Determination of gamma-butyrolactone (GBL) - A tool for the detection of the administration of gamma-hydroxybutyric acid (GHB)

GHB is an endogenous compound. It is formed in the body as a metabolite of glutamic acid and gamma-aminobutyric acid (GABA). GHB itself is converted into succinic acid. GHB can also be produced synthetically. It is almost achromatic, odourless and tasteless. In detoxication of heroin or alcohol GHB is used to medicate withdrawal syndromes. Furthermore, it is used for the treatment of narcolepsy and as an anaesthetic in caesarean operation. The effects of GHB strongly depend on the administrated amounts. At lower dosage sedative effects predominate. This clearly offers the potential for the abuse of GHB in sports. For instance, small doses of GHB can be used as a substitute for ß-receptor blockers. Moreover, the sedative, as well as the anxiolytical and mood enhancing effects, will give rise to possible abuse in a large variety of disciplines. At higher dosage however, the effects of the drug increasingly become disadvantageous. GHB can be analysed by GC-MS following lactonisation to GBL at pH 1 and subsequent liquid-liquid extraction. In the 1980s Donike and Kraft detected elevated concentrations of GBL in doping control samples taken after shooting events in modern pentathlon. Because of its potential of abuse in certain sport disciplines, we developed a quick and simple screening method to detect GBL in urine. It is based on the above mentioned work of Donike and Kraft. Einleitung (geändert)