Characterization of organic nitrate constituents of secondary organic aerosol (SOA) from nitrate-radical-initiated oxidation of limonene using high-resolution chemical ionization mass spectrometry

Abstract

Abstract. The gas-phase nitrate radical (NO q 3 ) initiated oxidation of limonene can produce organic nitrate species with varying physical properties. Low-volatility products can contribute to secondary organic aerosol (SOA) formation and organic nitrates may serve as a NO x reservoir, which could be especially important in regions with high biogenic emissions. This work presents the measurement results from flow reactor studies on the reaction of NO q 3 with limonene using a High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (HR-ToF-CIMS) combined with a Filter Inlet for Gases and AEROsols (FIGAERO). Major condensed-phase species were compared to those in the Master Chemical Mechanism (MCM) limonene mechanism, and many non-listed species were identified. The volatility properties of the most prevalent organic nitrates in the produced SOA were determined. Analysis of multiple experiments resulted in the identification of several dominant species (including C 10 H 15 NO 6 , C 10 H 17 NO 6 , C 8 H 11 NO 6 , C 10 H 17 NO 7 , and C 9 H 13 NO 7 ) that occurred in the SOA under all conditions considered. Additionally, the formation of dimers was consistently observed and these species resided almost completely in the particle phase. The identities of these species are discussed, and formation mechanisms are proposed. Cluster analysis of the desorption temperatures corresponding to the analyzed particle-phase species yielded at least five distinct groupings based on a combination of molecular weight and desorption profile. Overall, the results indicate that the oxidation of limonene by NO q 3 produces a complex mixture of highly oxygenated monomer and dimer products that contribute to SOA formation.

Organic aerosol source apportionment in Zurich using an extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF-MS) – Part 1: Biogenic influences and day–night chemistry in summer

“…Another major series of compounds in the spectra is found for C 10 H 15 O x N, which can be observed at m/z 268.08 (C 10 H 15 O 6 N), 284.07 (C 10 H 15 O 7 N), 300.07 (C 10 H 15 O 8 N), and 316.06 (C 10 H 15 O 9 N) and contribute 1.6 %, 1.5 %, 1.8 %, and 1.5 %, respectively, to the profile signal, resulting in the highest contributions compared to all the other factors except for C 10 H 15 O 7 N and C 10 H 15 O 8 N, which contribute ∼ 1.3 % and ∼ 1.7 % to the NightSOA2 EESI profile signal (ag s −1 ). These species are consistent with NO 3 oxidation products of atmospherically relevant monoterpenes such as limonene (Faxon et al, 2018).…”

Chemical Composition and Hydrolysis of Organic Nitrate Aerosol Formed from Hydroxyl and Nitrate Radical Oxidation of α-pinene and β-pinene

“…The chemical mechanism used in Browne et al (2013) and Zare et al (2018) are based on the Master Chemical Mechanism (MCM) that is well known in the degradation chemistry of VOC in the gas phase (Jenkin et al, 1997;Saunders et al, 2003). However, the same mechanism performs poorly in regards to the chemical composition of SOA (Faxon et al, 2018) as well as the prediction of SOA formation (Ruggeri et al, 2016;Boyd et al, 2017) when equipped with gasparticle partitioning modules based on the absorptive gas-particle partitioning theory (Pankow, 1994). It is, therefore, reasonable to argue that the chemical composition of pON could greatly differ from that of total ON predicted by the MCM.…”

Chemical Characterization of Secondary Organic Aerosol at a Rural Site in the Southeastern U.S.: Insights from Simultaneous HR-ToF-AMS and FIGAERO-CIMS Measurements

“…The most abundant pON species in NGT-ONRich were C 5 H 9 NO 7 and 10 C 10 H 15 NO 8 , accounting for 7.8 and 3.5 % of pON signals in this factor, respectively. C 10 H 15 NO 8 has been characterized in multiple chamber studies as major products of α-/β-pinene/limonene+NO 3 ⋅ and α-/β-pinene photooxidation with the presence of NO x (Nah et al, 2016;Lee et al, 2016;Faxon et al, 2018;Takeuchi and Ng, 2019). At Yorkville, the majority of C 10 H 15 NO 8 was presented in NGT-ONRich, implying that nocturnal chemistry is its most important source.…”

“…The efficient nocturnal isoprene oxidation is possibly via the reaction with nitrate radicals rather than with ozone (Ng et al, 2008;Brown et al, 2009;Schwantes et al, 2015;Fry et al, 2018). In addition, the recent work by Fry et al (2018) suggested a substantially longer nighttime peroxy radical lifetime in 5 ambient air versus under chamber conditions, which allows for the formation of lower-volatility products and thus higher SOA yields from isoprene nocturnal chemistry.…”