Background Nitrosamines in drinking water are a new group of disinfection by-products, with various kinds, high toxicity, and potential health hazards. At present, no relevant standards and methods are issued in the field of drinking water monitoring in China.
Objective This method ological study aims to develop and modify a solid phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of nine nitrosamines in drinking water and source water.
Methods Nitrosamines were extracted by passing a 500 mL water sample through a SPE cartridge composed of coconut charcoal. After elution with methylene chloride, the extracts were analyzed by GC-MS with a VF-624 MS column using isotope internal standard. Nitrosamines in different kinds of water samples collected in Shanghai were detected by the established method.
Results The calibration curves of nitrosamines had good linearity in 10-500 ng/L with correlation coefficients greater than 0.995. The method detection limits for both pure water and source water were below 4 ng/L. Recoveries ranged between 68.7%-113% with the relative standard deviations below 10% at 20, 100, and 200 ng/L for pure water, source water, and pipe water, respectively. Nitrosamines were detected in various water samples from Shanghai, with highest positive rates of N-nitrosodimethylamine (NDMA) and N-nitrosodibutylamine (NDBA).
Conclusion This method featured with high sensitivity, low detection limit, and good accuracy is applicable to the determination of nine nitrosamines in water simultaneously.
DownLoad: