A year-round observation of the free amino acids (FAA) and combined amino acids (CAA) in coarse and fine aerosols were conducted at an urban site in Japan. The averaged concentrations of the total FAA and total CAA measured in this study were 149.9 and 237.6 pmolN m⁻³, respectively, in coarse aerosols, and 177.9 and 562.2 pmolN m⁻³, respectively, in fine aerosols. The concentrations of the total CAA were higher than those of the total FAA in both mode ranges. The CAA were mainly partitioned into the fine-mode range, whereas the FAA were contained in both mode ranges with a similar concentration level. Only 8.1% of the water-soluble organic nitrogen (WSON) in fine aerosols was explained by these amino acids, although a significant contribution (26.4%) of them to the WSON was found in coarse aerosols. Correlation and factor analyses including these amino acids and other chemical species in the aerosols and gas phase were conducted to discuss potential sources of these amino acids. Plant debris and their associated materials, sea-salt, and Asian dust particles would be important potential sources of the coarse-mode FAA. The most dominant FAA in coarse aerosols was serine that is considered to be derived from sea-salt and Asian dust particles, whereas the other major FAA in coarse aerosols would be from plant debris and associated materials. The coarse-mode CAA can be also considered to be mainly from plant debris and associated materials. Glutamic acid and aspartic acid were dominant in the coarse-mode CAA, and estimated to be from these sources. Significant parts of the fine-mode FAA would be derived from the photochemical aging of the fine-mode CAA in polluted air masses from the Asian continent. Glycine and arginine were dominant in the fine-mode FAA, and estimated to be from the photochemical aging process. The fine-mode CAA is considered to be mainly from both the fossil fuel and biomass burning particles from both the Asian continental and local sources. Glutamic acid and glycine were dominant in the fine-mode CAA, and would be mainly from these sources, especially the Asian continental sources. Serine that is the most dominant compound in the fine-mode CAA, however, is considered to be derived from other unidentified sources.

在日本的一个城市地点对粗气溶胶和细气溶胶中的游离氨基酸 (FAA) 和结合氨基酸 (CAA) 进行了全年观察。本研究中测量的总 FAA 和总 CAA 的平均浓度分别为 149.9 和 237.6 pmolN m ^-3，在粗气溶胶中，以及 177.9 和 562.2 pmolN m ^-3，分别在细气溶胶中。在两种模式范围内，总 CAA 的浓度均高于总 FAA 的浓度。CAA 主要分为精细模式范围，而 FAA 包含在具有相似浓度水平的两个模式范围内。在细气溶胶中只有 8.1% 的水溶性有机氮 (WSON) 可以用这些氨基酸来解释，尽管在粗气溶胶中发现了其中对 WSON 的显着贡献 (26.4%)。进行了包括这些氨基酸和气溶胶和气相中的其他化学物质的相关性和因素分析，以讨论这些氨基酸的潜在来源。植物残骸及其相关材料、海盐和亚洲尘埃颗粒将是粗模式 FAA 的重要潜在来源。粗气溶胶中最主要的 FAA 是丝氨酸，它被认为来自海盐和亚洲尘埃颗粒，而粗气溶胶中的其他主要 FAA 将来自植物碎片和相关材料。也可以认为粗模式 CAA 主要来自植物碎片和相关材料。谷氨酸和天冬氨酸在粗模式 CAA 中占主导地位，估计来自这些来源。细模式FAA的重要部分将来自亚洲大陆污染气团中细模式CAA的光化学老化。甘氨酸和精氨酸在精细模式 FAA 中占主导地位，估计来自光化学老化过程。精细模式 CAA 被认为主要来自亚洲大陆和本地来源的化石燃料和生物质燃烧颗粒。谷氨酸和甘氨酸在精细模式CAA中占主导地位，并且主要来自这些来源，特别是亚洲大陆来源。然而，作为精细模式 CAA 中最主要的化合物丝氨酸被认为来自其他不明来源。