Measurements of Low Molecular Weight Carboxylic Acids during the Southern California Air Quality Study

摘要

The report describes measurements of ambient levels of gas phase and particulate phase formic acid and acetic acid obtained during the South Coast Air Quality Study (SCAQS) at the Claremont site (summer 1987) and the Long Beach site (summer and winter 1987). Samples were collected using alkaline cartridges, water impingers and Teflon filters, and were analyzed by size exclusion liquid chromatography with ultraviolet detection. Gas phase concentrations of formic and acetic acid were in the range 0-20 and 0-18 ppb, respectively, with substantial diurnal (both sites), seasonal and spatial variations. Acetic acid to formic acid concentration ratios also varied with time and location. Gas phase concentrations measured with water impingers were lower than those measured with alkaline cartridges, and possible reasons for the differences are discussed in the report.