OH- radical reactivity with total volatile org. compds. (VOC), SkVOC[VOC], is directly obtained in the planetary boundary layer (PBL). A method is based on a perturbation technique where high initial OH- concns. are created by flash photolysis of O3 and subsequent reaction of O(1D) with H2O. Laser-induced fluorescence measures residual OH- concn. at different time delays after the perturbation (
,