Alternative methods for the analysis of NDMA and other nitrosamines in water

摘要

N-nitrosodimethylamine (NDMA) and other nitrosamines have been reported in drinking and recycled water at low parts-per-trillion levels, both as contaminants and disinfection byproducts. Many of these nitrosamines cause cancer in animals and are probable human carcinogens. In this study, three existing analytical methods were expanded, refined, and validated for the analysis of NDMA and seven other nitrosamines in potable, waste, and recycled water. Method detection limits for a solid-phase extraction (SPE) method and a cartridge SPE (CSPE) coupled with gas chromatography-tandem mass spectrometry were 0.7-0.8 ng/L for NDMA and 0.3-1.4 ng/L for other nitrosamines. The micro-liquid-liquid extraction (MLLE) method that was developed used less volume and was effective at analyzing the different sample matrixes but yielded higher detection limits (2-4 ng/L). NDMA was the only nitrosamine detected in potable water; however N-nitrosodiethylamine, N-nitrosomorpholine, N-nitrosopiperidine, N-nitrosodi-n-butylamine, and N-nitrosopyrrolidine were present in other matrixes tested. The SPE methods and the MLLE method have been submitted for inclusion in the next revision of Standard Methods for the Examination of Water and Wastewater, and the CSPE method will be submitted for approval in the future.