SELECTIVE DETERMINATION OF INORGANIC SELENIUM SPECIES IN PARENTERAL SOULTIONS USING L-METHIONINE AS RETAINING AGENT IN ETAAS

PABLO H. PACHECO, RAÚL A. GIL, GRISELDA POLLA, PATRICIA SMICHOWSKI, LUIS D. MARTINEZ

JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY

Royal Society of Chemistry

Año: 2008 vol. 23 p. 397 - 401

0267-9477

A time-based flow injection (FI) separation system coupled to an electrothermalatomic absorption spectrometer (ETAAS) has been developed for the determination ofselenium in parenteral solutions. Selenate interacts with L-methionine, which isimmobilized on controlled pore glass (CPG), at pH 3.0 and eluted with HCl (10% v/v).Total selenium content is determined, then selenite is calculated by difference. Thefeatures of the separation system: 100% efficiency of retention and an enhancementfactor of 20 for a pre-concentration time of 6 s (sample flow rate = 10 ml min−1) withHCl elution volumes of 50µl. The detection limit (3σ) is 5 ng l−1, and the relativestandard deviation (n = 10) at the 0.2 µg l−1 level is 2.3 %. The method has highselectivity and was applied to the determination of Se (VI) in parenteral solutions withsatisfactory results. Total selenium contents were determined directly by ETAAS.