title: Immunoaffinity trapping of urinary human chorionic gonadotropin and its high-performance liquid chromatographic-mass spectrometric confirmation.
abstract: A method has been developed for confirmation of the glycopeptide human chorionic gonadotropin (hCG) in urine. A solid-phase immunoaffinity trapping technique utilizing a monoclonal antibody recognizing both intact hCG and free hCG beta-subunits was developed for the extraction of hCG from urine. Recovery of hCG from a urine matrix was essentially quantitative. The hCG was quantitatively eluted with 6 M guanidine hydrochloride, reductively alkylated with vinylpyridine, and subjected to tryptic digestion. The tryptic digest was analyzed by HPLC-MS. Ions from three tryptic fragments were monitored with selected ion monitoring to provide specific detection of hCG. The signal observed for a concentration of 25 mIU/ml of hCG could be clearly distinguished from background with a signal-to-noise ratio of 12:1.
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University Medical Center, Indianapolis 46202-5120, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Liu
authors.forename: L D
authors.initials: LD
authors.lastname: Bowers
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D006063:Chorionic Gonadotropin / Q000652:urine*; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D015813:Substance Abuse Detection
chemical_list: D000911:Antibodies, Monoclonal; D006063:Chorionic Gonadotropin