Simultaneous and high-throughput analysis of iodo-trihalomethanes, haloacetonitriles, and halonitromethanes in drinking water using solid-phase microextraction/gas chromatography-mass spectrometry: an optimization of sample preparation

摘要

When iodide and natural organic matter are present in raw water, the formation of iodo-trihalomethanes (lodo-THMs), haloacetonitriles (HANs), and halonitromethanes (HNMs) pose a potential health risk because they have been reported to be more toxic than their brominated or chlorinated analogs. In the work, simultaneous analysis of lodo-THMs, HANs, and HNMs in drinking water samples in a single cleanup and chromatographic analysis was proposed. The DVB/CAR/PDMS fiber was found to be the most suitable for all target compounds, although 75 pzi CAR/PDMS was better for chlorinated HANs and 651.1.m PDMS/DVB for brominated HNMs. After optimization of the SPME parameters (DVB/CAR/PDMS fiber, extraction time of 30 min at 40 C, addition of 40% w/v of salt, (NH4)2SO4 as a quenching agent, and desorption time of 3 min at 170 C), detection limits ranged from I to 50 ng/L for different analogs, with a linear range of at least two orders of magnitude. Good recoveries (78.6-104.7%) were obtained for spiked samples of a wide range of treated drinking waters, demonstrating that the method is applicable for analysis of real drinking water samples. Matrix effects were negligible for the treated water samples with total organic carbon concentration of less than 2.9 mg/L. An effective survey conducted by two drinking water treatment plants showed the highest proportion of lodo-THMs, HANs, and HNMs occurred in treated water, and concentrations of 13 detected compounds ranged between the ng/L and the p.g/L levels. (C)2014 Elsevier B.V. All rights reserved.