Measurement of pollution levels of N-nitroso compounds of health concern in water using ultra-performance liquid chromatography–tandem mass spectrometry

Abstract This paper reports the development of a highly sensitive analytical method combining solid-phase extraction (SPE) with ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS), for the monitoring of ultra-trace levels of N-nitrosamines in water samples. Under optimized analytical conditions, chromatographic separation was performed in 3 min, in isocratic mode, using an Acquity UHPLC C18 column and a mobile phase consisting of acetonitrile, water, and formic acid (60:40:0.1, v/v/v) at a flow rate of 0.4 mL min −1 . Electrospray ionization tandem interface was employed prior to mass spectrometric detection. Good linearity ( R 2  ≥ 0.9987) and low limits of detection (0.04–0.4 ng L −1 ) and quantification (0.1–1.2 ng L −1 ) were obtained. The extraction recoveries ranged from 98 ± 1% to 100 ± 1% and the relative standard deviations were less than 1.53%. The matrix effect was between 98 ± 2 and 100 ± 1%. The obtained results clearly demonstrate that the developed method is accurate and highly sensitive for the simultaneous determination of N-nitroso-n-propylamine, N-nitrosomorpholine, N-nitrosomethylethylamine and N-nitrosodimethylamine at ultra-trace levels (ng L −1 ) in different types of water samples. Therefore, this method can be a useful analytical tool for future toxicological, water quality surveillance studies and for the investigation of drinking water quality.