Research Article

A New Spectrophotometric Method for Determination of Selenium in Cosmetic and Pharmaceutical Preparations after Preconcentration with Cloud Point Extraction

Table 2

Tolerance limits of diverse ions on the determination of 50 ng mL−1 selenium at optimum conditions.

IonsTolerated ratio of foreign ion to Se(IV)

Na+, , , Mg2+, , , , F, Co2+1000
Pb2+, Zn2+800
Cu2+, Ag+, Hg2+, Fe3+250a
Ni2+200
5

aAfter removal with cation exchange resin.