Observations of nitrated phenols in four sites in North China: Concentrations, source apportionment, and secondary formation

Abstract

Abstract. Samples of fine particulate matters were collected at four sites in North China (urban, rural, and mountain) in summer and winter, and the contents of nine nitrated phenols were quantified in the laboratory with the use of ultra-high-performance liquid chromatography coupled with mass spectrometry. During the sampling periods, the concentrations of particulate nitrated phenols exhibited 20 distinct temporal and spatial variation. On average, the total concentrations of particulate nitrated phenols in urban Ji'nan in the wintertime reached 48.4 ng m -3 , and those in the summertime were 9.8, 5.7, 5.9, and 2.5 ng m -3 in urban Ji'nan, rural Yucheng and Wangdu, and Mt. Tai, respectively. The elevated concentrations of nitrated phenols in wintertime and in urban areas demonstrate the apparent influences from anthropogenic sources. The positive matrix factorization receptor model was then 25 applied to determine the origins of particulate nitrated phenols in North China. The five major source factors were traffic, coal combustion, biomass burning, secondary formation, and aged coal combustion plume. Among them, coal combustion played a vital role, especially at the urban site in the wintertime, with a contribution of around 55%. In the summertime, the observed nitrated phenols were highly influenced by aged coal combustion plumes at all of the sampling sites. Meanwhile, in remote areas,