Single hair analysis for gamma ‐hydroxybutyric acid—Method optimization, validation, and application

The development and validation of a method for micro-segmental single hair analysis for GHB is presented. The method was additionally applied on samples from non-users and persons with presumed GHB intake in the past. Concentrations were up to 55.2  pg GHB/segment, and concentration profiles from five single hairs were reproducible in each case. AbstractAs gamma-hydroxybutyric acid (GHB) underlies fast metabolization, its determination from hair may presumably offer a detection window superior to that of body fluids. Due to the wide range of endogenous concentration levels, the evidence of an exogenous ingestion is challenging. As already shown for other drugs, the temporal resolution obtained by applying single hair microanalysis provides further information. Therefore, a method for the extraction and quantification of GHB in 2-mm hair segments (seg) was optimized and validated (limit of detection [LOD]: 2.5  pg/seg, lower limit of quantification [LLOQ]: 5 pg/seg), and five single hairs were examined, each for three non-users and for three (alleged) users. A major challenge was the choice of appropriate extraction tubes without remains of GHB. In two samples from non-users, GHB could not or could on ly be detected in trace amounts. In the third sample, concentrations between the LOD and 31.1 pg/seg (mean: 9.5, median: 8.4; each pg/seg) were detected with decreasing values towards the tips. In two samples of persons with assumed GHB intake, maximum concentrations of 6...
Source: Drug Testing and Analysis - Category: Drugs & Pharmacology Authors: Tags: RESEARCH ARTICLE Source Type: research