Quantitative determination of small selenium species in human serum by HPLC/ICPMS following a protein-removal, pre-concentration procedure

• Published in: Analytical and bioanalytical chemistry Vol. 400; no. 8; pp. 2323 - 2327
• Main Authors: Kokarnig, Sabine, Kuehnelt, Doris, Stiboller, Michael, Hartleb, Ulrike, Francesconi, Kevin A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2011; Springer
• Subjects: Adult; Analysis; Analytical Chemistry; Biochemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chromatography, High Pressure Liquid; Dietary Supplements; Female; Food Science; High performance liquid chromatography; Humans; Laboratory Medicine; Male; Mass spectrometry; Monitoring/Environmental Analysis; Organoselenium Compounds - blood; Precipitation (Meteorology); Protein binding; Proteins - isolation & purification; Selenium; Selenium - administration & dosage; Selenium - blood; Spectrometry, Mass, Electrospray Ionization; Technical Note; HPLC/ICPMS; Human serum; Sample preparation; Selenium metabolism
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-011-4992-5

Protein precipitation was incorporated into a sample preparation method for the quantitative determination of small “non-protein” selenium species in human serum by high-performance liquid chromatography–inductively coupled plasma mass spectrometry (HPLC/ICPMS). The advantages of cleaner matrix and concomitant concentration of the small compounds result in quantification limits in the native serum at the sub-micrograms Se per litre level. Spiking experiments with methyl 2-acetamido-2-deoxy-1-seleno-β- d -galactopyranoside (selenosugar 1), trimethylselenonium ion, selenomethionine, methylselenocysteine (MeSeCys) and selenate yielded recoveries from 73% to 103%. Selenite had a low recovery (44%), possibly owing to protein binding. The validated method was applied to serum samples from two volunteers before and after ingestion of a selenium food supplement. HPLC/ICPMS analysis showed, besides ingested selenate, the presence of selenosugar 1 and trace amounts of MeSeCys and methyl 2-amino-2-deoxy-1-seleno-β- d -galactopyranoside, which have not been reported in human serum before. Figure A protein-removal pre-concentration procedure facilitates the determination of low concentrations of small selenium compounds in human serum by HPLC/ICPMS