January 15, 2008
Journal Article

Direct Spectrophotometric Analysis of Cr(VI) Using a Liquid Waveguide Capillary Cell

Abstract

A simple and sensitive method for was developed and evaluated for determination of hexavalent chromium Cr(VI) in the environmental water samples. Cr(VI) is a notorious ground water contaminant toxic for humans and animals, and assessment of an exposure risk for aquatic receptors necessitates frequent Cr(VI) concentration data from a range of surface and groundwater locations. In this work we demonstrated, that enhanced UV-vis spectroscopy using Liquid Waveguide Capillary Cell (LWCC) offered an easy-to-use and economical methodology for the determination of chromate anion CrO42- in the natural waters under field conditions without chemical pretreatment. Direct determination of CrO42- in the groundwater and surface water (Columbia River) samples was achieved by measuring the chromate optical absorbance at 372 nm. A quantitative relationship between intensity of the absorbance signal and water pH allowing straight forward calculation of total Cr(VI) content in natural water was obtained. For a 100 cm pathlength LWCC, the detection limit for chromate in Columbia River water was found to be as low as 0.073 ppb. The described method is applicable for the in-field monitoring of Cr(VI) in the environmental waters at trace levels.

Revised: April 11, 2008 | Published: January 15, 2008

Citation

Levitskaia T.G., M.J. O'Hara, S.I. Sinkov, and O.B. Egorov. 2008. Direct Spectrophotometric Analysis of Cr(VI) Using a Liquid Waveguide Capillary Cell. Applied Spectroscopy 62, no. 1:107-115. PNNL-SA-54317.