|Name||Miss Vanessa Susi|
|Organization or Institution||Florida Gulf Coast University|
Rapid Speciation and Quantification of Trace Trivalent and Hexavalent Chromium in Drinking Water by X-Ray Fluorescence Spectroscopy Combined with Ion Exchange Membranes
Vanessa Susi, Brandon Cooper, Ju Chou
Florida Gulf Coast University
The ability to accurately measure chromium levels in drinking water is a significant component of water testing, both in terms of addressing public health concerns and in the monitoring of drinking water safety. Current EPA approved assessment of chromium levels in drinking water does not distinguish between trivalent chromium, Cr(III) or Cr3+, and hexavalent chromium, Cr(VI)—which commonly exists as anionic molecule, CrO42-. In this study, the use of ion exchange membranes was proposed for the selective adsorption of Cr3+and Cr (VI) in drinking water, with consideration for the effect of pH. The selective accumulation of chromium levels for Cr3+ and Cr(VI) on the corresponding ionic membranes were analyzed by x-ray fluorescence (XRF). The resulting detected signals were proportional to tested chromium concentrations and produced a good linear correlation of R2 =0.998 for Cr3+ and 0.993 for Cr(VI). The detection limits imposed by the XRF analysis were 5 ppb and 6 ppb for Cr3+ and Cr(VI) respectively. The proposed method exhibited excellent repeatability and showed reliable quantification for both Cr3+ and Cr(VI).