Analytical methods for the determination of perchlorate anion in foods

AGRO 180

Richard A. Niemann, rniemann@cfsan.fda.gov and Alexander J. Krynitsky, Alex.Krynitsky@cfsan.fda.gov. Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, MD 20740-3835
Perchlorate anion, a rocket fuel component as well as occurring naturally, has been found in many water systems in the U.S. and can bioconcentrate in growing plants used as food. Because perchlorate competitively inhibits iodide uptake by the thyroid, its presence in the food supply is a public health concern. In order to assess the risks from dietary exposure to perchlorate, FDA developed a rapid, sensitive, and specific analytical method. Since 2004, over 1500 food samples were analyzed for perchlorate presence by ion chromatography (IC) with isotope dilution tandem mass spectrometry (MS) capable of 1 µg/kg limit of quantitation. Commodities consisted primarily of leafy vegetables as well as select fruits collected from growers nationwide with emphasis on fields in the Southwest irrigated by perchlorate-contaminated Colorado River water. Some imported crops were included in the survey. Bovine milk and feed were sampled at dairy farms. The IC-MS/MS method will be described, and perchlorate findings will be discussed in the presentation. Comparative results will be shown obtained by a column-switching IC method with suppressed conductivity detection offered as a cheaper alternative for limited purposes.
 

Plant Nutrient Issues Impacting Trade, Water, Air & Soils
9:00 AM-11:50 AM, Wednesday, 13 September 2006 San Francisco Marriott -- Salon 1, Oral

Division of Agrochemicals

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006