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.

Odor intensities, odor concentrations and volatile amine compounds were investigated at the two piggeries in Korea and the one in Japan. It was confirmed that the piggery where odor control had been carried out intentionally showed the lower values of sensory measurement than those where the odor control had not been under consideration and also found that the concentrations of volatile amines in the odor-controlled piggery showed lower values rather than the uncontrolled. In this investigation, we conclude that the activities such as circulation of air in pig houses, spraying deodorants and feeding the additive that is effective for reducing malodors from piggery could decrease the odors and the concentrations of volatile amines that are the cause of offensive odors from piggery.

In this study, the spatial and temporal distribution of odorants in ambient air was investigated at three measurement points in a University campus in Seoul city during a 15 day study period. The concentrations of 12 target analytes designated as malodor compounds by KMOE were measured through time. The highest mean concentration (in ppb unit) was found from NH₃(25.3) followed by styrene (0.51) ＞ acetaldehyde (0.13) ＞ H₂S, propionaldehyde (0.07) ＞ butyraldehyde, isovaleraldehyde, and valeraldehyde (0.06) ＞ DMDS (0.04) ＞ TMA (0.03) ＞ CH₃SH and DMS (0.01). Comparison of odorant data showed fairly strong distinctions across diurnal period, while differences in concentration levels were not clear enough between different sampling locations. The results of correlation analysis showed that the concentrations of DMS and NH₃ were strongly correlated with relative humidity. In addition, most of reduced sulfur compounds (RSC) exhibited strong correlations with each other. When the odorant concentrations were converted into odor intensity, the values were typically found below the odor degree of 1. The odor intensity, if assessed by the maximum values of each compound, were generally in between 1~2 odor degree level (e.g., H₂S, CH₃SH, DMDS, acetaldehyde, and TMA). The results of this study thus show that most odorant species occurred below the threshold value at clean space like a University campus. Hence, more efforts are desirable toward the development of the analytical technique at various concentration levels.

In this study, we attempted to evaluate the relationship between air dilution sensory test and instrumental detection method for samples containing various odorous compounds. For the purpose of our comparative study, the analysis of malodor compounds was made using a total of 70 samples collected from three industrial sectors which include: Food & beverage, Waste treatment and cleaning, and Miscellaneous facilities. The results of instrumental analyses converted into three different odor indices (the odor concentration (OC), odor quotient (OQ), and odor intensity (OI)) were used to statistically sort out individual odorous components with the major impact. The results of multiple regression analysis between air dilution ratio value and instrumental odor concentration (of individual 12 compounds) indicate that butyraldehyde, CH₃SH, NH₃, and H₂S are the major odorous compounds that contribute most significantly to odor strength for the sample types investigated in this study.

The emission concentrations of VOC and various odorous compounds were measured from different indoor process units located in 19 companies at the Ban Wall industrial complex from Jun. 2004 to Jan. 2005. The purpose of this study was to investigate the indoor pollution levels of various industrial facilities with respect to bothmalodorous compounds and volatile organic compounds (VOC). We also intended to build the database under the conditions affected by various anthropogenic processes with an aid of a statistical treatment. The three samplingmethods and five analytical techniques were applied tomeasure the sum of up to 32 individual compounds. According to this study, we were able to identify the importance ofmajormalodor compounds which include carbonyl compounds, reduced sulfur compounds, ammonia and trimethylamine. On the other hand, relative contribution of VOC as sources ofmalodor was ofminor significance except such compound as toluene. The overall results of this study thus indicate that the concentration levels of VOC in themanufacturing facilities are high enough to affect indoor laboring conditions.

Increasing public concerns over odors and air regulations in nonattainment zones necessitate the remediation of a wide range of odorous compounds used for industrial purpose. Currently, spraying technique using neutralizing essential oils is utilized to treat ammonia odors. The chemical analysis was performed to analyze the composition of an essential oil by GC-MS. The monoterpenes in an essential oil react with ammonia by neutralization and their reaction mechanism was elucidated. However, little information is available on the neutralization reaction with rendering air pollutants in detail. The objective of this study was to clarify the possibility of the neutralization of odors sprayed in indoor and determine the removal efficiencies in the misty aerosol by different input odor concentration. It was found that an ammonia was significantly removed by the spraying technique, and the removal efficiency of ammonia was 98 %. The removal efficiencies of ammonia were also studied by the optimal conditions such as temperature and pH.

Background : Gastrodia elata Blume (G. elata) is important medicinal resource in korea. Gastrodin and 4-hydroxybenzyl alcohol (4-HBA) are major active compounds of G. elata, and ρ-cresol is major cause of off-odor like pig slurry from G. elata. The off-odor can decrease the quality of fresh G. elata as well as its products. Therefore, this study was performed to investigate the influence of extraction temperature on bio-active and odorous compounds of G. elata extract. Methods and Results : G. elata was extracted with distilled water at 0, 30, 60, and 90℃ for 20, 40, 60, and 120 min. Gastrodin and 4-HBA contents were analyzed by using a HPLC-UVD, and ρ-cresol content was analyzed by using a SPME-GC-MS. Gastrodin content increased as increasing extraction temperature and time, and showed the highest value in extract at 90℃. 4-HBA content showed the highest value at 60℃, and increased as increasing extraction time. Total content of gastrodin and 4-HBA was higher in extract from G. elata at 60℃ for 120 min than other extracts. ρ-Cresol content was varied according to extraction temperature, and was lower in extract at 30 and 60℃ than 0 and 90℃. Conclusion : These results indicated that the extraction temperature can affect the bio-active components and off-odor of G. elata extract, and 60℃ is appropriate to improve the qualities including bio-active component and off-odor of G. elata extract and its products.