Amine and guanidine emissions from a boreal forest floor

Abstract

<p><strong>Abstract.</strong> We measured amine and guanidine emission rates from a boreal forest floor in Finland with 1-h time resolution, using an online ion chromatograph (instrument for Measuring AeRosols and Gases in Ambient air – MARGA) coupled with an electrospray ionization-quadrupole mass spectrometer (MS). MARGA-MS was connected to a closed dynamic flow-through poly(methyl methacrylate) chamber. Chamber recovery for the emission measurements was tested semi-quantitatively for monomethyl-, dimethyl- and trimethylamine (MMA, DMA and TMA), and the results were 19 %, 29 % and 24 %, respectively. MMA, DMA and TMA showed maximum emission rates in July, but the highest emission rates for guanidine were in April, when snow was melting. The MMA, DMA and TMA emission rates also clearly varied diurnally, especially in July with maxima at afternoon. Diethylamine (DEA) also showed higher emission rates, with clear diurnal cycles in July. Other amine emission rates were mostly below the detection limits.</p> <p>The temperature dependencies of the emissions were studied, and we noted a correlation between the emission rates and chamber temperature (T<sub>chamber</sub>). Especially in July emission rates of DMA followed T<sub>chamber</sub> measured two hours earlier and guanidine showed a similar pattern. On the other hand, the TMA emission rates correlated with T<sub>chamber</sub> measured at the same time. This could be due to lower vaporizing temperature of TMA. Emission rates of DMA and TMA showed some air temperature (T<sub>air</sub>) dependency, but for MMA dependency was not as clear.</p>

Amine-Enhanced Methanesulfonic Acid-Driven Nucleation: Predictive Model and Cluster Formation Mechanism

“…It deserves mentioning that the amino acids with five to seven C atoms have only been detected in the particle phase . Gaseous Gud and agmatine have been detected in the ambient atmosphere. , Therefore, it is more likely that two guanidino-containing compounds will participate in MSA-driven nucleation, compared to the amino acids with five to seven C atoms. Based on the simplicity and their similarity, Gud (CH 5 N 3 ) was selected to study the nucleation mechanism of the guanidino-containing compounds based on larger cluster sizes up to (Gud) x (MSA) y ( x = 0–4, y = 0–4).…”

Modeling the formation and growth of atmospheric molecular clusters: A review

“…In continental regions, sulfuric acid and water have been definitively established as important components in particle formation (Sipilä et al, 2010). Nitrogen-containing compounds with high basicity such as ammonia (Kirkby et al, 2011;DePalma et al, 2012DePalma et al, , 2014, monoamines (Kurtén et al, 2008;Almeida et al, 2013;Jen et al, 2014;Glasoe et al, 2015), diamines (Jen et al, 2016a;Elm et al, 2016aElm et al, , 2017d and guanidine (Myllys et al, 2018(Myllys et al, , 2019bHemmilä et al, 2020) have been shown to efficiently enhance sulfuric acid based new particle formation provided that they are present at even ppt-level mixing ratios. Carboxylic acids have also been claimed to enhance sulfuric acid based new particle formation (Zhang et al, 2004).…”

Atmospheric Sulfuric Acid–Multi-Base New Particle Formation Revealed through Quantum Chemistry Enhanced by Machine Learning

“…This gas-to-particle conversion is called new particle formation (NPF). Various theoretical and experimental studies have pointed out the exceptional stability of acid–base molecular clusters under atmospheric conditions. − Therefore, NPF modeling and the stability of molecular clusters made of different pairs of acid and base molecules have been extensively investigated: SA–AM, − SA–DMA, ,,,− SA–guanidine, ,− SA–piperazine, various SA–amine and SA–diamine systems, ,,− methanesulfonic acid–AM, phosphoric acid–AM, etc. (see Figure for abbreviations).…”