SIMPLE DECOMPOSITION PROCEDURE FOR DETERMINATION OF SELENIUM IN WHOLE-BLOOD, SERUM AND URINE BY HYDRIDE GENERATION ATOMIC-ABSORPTION SPECTROSCOPY

A digestion procedure for selenium determination by hydride generation atomic absorption spectroscopy (AAS) in whole blood, serum and urine is described, it employs sulfuric acid, hydrogen peroxide and vanadium (V) sulfuric acid reagent solution. The method is rapid, uses no explosive reagents and can be performed at a constant temperature of 100 degrees C. Therefore, it is easily applicable in a routine clinical laboratory for a large amount of samples. The coefficient of intra-assay variation was 4.3-5.6%, the coefficient for inter-assay variation was 5-5.9% in the medium and high concentration range, and 5.8-8.6% in the low range. In analyzing several commercial reference materials our results showed good agreement with the target values. Analytical recovery by addition of sodium selenite and seleno-DL-methionine to samples ranged between 97 and 104%. The correlation between the described digestion procedure and the nitric, sulfuric and perchloric acid digestion procedure recommended by the International Union of Pure and Applied Chemistry showed good agreement for whole blood, serum and for urine. We determined selenium in serum (n = 58) and whole blood (n = 50) in a collective of healthy children from 1 to 5 years living in Styria, Austria. The low values in serum (35 +/- 11 mu g/L) and whole blood (42 +/- 6 mu g/L) at one year of life increased significantly to 48 +/- 13 mu/L (p = 0.033) and 55 +/- 6 mu g/L (p = 0.004) at three years of life in serum and whole blood, respectively. The selenium concentration showed no further increase up to five years of age. In comparison to other European countries these selenium levels are among the lowest.