This study assessed the measurement technique of odorous substances using a GC/MOS system with MOS sensor at the detector and the method detection limits were determined for odorous substances such as hydrogen sulfide, acetaldehyde, toluene, m,pxylene, and o-xylene. The portable GC/MOS system was able to separate and measure about 16 out of 22 odorous substances including sulfur compounds, aldehydes, and VOCs. The peak values for hydrogen sulfide, acetaldehyde, toluene, m,p-xylene, and o-xylene showed a nonlinear relationship with concentration and a correlation coefficient of 0.95 or higher was confirmed. The method detection limits for hydrogen sulfide, acetaldehyde, toluene, m.pxylene, and o-xylene using the portable GC/MOS system were determined to be 0.005, 0.023, 0.016, 0.004, and 0.051 ppm, respectively. It is expected that the system can measure odor samples with concentrations of least 50 ppb without additional pretreatment or concentration processes.

The purpose of this study is to create a new odor analysis technology that combines the separation technology of GC and the measurement of MOS sensors. The detector of the GC system is replaced with the MOS sensor to analyze various odor compounds. Carrier gas also used air in the normal atmosphere through a micro pump. Therefore, it is possible to develop a portable odor analysis device since no additional cylinder is needed. Retention times for H2S, C7H8, and C2H4O analyzed by the combined GC/MOS system were identified as 1.28 minutes, 3.88 minutes and 1.77 minutes, respectively. Measurement reproducibility of odorous RT was very good at less than 1.2 %RSD. Also, the magnitude of the peak as a result of changes in the concentration of each odor showed a linear proportional relationship. Thus, a new method could be proposed to analyze various odorous substances with the combined GC/MOS system.