Investigation into the Best Available Moisture Pretreatment Approach for the Measurement of Trichloroethylene and Nitrous Oxide Emitted from Semiconductor Industries

In this study, the effects of various moisture pretreatment devices (MPDs) on the analytical process of trichloroethylene (TCE) and nitrous oxide (N2O), which are representative organic and inorganic compounds emitted from semiconductor industries, were investigated. Three types of MPDs—a KPASS (MPD_K), a Nafion™ dryer (MPD_N), and a cooler (MPD_C)—were evaluated for their performance under sample gas conditions of 25 °C and 150 °C at various flow rates. MPD modification was also carried out to improve their performance at high loading capacities. The results indicated that humidity introduced significant bias in the measurement of TCE and N2O according to the analyzers explored in this study. At a flow rate of 1 L/min, among the MPDs, MPD_N exhibited the highest moisture removal efficiency, followed by MPD_K and MPD_C. In terms of analyte recovery rates, MPD_K achieved the highest TCE recovery, followed by MPD_N and MPD_C, across all tested conditions. Conversely, MPD_C resulted in the lowest N2O recovery rates, whereas MPD_K and MPD_N maintained over 95% recovery rates. At a flow rate of 4 L/min, MPD_N and MPD_C did not work at high temperatures. In contrast, the modified MPD_K, which received less investment compared to many other membranes, showed an acceptable moisture removal efficiency (>85%) and analyte recovery (>98%). Therefore, modified KPASS is recommended as a useful moisture pretreatment device for the analytical process of TCE and N2O at both normal and high loading capacities.