The degree and intensity of unpleasant and disgusting odors perceived through a person's sense of smell can vary depending on personal or social and cultural characteristics. In addition, it is not effective to manage odors solely on the basis of concentration levels because odors can be combined according to temperature, humidity, and frequency, so that they can be recognized differently even if the same person smells the same substance. The mobile odor application was developed to enable real time monitoring of odor characteristics reflecting the actual condition of the field. Accordingly, the Green Future Foundation, a civic group, conducted an environmental campaign to record and share the information of odors in school zone using the first version of the application. The real time monitoring of field odor was able to improve the problems of the current standard methods for the examination and assessment of odors. However, with regard to the first version of the application, the process and results of odor recording through odor measurement applied the direct olfactory method and were less relevant. Therefore, it was difficult to organize data due to duplicate selection. For that reason, this study was conducted to overcome the problems of the first version of the mobile application and to effectively and accurately reflect odors and personal characteristics. This odor application that has been developed is able to monitor and assess odors based on 5 features: classification, character, strength level, hedonic tone, and acceptability.

This study investigated the odor dilution rate at 15 locations around three schools in Seoul using an onsite olfactometer. In addition, odor intensity, odor quality, and hedonic tone by direct sensory method were measured along with measurement of the field odor dilution rate, and instrument analysis using odor sensor array and TD-GC was also measured. Onsite olfactometer measurements show that only one of the three schools measured odors exceeding the strict emission acceptance standard of 10 at three points. The average odor intensity at each point measured by the direct sensory method of five persons was in the range of 2.7 to 0.3. The difference in the number of odor dilution rates around schools in Seoul could be related to the level of income by region. The odor environment around each school was judged to be well managed in areas with higher income levels, indicating a lower odor dilution rate. The correlation coeffcient between the odor intensity measured by the direct sensory method and the onsite olfactometer was 0.79, indicating high correlation. The correlation coefficient of sensor array and TD-GC toward the odor intensity was -0.28 and 0.02, respectively. This suggests that a method based on a person's sense of smell should be introduced when measuring low-level odor dilution rates in non-industrial areas, such as school zones.

This study compared the stability of odor compounds in three different types of polymer sampling bags. Tedlar, PET (polyethylene terephthalate) and aluminized polyester bag were used. A sample was collected from the interior of a new automobile which was parked in an outdoor parking lot. It was found that the Tedlar bag showed lower stability for odor active compounds than the PET bag. Meanwhile, the PET bag had good stability for odor compounds compared to the aluminized polyester bag. The PET bag showed a stability for the molecules smaller than toluene that was comparable to the canister, but showed a lower recovery for molecules bigger than C7. The FID signal of the sample in the PET bag was reduced by 1.7times after 3days storage compared to 24 h storage. The number of detected odor active compounds was reduced by half, and odor intensity was also decreased by 2~3 degrees. Considering the factors of repeated use, usability and price, a PET bag covered with a black plastic bag was the most appropriate approach for odor sampling in an automobile interior.

An effective method, use of a 2,4-dinitrophenylhydrazine (DNPH) derivatization and high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection, has been used for separation carbonyl compounds. In particular, acetonitrile/water composition as a mobile phase could not separated acrolein/acetone and 2-butanone/ butyraldehyde. In this study, however, that"s compounds separated using acetonitrile/water/tetrahydrofuran as a mobile phase. The resolution was 1.48 and 1.46, respectively. Also, aldehydes and ketones was shown different decrease rate and increase resolution at increase tetrahydrofuran ratio. But butyraldehyde become coeluted methacrolein. Therefore, it is need to consider of mobile phase for separation of butyraldehyde.

In this study, A method for confirming the putrefaction point of apples by using odor variation as applied in apple storage. The samples were obtained from apple storage at Chuncheon shi Dongnae-myeon using by lung sampler. The complex odor was separated by GC/O and individual odors were then analyzed. In the apple storage, the varieties and number of apples vary based on cultivarsand sales volume of apples. Thus, using an emission chamber in the apple storage is difficult. The odor value of the emission chamber and apple storage is denoted by standardizing the sizes and number of apples. The variations in the ratios of aroma value and off-odor value were investigated. The ratio of the aroma value and off-odor value in the emission chamber increased. However, the apple storage values were applied on the number of apples, thus the values alternately increased and decreased in most cases. If the internal change of apple started, it is ratio of aroma value and off-odor value is cloese to zero. and If the External putrefaction on the apple surface is confirmed, the log value becomes larger than 0.5. Complete putrefaction in the stored apples, the log value close to 1.5. We therefore confirmed that this noninvasive method using odor variation can apply to monitoring the quality of apples in storage.

Investigation of the odor source is necessary to establish of the effective counter plan for reducing the odor emitted from the industrial complexes. This study was carried out to investigate the characteristics of the odor emitted from leather manufacturing plants, using three methods which are a direct sensory technique, an air dilution sensory test and a instrumental analysis. Total 7 samples were sampled at 3 points of three factories in this study. As a results of this study, while odor intensity of 7 samples ranges from 2 degree to 4 degree, dilution ration of olfactory test shows the range from 300 to 600. It was estimated that main malodorous compounds ordered hydrogen sulfide, methyl mercaptan, i-valeraldehyde.

In this study fuji apples variation were measured during gradual decay, stored 5 weeks at 25℃. A aluminum and glass emission chamber were used for visual inspection throughout the experiment. The sampling was performed by using polyester aluminum bags and Tenax-TA tubes. In addition, GC/FID/O and TD-GC/MS were used for monitoring the compound of odor and its density variation during each storing period. By visual inspection, we found that the apples started decaying in 4th week and were rotten to core in 5th week. In contrast, individual odor analysis shows that the apples flavor reduced gradually and dramatically increased with the odor of old apples and apple cider in 3rd week, which was before visual identification of decay. This phenomenon was due to ongoing internal decay. ethyl 2-methylbutanoate, ethyl propanoate and 2-methylbutyl acetate were the major factor of this off-flavor in this period (3rd week). After visible observation of decay (4th week and 5th week), ethyl acetate, ethyl butanoate and hexyl ethanoate were emitted, which smells bitter or sour. Above 6 odors are closely related with apples decay, and measurement of smell or density of these odors could easily check the apples status. We expect measuring composition variation can be applied for food storage and management cause of not only internal change checking but also monitoring pre-decay phenomenon.

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.

Five kinds of odorous aldehyde were investigated at industrial complex in Busan. Samples were collected by DNPH cartridge at 24 work places, 81 samples in 44 sites, and analysed by HPLC/UV system. Acetaldehyde was detected in 78 samples with range of 1.2~299.7 ppbv. Propionaldehyde, butyraldehyde, n-valeraldehyde and i-valeraldehyde were detected in 7 samples, 11 samples, 2 samples and 9 samples, respectively. Measured concentration of propionaldehyde, butyraldehyde, n-valeraldehyde and iso-valeraldehyde were ranged 14.8~74.1 ppbv, 1.6~132.0 ppbv, 11.7~13.3 ppbv and 113.9~8858.9 ppbv, respectively. Among total analysed samples, 15 samples were over than degree 3 of calculated odor intensity. All of i- Valeraldehyde detected samples were showed over than degree 3. The work places subsisted aldehydes with high concentrations were related with leather-factory wastes disposal plant, leather, feedstuff, producing synthetic seasoning and textile mill.

This study attempts to identify whether Phenethylamine (PTA), having a similar smell to fish malodor, is appropriate as a replacement of Trimethylamine (TMA). In a continuous measurement test, the odor intensity of both reagents TMA and PTA measured within 5 minutes showed between 0.4~0.7, indicating a dramatic reduction in olfactory sense, while the measurement test conducted after olfactory recovery did not represent much decrease. The result shows that both TMA and PTA have odors that stay long, but are judged to be inappropriate as a replacement as they stimulate the olfactory sense of the panel and give direct impact on the panel"s next judgement.

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.

In this study, the most effective salting-out effect has been examined in terms of application of various inorganic salts (NaCl, Na₂S0₄, NaHSO₃) using Alkali impregnated filter-Headspace-GC/FID. Five various VFAs (propionic acid (99.5%), r-butyric acid (99%), butyric acid (99%), i-valerie acid (99%), valerie acid (99%)) have been used. VFAs have been analyzed by adding 30%, 70%, 100%, 150%, 200% of different inorganic salts with HS-GC/FID. The efficiency of salting-out effect was obtained from the values of peak area in chromatogram. The most effective salting-out effect for applired inorganic salts was observed at 100% saturation. It was confirmed NaHSO₃ for salting-out effect was the best among inorganic salts. In addition, NaHSO₃ showed more efficiency of salting-out effect than NaCl as molecular weight of VFAs increases.

In this study, simple preprocessing method for the analysis of headspace phase has been examined. The odor causing components were verified from the analysis of amine species emitted from squid waste. The concentrations of odor causing chemical components were confirmed in terms of four different sample treatments (treatment at 60℃, sonification, pressure treatment, addition of microorganism). HS-autosampler/GC/FID has been used for the analysis of chemical components and standard material addition method was utilized for quantification. The analysis results indicated that the major odor causing amine compounds emitted from squid waste were DMA and TMA. In addition, it was confirmed TMA showing higher malodor concentration predicted was relative malodor causing chemical component. Sonification and pressure treatment reduced the production of DMA and TMA by lowering the activity of microorganisms, while the addition of microbial accelerated the metabolism of microorganisms leading to the increased production of DMA and TMA.

In this study, odor active compounds, emitted from food waste composting facility, were analyzed and their contribution degree were evaluated. Sample gases were collected at the inlet and outlet of scrubbing tower and bio-filter, respectively. The odor active compounds were separated by GC/FID/Olfactometry (GC/FID/O) and identified by GC/MS. Odor intensity and SNIF (Surface of Nasal Impact frequency) were used to evaluate contribution of each odor active compound. It was possible to calculate contribution rate (%) and reduction rate (%) of odor active compounds using analysis and evaluation of contribution degree of odor active compounds. As a result, the compounds showing the high contribution degree were fatty acids, ketones at inlet and aldehydes, ketones at outlet. Deodoring equipment of food waste composting facility appeared effective for the reduction of aldehydes, ketones but appeared week for the reduction of aldehydes. Although scrubbing tower and bio-filter could reduce 7 times of odor level, the outlet gases had odor dillution ratio of 3000, which exceed the allowable levels of Korean guideline by 6 times.

Volatile fatty acids (VFAs) are malodor compounds which are produced from the decomposition of animal or plant species. It is very difficult to detect VFAs due to their strong adsorptive properties. In this study we develop an analytical method using headspace-GC/FID with an alkali-impregnated filter sampling. The addition of NaCl and H₂S0₄ makes the salt-out and pH-lowering effect, respectively. The high boiling points (141~185℃) and vapor pressures require a high temperature and long heating time for the standard sample in vials to reach an equilibrium. The analytical response was highest when the absolute quantity in the sample was 5 mL in a 22 mL vial. The addition of NaCl for the salt-out effect can give a higher sensitiviry by a factor of 1.1~4.2 than that of Na₂SO₄. The mass amount of 4.6 g of NaCl can result in a higher sensitivity, which is higher than the supersaturated solubility of 4.2 g. The concentration of H₂SO₄ is as low as 2% (v/v). When the concentration range is 8.3 -562.1 ppb, a coefficient of R²~0.99 can be obtained for the five VFAs samples. The analytical errors in a reproducibility test are less than 10% and the detection limit is estimated to be 0.05~0.1 ppb. Our headspace-GC/FID analytical method can be utilized to effectively detect the five kinds of VFAs which shall be restricted in Republic of Korea from the year of 2010.

An analytical method for trimethylamine in ambient air was developed, using headspace gas chromatography with flame ionization detection. Trimethylamine was collected on the acid filter which was impregnated sulfuric aicd in the 47 ㎜ diameter of glass fiber filter. Trimethylamine collected on the acid filter was regenerated in the headspace vial and introduced into the GC analytical column directly. Several parameters such as sample volume, equilibrium temperature and time, and slurry method of filter were optimized to provide maximum detection response. Resolution power also compared according to liquid phase of analytical column. The detection limit of method was 0.13 ppb with 50 L sampling volume. The developed acid filter method is easy to deal with the field sampling and the method was adopted as the standard method for odor analysis in Korea.

In this study, the TVOCs and odor active compounds emitted from 3 PVC and 5 natural wallpapers were analyzed. The emitted odor intensities and characteristics of the wallpapers were estimated using air dilution sensory and direct olfactory methods. The emissions of TVOCs were measured using the SPME-cryogenic emission test method, which was modified from the RAL-GZ 479 method, which is used in Germany to evaluate the quality of wallpapers. It was found that there was no significant correlation between the emissions of TVOCs and the odor concentration. However, a correlation (0.57) was found between the emitted VOCs and the odor concentration of the low molecular weight compounds, which have strong volatilities, ranging from n-C6 to n-C10. For all 8 wallpapers, vinegar like odor was commonly perceived, with acetic acid identified as the main odor active compound withinthe odor. Benzaldehyde and esters, such as ethyl acrylate and n-butyl acrylate, were identified as odor active compounds, which were expressed as having rubber like smells by the panelists. These results indicate that odor should be included as a domestic regulation for the pollutants emitted from building materials. The identification of odor active compounds emitted from building materials could be useful in the production of eco-environment products.

In this study, alkali impregnated filter sampling method was considered for VFAs in ambient air. When KOH concentration was 0.5 N and sampling flow velocity was 5~10 L/min the sampling efficiency was higher than 90 percent. More than 3 minute shaking make the sampled filter to be suspended in the 22.3 mL Vial. Alkali impregnated filter sampling method showed more than 4 times higher response compared to alkali solution sampling method, when the sample was analysed by headspace-gas chromatography. Five kinds of volatile fatty acids (propionic acid, i-butyric acid, n-butyric acid, i-valeric acid, valeric acid) were detected within 1.0~9.8 ppbv in the cow shed by alkali impregnated filter method and headspace gas chromatography. The alkali impregnated filter method was the most suitable sampling method for ambient volatile fatty acids with headspace gas chromatography analysis.

In this study, we identified the odor active compounds among MVOCs (Microbial Volitile Organic Compounds) emitted from Geotrichum sp. which was previously identified as the main kinds of mold in indoor air. To sample the odor active compounds emitted from Geotrichum sp. while metabolizing, head space-solid phase microextraction (HS-SPME) method, which is well known for sampling odorants, was used. GC/Flame Ionization Detector/Olfactometry was used to identify main odor active compounds. GC/Atomic Emission Detector was used to identify if some compounds had atoms like oxygen, nitrogen, sulfur which are typically found from odorants. GC/Mass Spectrometry was used to identify the odorants. Finally, Retention Index (RI) of each system was verified. In this study, hydrogen sulfide, methanthiol, 1-butanol, carbon disulfide, dimethyl sulfide, dimethyl disulfide, S-methyl thiobutyrate, dimethyl trisulfide, geosmin were identified as MVOCs. Among them, identified main odor active compounds were dimethyl disulfie and dimethyl trisulfide which induce ordure smell and geosmin which induce moldy, earthy smell.