Identification of gamma-hydroxybutyrate (GHB)–β-ribose as a promising biomarker enabling prolonged detection of GHB intake

For several years, forensic toxicologists have sought biomarkers to extend the detection window of gamma-hydroxybutyric acid (GHB), a drug suspected to be involved in drug-facilitated sexual assaults yet difficult to detect due to its rapid elimination, endogenous presence, and postsampling formation. In this study, we used samples from 30 participants in a double-blind, controlled trial, randomized to placebo or a single oral dose (50 milligrams per kilogram) of sodium oxybate, a GHB salt. We collected whole blood and urine samples over 5 days and used untargeted metabolomics to search for biomarkers. The most promising feature, previously suggested as a GHB-pentose, was identified as GHB-β-ribose by chemical synthesis and liquid chromatography–tandem mass spectrometry. Quantification showed elevated levels of GHB-β-ribose for up to 48 in blood and 24 hours in urine after GHB intake compared with endogenous levels in the placebo group and authentic forensic cases. Thus, we present GHB-β-ribose as a very promising biomarker for GHB intake, with the potential to extend the detection window for GHB.