The objective of this project is to integrate various instruments and operation procedures into the mobile laboratory to further enhance its investigation abilities in the event of air pollution, which are often times illusive, abrupt and complex in nature. This project has successfully integrated the following devices: PTR-QMS, PTR-TOF, SCI-TOFMS, ADS-GC/MS, trigger-sampling device, etc., and also has successfully developed procedures to operate the aforementioned instruments, as well as the methods to efficiently analyze field data. To test the mobile laboratory, 5 field tests were conducted in 3 selected industrial parks; they are: Yaoyuan Pingjhen (平鎮) industrial park Shiang-An elementary school (祥安國小), Kaohsiung Linyuan (林園) industrial park Sanwei elementary school (汕尾國小) and Jhong Yun Junior high school (中芸國小), Kaohsiung Linhai (臨海) industrial park Hospitality junior high school (餐旅國中) and Siaogang senior high school (小港高中).
The outcome of the project can be described in two parts. The first part, with the aim to setup the mobile laboratory for rapid deployment in the events of emergency, includes two tasks: (1) literature search and compilation, and (2) method development for the use of the integrated mobile laboratory. The second part, which is to test the mobile laboratory, includes the following two tasks: (1) 5 field measurements in 3 selected industrial parks, and (2) the procedures and knowhow to operate the relevant instruments based on the field campaigns in the past.
Since the core of the mobile laboratory technology is PTR-MS, literature search was mainly focused on the applications of PTR-MS or similar techniques in the subjects of air quality and atmospheric chemistry.
System integration includes PTR-QMS, PTR-TOF, SCI-TOFMS, ADS-GC/MS and trigger-sampling device. They all can be used alone or coupled on the mobile platform, depending on the needs. The PTR-MS technique can detect organic compounds real-time, with superior sensitivity towards alkenes (> C3), aromatics, N-containing compounds, O-containing compounds and organic acids. In addition to PTR-MS, the modified ADS-GC/MS method can complement PTR-MS by analyzing 85 target VOCs within each analysis. The technique of trigger sampling has also been successfully tested by coupling to both types of PTR-MS and an on-line GC. The triggered samples were then returned to the central laboratory to analyze for 108 VOCs by GC/MS/FID. Method development for rapid data analysis includes the snow-ball sampling technique and accurate identification of compounds based on MS data, which have all been sufficiently tested in the field.
For the second part of the project, field campaigns were conducted at 5 sites to capture distinct chemical compounds representative of each industrial park, including one site in the Pingjhen industrial park for pre-testing the mobile lab, and the other 4 sites in two industrial parks in Kaohsiung.
At the Shiang-An elementary school in the Pingjhen industrial park, 19 VOCs were detected. The PTR-QMS also triggered 20 canisters and analyzed by in-lab GC/MS/FID for 108 VOCs. At the Sanwei elementary school near the Linyuan industrial park, 13 VOCs were detected, whose mixing ratios increased whenever the northerly winds prevailed. At the JhungYun elementary school, the SCI-TOFMS monitored the target compounds found at the Sanwei elementary school and observed minor emissions for the target compounds, despite a slight elevated baseline. Nine and 12 VOCs were detected at the Hospitality junior high school and Siaogang senior high school, respectively. Overall, the levels of the observed VOCs were quite low (< 50 ppbv), and the field missions did not observe significant emissions due possibly to terrain and meteorological factors. At the Siaogang senior high school, trigger-sampling using the on-line GC, instead of the PTR-MS, by targeting C3-C5 species led to 3 triggered samples, which were then analyzed by both the ADS-GC/MS and in-lab GC/MS/FID systems for their chemical compositions.
