Fast Analytical Methodology Based on Mass Spectrometry for the Determination of Volatile Biomarkers in Saliva

We report a methodology for the rapid determination of biomarkers in saliva. The method is based on direct coupling of a headspace sampler with a mass spectrometer. The saliva samples are subjected to the headspace generation process, and the volatiles generated are introduced directly into the mass spectrometer, thereby obtaining a fingerprint of the sample analyzed. The main advantage of the proposed methodology is that no prior chromatographic separation and no sample manipulation is required. The following model compounds were studied to check the possibilities of the methodology: methyl tert-butyl ether and styrene as biomarkers of exposure and dimethyl disulfide, limonene, and 2-ethyl-1-hexanol as biomarkers of diseases. The method was applied to the determination of biomarkers in 28 saliva samples: 24 of them were from healthy volunteers, and the others were from patients with different types of illness (including different types of cancer). Additionally, a separative analysis by GC/MS was performed for confirmatory purposes, and both methods provided similar results.