Quantifying the ambient formaldehyde sources utilizing tracers

Formaldehyde(HCHO) is one of the most important intermediate products of atmospheric photochemical reactions in the troposphere, therefore understanding of HCHO sources is essential for effective ozone control measures. The objective of this work is to distinguish between primary and secondary sources of HCHO. Based on about one month of online measurements in winter in Ziyang,Sichuan, the multi-linear regression analysis of ambient concentrations of HCHO and possible tracers(acetonitrile, propane and peroxyacetyl nitrate) was performed. The results show that during winter in Ziyang, biomass burning contributed an average of 53.2% to ambient HCHO levels, while secondary processes contributed about 30.1%, and vehicular sources accounted for 7.1%.