Free Access
Volume 28, Number 9, November 2000
Endocrine disruptors
Page(s) 878 - 884
Section Original articles
Analusis 28, 878-884 (2000)
DOI: 10.1051/analusis:2000160

Use of high surface area TiO2 for preconcentration and following determination of Cr species by on-line flow injection inductively coupled plasma atomic emission spectrometry

E. 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 $\mu$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