On-Line Preconcentration System by Coprecipitation with Lanthanum Hydroxide Using Packed-Bed Filter for the Determination of Tellurium in Water by ICP-OES with USN

M. KAPLAN, S. CERUTTI, S. MOYANO, R.A. OLSINA, L.D. MARTINEZ, J.A. GÁSQUEZ

INSTRUMENTATION SCIENCE AND TECHNOLOGY

Taylor and Francis

Año: 2004 vol. 32 p. 423 - 431

1073-9149

A sensitive procedure for the determination of total tellurium traces in water samples is described, which combines an on-line analyte preconcentration system coupled to inductively coupled plasma optical emission spectrometry (ICP-OES) associated with flow injection (FI) and ultrasonic nebulization (USN). Tellurium was preconcentrated by co-precipitation at pH 9.1 with lanthanum hydroxide precipitate. The precipitate was quantitatively collected on a packed-bed filter with Amberlite XAD-4 resin and subsequently eluted with 5% (v/v) nitric acid. A total enhancement factor of 140-fold was obtained with respect to ICP-OES using pneumatic nebulization. The detection limit (3σ) for the preconcentration of 10 mL of aqueous solution (3σ) was 0.15 µg L-1. The precision for 10 replicate determination at the 10 µg L-1 tellurium level was 2.6%, relative standard deviation (RSD), calculated with the peak heights obtained. The calibration graph using the preconcentration system for tellurium was linear with a correlation coefficient of 0.9995 at levels near the detection limit up to at least 100 µg L-1. Satisfactory results were obtained for the analysis of tellurium in the standard reference material NIST 1643d “Trace Elements in Water” and tap water.