Determination of the illicit drug gamma‐hydroxybutyrate (GHB) in human saliva and beverages by ¹H NMR analysis

Abstract

High resolution 1H NMR spectroscopy has been employed to investigate the detection and quantification of the illicit "date-rape" drug gamma-hydroxybutyrate (GHB) in both human saliva and a commonly-consumed low-alcohol beer product. Data acquired revealed that this multicomponent analytical technique provided unequivocal evidence for the detection of this agent by this technique in both of these matrices, i.e., all three of its resonances [those ascribable to the alpha-CH2 (t, delta=2.25 ppm), beta-CH2 (tt, delta=1.81 ppm) and gamma-CH2 (t, delta=3.61 ppm) group protons] were present in spectra acquired on human saliva, and two of these (the alpha- and beta-CH2 group signals) in the beverage product examined, the latter observation attributable to overlap of the gamma-CH2 1H resonance with those of carbohydrates. Since good linear calibration relationships between the intensities of each of the NMR-visible signals and added GHB concentration (the former normalised to that of an external 3-trimethylsilyl [2,2,3,3-2H4]- propionate standard present in a coaxial NMR tube insert) were observed, this illicit drug is also readily quantifiable in such multicomponent samples. Our data demonstrate the advantages offered by this technique when applied to the analysis of illicit drugs in multicomponent sample matrices such as human biofluids and beverage products.

Understanding the human salivary metabolome

“…Some salivary metabolites have been successfully identified using 1 H NMR (13)(14)(15)(16)(17)(18), and inter-subject variability has been studied (16,17), but to date chemometrics has not been applied to saliva metabolite datasets to find potential markers for disease.…”

Spectroscopic Trends for the Determination of Illicit Drugs in Oral Fluid

“…GBL is a synthetic precursor of the GHB (obtained from it thanks to a rapid and reversible conversion) and it was used for the clandestine manufacture of GHB. [42,43] For its forensic interest, Grootveld et al [42] used 1 H NMR spectroscopy to detect and quantify GHB in oral fluid and in a common beer. At first, the characteristic peaks of the GHB were identified by analysing an aqueous solution of the analyte at pH 7.00.…”

“…Moreover, it is possible to obtain much information about the molecular nature of both endogenous and exogenous species present in the sample. GBL was not directly investigated but the spectra collected demonstrated that the precursor is readily detectable and easily distinguishable from GHB by observing the chemical shifts [42].…”

A Rapid GC-MS Determination of Gamma-Hydroxybutyrate in Saliva

“…Concerning this, GHB has been investigated in hair (40)(41)(42)(43)(44)(45), vitreous humor, urine, bile, brain, liver, kidney, and cerebrospinal fluid (46)(47)(48)(49) in both antemortem and postmortem samples. To date, there are only two articles in literature concerning GHB analysis in saliva (50,51).…”