A FULLY AUTOMATED SYSTEM FOR INORGANIC ANTIMONY PRECONCENTRATION AND SPECIATION IN URINE

P.H. PACHECO, R.A. GIL, G. POLLA, L.D. MARTINEZ P. SMICHOWSKI

ANALYTICA CHIMICA ACTA

Elsevier

Año: 2007 vol. 603 p. 1 - 7

0003-2670

A study was undertaken to ascertain the analytical capabilities of l-methionine immobilizedon controlled pore glass for Sb preconcentration and speciation. A fully automated on-linesystem, implemented with hydride generation (HG) and inductively coupled plasma opticalemission spectrometry (ICP OES), was used. Sb(III), at pH 10 was selectively retained inthe column containing the immobilized aminoacid, while Sb(V) was not retained at all. A30% HCl solution was used as eluent agent. Prior to total Sb determination, a pre-reductionstep with thiourea was necessary. An on-line pH adjusting and pre-reduction of Sb(V) wasachieved in a fully automated system. The detection limit for the preconcentration of 10mLof an aqueous solution was 70ng L−1 with a relative standard deviation of 2%. An enrichmentfactor of 20 was achieved when 10mL of sample was passed through the system,reaching a throughput of 23 samples per hour. The method was successfully applied to thedetermination of Sb(III) and total Sb in urine.