Alternative Methods For The Analysis Of Ndma And Other Nitrosamines In Water

Abstract

N‐nitrosodimethylamine (NDMA) and other nitrosamines have been reported in drinking and recycled water at low parts‐per‐trillion levels, both as contaminants and disinfection byproducts. Many of these nitrosamines cause cancer in animals and are probable human carcinogens. In this study, three existing analytical methods were expanded, refined, and validated for the analysis of NDMA and seven other nitrosamines in potable, waste, and recycled water. Method detection limits for a solid‐phase extraction (SPE) method and a cartridge SPE (CSPE) coupled with gas chromatography–tandem mass spectrometry were 0.7–0.8 ng/L for NDMA and 0.3–1.4 ng/L for other nitrosamines. The micro‐liquid–liquid extraction (MLLE) method that was developed used less volume and was effective at analyzing the different sample matrixes but yielded higher detection limits (2–4 ng/L). NDMA was the only nitrosamine detected in potable water; however N‐nitrosodiethylamine, N‐nitrosomorpholine, N‐nitrosopiperidine, N‐nitrosodi‐N‐butylamine, and N‐nitrosopyrrolidine were present in other matrixes tested. The SPE methods and the MLLE method have been submitted for inclusion in the next revision of Standard Methods for the Examination of Water and Wastewater, and the CSPE method will be submitted for approval in the future.

Trace Analysis of N-Nitrosamines in Water Using Solid-Phase Microextraction Coupled with Gas Chromatograph–Tandem Mass Spectrometry

“…The sample volumes needed for the methods are 100 to 500 ml, and the time required for extraction and quantification may range from 3 to 16 h. For MLLE method, a shortened shaking/extraction time of 10 min was achieved, but a volume of 100 ml is still needed (Cheng et al 2006). The MDLs based on the SPE and MLLE for NDMA ranged from 0.7 to 2.3 ng/l, with similar MDLs for NDEA, NDPA, and NMor (Charrois et al 2004;Cheng et al 2006). Although the MDLs for the four tested N-nitrosamines using the proposed SPME/GC/MS/MS method were slightly higher than those using the SPE and LLE/MLLE techniques, smaller sample volume and/or shorter extraction time may make the SPME/GC/MS/MS method routine analyses more economical, as the sample size and analytical time were only 1/20-1/100 and 1/2-1/10 of the conventional SPE and LLE method, respectively.…”

“…Most studies employed SPE and LLE as the extraction method (Mitch et al 2003b;Charrois et al 2004;Cheng et al 2006;Munch and Bassett 2006;Schreiber and Mitch 2006;Lee et al 2007;Jurado-Sáncheza et al 2007). The sample volumes needed for the methods are 100 to 500 ml, and the time required for extraction and quantification may range from 3 to 16 h. For MLLE method, a shortened shaking/extraction time of 10 min was achieved, but a volume of 100 ml is still needed (Cheng et al 2006). The MDLs based on the SPE and MLLE for NDMA ranged from 0.7 to 2.3 ng/l, with similar MDLs for NDEA, NDPA, and NMor (Charrois et al 2004;Cheng et al 2006).…”

“…NDMA has been reported in drinking waters, wastewaters, and reclaimed waters after chlorination and chloramination (Najm and Trussell 2001;Mitch and Sedlak 2002;Mitch et al 2003a;Cheng et al 2006) as an emerging pollutant. The drinking water quality standard for NDMA in Ontario, Canada, was set at 9 ng/l in 1992 (MOE 2002).…”

“…The process is very labor-intensive and time-consuming since N-nitrosamines are hydrophilic, polar compounds. To overcome the drawback of LLE, micro-liquid-liquid extraction (MLLE) was developed for N-nitrosamines in water (Cheng et al 2006). SPE generally uses various types of sorbent materials, such as carbonaceous resin and coconut charcoal, to extract target chemicals from aqueous samples (Charrois et al 2004;Cheng et al 2006).…”

Improving the Chromatographic Analysis of N-Nitrosamines in Drinking Water by Completely Drying the Solid Sorbent Using Dry Air

“…Gas chromatography or liquid chromatography has usually been used to determine NAs in drinking water [8]. NAs have been extracted by passing drinking water through a solid-phase extraction (SPE) cartridge packed with coconut charcoal or Ambersorb 572, drying the sorbent under vacuum for 10 min [9] or between 30 and 60 min [10][11][12], then eluting the NAs with dichloromethane (DCM) or a mixture of DCM and methanol. However, no researchers have previously stated that the SPE sorbent was completely dried before the eluting solvent was applied.…”