Trace Analysis of Bromate, Chlorate, Iodate, and Perchlorate in Natural and Bottled Waters

Abstract

A simple and rapid method has been developed to simultaneously measure sub-µg/L quantities of the oxyhalide anions bromate, chlorate, iodate, and perchlorate in water samples. Water samples (10 mL) are passed through barium and hydronium cartridges to remove sulfate and carbonate, respectively. The method utilizes the direct injection of 10 µL volumes of water samples into a liquid chromatography-tandem triple-quadrupole mass spectrometry (LC-MS/MS) system. Ionization is accomplished using electrospray ionization in negative mode. The method detection limits were 0.021 µg/L for perchlorate, 0.045 µg/L for bromate, 0.070 µg/L for iodate, and 0.045 µg/L for chlorate anions in water. The LC-MS/MS method described here was compared to established EPA methods 300.1 and 317.1 for bromate analysis and EPA method 314.0 for perchlorate analysis. Samples collected from sites with known contamination were split and sent to certified laboratories utilizing EPA methods for bromate and perchlorate analysis. At concentrations above the reporting limits for EPA methods, the method described here was always within 20% of the established methods, and generally within 10%. Twenty-one commercially available bottled waters were analyzed for oxyhalides. The majority of bottled waters contained detectable levels of oxyhalides, with perchlorate e0.74 µg/L, bromate e76 µg/L, iodate e25 µg/ L, and chlorate e5.8 µg/L. Perchlorate, iodate, and chlorate were detectable in nearly all natural waters tested, while bromate was only detected in treated waters. Perchlorate was found in several rivers and reservoirs where it was not found previously using EPA 314.0 (reporting limit of 4 µg/L). This method was also applied to common detergents used for cleaning laboratory glassware and equipment to evaluate the potential for sample contamination. Only chlorate appeared as a major oxyhalide in the detergents evaluated, with concentrations up to 517 µg/g. Drinking water treatment plants were also evaluated using this method. Significant formations of chlorate and bromate are demonstrated from hypochlorite generation and ozonation. From the limited data set provided here, it appears that perchlorate is a ubiquitous contaminant of natural waters at trace levels.

Perchlorate in sewage sludge, rice, bottled water and milk collected from different areas in China

“…In accordance with the ever-increasing concern regarding perchlorate in the United States, more and more reports have been published on the occurrence of perchlorate in different environmental matrices such as groundwater, milk, biological sample, et al (Krynitsky et al, 2004;Snyder et al, 2005;Valentin-Blasini et al, 2005 (Snyder et al, 2005) et al determined perchlorate in 11 different natural water bodies and 21 brand bottled drinking water, and found that there was perchlorate pollution in most samples.…”

Widespread Presence of Naturally Occurring Perchlorate in High Plains of Texas and New Mexico

“…Other reports of natural ClO4 -occurrences in the U.S. include a nitrate deposit in California (13) and potash minerals and other evaporites from California and New Mexico (14). A relatively large areal distribution of ClO4 -in west Texas groundwater (15) and groundwater, surface water, and bottled water from other areas (16) has been tentatively attributed to natural sources as well as ClO4 -in Pleistocene and Holocene groundwater in New Mexico (17).…”

Determination of Perchlorate in Bottled Water from Italy

“…Therefore, several studies developed the application of reversed phase LC-ESI-MS/MS for perchlorate analysis [38][39][40].…”