Measurement of tropospheric HO2 radical using fluorescence assay by gas expansion with low interferences

An instrument to detect atmospheric HO2 radicals using fluorescence assay by gas expansion (FAGE) technique has been developed. HO2 is measured by reaction with NO to form OH and subsequent detection of OH by laser-induced fluorescence at low pressure. The system performance has been improved by optimizing the expansion distance and pressure, the influence factors of HO2 conversion efficiency are also studied. The interferences of RO2 radicals...