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As one of the characteristics of traditional food in Beijing, there is a significant difference between roast duck and other foods in the cooking process, in that fruit trees are used as fuel in the former. However, system research about the emission characteristics of this food source has not been done domestically. In order to grasp such food source emission characteristics and provide technical basis for pollution control, we selected the representative roast duck restaurant in Beijing and studied the emission characteristics of atmospheric pollutants in the cooking process of roast duck. The results showed that the emission concentrations of cooking fumes, particulate matter, volatile organic compounds (VOCs), and aldehyde and ketone compounds were (0.74±0.45), (15.32±7.93), (7.60±3.41), and (1.22±0.59) mg·m -3 , respectively. The emission concentration of particulate matter was much higher than that of cooking fumes. The VOC component composition was very complex, containing alkanes, alkenes, aromatic hydrocarbons, and oxygen VOCs, such as aldehydes, ketones, alcohols, ester compounds, and halogenated hydrocarbons, with the highest concentrations of 3-methylfuran, ethanol, and methyl acetate. The main components of aldehyde and ketone compounds were acetaldehyde, formaldehyde, and acrolein, of which C1-C3 compounds were 72.27%.

The mass concentration of PM₂.₅ associated with its online and off-line water-soluble ions were obtained during 2014- 10- 2014-11. Secondary inorganic species NO₃⁻, SO₄²⁻ and NH₄⁺ were the major components of PM₂.₅ during different observation periods. The total concentration of NO₃⁻, SO₄²⁻ and NH₄⁺ was (26.8 ± 22.5) µg · m⁻³, which contributed (41.7 ± 8.5)% to PM₂.₅. The concentration of NO₃⁻ was higher than those of others and contributed most to PM₂.₅. The ions of NO₃⁻, SO₄²⁻ NH₄⁺ and Cl⁻ all showed three different periods during 2014 Beijing APEC, besides the different meteorological condition, the cumulative effect caused by local emissions and regional pollution could also not be ignored. Although the characteristics of water-soluble ions was different during different observation periods, there was no obvious acidification of PM₂.₅ in Beijing at the end of autumn and beginning of winter.