By the Offensive Odor Control Law of Japan, there are method for the measurement of offensive odor substances using the gas chromatograph and method for measurement of odor index regulation using the triangular odor bag method.
In addition, the gas chromatography mass spectrometry-olfactometry and the odor sensor are used in the measurement of the smell in living.
In this paper, it was a summary of the method for measurement of the offensive odor and content about the application of the measurement technology to the smell in living.
With the aim to propose to ISO, international organization for standardization, a new measurement method for determination of hydrogen sulfide and methyl mercaptan to evaluate of the deodorizing fiber was developed using instrumental analysis.
In order to enhance the sensitivity ion chromatography was performed for the solutions obtained by improved air sampling. The quantitative limits for both hydrogen sulfide and methyl mercaptan in the air was found to be 0.005 ppm comparable with those of the conventional sensory test.
There are deodorant textiles with functions to reduce odors in daily life. However it is difficult to evaluate deodorant property accurately because methods for objectively evaluation of deodorant performance have not been standardized. The conventional domestic method for deodorant performance of textile products is a test to detect every single component that consists of the odor. In this work, it reports that we developed a test method to evaluate deodorant property of textile products by using simulated mixing unpleasant odors and the measurement equipment which has metal-oxide semiconductor sensors with different responsive.
In Japan, since 1971, regulation based on the concentration of specified offensive odor substances has been adopted as one of the methods for regulation of offensive odor, and the measurement methods are stipulated in Notification of Ministry of Environment. Meanwhile, various measurement methods, not stipulated in the notification but may have applicability to measuring offensive odor substances, have been developed with recent outstanding progress of measurement technologies. We will introduce measurement methods of component corresponding to offensive odor which have been officially adapted in different fields from the regulation of offensive odor, such as measurement of exhaust gases, indoor environment and working environment.
Thermal desorption-gas chromatography-mass spectrometry/olfactometry (TD-GC-MS/O) is a useful method to specify odor compounds in the complex odor. However, a number of odor compounds are chemically unstable, odor quality often changes by thermal decomposition and/or oxidation of the odor compounds in multistep analytical procedures. In this work, to minimize the change in odor quality, 3 steps of test methods were examined; Test 1: Determination of the most appropriate temperature at the thermal desorption process, Test 2: Confirmation of optimal analytical conditions of TD-GC-MS/O, and Test 3: Verification of the detected odors in TD-GC-MS/O analysis. To achieve these test methods, the specific odor of new Tenax TA porous polymer beads produced by heating at 280°C(Tenax TA odor) was used along with Carbotrap300 adsorbent. Both the most appropriate temperature at the thermal desorption process and the maximum temperature in the instrument were estimated to be 250°C by Test 1 and 2. Under the optimized conditions, twelve element odor compounds in Tenax TA odor were specified by three panels using TD-GC-MS/O, among which seven odor compounds were identified by mass spectrum. These results demonstrated that the 3 steps of the proposed test methods were suitable for the optimization of TD-GC-MS/O analytical conditions.
Among researchers of human olfaction, there is no consensus definition of adaptation yet, because few studies have clearly defined the time-course transition of perceived intensity regarded as adaptation. In order to address this situation, we defined adaptation as a situation in which perceived intensity decreases exponentially with the passage of time. In this study, we performed real-time evaluation of perceived intensity of continuously presented odors, using nine odorants. In order to develop a quantitative method for classifying perceived-intensity curves as ‘adaptation’ or ‘non-adaptation’, each perceived-intensity curve was approximated by an exponential model. We classified perceived-intensity curves as ‘adaptation’, if they fulfilled the following two criteria : (1) theoretical values of perceived intensity correlated strongly with measured values of perceived intensity, and (2) theoretical values of perceived intensity decreased below the detection threshold during odor presentation. Furthermore, we calculated the ratio of the numbers of ‘adaptation’ and ‘non-adaptation’ perceived-intensity curves, for each odor. We called this value the ‘adaptation index’, and proposed it as a quantitative index of the facility with which adaptation to each continuously presented odor occurs.