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

Abstract

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).

Keywords:

• LC-APCI-MS/MS
• nitrosamines
• solid-phase extraction
• water

Acknowledgements

This work was supported by the Korea Ministry of Environment (MOE) through the Environment Health Action Program and the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education, Science and Technology (MEST) (No. 2010–0006942).