Differential pulse polarographic determination of selenium(IV) in whole blood using the catalytic hydrogen wave

The selenium content in blood was determined using the hydrogen catalytic peak. This peak at −1.1 V was obtained in the presence of selenium and molybdenum at pH values of 1–4 in different buffers. For the determination of selenium, the Mo(VI) concentration has to be ∼100–200 times higher than the selenium present. The linear domain range of selenium is 1×10−6–5×10−9 M. The interference of zinc is eliminated by the addition of EDTA at pH 3.5 acetate buffer. The method was applied to 1.0 ml of digested blood, and 620±44 μg l−1 Se and 7.15 mg l−1 Zn could be determined with a 90% (n=6) confidence interval.