Determination of selenium in blood by Zeeman graphite furnace atomic absorption spectrometry using a palladium-ascorbic acid chemical modifier

Abstract

A method for the determination of selenium in whole blood using a new Zeeman graphite furnace system is presented. A two-part chemical modifier was used in which palladium is reduced to the metallic state in the graphite tube. This reduced palladium modifier gave enhanced thermal stability and sensitivity for selenium compared with the often used nickel modifier. The palladium modifier is injected into the graphite tube prior to adding the blood which has been previously diluted (1 + 4) with a mixture of 0.5%V/V Triton X-100, 0.125%V/V antifoam B and 0.25%m/VL-ascorbic acid, the reducing agent. Optimisation of the analytical parameters is described. Calibration was established using the standard additions method, with additions being made automatically by an autosampler. Precisions were in the range 2.5–8.7% relative standard deviation for levels of selenium in whole blood of 80.5–159 ng ml^–1.