title: Screening and confirmation methods for GHB determination in biological fluids.
abstract: The purpose of this review is to provide a comprehensive overview of reported methods for screening and confirmation of the low-molecular-weight compound and drug of abuse gamma-hydroxybutyric acid (GHB) in biological fluids. The polarity of the compound, its endogenous presence, its rapid metabolism after ingestion, and its instability during storage (de novo formation and interconversion between GHB and its lactone form gamma-butyrolactone) are challenges for the analyst and for interpretation of a positive result. First, possible screening procedures for GHB are discussed, including colorimetric, enzymatic, and chromatography-based procedures. Confirmation methods for clinical and forensic cases mostly involve gas chromatography (coupled to mass spectrometry), although liquid chromatography and capillary zone electrophoresis have also been used. Before injection, sample-preparation techniques include (a combination of) liquid-liquid, solid-phase, or headspace extraction, and chemical modification of the polar compound. Also simple "dilute-and-shoot" may be sufficient for urine or serum. Advantages, limitations, and trends are discussed.
authors: Laboratory of Toxicology, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000, Ghent, Belgium.
authors: Ann-Sofie M E
authors: AS
authors: Ingels
authors: Sarah M R
authors: SM
authors: Wille
authors: Nele
authors: N
authors: Samyn
authors: Willy E
authors: WE
authors: Lambert
authors: Christophe P
authors: CP
authors: Stove
mesh_terms: D015107:4-Butyrolactone / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry; D002151:Calorimetry; D002849:Chromatography, Gas; D002853:Chromatography, Liquid; D019075:Electrophoresis, Capillary; D005374:Filtration; D053593:Forensic Toxicology; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006885:Hydroxybutyrates / Q000737:chemistry*; D013058:Mass Spectrometry; D008970:Molecular Weight; D052616:Solid Phase Extraction; D015813:Substance Abuse Detection; D053719:Tandem Mass Spectrometry
chemical_list: D006885:Hydroxybutyrates; C111420:4-hydroxybutyric acid; D015107:4-Butyrolactone