Ultratrace-level determination of N-Nitrosodimethylamine, N-Nitrosodiethylamine, and N-Nitrosomorpholine in waters by solid-phase extraction followed by liquid chromatography-tandem mass spectrometry

• Published in: Central European journal of chemistry 2014-09, Vol.12 (9), p.928-936
• Main Authors: Kadmi, Yassine, Favier, Lidia, Soutrel, Isabelle, Lemasle, Marguerite, Wolbert, Dominique
• Format: Article
• Language: English
• Subjects: Biochemistry; Biological and Medical Physics; Biophysics; Byproducts; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Chromatography; Disinfection by-products; Drinking water; Extraction; Geochemistry; Linearity; Liquid chromatography; Mass spectrometry; Mathematical analysis; N-nitrosamines; Riccce 18; Solid-phase extraction; Ultra high pressure liquid chromatography coupled with tandem mass spectrometry
• ISSN: 1895-1066; 2391-5420; 1644-3624; 2391-5420
• DOI: 10.2478/s11532-014-0537-z

N-nitrosamines are a new class of emerging nitrogenous drinking water disinfection by-products. These compounds are probably carcinogenic which could seriously affect the safety of drinking water consumers. The aim of this study is to develop a simple, fast, and specific analytical method for the routine determination of low part per trillion levels of N-nitrosamines in waters. An ultra high pressure liquid chromatography coupled with tandem mass spectrometry (UHPLC/MS/MS) method was developed for the qualitative and quantitative analysis of N-nitrosamines in waters. N-nitrosamines were extracted, purified and concentrated from water samples in one step using a solid-phase extraction (SPE). The compounds were detected in multiple reaction monitoring via electrospray ionisation source with positive ionisation mode. To achieve symmetrical peak shapes and a short chromatographic analysis time, the mobile phase consisting of acetonitrile, water and formic acid (60:40:0.1, v/v/v) was used in the experiment. Chromatographic separation of N-nitrosamines was done in less than two minutes. All calibration curves had good linearity (r 2 ≥ 0.9989). The intra- and inter-day precision of the assay ranged from 0.59% to 3.11% and accuracy ranged from 99.66% to 104.1%. The mean recoveries of N-nitrosamines in spiked water were 98%-101%. The reproducability was acceptable with relative standard deviations of less than 3.53%. The proposed method yielded detection limits very low which ranges from 0.04 to 0.16 ng L −1 . Finally, the developed analytical method was successfully applied to the analysis of N-nitrosamines in natural water sample