Measurement of formic acid, acetic acid and hydroxyacetaldehyde, hydrogen peroxide, and methyl peroxide in air by chemical ionization mass spectrometry: airborne method development

Abstract

Abstract. A chemical ionization mass spectrometry (CIMS) method utilizing a reagent gas mixture of O2, CO2, and CH3I in N2 is described and optimized for quantitative gas-phase measurements of hydrogen peroxide (H2O2), methyl peroxide (CH3OOH), formic acid (HCOOH), and the sum of acetic acid (CH3COOH) and hydroxyacetaldehyde (HOCH2CHO; also known as glycolaldehyde). The instrumentation and methodology were designed for airborne in situ field measurements. The CIMS quantification of formic acid, acetic acid, and hydroxyacetaldehyde used I− cluster formation to produce and detect the ion clusters I−(HCOOH), I−(CH3COOH), and I−(HOCH2CHO), respectively. The CIMS also produced and detected I− clusters with hydrogen peroxide and methyl peroxide, I−(H2O2) and I−(CH3OOH), though the sensitivity was lower than with the O2− (CO2) and O2− ion clusters, respectively. For that reason, while the I− peroxide clusters are presented, the focus is on the organic acids. Acetic acid and hydroxyacetaldehyde were found to yield equivalent CIMS responses. They are exact isobaric compounds and indistinguishable in the CIMS used. Consequently, their combined signal is referred to as the acetic acid equivalent sum. Within the resolution of the quadrupole used in the CIMS (1 m∕z), ethanol and 1- and 2-propanol were potential isobaric interferences to the measurement of formic acid and the acetic acid equivalent sum, respectively. The CIMS response to ethanol was 3.3 % that of formic acid and the response to either 1- or 2-propanol was 1 % of the acetic acid response; therefore, the alcohols were not considered to be significant interferences to formic acid or the acetic acid equivalent sum. The multi-reagent ion system was successfully deployed during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) in 2014. The combination of FRAPPÉ and laboratory calibrations allowed for the post-mission quantification of formic acid and the acetic acid equivalent sum observed during the Deep Convective Clouds and Chemistry Experiment in 2012.

Supplementary material to "An ion-neutral model to investigate chemical ionization mass spectrometry analysis of atmospheric molecules – application to a mixed reagent ion system for hydroperoxides and organic acids"

“…We have normalized their predicted sensitivities to − ( ) and the relative sensitivities are 1.000, 0.034, 0.007, and 0.001for − ( ), − ( ), − ( 2 2 ), and − ( 3 ), respectively. This ranking is consistent with the observations of O'Sullivan et al (2017) in which they noted observing − ( 2 2 ) but not − ( 3 ) clusters with the PCIMS instrument and with Treadaway et al (2017) in which they observed a weak standard addition calibration signal for − ( 3 ) in the laboratory and during FRAPPE (Treadaway et al, 2017;Fig. 3).…”

On the sources and sinks of atmospheric VOCs: An integrated analysis of recent aircraft campaigns over North America

“…We used a source tracer analysis to investigate the likely role of biogenic versus anthropogenic sources in driving model biases for key oxygenated VOCs. Table S1 (O'Sullivan et al, 2018;Treadaway et al, 2018;Lerner et al, 2017;Min et al, 2016;Müller et al, 2016b;Cazorla et al, 2015;Richter et al, 2015;Lee et al, 2014;Müller et al, 2014;Yacovitch et al, 2014;Kaser et al, 2013;DiGangi et al, 2011;Fried et al, 2011;Zheng et al, 2011;Apel et al, 2010;Pollack et al, 2010;St Clair et al, 2010;Weibring et al, 2010;Wooldridge et al, 2010;Gilman et al, 2009;Hottle et al, 2009;Osthoff et al, 2008;de Gouw and Warneke, 2007;Huey, 2007;Kim et al, 2007;Crounse et al, 2006;Slusher et al, 2004;Blake et al, 2003;Schauffler et al, 2003;Wisthaler et al, 2002;Colman et al, 2001;Ryerson et al, 1999;Ryerson et al, 1998;Weinheimer et al, 1994).…”

Analysis of Global Warming Potential in Tofu Industry (Case Study: Industry X, Gresik)

“…The use of these materials can cause the formation of CO2 and CH4 gases. Acetic acid CH3COOH which is oxygenated into volatile organic compounds is found in remote and urban environments in the form of gases and particles [15].…”