Determination of selenium metabolites in biological fluids using instrumental and molecular neutron activation analysis

Abstract

The dispersion coefficient (D) Is the most popular peak descriptor In flow Injection analysis (FIA). Yet this concept of

Selenium Metabolites in Urine: A Critical Overview of Past Work and Current Status

“…They were also the first to report TMSe in normal human urine (i.e., without selenium supplementation). The data, however, were variable; in one report (25 ) they claimed that TMSe constituted ϳ30% of the total selenium in normal urine, whereas in two other very similar studies (26,28 ), they reported up to 90% TMSe in normal urine.…”

“…Blotcky and coworkers (25,26,28 ) were especially conspicuous in this area with several publications focusing on determining TMSe with use of neutron activation analysis for detection. They were also the first to report TMSe in normal human urine (i.e., without selenium supplementation).…”

“…Despite this anomaly, TMSe was regarded as a major selenium urinary metabolite and was generally thought to increase when selenium exposure was above nutritional requirements. Unknown selenium species were also reported in urine, but the only other known selenium species claimed to be in urine were selenite (26,28,53 ) and selenodiglutathione (53 ). After the introduction and application of HPLC/ ICPMS for the determination of selenium urinary species, one may have anticipated that TMSe would be regularly reported as a major metabolite.…”

Speciation of Selenium Compounds

“…Because of its cationic nature, TMSe + is preconcentrated and separated, usually from inorganic selenium species, on the cationexchange columns. 18,31,34 The high resolution obtained by HPLC permits a clear separation of TMSe + from inorganic selenium and also from other organoselenium compounds. 28,29,32,35 Reversed-phase partitioning and ion exchange chromatography have been applied.…”

“…31,34,[41][42][43] Organoselenium species (other than TMSe + ) adsorbed on Amberlite XAD-2 resin at pH 8 were classified as neutral and basic forms, while those absorbed at pH 3 were classified as acidic. 31 As the acidic forms dominated in lake water samples, it was concluded that most of these compounds were selenium-containing humic substances.…”