s t r a c t
Recently,newphysiologicalrolesofvitaminKhomologueshavebeenestablishedinthetreatmentof
rheumatoidarthritis,osteoporosis,hepatocellularcarcinomaandleukemia.However,relativelyhigh
plasma proteinbinding,lowplasmaconcentrationsandoccurrencesofinterferinglipidsmakeaccurate
determination ofvitaminKhomologuesachallengingtask.Therefore,asensitiveandreliablesalting-out
assisted liquid/liquidextraction(SALLE)methodcoupledwithHPLC-Fluorescencedetectionwasde-
signed forefficient extractionandquantification oftracelevelsofvitaminKhomologuesinhuman
plasma. TheinvestigatedvitaminKhomologueswerephylloquinone(PK,vitaminK1), menaquinone-4
(MK-4)andmenaquinone-7(MK-7).Themethodemployedanewefficient fluorescencederivatization
reaction usingethanolicsolutionofstannouschlorideinacidicsolutiontogeneratehighly fluorescent
naphthohydroquinonederivatives.Correlationcoefficients weremorethan0.998intheconcentration
rangesof0.3–100ngmL1 with detectionlimitsof0.1–0.17ngmL1 in humanplasma.Thedeveloped
HPLC-FL systemwassuccessfullyappliedforsensitivedeterminationofvitaminKhomologuesinplasma
of healthyvolunteers.Thedevelopedmethodmayprovideavaluabletoolinthepharmacoinformatic