Ammonium perchlorate, a key ingredient in solid rocket propellants, has recently been found in ground and surface waters in the USA in a number of states, including California, Nevada, Utah, and West Virginia. Perchlorate poses a health risk and preliminary data from the US Environmental Protection Agency reports that exposure to less than 4-18 mu g/l provides adequate human health protection. An ion chromatographic method was developed for the determination of low mu g/l levels of perchlorate in drinking and ground waters based on a Dionex IonPac AS11 column, a 100 mM hydroxide eluent, large loop (1000 mu l) injection, and suppressed conductivity detection. The method is free of interferences from common anions, linear in the range of 2.5-100 mu g/l, and quantitative recoveries were obtained for low mu g/l levels of perchlorate in spiked drinking and ground water samples. The method detection limit of 0.3 mu g/l permits quantification of perchlorate below the levels which ensure adequate health protection. A new polarizable anion analysis column, the IonPac AS16, and its potential applicability for this analysis is also discussed. (C) 1999 Elsevier Science B.V. All rights reserved.
