Non-invasive investigation of local skin chemistry

Local skin chemistry was investigated in human participants using non-invasive approaches to characterise volatile organic compounds, cutaneous pH and tissue dielectric constants (TDC). A total of 26 volatile compounds were identified through headspace solid-phase microextraction sampling with gas chromatography-mass spectrometry analysis. Acids and aldehydes were the predominant volatile species, accompanied by a variety of alcohols, ketones, hydrocarbons and esters. Measured values for pH and TDC were within the normal range for healthy skin. Principle component analysis classified participants into sub-groups, wherein specific volatile markers and skin pH were found to be strongly predictive of participant gender