September 2007, Sunnyvale, CA—Dionex Corporation announces the pending approval of two EPA methods developed in collaboration with the EPA Office of Ground Water and Drinking Water in Cincinnati, OH. Both methods use a two-dimensional approach that allows quantification in high salt matrices, confirmation, and enhanced sensitivity from one injection.

The new methods for Bromate, 302.0, and Perchlorate, 314.2, are currently in the EPA review process. Bromate, formed from the ozonation of drinking waters contaminated with bromide, is a regulated disinfection by-product with well documented toxicological effects. The U.S. EPA has established a regulatory maximum contaminant level (MCL) of 10 μg/L bromate in drinking waters. In the U.S., bottled water is considered a food product and is therefore regulated by the U.S. Food and Drug Administration (FDA). In 2001, the U.S. FDA also established an MCL of 10 μg/L bromate in bottled drinking water. More recently, the European Commission set a lower MCL of 3 μg/L bromate for natural mineral waters and spring waters treated by ozonation. However, these limits were based on the feasibility of detection and removal, even though studies suggest concentrations lower than 1 μg/L pose increased lifetime cancer risks. Pending method 302.0 expands on existing methods in high salt matrices, and does not require postcolumn reagent addition.

Originating from man-made and natural sources, perchlorate is a relatively common ground water contaminant. Perchlorate inhibits the normal uptake of iodide by the thyroid gland, which results in reduced thyroid hormone production. Low thyroid hormone production results in improper metabolic regulation and can potentially lead to the development of thyroid tumors in adults. The fetuses of pregnant women with hypothyroidism are particularly at risk because reduced thyroid hormone production can cause impaired mental development, and in some cases birth defects. In 2005, the National Academy of Sciences recommended a reference dose of 0.7 μg/kg/day from all available sources, which it believes should not threaten the health of even the most sensitive populations. Perchlorate has been detected at nearly 400 sites across the United States, where most contamination appears to be confined to the western and southwestern regions. It is estimated that over 11 million people have perchlorate in their drinking water supplies at a concentration of 4 μg/L (ppb) or greater. Method 314.2 also builds on existing perchlorate methods by adding simplicity for the quantification of perchlorate in high salt matrices typically found in ground waters that are potential sources for drinking water.

Developed between EPA and Dionex analytical scientists, the methods have passed stringent EPA validation requirements.

Dionex (NASDAQ:DNEX) is a global leader in the manufacturing and marketing of liquid chromatography and extraction systems, consumables, and software for chemical analysis. The Company's systems are used worldwide in environmental analysis and by the life sciences, chemical, petrochemical, food and beverage, power generation, and electronics industries. Our expertise in applications and instrumentation helps analytical scientists to evaluate and develop pharmaceuticals, establish environmental regulations, and produce better industrial products.