| Title: | Atmospheric Autoxidation of Organophosphate Esters |
| Author(s): | Fu Z; Xie HB; Elm J; Liu Y; Fu Z; Chen J; |
| Address: | "Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China. Department of Chemistry and iClimate, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark. School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "Organophosphate esters (OPEs), widely used as flame retardants and plasticizers, have frequently been identified in the atmosphere. However, their atmospheric fate and toxicity associated with atmospheric transformations are unclear. Here, we performed quantum chemical calculations and computational toxicology to investigate the reaction mechanism of peroxy radicals of OPEs (OPEs-RO(2)(*)), key intermediates in determining the atmospheric chemistry of OPEs, and the toxicity of the reaction products. TMP-RO(2)(*) (R(1)) and TCPP-RO(2)(*) (R(2)) derived from trimethyl phosphate and tris(2-chloroisopropyl) phosphate, respectively, are selected as model systems. The results indicate that R(1) and R(2) can follow an H-shift-driven autoxidation mechanism under low NO concentration ([NO]) conditions, clarifying that RO(2)(*) from esters can follow an autoxidation mechanism. The unexpected autoxidation mechanism can be attributed to the distinct role of the horizontal line (O)(3)P( horizontal lineO) phosphate-ester group in facilitating the H-shift of OPEs-RO(2)(*) from commonly encountered horizontal line OC( horizontal lineO) horizontal line and horizontal line ONO(2) ester groups in the atmosphere. Under high [NO] conditions, NO can mediate the autoxidation mechanism to form organonitrates and alkoxy radical-related products. The products from the autoxidation mechanism have low volatility and aquatic toxicity compared to their corresponding parent compounds. The proposed autoxidation mechanism advances our current understanding of the atmospheric RO(2)(*) chemistry and the environmental risk of OPEs" |
| Keywords: | Atmosphere/chemistry China Environmental Monitoring Esters *Flame Retardants/analysis *Organophosphates Phosphates atmospheric oxidation peroxy radicals (RO2*) quantum chemical calculations secondary organic aerosol (SOA) volatile chemical products (VCPs); |
| Notes: | "MedlineFu, Zihao Xie, Hong-Bin Elm, Jonas Liu, Yang Fu, Zhiqiang Chen, Jingwen eng Research Support, Non-U.S. Gov't 2021/11/19 Environ Sci Technol. 2022 Jun 7; 56(11):6944-6955. doi: 10.1021/acs.est.1c04817. Epub 2021 Nov 18" |
