Comparative determination of selenium in the serum of various animal species and humans by means of electrothermal atomic absorption spectrometry.

It was the goal of this paper to establish total selenium reference values for Switzerland in different animal species and in humans. To this purpose, a flameless atomic absorption method with deuterium background compensation utilizing a graphite furnace atomization system with a pyrolytic platform inside and palladium solution as matrix modifier was developed for the measurement of selenium in serum. The method was characterized by rapid performability, small sample requirement, acceptable detection limit (0.04 mumol/L) and precision and a linear range of measurement up to 4 mumol/L. The method proved to be suited for routine application in species with low selenium concentrations, such as cattle. It may be useful wherever small amounts of serum have to be analysed, e.g. in neonatology. Reference values of serum selenium concentration were determined in healthy subjects of various species, including man. They were as follows (min = 5%, max = 95% percentile values in mumol/L): humans (20-60 years): 0.78-1.48, humans (60-100 years): 0.61-1.73, horse: 0.36-1.68, dog: 1.90-4.31, cat: 3.60-10.09, cattle greater than 9 months: 0.10-0.82, calves 3-9 months: 0.19-0.65, sheep: 0.09-0.54, goat: 0.14-1.42, chicken: 1.68-4.28 and pig: 1.97-3.32. From the data it was concluded (i) that the serum selenium concentration depended on the amount of selenium in the food, and on the type of digestive tract; (ii) that carnivors had the highest and ruminants the lowest selenium values; and (iii) that up to 20% of the geriatric donors had inadequate selenium levels.