루미놀 반응을 이용한 NO2 고속측정장비 개발 및 평가

Abstract

Recently, aircraft observations play an important role in monitoring of NO2 emissions and spatial distributions using fast response instruments with laser optics or mass spectrometry. These research-grade instruments have great advantages, such as low detection limits and fast sampling frequencies. However, they require a great amount of space and electrical power to use in an aircraft. We developed and tested a small-size airborne NO2 sensing instrument based on luminol chemiluminescence detection (LCD). We found that NO2 detection limit of LCD was 70 pptv in 1 Hz sampling rate and decreased to 20 pptv in two-minute averaging interval, which is suitable for aircraft measurement. Although photon yields of NO2 with luminol were 20 times larger than that of O3, O3 interference must be counted before determining ambient NO2 concentrations, especially in the background air where O3 concentrations are much higher than NO2. NO2 measurement with LCD on the small research aircraft (KingAir-C90GT) was conducted over the industrial areas in Chungnam Province, Korea on Apr 15th, 2022. Comparison of NO2 observed by LCD and a commercial Cavity Attenuated Phase Shift (CAPS) instrument showed that LCD was capable to trace NO2 plumes in more details from multiple NO2 point sources.