Analysis of nine nitrosamines in water by combining automated solid-phase extraction with high-performance liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry

摘要

In this study, a highly sensitive analysis method was developed for measuring the ng L~(-1) levels of nine nitrosamines in various water samples. Comparison of recoveries calculated by using four different cartridge types of solid-phase extraction (SPE) indicated that the UCT activated carbon cartridge combined with the HLB cartridge showed the highest recoveries for all target nitrosamines with over 70% recoveries except NDPhA (～ 50%). To optimise the mass spectrometric conditions, the sensitivity of nitrosamines applying atmospheric pressure chemical ionisation (APCI) and electrospray ionisation (ESI) was tested, and the APCI mode showed 2-20 times higher sensitivity. The method developed in this study was evaluated with certified reference material (CRM), and the result showed good accuracies of 83.3-98.4%. Using the optimised method, nine nitrosamines were analysed in the wastewater of the sewage treatment plants and rivers. The influents showed the highest total concentrations (3061-28,268 ng L~(-1)), followed by the effluents (32.3-339 ng L~(-1)) and river water (106-300 ng L~(-1)).