Determination of endogenous GHB in ante-mortem whole blood, urine, and oral fluid by LC–MS/MS: The effect of different additives and storage conditions on the stability of GHB in blood

• Published in: Forensic science international 2024-12, Vol.365, p.112286, Article 112286
• Main Authors: Sørensen, Lambert K., Faldborg, Kathrine B., Andersen, Charlotte U., Hasselstrøm, Jørgen B.
• Format: Article
• Language: English
• Subjects: Acetonitrile; Additives; Adult; Anion exchange; Anion exchanging; Blood; Blood levels; Chromatography; Chromatography, Liquid; Citric Acid; Drug dosages; Endogenous concentration; Female; Fluorides; Forensic Toxicology - methods; Gamma-hydroxybutyrate; Gamma-hydroxybutyric acid; GHB; Humans; Hydroxybutyrates - blood; In vitro methods and tests; Isomers; LC–MS/MS; Limit of Detection; Liquid Chromatography-Mass Spectrometry; Male; Mass spectrometry; Mean; Oxalates; Potassium; Reproducibility of Results; Saliva - chemistry; Scientific imaging; Sodium; Solid Phase Extraction; Solid phases; Specimen Handling - methods; Stability; Storage conditions; Tandem Mass Spectrometry; Urine; γ-Hydroxybutyric acid
• ISSN: 0379-0738; 1872-6283; 1872-6283
• DOI: 10.1016/j.forsciint.2024.112286

Two challenges in detecting γ-hydroxybutyric acid (GHB) intake are its endogenous presence and in vitro production after sampling. This study developed an LC–MS/MS method for selective GHB determination in human antemortem blood, urine, and oral fluid at endogenous concentrations. Furthermore, the stability of GHB in blood samples and its endogenous concentrations in samples taken under controlled circumstances were investigated. Samples were extracted in methanol/acetonitrile and processed by anion exchange solid-phase extraction. GHB was separated from structural isomers using a reversed–phase LC column with anion properties. The validated limit of quantification was 0.005 µg/mL in blood and 0.010 µg/mL in urine and oral fluid, at which the relative reproducibility standard deviation and bias were