Development of an analytical method for volatile fatty acids (VFFA) in air: Hardship of gaseous VFA analysis and its breakthrough = Development of an analytical method for volatile fatty acids (VFFA) in air: Hardship of gaseous VFA analysis and its breakthrough

다국어 초록 (Multilingual Abstract)

In this research, the experimental feasibility of volatile fatty acids (VFA) analysis is evaluated with respect to alkali absorption method recommended as the official test guideline of the KMOE according to its malodor prevention law. To this end, sampling efficiency of gaseous VFA is first evaluated with respect to the vaporization efficiency in relation to Henry`s law, A number of experimental steps such as absorption of VFA into the solution, extraction of absorbed VFA from solution, and SPME analysis of extracted vapor are all prone to considerable biases, The extent of bias involved in the extraction stage is estimated under the simulated conditions of active purging at two temperature conditions of 25 and 9OoC. The results of computation based on this simulated condition indicated that recovery rate of VFA from absorbed solution can be 1.1% and 30.2% after 1 hour of purging, respectively. This low recovery rate is directly associated with low sensitivity and poor reproducibility. Hence, this official testing method is demonstrated to be prone to various sources of experimental biases. Because of these limitations in VFA analysis, this official KMOE method is not reliable in their quantitation of samples in ambient air. As an alternative tool, we propose the use of the combined approach based on sorbent tube (ST) and thermal desorption (TO). Our research team is going to provide the most accurate and least biased measurement technique based on ST-TO method. As such, the results of our study will provide the most reliable approach to acquire the VFA data under real environmental samples.