Using Gas Chromatography-Ion Mobility Spectrometry to Investigate Volatile Compound Profiles in Human Sweat during COVID-19 Vaccination

In this study, gas chromatography-ion mobility spectrometry (GC-IMS) was applied to analyze sweat volatile compounds for differentiation of population with COVID-19 vaccination. This involves tentative identification of the compounds in 50 axillary swab samples obtained from 10 healthy female volunteers before or after nucleic acid-based COVID-19 vaccination at different periods up to two days. The samples were collected by using sterilized cotton rods with the sampling time of 15 min. The data were analyzed using partial least squares discriminant analysis (PLS-DA) showing separation of the groups before and after the vaccination. Receiver operating characteristic (ROC) curves were then constructed for the detected peaks which revealed four possible marker peaks with the significantly downregulated or upregulated contents in the vaccinated samples. One of these markers was tentatively identified as methanol. With the optimum peak volume thresholds, the sensitivity, specificity and accuracy were up to 100 %, 85 % and 94 %, respectively. The marker peak volumes along the vaccination progresses were also monitored showing the significant decrease or increase of their contents within 6 h after the vaccination. The analysis approaches are expected to be useful to confirm stages of other vaccination. This study applied GC-IMS approach to obtain volatile compound fingerprints of human sweat samples. The data could be used to diffetentiate the volunteers without and with COVID-19 vaccination.image