Determination of selenium(IV) after co-precipitation with Fe-Ti layered double hydroxides

Abstract

The narrow margin between beneficial and toxic properties of selenium requires precise analytical methods for its fast and reliable determination. We have developed a precise co-precipitative preconcentration and separation procedure for SeO32- in the pH range 4.0-6.0 using Fe-Ti layered double hydroxides prepared from synthetic solutions of Fe(III) and Ti(IV), and industrial effluent. The obtained layered double hydroxide co-precipitant with SeO32- was dissolved in 2 mol L-1 H2SO4 and concentration of selenium was determined 3 spectrophotometrically. Calibration plot was linear over the concentration range of selenium (IV) 1-100 mu g L-1. Detection limit (S/N = 3) for selenium(IV) was 1.0 mu g L-1. Relative standard deviation for 5 mu g L-1 of the analyte was 3.0% (n = 5). The accuracy of the developed method was tested by analyzing certified reference materials of marine sediment (MESS-3) and soil (IAEA-Soil 7). Further-more, the developed procedure has been successfully applied to the analysis of selenium(IV) in soil and river and marine sediment samples.