title: A novel salting-out assisted extraction coupled with HPLC- fluorescence detection for trace determination of vitamin K homologues in human plasma.
abstract: Recently, new physiological roles of vitamin K homologues have been established in the treatment of rheumatoid arthritis, osteoporosis, hepatocellular carcinoma and leukemia. However, relatively high plasma protein binding, low plasma concentrations and occurrences of interfering lipids make accurate determination of vitamin K homologues a challenging task. Therefore, a sensitive and reliable salting-out assisted liquid/liquid extraction (SALLE) method coupled with HPLC-Fluorescence detection was designed for efficient extraction and quantification of trace levels of vitamin K homologues in human plasma. The investigated vitamin K homologues were phylloquinone (PK, vitamin K1), menaquinone-4 (MK-4) and menaquinone-7 (MK-7). The method employed a new efficient fluorescence derivatization reaction using ethanolic solution of stannous chloride in acidic solution to generate highly fluorescent naphthohydroquinone derivatives. Correlation coefficients were more than 0.998 in the concentration ranges of 0.3-100 ng mL(-1) with detection limits of 0.1-0.17 ng mL(-1) in human plasma. The developed HPLC-FL system was successfully applied for sensitive determination of vitamin K homologues in plasma of healthy volunteers. The developed method may provide a valuable tool in the pharmacoinformatic studies concerning the roles of vitamin K homologues.
authors.affiliation: Department of Pharmacognosy and Pharmaceutical Chemistry, College of Pharmacy, Taibah University, Al Madinah AlMunawarah 30001, Kingdom of Saudi Arabia; Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt. Electronic address: sameh_aa@yahoo.com.
authors.forename: Sameh
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt; Department of Pharmaceutical Chemistry, College of Pharmacy, Najran University, Najran, P.O. 1988, Kingdom of Saudi Arabia.
authors.forename: Ashraf M
authors.initials: AM
authors.lastname: Mahmoud
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005453:Fluorescence; D006801:Humans; D006873:Hydroquinones / Q000737:chemistry; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D017971:Tin Compounds / Q000737:chemistry; D014812:Vitamin K / Q000031:analogs & derivatives* / Q000097:blood*
chemical_list: D006873:Hydroquinones; D017971:Tin Compounds; D014812:Vitamin K; C023599:stannous chloride
keywords: Fluorescence detection; Human plasma; Pharmacoinformatics; Salting-out assisted liquid/liquid extraction; Vitamin K homologues