Spin Trapping of Hydroxyl Radical in the Troposphere for Determination by Electron Spin Resonance and Gas Chromatography/Mass Spectrometry

Article abstract of DOI:10.1021/ac00251a015

An airborne sampling system using a spin trapping method has been developed to determine the concentration of hydroxyl radical in the troposphere.Hydroxyl radical was trapped in a α-4-pyridyl-N-tert-butylnitrone α-1-oxide (4-POBN) in situ to form a stable hydroxy adduct of 4-POBN and determined by electron spin resonance (ESR) later in the laboratory.The concentration of hydroxyl radical ranged from less than 5E5 molecules/cm³ at an altitude of 10 km to a maximum of 5E6 molecules/cm³ at an altitude of 6 km at 37<*>N 140<*>E during the period of May 1980 to Feb 1981.The limit of detection of the present system was about 5E5 molecules/cm³ if 200 m³ of air was sampled.The uncertainty of the concentration was estimated to be less than 30percent.