Rapid and non-invasive method to determine toxic levels of alcohols and γ-hydroxylbutyric acid in saliva samples by gas chromatography-differential mobility spectrometry

A polydimethylsilicone oral sampler was used to extract methanol, ethanol, ethylene glycol, 1,3-propandiol and y-hydroxybutyric acid from samples of human saliva obtained using a passive-drool approach. The extracted compounds were recovered by thermal desorption, isolated by gas chromatography and detected with differential mobility spectrometry, operating with a programmed dispersion field. Complex signal behaviours were also observed that were consistent with hitherto unobserved fragmentation behaviours in differential mobility spectrometry. These yielded high-mobility fragments obscured within the envelope of the water-based reactant ion peak. Further, compensation field maxima shifts were also observed attributable to transport gas modification phenomena. Nevertheless, the responses obtained indicated that in-vivo saliva sampling with thermal desorption gas chromatography may be used to provide a semi-quantitative diagnostic screen over the toxicity threshold concentration ranges of 100 mg.dm-3 to 3 g.dm-3. A candidate method suitable for use in low resource settings for the non-invasive screening of patients intoxicated by alcohols and volatile sedatives has been demonstrated.