A high performance liquid chromatography-inductively coupled plasma mass spectrometry(HPLC-ICP/MS) was developed for the determination of five speciations of selenium

i.e.selenocystine(SeCys2)

methylselenocysteine(MeSeCys)

selenite［Se(Ⅳ)］

selenomethionine(SeMet) and selenate［Se(Ⅵ)］ in human urine.The samples were diluted with ultra pure water

and separated on a Hamilton PRP-X100 column(250 mm×4 mm，10 μm) by isocratic elution using 40 mmol/L diammonium hydrogen phosphate containing 1% methanol(pH 5) as mobile phase.Five selenium speciations could be separated within 13 min.There were linear relationships for five selenium speciations in the range of 0-300.0 μg/L with correlation coefficients(r) larger than 0.999.The detection limits of the method were 0.2-0.5 μg/L.Recoveries for MeSeCys

Se(Ⅳ)

SeMet and Se(Ⅵ) were in the range of 80.0%-123%

except that the recovery for SeCys2 was 37.7%-70.4%.The relative standard deviations(RSD) were not more than 7.8%.Results showed that SeCys2 was the main selenium speciation in human urine

and a small amount of MeSeCys

SeMet

inorganic selenium and some unknown selenium compounds were also found.