Determination of halonitromethanes and haloacetamides: An evaluation of sample preservation and analyte stability in drinking water

Abstract

Simultaneous quantitation of 6 halonitromethanes (HNMs) and 5 haloacetamides (HAAms) was achieved with a simplified liquid-liquid extraction (LLE) method, followed by gas chromatography-mass spectrometry. Stability tests showed that brominated tri-HNMs immediately degraded in the presence of ascorbic acid, sodium sulphite and sodium borohydride, and also reduced in samples treated with ammonium chloride, or with no preservation. Both ammonium chloride and ascorbic acid were suitable for the preservation of HAAms. Ammonium chloride was most suitable for preserving both HNMs and HAAms, although it is recommended that samples be analysed as soon as possible after collection. While groundwater samples exhibited a greater analytical bias compared to other waters, the good recoveries (>90%) of most analytes in tap water suggest that the method is very appropriate for determining these analytes in treated drinking waters. Application of the method to water from three drinking water treatment plants in Western Australia indicating N-DBP formation did occur, with increased detections after chlorination. The method is recommended for low-cost, rapid screening of both HNMs and HAAms in drinking water.

The control of emerging haloacetamide DBP precursors with UV/persulfate treatment

“…As shown in Fig. 1 (Chlorination only), di-HAcAms accounted for the majority of the HAcAms formed upon chlorination of all three waters, and DCAcAm was the most abundant species, which is in agreement with previous occurrence studies (Krasner et al, 2006;Richardson et al, 2008;Chu et al, 2012a;Liew et al, 2012). Besides three chlorinated HAcAms (CAcAm, DCAcAm, and TCAcAm), only a small amount of BCAcAm was detected in ZQ water, due to the low bromide level (Table 1).…”

“…After the 24-h chlorination experiment, the disinfectant residual was quenched with a stoichiometric amount of ascorbic acid and was analyzed as soon as possible (Chu et al, 2012b;Liew et al, 2012). All samples were prepared in duplicate (Fig.…”

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

“…LODs ranged from 6 ng/L for TCAN to 50 ng/L for DCAN and LOQs were 20 ng/L for TCAN and 165 ng/L for DCAN; these are consistent with the results obtained using the same fiber for HANs [14,16]. LODs ranged from 1 ng/L for TCNM to 50 ng/L for BCNM and LOQs were 5 ng/L for TCAN and 165 ng/L for BCNM using SPME; results were similar to or higher than those obtained by LLE [12,13]. LODs ranged from 2 ng/L for DBIM (5 ng/L for CDIM) to 70 ng/L for DCIM.…”

“…The two extraction and pre-concentration methods, traditional liquid-liquid extraction (LLE) and solid-phase microextraction (SPME), are universal and are able to achieve the required sensitivity. LLE is the primary method used to extract and concentrate volatile DBPs (especially HANs and TCNM) by U.S. EPA Method 551 [11,12]. A method based on single-drop microextraction in the static headspace has been proposed to decrease the length of time required for the extraction process as well as the amount of work required; this method allows for low detection limits for the nine HNMs (0.06-1.2 g/L) [13], similar to SPME for TCNM (chloropicrin) (0.04-0.5 g/L) [14,15].…”

Impact of UV/H2O2 Pre-Oxidation on the Formation of Haloacetamides and Other Nitrogenous Disinfection Byproducts during Chlorination

“…10,24 All samples were prepared in duplicate (SI Figure S1), and the error bars in Figure 1 encompass the range for two replicates. All comparisons were done by one-way analysis of variance as calculated by SPSS software (Version 17, SPSS Inc., Chicago, IL); p < 0.05 was considered statistically significant.…”