Selective determination of inorganic selenium species in parenteral solutions using l-methionine as retaining agent in ETAAS

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

JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY

Royal Society o Chemistry

Año: 2008 vol. 23 p. 397 - 401

0267-9477

A time-based flow injection (FI) separation system coupled to electrothermal atomic absorptionspectroscopy (ETAAS) has been developed for the determination of selenium in parenteralsolutions. Selenate interacts with L-methionine, which is immobilized on controlled pore glass(CPG), at pH 3.0 and eluted with HCl (10% v/v). Total selenium content is determined directlyby ETAAS without preconcentration and selenite is calculated by difference. The features of theseparation system are: 100% efficiency of retention and an enhancement factor of 20 for a preconcentrationtime of 6 s (sample flow rate = 10 mL min
1) with HCl elution volumes of 50 mL.The detection limit (3s) was 6 ng L
1, and the relative standard deviation (n = 10) at the0.1 mg L
1 level is 3.0%. The method has high selectivity and was applied to the determination ofSe (IV) and (VI) in parenteral solutions with satisfactory results