A novel fiber-packed column for on-line preconcentration and speciation analysis of chromium in drinking water with flame atomic absorption spectrometry

MONASTERIO, R.P.; ALTAMIRANO, J.C.; MARTINEZ, L. D; WILLOUD, R.G

TALANTA

Elsevier

Año: 2009 p. 1290 - 1294

0039-9140

A novel on-line preconcentration and determination system based on a fiber-packed column was developedfor speciation analysis of Cr in drinking water samples prior to its determination by flame atomicabsorption spectrometry (FAAS). All variables involved in the development of the preconcentrationmethod including, pH, eluent type, sample and eluent flow rates, interfering effects, etc., were studied inorder to achieve the best analytical performance. A preconcentration factor of 32 was obtained for Cr(VI)and Cr(III). The levels of Cr(III) species were calculated by difference of total Cr and Cr(VI) levels. TotalCr was determined after oxidation of Cr(III) to Cr(VI) with hydrogen peroxide. The calibration graph waslinear with a correlation coefficient of 0.999 at levels near the detection limit and up to at least 50gL−1.The relative standard deviation (R.S.D.) was 4.3% (C=5gL−1 Cr(VI), n = 10, sample volume = 25 mL). Thelimit of detection (LOD) for both Cr(III) and Cr(VI) species was 0.3gL−1. Verification of the accuracy wascarried out by the analysis of a standard reference material (NIST SRM 1643e “Trace elements in naturalwater”). The methodwas successfully applied to the determination of Cr(III) and Cr(VI) species in drinkingwater samples.