Capillary GC Determination of Short-Chain Dicarboxylic Acids in Rain, Fog, and Mist

摘要

A capillary GC and GC-MS method, employing dibutyl esters is described for determining short-chain dicarboxylic acids in rain, fog and mist samples collected in the Los Angeles area. Approximately twenty dicarboxylic acids (C2-C10) were identified in the water samples, includingcis(maleic) andtrans(fumaric) unsaturated, saturated, normal, branched and aromatic. Oxalic acid is the dominant acid, followed by succinic and malonic acids. The total concentrations measured are 2.9#x2013;51#x3BC;M, 64#x2013;66 #x3BC;M and 12 #x3BC;M for rain, fog and mist samples, respectively. These diacids are probably produced by photooxidation of anthropogenic and possibly biogenic organic compounds in the atmosphere.