Stronger associations of oil-based sexual lubricants and hygiene products using GC×GC–MS

Abstract

The profile of minor compounds in complex sexual lubricants was investigated by traditional one-dimensional gas chromatography-mass spectrometry (GC–MS) and comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC–MS). Although GC–MS is a powerful instrument, it has some limitations with truly complex mixtures that have many components that can co-elute. This is the primary advantage of GC×GC. By coupling a second-dimension column in series with the first-dimension column using a modulator, components that co-elute on the first column may be resolved on a second column with orthogonal selectivity. This study utilized a forward fill/reverse flush differential flow modulator run in both two-dimensional mode (GC×GC–MS) and single dimensional mode (GC–MS) in the same instrumental sequence. Pearson correlation coefficients were calculated for each intra-method pairwise comparison to determine which methodology provided an accurate measure of similarity or difference. The use of GC×GC–MS analysis can increase the differentiation of complex mixtures when GC chromatograms shows high similarity of two different samples. In this study, when GC chromatograms of two similar samples were compared they had low correlation scores. However, the comparison of the GC×GC chromatograms of the same samples had higher correlation scores shows high similarity based on the increased sensitivity and separation of co-eluting peaks by the two-dimensional GC×GC column configuration.