title: Determination of growth hormone-releasing hexapeptide by reversed-phase high-performance liquid chromatography with electrochemical detection.
abstract: A novel HPLC method with electrochemical detection is described for the determination of a growth-hormone-releasing hexapeptide (GHRP-6). HPLC conditions, such as the column, mobile phase, and oxidation potential, were optimized for sensitivity and selectivity of analysis. GHRP-6 was separated on a reversed-phase CN column with 37% acetonitrile in 100 mM phosphate buffer (pH 7.0) as the mobile phase. The optimum electrochemical oxidation signal was obtained at 0.85 V vs. Ag/AgCl in a glassy carbon working electrode due to two electroactive tryptophans and a histidine residue. Solid-phase extraction using octadecyl cartridges was optimized for sample cleanup of GHRP-6 from serum samples and the method was successfully applied over the concentration range of 5 to 100 ng/ml of analyte. reserved.
authors.affiliation: Bioanalysis Laboratory, College of Pharmacy, Wonkwang University, Iksan, South Korea.
authors.forename: S J
authors.initials: SJ
authors.lastname: Choi
authors.forename: H Y
authors.initials: HY
authors.lastname: Lee
authors.forename: S B
authors.initials: SB
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Kim
authors.forename: S S
authors.initials: SS
authors.lastname: Lee
authors.forename: S D
authors.initials: SD
authors.lastname: Yoo
authors.forename: K C
authors.initials: KC
authors.lastname: Lee
authors.forename: H S
authors.initials: HS
authors.lastname: Lee
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004563:Electrochemistry; D006801:Humans; D009842:Oligopeptides / Q000097:blood* / Q000378:metabolism; D010084:Oxidation-Reduction; D015203:Reproducibility of Results
chemical_list: D009842:Oligopeptides; C041048:growth hormone releasing hexapeptide