Study on ion-association system of determination trace selenium(IV) and its analytical application

In this paper,an absorption spectrum character of ternary ion-association complex of trace selenium(IV) was studied.It is based on the fact that selenium(IV) forms ternary complex with thiocyanate (SCN~-) and ethyl rhodamine B (ERB) in the presence of Tween-60.The maximum absorption peak is 605nm and its apparent molar absorptivity is 1.5×10~6 L/mol·cm.The linear range is 0～2.0 μg/25 mL for selenium(IV).After interfeing ions of samples are eliminated by thiohydroxy cotton of enrichment and separation, this method was applied to the determination of trace selenium(IV) in water and food samples with satisfactory resulta.