Improved Procedure for the Analysis of Gamma-Hydroxybutyrate and Ethylene Glycol in Whole Blood

Abstract

The modification of a procedure originally developed for the analysis of ethylene glycol (EG) in serum was also found to permit the simultaneous analysis of gamma-hydroxybutyrate (GHB) in whole blood. The primary feature of the EG procedure was that it employed a water scavenger, 2,2-dimethoxypropane, which reacted with water to produce volatile methanol. Water scavenging is a technique that could be adapted for the analysis of drugs such as GHB as their respective di-t-butyldimethylsilyl derivatives. A close structural analogue of GHB, 2-hydroxy-3-methylbutyric acid, was successfully employed as the internal standard for both EG and GHB. The advantages of the modified procedure are that it is very quick and easy to perform and produces remarkably clean extracts for GHB, especially when compared to other liquid-liquid techniques. We have successfully applied this technique for the analysis of GHB and EG in several postmortem and driving-under-the-influence cases. There is an apparently wide variability between levels of GHB that can be associated with impairment versus those levels that can be associated with death.

Effect of γ-hydroxybutyrate (GHB) on driving as measured by a driving simulator

“…In studies of cases of driving under the influence (DUI) of GHB, mean reported blood GHB concentrations were between 87 and 100 mg/L (range 16–350 mg/L) (Jones 2007, Pan 2001, Couper 2001, Couper 2004, Burch 2013) and reported clinical findings included slurred speech, stagger, drowsiness, stopping in the middle of the road and sleeping (Jones 2007, Pan 2001, Burch 2013). Although the one hour concentrations in our study (median 83.1 mg/L) are comparable to the reported DUI values, in the DUI cases, the blood samples were typically drawn one or more hours after the arrest.…”

Gamma hydroxybutyrate (GHB), gamma butyrolactone (GBL) and 1,4-butanediol (1,4-BD; BDO): A literature review with a focus on UK fatalities related to non-medical use

“…As with other psychoactive substances, the levels of GHB found in fatalities overlap with levels found in drivers under the influence of the substance (Bosman and Lusthof, 2003;Pan et al, 2001) and therapeutic levels (Moriya and Hashimoto, 2004). In post-mortem peripheral blood samples, depending on the methodology used, high concentrations of GHB from zero to 197 mg/L could be measured, even in cases without GHB ingestion.…”

L'acide γ-hydroxybutyrique (GHB) : un vieux produit, de nouveaux problèmes

“…Une démarche commune pourrait être adoptée, en se fondant sur les résultats obtenus (19,46,48,49,52,56). La prise de GHB sera confirmée par l'ensemble des données suivantes ; état du patient décrit par une observation clinique rigoureuse, forte présomption de prise de GHB (produit retrouvé et identifié, témoi-gnages de l'entourage direct), concentration sanguine supérieure à 5 ug/mL (sang prélevé sur EDTA), concentration urinaire supérieure à 10 ug/mL, concentration dans les cheveux supérieure à 2 ng/mg, recherche dans la sueur positive après 12 h. Cependant, dans les cas de soumission chimique, les doses administrées sont moins fortes que celles utilisées dans les milieux festifs et les délais entre l'administration et les prélèvements encore plus longs : l'interprétation des résultats sera encore plus difficile et les analyses dans les cheveux encore plus importantes.…”