In this paper, the URG's multi-channel sampler and the Aerosol Chemical Speciation Monitor (ACSM) are used for off-line sampling and online monitoring, focusing on the chemical components of atmospheric submicron particles (PM₁) in Beijing in October 2016. It is shown that the average concentration of PM₁ in Beijing during the whole observation periods is 66.04 ±51.45 μg/m³ and the mass concentration of PM₁ in heavy haze (103.16~160.23 μg/m³) is 27.29~45.78 times of that in clean days (3.50~3.78 μg/m³). Significant differences are observed of the chemical components between heavy haze days and clean days in autumn in Beijing. The organic materials are the main chemical components of PM₁, contributing up to 64.90% during the clean days. While the secondary inorganic components increase significantly, reaching as high as 69.72% during the heavy haze days. The diurnal variation of sulfate is relatively small, reflecting the regional characteristics; while other components (organic matter, nitrate, ammonium and chloride) see significant diurnal variations. Overally, the composition of PM₁ is affected by sources of pollution, atmospheric chemical reactions and the weather conditions.

ACSM  /  PM₁  /  chemical components