TOTAL INORGANIC Se AND Te PRECONCENTRATION AND THEIR DETERMINATION BY ON-LINE COUPLING OF A SOLID-PHASE EXTRACTION PROCEDURE WITH HG-AAS

RAÚL A. GIL, MARCOS M. KAPLAN, JOSÉ A. SALONIA, JOSÉ A. GÁSQUEZ, AND LUIS D. MARTINEZ

ATOMIC SPECTROSCOPY

Perkin Elmer

Año: 2007 vol. 28 p. 66 - 71

0195-5373

A flow injection system including hydride generation was coupled to an atomic absorption spectrometer (FI-HG-AAS) and was used for the on-line preconcentration and subsequent determination of selenium and tellurium. Trace amounts of both elements were on-line preconcentrated by coprecipitation with La(OH)3 and adsorbed later on a minicolumn packed with ethyl vinyl acetate in absence of complexing reagent. The analytes were removed from the minicolumn with HCl solution. The time required for pre-concentration, total elution and the registration steps with subsequent column conditioning was about 2.3 min (throughput sample = 26). An enrichment factor of 28-fold for a sample volume of 10 mL was obtained for both analytes. The relative standard deviation (%RSD) for 6 replicates containing 1.0 µg L-1 of Se was 0.9 % and 1.1 % for Te. The detection limit (DL) calculated as the amount of the analyte required to yield a net peak equal to three times the standard deviation of the background signal (3s), was 30 and 10 ng L-1 for Te and Se, respectively.This preconcentration system was successfully applied for the determination of total Se and Te in drinking water samples and in a standard certified reference material:  NIST CRM 1643e Trace Elements in Water.