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.

In this study, we attempted to evaluate the relationship between dilution‐to‐threshold (D/T) ratio derived by air dilution sensory (ADS) test and the concentration levels of both individual odorant (using H₂S and acetaldehyde (AA)) and their mixture. For the purpose of our comparative study, we prepared both standard gases of two individual compounds and their mixture at 9 concentration levels. Each of all these samples were analyzed by ADS test, and the results were analyzed in relation to their odor intensity. The results of individual odorant samples showed the two contrasting characteristics of each individual compound. H2S generally showed sensitive detection at low concentration but less sensitive detection with increasing concentration. In contrast, AA showed fairly contrasting trend with slow increasing sensitivity. When the D/T ratios estimated from individual samples were used to predict those of mixed samples, the results were reflecting the mixed effects of the basic characteristics owned by each individual compound. As the lower and upper odor intensities of mixed samples were best reflected by AA and H2S, respectively, the D/T ratio of mixed samples complied with the larger D/T values of each compound at a given odor intensity.

In this study, Complex odor was measured by direct sensory method on site. Air samples of the fish factories were sampled with polyester aluminum bag and were analyzed by GC/FID/O and GC/MS. The feature of the complex odor was fishy, boild fish paste and dried slices of file fish. The odor active compounds of individual odor which chotribute these smell were mainly Hydrogen sulfide, Heptanal, 1-Hexanal, 2-Heptanal, TMA. Also contribution level of The designated malodor materials were higher than other industrial complex.

The malodor as the sense pollutions is rising to surface with a new environmental matter. Especially, malodor"s appeal is increasing steadily from a residential area of the industrial complex. The odor characteristic and odor active compounds of industries should be identified to solve this problem. The dye company was selected as a sample among the industries. Air samples of the dye company were sampled with polyester aluminum bag and it was analyzed by GC/FID/O and GC/MS. The feature of the complex odor was ironing, sour and burnt smell. The odor active compounds of individual odor which contribute these smell were mainly 2-ethyl-hexanal, octanal, 2-ethyl-1-hexanol and nonanal. This study will help odor problem of industries to solve effectively.