Breath Analysis by a GC/MS Coupled to a Gas Sensor Detector

A peculiar experimental configuration of a gas chromatograph (GC) coupled, by a splitter, to two detectors, i.e. a mass spectrometer (MS) and a semiconducting gas sensor (SGS), operating in dual mode, was arranged. A suitable breath sampling system was used to sample the alveolar air volume in a bag from the air volume of a single expiration by discarding the dead volume. Breath volatiles (VOCs) were isolated and preconcentrated by solid-phase microextraction (SPME). Breath tests on alveolar air sampled by a sample of smokers volunteers were carried out. Statistical analysis techniques (descriptive statistics, Mann-Whitney test, PCA, Probit nonlinear regression model) applied to GC-MS data and sensor data showed good results in discriminating the subset of smokers sampled in resting condition ("blank" smokers) and after the action of smoking a cigarette.