Volume 28, Number 9, November 2000Endocrine disruptors
|Page(s)||878 - 884|
Use of high surface area TiO2 for preconcentration and following determination of Cr species by on-line flow injection inductively coupled plasma atomic emission spectrometryE. Vassileva
University of Sofia, Faculty of Chemistry, 1 J. Bourchier av., 1126 Sofia, Bulgaria
(Received 13 November, 2000; accepted 14 November, 2000.)
A flow-injection analysis (FIA) system incorporating two microcolumns of TiO2 was used for the developing of an on-line method for preconcentration and sequential determination of Cr3+ and Cr6+ species by inductively coupled plasma atomic emission spectrometry (ICP-AES). The optimal conditions for both analytes have been obtained. With a sample volume of 10-50 ml and an elution volume of 500 l, a signal was 20-100 times higher than the signal given by a continuous aspiration system. The method gave good reproducibility with precisions less than 7% RSD for 5 replicates at the 10 ng/ml level for both Cr-species. Recoveries between 95 and 98% were obtained for Cr3+ and Cr6+. The preconcentration system and the methodology proposed were validated on several natural water samples, on reference water samples as well as on synthetic seawater. It was found that the on-line detection using ICP-AES allows sequential Cr speciation analysis at the low concentration levels (ng/l) usually encountered in these media.
Key words: Inductively coupled plasma atomic emission spectrometry - on-line preconcentration - flow-injection analysis - high surface TiO2 (anatase) - Cr species - natural waters.
© EDP Sciences, Wiley-VCH 2000