Synthetic strategies for oxidation products from biogenic volatile organic compounds in the atmosphere: A review

Volatile organic compounds (VOCs) emitted by biogenic and anthropogenic sources undergo complex reactions with atmospheric oxidants to generate low-volatility organic species that can form secondary organic aerosols (SOA). SOA accounts for up to 80% mass of the tropospheric fine particulate matter and can significantly impact air quality, public health, and climate. Biogenic VOCs (BVOCs) emitted by terrestrial vegetation, including isoprene and terpenes, account for 90% of the global VOC emission and largely contribute to the total SOA budget. However, the formation of SOA from BVOCs is still under active research due to the complex chemistry involved. To accurately identify and quantify the SOA components and elucidate their formation mechanisms, authentic standards are necessary and often need to be synthesized due to their commercial unavailability. This review summarizes the tremendous progress made in synthesizing marker compounds that fingerprint SOA originating from key BVOCs. The up-to-date synthetic procedures in this article are systematically organized by the oxidation reaction pathways of each BVOC. This review demonstrates the importance of organic synthesis in understanding air quality and climate change, and provides future directions to further connect atmospheric sciences with organic chemistry.