P-294 DEVELOPMENT OF AN ION MOBILITY SPECTROMETER FOR REAL-TIME MEASUREMENT OF CHEMICAL SUBSTANCES IN THE WORK ENVIRONMENT

Abstract Introduction For the chemical industry, regulations concerning industrial pollutant emissions are becoming stricter in many countries, and real-time monitoring of such emissions is essential. Concentrations of substances in the work environment may vary by the minute, depending on temperature, wind volume and direction, and environmental conditions at their source, with some substances having transient high concentrations under certain conditions. Methods and results In this study, an ion mobility spectrometer (IMS) was developed to analyze chemical substances at high concentrations. We measured concentrations of chemical substances in real-time by using the IMS in a real work environment. As sample ions are produced by corona discharge in the IMS system, quantitative analyses of chemical substances with a high proton affinity are generally not possible at high concentrations (~1000 ppm). This is because multimeric complexes are generated during the ionization process. We found that calibration curves derived from shifts in nominal arrival-time spectra of chemical substances overlapping with water clusters enable quantitative analysis at high concentrations. The conventional IMS cannot measure chemical substances in a wide range of concentrations in the work environment because the conventional IMS has a narrow quantitative concentration range (less than 2 orders). Discussion and Conclusion In this study, the analysis technique was improved to extend the measurable concentration range. The range of concentrations measurable by IMS was extended using the analysis technique.