Determination of selenium in human spermatozoa and prostasomes using base digestion and electrothermal atomic absorption spectrophotometry

Abstract

A method for the determination of selenium in human spermatozoa and prostasomes is described. The samples were digested with 25% (w/v) tetramethylammonium hydroxide (TMAH) in methanol and analyzed by atomic absorption spectrometry with electrothermal atomization and Zeeman background correction (ET-AAS). Nickel was used as a matrix modifier. Calibration was performed using the matrix-based calibration curve. The TMAH-digestion method agreed well with a conventional digestion procedure using concentrated nitric acid. The TMAH-digestion does not require heating or strong acids and it was suitable for small biological samples. The average recovery of added selenium in spermatozoan digests was 95.1 ± 5.2% ( n = 5). The coefficient of variation was 9.1% ( n = 21). The accuracy of the method tested with the NBS standard 1577 (bovine liver, certified at 1.1 ± 0.1 μg Se/g) resulted in a value of 0.98 ± 0.10 μg Se/g ( n = 16). The method was further tested in an interlaboratory comparison study.