Methods for Analysis of Odor-related Volatile Compounds in Railway Facilities

Attention to hygienic environments in public spaces is increasing, and we believe that it is important to understand and evaluate this aspect of railways in their role as a means of public transportation. Previously, we carried out investigation regarding types and amounts of airborne microbes (mainly fungi) floating in station precincts as well as evaluating railway passengers’ perception of hygiene as the ones that affect hygienic environments. The results revealed some cases in which greater amounts of airborne fungi were detected in underground premises than in above-ground environments [1], and showed that there was a high correlation between subjective evaluation for odors in areas of stations as detected by monitoring investigation and the amounts of airborne fungi in them [2, 3]. From these results, we concluded that volatile compounds released by fungi partially caused odors in stations, and we subsequently analyzed them. The concentrations of the volatile compounds analyzed were assumed to be extremely low; accordingly, we needed effective sampling techniques and highly sensitive detection methods. Furthermore, for sampling on station premises, a compact method is required to avoid hindering passenger movement. In this report, we introduce the characteristics of the SPME (solid phase microextraction)-GCMS (gas chromatography-mass spectrometry) technique adopted as a method for the sampling and analysis of volatile compounds in the target areas, and report on examples of application to field analysis.