南昌市PM2.5中结合氨基酸的浓度组成及来源

采集了春季南昌市城市和森林地区的大气PM_2.5样品及潜在大气氨基酸排放源（植物和土壤）样品，测定并分析了样品中结合氨基酸（CAAs）的浓度、组成及甘氨酸（Gly）的氮同位素值.结果表明，城市和森林地区PM_2.5中总CAAs的浓度分别为0.507~3.912和0.497~2.647nmol/m³.通过对PM_2.5中CAAs组成占比分析发现，城市和森林地区CAAs组成成分相似，其中Pro、Gly、Ala、Leu和His是PM_2.5中丰富的CAAs物种.结合Gly的氮同位素值可知，城市地区（+0.62‰~+22.67‰）和森林地区（+1.99‰~+23‰） PM_2.5中δ¹⁵N_C-Gly值表现出较大的变化范围.根据大气CAAs潜在排放源δ¹⁵N值清单，本研究中生物质燃烧、土壤源和植物源是PM_2.5中CAAs的主要来源.贝叶斯稳定同位素模型计算源分配结果表明生物质燃烧、土壤源和植物源对城市地区PM_2.5中CAAs的平均贡献为42%、40%和18%，对森林地区PM_2.5中CAAs的平均贡献为38%、38%和24%.

Concentration composition and source of combined amino acids in PM2.5 in Nanchang city

Fine particulate matter (PM_2.5) and potential atmospheric amino acid emission sources (including plants and soil) samples were collected from the urban and forest areas of Nanchang city in spring. The concentration of combined amino acids (CAAs) and the nitrogen isotope of glycine (Gly) were analyzed. The results showed that the concentration of total CAAs ranged from 0.507 to 3.912 and from 0.497 to 2.647 nmol/m³ in the urban and forest areas, respectively. The composition profiles of CAAs in the urban and forest were similar. Among CAAs, Pro, Gly, Ala, Leu and His were the most abundant species in PM_2.5. The δ¹⁵N_C-Glyvalue in PM_2.5 collected in both the urban (ranged from+0.62‰ to +22.67‰) and forest (ranged from +1.99‰ to +23‰) sites exhibited a broad range in this study. According to the δ¹⁵N inventories of potential emission sources of atmospheric combined Gly, biomass burning, soil source and plant source were the main sources of combined Gly in this study. Furthermore, the results of the Bayesian Stable Isotope model showed the biomass burning, soil source and plant source average contributed 42%, 40% and 18% to the total CAAs in PM_2.5 in the urban and contributed 38%, 38% and 24% to the total CAAs in PM_2.5 in the forest site.