title: Simple and sensitive liquid chromatographic method with fluorimetric detection for the analysis of gamma-amino-n-butyric acid in human urine.
abstract: A simple and sensitive liquid chromatographic method is described for the analysis of gamma-amino-n-butyric acid (GABA) in human urine. GABA is increased in the urine of cancer patients and could be used as a biomarker in the diagnosis and treatment of related patients. The method is based on derivatizing GABA with a fluorescent reagent (naproxen acyl chloride) for transforming the non-chromophoric GABA to a derivative with chromophoric and fluorophoric properties. The resulting derivative is highly responsive to a fluorimetric detector (lambda(ex)=230 nm, lambda(em)=350 nm). The lower quantitation of the method is attainable at 100 nM GABA with a detection limit about 10nM (S/N=3 with 20 microL injected). Application of the method to the analysis of GABA in the urine of patients with ovarian and uterine cancer was demonstrated.
authors.affiliation: Graduate Institute of Pharmaceutical Sciences, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
authors.forename: Chun-Yu
authors.initials: CY
authors.lastname: Hsieh
authors.forename: Eing-Mei
authors.initials: EM
authors.lastname: Tsai
authors.forename: Hsin-Lung
authors.initials: HL
authors.lastname: Wu