Talanta 76 (2008) 906–913 Contents lists available at ScienceDirect Talanta journal homepage: www.elsevier.com/locate/talanta Analysis of nitrosamines in water by automated SPE and isotope dilution GC/HRMS Occurrence in the different steps of a drinking water treatment plant, and in chlorinated samples from a reservoir and a sewage treatment plant effluent Carles Planas a , ´ Oscar Palacios a , Francesc Ventura b , Josep Rivera a , Josep Caixach a,∗ a Mass Spectrometry Laboratory, Department of Ecotechnologies, IIQAB, CSIC, Jordi Girona Salgado 18, 08034 Barcelona, Spain b AGBAR, Aig¨ ues de Barcelona S.A., Avinguda Diagonal 211, 08018 Barcelona, Spain article info Article history: Received 20 December 2007 Received in revised form 22 April 2008 Accepted 23 April 2008 Available online 8 May 2008 Keywords: NDMA Automated SPE GC/HRMS Drinking water abstract A method based on automated solid-phase extraction (SPE) and isotope dilution gas chromatography/high resolution mass spectrometry (GC/HRMS) has been developed for the analysis of nine nitrosamines in water samples. The combination of automated SPE and GC/HRMS for the analysis of nitrosamines has not been reported previously. The method shows as advantages the selectivity and sensitivity of GC/HRMS analysis and the high efficiency of automated SPE with coconut charcoal EPA 521 cartridges. Low method detection limits (MDLs) were achieved, along with a greater facility of the procedure and less dependance on the operator with regard to the methods based on manual SPE. Quality requirements for isotope dilution-based methods were accomplished for most analysed nitrosamines, regarding to trueness (80–120%), method precision (<15%) and MDLs (0.08–1.7ng/L). Nineteen water samples (16 samples from a drinking water treatment plant {DWTP}, 2 chlorinated samples from a sewage treatment plant {STP} effluent, and 1 chlorinated sample from a reservoir) were analysed. Concentrations of nitrosamines in the STP effluent were 309.4 and 730.2 ng/L, being higher when higher doses of chlorine were applied. N-Nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) were the main compounds identified in the STP effluent, and NDEA was detected above 200 ng/L, regulatory level for NDMA in effluents stated in Ontario (Canada). Lower concentrations of nitrosamines were found in the reservoir (20.3 ng/L) and in the DWTP samples (n.d. -28.6 ng/L). NDMA and NDEA were respectively found in the reservoir and in treated and highly chlorinated DWTP samples at concentrations above 10 ng/L (guide value established in different countries). The highest concentrations of nitrosamines were found after chlorination and ozonation processes (ozonated, treated and highly chlorinated water) in DWTP samples. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Interest in the determination of N-nitroso compounds in dif- ferent matrices was stimulated after the discovery in 1956 that N-nitrosodimethylamine (NDMA) produced liver tumors in rats. From about 300 nitrosamines subjected to carcinogenicity tests, 85% of them have been classified as carcinogens for animals. In addition to their presence in cigarette smoke, nitrosamines can originate from the production of pesticides and in several indus- tries (i.e. rubber, metal, cosmetic, tanneries). However, the most important source of nitrosamines for water treatment companies is their formation during disinfection of drinking water [1]. ∗ Corresponding author. Tel.: +34 93 4006174; fax: +34 93 2045904. E-mail address: jcgeco@iiqab.csic.es (J. Caixach). Occurrence of nitrosamines in source water, wastewater and fin- ished drinking water is an emerging issue of environmental and public health significance because many nitrosamines are proba- ble human carcinogens [2,3]. NDMA has been detected in drinking water and wastewater after chlorination and chloramination [4]. Dimethylamine and nitrogen compounds (e.g., natural ammonia or nitrogen-containing coagulants used in water treatment) have been identified as precursors of NDMA in drinking water [5,6]. In 1989, NDMA was first detected as a disinfection byproduct in the Province of Ontario (Canada), and in 1999 this compound was found in drinking waters and wastewaters throughout California (USA) [4]. Recommendations about the presence of NDMA and other volatile nitrosamines in drinking water have been recently adopted in different countries [1]. The California Department of Health Services (CDHS) has established a notification level 0039-9140/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.talanta.2008.04.060