Particulate carbon in Los Angeles air

Abstract

A selective combustion method has been applied to the determination of total, organic and elemental particulate carbon in Los Angeles air. Carbon concentrations (10–56 μ m −3) and their temporal variations are presented for multiday smog episodes. Organic carbon/elemental carbon concentration ratios ranged from ∼ 3 during the winter months to ∼ 10 during the smog season. Photochemical production of particulate organic carbon is estimated to be ∼ 76–118 × 10 3 kg/day, as compared to ∼ 31 × 10 3 kg/day from direct emissions. This estimate is also consistent with gas-to-particle conversion considerations for precursor hydrocarbons.