Determination of N-nitrosamines in Water by Automated Headspace Solid-Phase Microextraction

Abstract

An automated headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (automated HS-SPME/GC–MS) for the determination of four N-nitrosamines N-nitroso-di-n-ethylamine, N-nitroso-di-n-propylamine, N-nitrosopiperidine and N-nitroso-di-n-butylamine in groundwater samples was developed. Response surface methodology was employed to optimize relevant extraction parameters including extraction time, sample pH, incubation temperature and salt addition. The optimal HS-SPME were 20 min of extraction time, sample pH of 7, incubation temperature of $$65\,{^{\circ }}\hbox {C}$$ and 30% (w/v) sodium chloride concentration. Under these conditions, good linearity for the analytes in the range from 0.1 to $$100\,\upmu \hbox {g}/\hbox {L}$$ with correlation coefficient (R) from 0.975 to 0.992 was obtained. The limits of detection based on a signal-to-noise ratio of 3 were between 0.78 and 11.92 ng/L with corresponding relative standard deviations from 1.8 to 5.7% $$({n}=4)$$ . The average relative recoveries of the four N-nitrosamines from spiked different groundwater samples by $$1\,\upmu \hbox {g}/\hbox {L}$$ and $$20\,\upmu \hbox {g}/\hbox {L}$$ of each analyte (mean ± standard deviation, $$n=4$$ ) were $$96.6\pm 4.4$$ and $$102.3\pm 4.86\,\%$$ , respectively. The method was applied to determine the N-nitrosamine in groundwater samples from different locations in Saudi Arabia. The average recoveries of spiked N-nitrosamines in different groundwater.