9.8范围内对NDMA的萃取能力影响较小.此外,研究发现同一根SPE柱能够重复使用多次,最大使用次数为5次.

In this paper,a solid-phase extraction（SPE） method suitable for gas chromatography-mass spectrometry（GC-MS） to detect the N-nitrosodimethylamine（NDMA） in drinking water was established.By comparing SPE columns with different fillings,the SPE column with the activated coconut charcoal was found to have good selectivity in extraction NDMA from water,with the instrument and method detection limits being 1 μg·L-1 and 5 ng·L-1,respectively.For the two different matrix solutions with NDMA concentrations of 15 μg·L-1 and 100 μg·L-1,respectively,the average recovery rate was 88.5%—100.8%.The SPE method was found to be effective over a wide range of pH,and the extraction of NDMA was slightly affected in the range of pH 2.5— 9.8.In addition,the SPE column could be reused for up to five times.