ON-LINE PRECONCENTRATION AND DETERMINATION OF CHROMIUM IN PARENTERAL SOLUTIONS BY INDUCTIVELY COUPLED PLASMA – OPTICAL EMISSION SPECTROMETRY

R.A.GIL, S.CERUTTI, J.A. GÁSQUEZ, R.A. OLSINA Y L.D. MARTINEZ

TALANTA

Elsevier

Lugar: ; Año: 2006 vol. 60 p. 531 - 535

0039-9140

An on-line flow injection (FI) preconcentration-electrothermal atomic absorption spectrometry (ETAAS) method is developed for trace determination of chromium in drinking water samples by sorption on a conical minicolumn packed with activated carbon (AC) at pH 5.0. The chromium was removed from the minicolumn with 1.0 % (v/v) nitric acid. An enrichment factor (EF) of 35-fold for a sample volume of 10 ml was obtained. The detection limit (DL) value for the preconcentration method proposed was 3.0 ng l-1. The precision for ten replicate determinations at the 0.5 mg l-1 Cr level was 4.0 % relative standard deviation (RSD), calculate with the peak heights obtained. The calibration graph using the preconcentration system for chromium was linear with a correlation coefficient of 0.9992 at levels near the detection limits up to at least 50 mg l-1. The method was successfully applied to the determination of Cr(III) and Cr(VI) in drinking water samples.