Intercomparison of the measurements of oxalic acid in aerosols by gas chromatography and ion chromatography

Abstract

Oxalate, the anion of oxalic acid, is one of the most abundant measurable organic species in atmospheric aerosols. Traditionally, this bifunctional species has been measured by gas chromatography (GC) after derivatization to butyl ester and by ion chromatography (IC) without derivatization. However, there are few published comparisons of the two techniques.Here, we report the results of an intercomparison study for the measurement of oxalic acid in Arctic aerosols (< 2.5 µm, n=82) collected in 1992 using GC and IC. The concentrations of oxalic acid by GC ranged from 6.5-59.1 ng m -3 (av. 26.0 ng m -3 , median 26.2 ng m -3 ) whereas those by IC ranged from 6.6-52.1 ng m -3 (av. 26.6 ng m -3 , median 25.4 ng m -3 ). They showed a good correlation (r=0.84) with a slope of 0.96. Thus, observations of oxalate obtained by GC employing dibutyl esters are almost equal to those by IC. Because the accuracy of oxalic acid by GC method largely depends on the method used, it is important to strictly examine the recovery in each study.

Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain

“…Although we did not measure organic acids in aerosol, the presence of oxalic acid and other low-molecular-weight dicarboxylic acids in aerosols is often reported (e.g. Hsieh et al, 2007;Kawamura et al, 2010Kawamura et al, , 2013Sauerwein and Chan, 2017). There is no doubt that there is a significant amount of dicarboxylic acid over the NCP particularly during summer (Kawamura et al, 2013).…”

Hygroscopic properties of oxalic acid and atmospherically relevant oxalates

“…Due to their strong hydrophilic and hygroscopic properties, dicarboxylic acids are able to reduce the surface tension of cloud condensation nuclei, which consequently affects the cloud formation and the global radiation balance (Kerminen et al, 2000;Kumar et al, 2003;Prenni et al, 2001;Yu, 2000). Oxalic acid (H 2 C 2 O 4 ) is the most abundant contributor to the total dicarboxylic acid mass in ambient organic aerosol particles, and has been detected in aqueous phases (fog, cloud, and precipitation) and particulate phases (Chebbi and Carlier, 1996;Hsieh et al, 2007;Kerminen et al, 2000;Kawamura et al, 2010;Mochida et al, 2003a;Yang and Yu, 2008;Yao et al, 2002;Yu, 2000). The primary sources of H 2 C 2 O 4 include fossil fuel combustion, biomass burning, and vehicle exhaust while the secondary formation pathways include photo-oxidation of volatile organic compounds (VOC) in gas-phase, aqueous phase, and heterogeneous processes (Carlton et al, 2007;Chebbi and Carlier, 1996;Ervens et al, 2004;Kawamura et al, 2005;Kundu et al, 2010;Mochida et al, 2003aMochida et al, , 2003bRöhrl and Lammel, 2001;Sorooshian et al, 2006;Wang et al, 2010;Warneck, 2003;Yu, 2000).…”

Contrasting the Effect of Iron Mobilization on Soluble Iron Deposition to the Ocean in the Northern and Southern Hemispheres

“…Organic acids are ubiquitous trace gases in the atmosphere. Low-molecular-weight dicarboxy-lic acids have been detected in aerosols in urban, remote continental, coastal, remote marine, and polar regions (Kawamura et al 2010). Therefore, a large proportion of dissolved iron in aerosols may be organically chelated.…”