Decrease of the recovery rate of light non-methane hydrocarbons by interference of air oxygen in a measurement of non-methane hydrocarbon concentration under air

Abstract

Non-methane hydrocarbons (NMHC) in the atmosphere are raw materials for photochemical oxidants, and many measurements of the NMHC gases have been performed. The treatment for concentration of the NMHC is required for its measurement. The author has concentrated the NMHC by passing air through a concentration tube containing quartz sand cooled with liquid nitrogen. In this treatment, it was confirmed that the recovery rate of pure air-based NMHC was likely to decrease even if nitrogen-based NMHC could be concentrated with a sufficient (close to 100%) recovery rate depending on experimental conditions for the concentration. Non-methane hydrocarbons (NMHC) in the atmosphere are raw materials for photochemical oxidants, and many measurements of the NMHC gases have been performed. The treatment for concentration of the NMHC is required for its measurement. The author has concentrated the NMHC by passing air through a concentration tube containing quartz sand cooled with liquid nitrogen. In this treatment, it was confirmed that the recovery rate of pure air-based NMHC was likely to decrease even if nitrogen-based NMHC could be concentrated with a sufficient (close to 100%) recovery rate depending on experimental conditions for the concentration.