Determination of selenium in tablets and therapeutical nutritions

Determination of selenium in tablets and therapeutical nutritions, using ad sorptive stripping voltammetry (AdSV), graphite furnance atomic absorption spectrometry (AAS) and inductively coupled plasma - mass spectrometry (ICP- MS) methods is reported. In AdSV a control growth mercury drop electrode (C GMDE) was used as the working electrode and 0.1 mol 1(-1) HClO4 solution co ntaining Cu(II) as supporting electrolyte. This method was applied to selec tive determination of Se(IV) in tablets (Curtis Healthcare's "Ekovit", Powe r Health's "Selenium and Zinc", Ferrosan's "Multi-tabs") and therapeutical nutrition (Abbott's "Ensure") after microwave digestion. The results obtain ed by AdSV were compared with those obtained by AAS and ICP-MS. Nickel nitr ate was used as a modifier in AAS method. The mass peak of Se-82 was used t o determine the selenium content by ICP-MS. The procedure developed enables to determine selenium quantitatively with a satisfactory accuracy and prec ision in multicomponent tablets and therapeutical nutritions with no need f or isolating it from the matrix.