1. Impact of Thermal Decomposition on Thermal Desorption Instruments: Advantage of Thermogram Analysis for Quantifying Volatility Distributions of Organic Species
- Author
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Reddy L. N. Yatavelli, Joel R. Kimmel, Brett B. Palm, Pedro Campuzano-Jost, John T. Jayne, Douglas A. Day, Jose L. Jimenez, Manjula R. Canagaratna, Weiwei Hu, Jordan E. Krechmer, S. Thompson, Hyungu Kang, Harald Stark, Patrick L. Hayes, and Douglas R. Worsnop
- Subjects
Aerosols ,Chemical ionization ,010504 meteorology & atmospheric sciences ,Chemistry ,Thermal decomposition ,Analytical chemistry ,Thermal desorption ,General Chemistry ,010501 environmental sciences ,Mass spectrometry ,01 natural sciences ,Mass Spectrometry ,Aerosol ,Thermography ,13. Climate action ,Ionization ,Thermal ,Environmental Chemistry ,Organic Chemicals ,Volatilization ,Volatility (chemistry) ,0105 earth and related environmental sciences - Abstract
We present results from a high-resolution chemical ionization time-of-flight mass spectrometer (HRToF-CIMS), operated with two different thermal desorption inlets, designed to characterize the gas and aerosol composition. Data from two field campaigns at forested sites are shown. Particle volatility distributions are estimated using three different methods: thermograms, elemental formulas, and measured partitioning. Thermogram-based results are consistent with those from an aerosol mass spectrometer (AMS) with a thermal denuder, implying that thermal desorption is reproducible across very different experimental setups. Estimated volatilities from the detected elemental formulas are much higher than from thermograms since many of the detected species are thermal decomposition products rather than actual SOA molecules. We show that up to 65% of citric acid decomposes substantially in the FIGAERO–CIMS, with ∼20% of its mass detected as gas-phase CO2, CO, and H2O. Once thermal decomposition effects on the det...
- Published
- 2017
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