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Updated: May 22, 2026
Production and Measurement of Organic Particulate Matter in the Harvard Environmental Chamber
Published on: November 18, 2018
Identification and Quantification of Isoprene-Derived Organosulfates in Atmospheric PM2.5 Based on Synthetic
Yuhong Zhou1, Yongkang Yang1, Dongjue Dai2
1Rural Environment Protection Engineering & Technology Center of Sichuan Province, College of Environmental Sciences, Sichuan Agricultural University, Chengdu, Sichuan, China.
Rationale:
Isoprene is the volatile precursor contributing the most to global secondary organic aerosols (SOA). 2-Methyltetrols organosulfates (2-MT-OS) and 2-methylglyceric acid organosulfates (2-MG-OS) are two common organic sulfate species formed from photochemical reactions of isoprene. Accurate measurement of isoprene-derived OSs is the basis for determining the formation mechanisms of isoprene-derived SOA and significant for PM2.5 prediction and pollution mitigation.
Methods:
In this work, 2-MT-OS and 2-MG-OS were synthesized. The structure of isomers of 2-MT-OS and 2-MG-OS in ambient aerosols was confirmed based on the spectra analyzed by various instruments. The concentrations of 2-MT-OS and 2-MG-OS in ambient PM2.5 aerosols were measured with ultra-high performance liquid chromatography/electrospray ionization/tandem mass spectrometry (UPLC/ESI/MS/MS).
Results:
The major isomers of 2-MT-OS are 3-methyl-1, 3, 4-trihydroxy-2-sulfate and 2-methyl-1, 3, 4-trihydroxy-2-sulfate. Meanwhile, the major isomer of 2-MG-OS is 2-methyl-2-hydroxypropionic acid-1-sulfate. The concentrations of 2-MT-OS and 2-MG-OS in Wenjiang (Chengdu, China) PM2.5 samples exhibit a strong seasonal variation, reaching their peaks in summer and far higher than in other seasons. The application of synthetic chemicals greatly reduces the analytical errors. The error of the entire analysis process is estimated to be ±14.1%.
Conclusions:
Standard substances are crucial for the quantification of OSs. Enabling the precise measurement of OSs in aerosols provides a critical tool for improving atmospheric models and developing effective strategies to mitigate pollution.
