ABSTRACT
One of the critical points in the study of selenium is the improvement in the quality of its analysis. Nowadays this is more easily achieved by interlaboratory comparisons, improvement in analytical methodology and instrumentation, and use of controls and reference materials. Fluorimetry and atomic absorption spectrometry with hydride generation or electrothermal atomization (GFAAS) are the most commonly used techniques for the analysis of selenium. The use of deuterium versus Zeeman background correction has been controversial, and Zeeman correction is essential for selenium analysis in blood and urine. Selenium is also an indirect regulator of metabolism of the essential fatty acids through the role that glutathione peroxidase (GPx) plays in the oxidation of arachidonic acid in the formation of prostaglandins, leucotrienes, and thromboxane. The selenium content varies according to the type of milk and the geographic origin.
