MATRIX EFFECTS IN THE DETERMINATION OF ZINC(II) ION IN WHOLE RAT-LIVER BY FLAME ATOMIC-ABSORPTION SPECTROMETRY

Analytical systems that might be of practical importance for the direc t determination of Zn-II ion in whole rat liver homogenates by flame a tomic absorption spectrometry were reliably evaluated based on the cha nge in calibration sensitivity. For that purpose synthetic samples wer e prepared in three extremely different media for tissue homogenizatio n, Hydrochloric acid medium proved to be more resistant to matrix comp onents (non-ionic detergent, albumin, inorganic salts) than water or T ris-acetate buffer (pH 8.7). Further, a highly acidic medium allows th e substitution of complex albumin and salt-containing standard solutio ns with simple acidic and even aqueous solutions. The convenience of 1 .0 mol l(-1) HCl as the medium for rat liver homogenization is emphasi zed, owing not only to quantitative extraction of metal ions but also to markedly reduced matrix effects.