SIMPLE AND FAST DETERMINATION FOR GAMMA-HYDROXYBUTYRATE (GHB) IN URINE SAMPLE BY LLE AND GC-MS

Abstract

Gamma-hydroxybutyrate (GHB) is a depressant of the central nervous system able to promote disinhibition, anterograde amnesia and its use is related to Drug-Facilitated Crimes (DFC). Urine is the biological matrix of choice for toxicological analysis in victims of rape and/or theft in suspected victims of DFC. The aim of this work was the development of a simple and ultra-fast methodology for GHB determination in urine samples using GC-MS. Briefly, 250 µL of urine was pipetted in a vial and fortified with 10 µL (250 µg mL-1) of internal standard GHB-d6. Then, the sample was acidified and submitted to extraction with ethyl acetate. After stirring, the material was taken to a microcentrifuge (1 minute at 5000 rpm). Then the dried residue was derivatized with BSTFA + 1% TCMS for 10 min at 70 oC before injection. This method was successfully validated according UNODC and EMEA guidelines on bioanalytical method validation with limit of detection and limit of quantification were 0.25 and 0.50 µg mL-1, respectively. Considering all steps for GHB determination, this analytical procedure allows the fastest detection of GHB in urine samples when compared to literature allowing the analysis of DFC suspect cases or clinical when endogenous GHB requires to be measured.