在线SPE-HPLC法测定水中N-亚硝基二甲胺

Online Solid Phase Extraction Coupled With High Performance Liquid Chromatography for Rapid Determination of N-nitrosodimethylamine in Water

水中N-亚硝基二甲胺(NDMA)的快速准确定量测定一直是国内外相关研究人员关注的一个难题。建立了采用在线固相萃取-高效液相色谱法(online SPE-HPLC)快速测定水中N-亚硝基二甲胺的方法。水样经Hypersil GOLD aQ固相萃取小柱在线富集后,通过六通阀切换改变管路流向,以乙腈-水作为流动相进行洗脱,采用Thermo Acclaim PAⅡ分析柱进行组分分离,通过二极管阵列检测器(DAD)进行检测。方法的检出限(LOD)为0.025μg/L、定量限为0.07μg/L,NDMA在0.09~20μg/L范围内线性关系良好(R2=0.9997),回收率为95.28%~114.93%,相对标准偏差≤9.72%。该方法仅需进样2.5 mL、耗时10 min,即可实现样品的自动固相萃取、洗脱分析,无需复杂的手动预处理过程,操作简便快捷、成本适中,可实现快速准确地检测水样中NDMA浓度,可满足我国有关饮用水卫生标准对NDMA检测的需求。

Rapid and accurate quantitative determination of N-nitrosodimethylamine(NDMA)in water has always been a difficult problem concerned by researchers at home and abroad.A method for rapid determination of NDMA in water was developed based on online solid phase extraction coupled with high performance liquid chromatography(online SPE-HPLC).After the water samples were enriched online by Hypersil GOLD aQ solid phase extraction column,the flow direction of the pipeline was changed through a six-way valve switch,acetonitrile and water were used as the mobile phase for elution of NDMA,and the components were separated by Thermo Acclaim PAⅡcolumn and detected by diode array detector(DAD).The limit of detection(LOD)of this method was 0.025μg/L,and the limit of quantification(LOQ)was 0.07μg/L.NDMA had good linearity in the range of 0.09-20μg/L(R~2=0.9997),the recoveries of NDMA were 95.28%-114.93%,and the relative standard deviation was less than 9.72%.The method only consumed 2.5 mL sample volumes and could automatically realize solid phase extraction,elution and analysis of samples in 10 min.The method does not require complex manual pretreatment process,and it is simple,quick and cost-effective,and can achieve rapid and accurate detection of NDMA concentration in water samples,which can meet the requirements of drinking water standards for NDMA detection in China.