Chemical properties of aerosols were investigated by analyzing the inorganic water-soluble content in PM2.5 collected in the downtown area of Jeju City in Jeju Island. Due to an increase in both the number of visiting tourists and the size of local population, the number of cars in this area is increasing, causing an increase in PM2.5. Eight PM2.5-bound major inorganic ions were analyzed during the summer and winter periods. The water-soluble inorganic component represents a significant fraction of PM2.5. In particular, secondary inorganic aerosols contribute 36.2% and 47.5% of PM2.5 mass in summer and winter, respectively. Nitrate concentrations increase for [NH4 +]/[SO4 2-]>1.5, and excess ammonium, which is necessary for ammonium nitrate formation, is linearly correlated with nitrate. These results are clearly observed during the winter because conditions are more conducive to the formation of ammonium nitrate. A significant negative correlation between Nitrogen Oxidation Ratio (NOR) and temperature was observed. The obtained results can be useful for a better understanding of the aerosol dynamics in the downtown area in Jeju City.

Abstract
 1. 서 론
 2. 연구 방법
  2.1. 시료채취 지점
  2.2. 시료채취 및 화학 분석
 3. 결과 및 고찰
  3.1. PM2.5에 함유된 이온성분들
  3.2. Sulfate와 Nitrate의 생성
  3.3. 황과 질소의 산화율
 4. 결 론
 REFERENCES

• 이기호(제주대학교 환경공학과) | Ki-Ho Lee (Department of Environmental Engineering, Jeju National University)
• 허철구(제주대학교 환경공학과) | Chul-Goo Hu (Department of Environmental Engineering, Jeju National University) Corresponding author