This study presents the chemical composition (carbonaceous and nitrogenous components) of aerosols (PM_2.5 and PM₁₀) along with stable isotopic composition (δ¹³C and δ¹⁵N) collected during winter and the summer months of 2015–16 to explore the possible sources of aerosols in megacity Delhi, India. The mean concentrations (mean ± standard deviation at 1σ) of PM_2.5 and PM₁₀ were 223 ± 69 µg m⁻³ and 328 ± 65 µg m⁻³, respectively during winter season whereas the mean concentrations of PM_2.5 and PM₁₀ were 147 ± 22 µg m⁻³ and 236 ± 61 µg m⁻³, respectively during summer season. The mean value of δ¹³C (range: − 26.4 to − 23.4‰) and δ¹⁵N (range: 3.3 to 14.4‰) of PM_2.5 were − 25.3 ± 0.5‰ and 8.9 ± 2.1‰, respectively during winter season whereas the mean value of δ¹³C (range: − 26.7 to − 25.3‰) and δ¹⁵N (range: 2.8 to 11.5‰) of PM_2.5 were − 26.1 ± 0.4‰ and 6.4 ± 2.5‰, respectively during the summer season. Comparison of stable C and N isotopic fingerprints of major identical sources suggested that major portion of PM_2.5 and PM₁₀ at Delhi were mainly from fossil fuel combustion (FFC), biomass burning (BB) (C-3 and C-4 type vegitation), secondary aerosols (SAs) and road dust (SD). The correlation analysis of δ¹³C with other C (OC, TC, OC/EC and OC/WSOC) components and δ¹⁵N with other N components (TN, NH₄⁺ and NO₃⁻) are also support the source identification of isotopic signatures.

本研究介绍了2015-16 年冬季和夏季收集的气溶胶（PM _2.5和 PM ₁₀ ）的化学成分（碳质和含氮成分）以及稳定同位素成分（δ ¹³ C 和 δ ¹⁵ N），以探索可能的印度大城市德里的气溶胶来源。冬季PM _2.5和PM ₁₀的平均浓度（平均值±标准差1σ）分别为223 ± 69 µg m ^-3和328 ± 65 µg m ^{-3 ，而PM} _2.5和PM ₁₀的平均浓度为147夏季分别为± 22 µg m ^-3和236 ± 61 µg m ^-3 。冬季PM _2.5的δ ¹³ C（范围：− 26.4 至− 23.4 ‰）和δ ¹⁵ N（范围：3.3 至14.4 ‰）平均值分别为− 25.3 ± 0.5 ‰ 和8.9 ± 2.1 ‰。夏季PM _2.5的δ ¹³ C（范围：− 26.7至− 25.3‰）和δ ¹⁵ N（范围：2.8至11.5‰）平均值分别为− 26.1 ± 0.4 ‰ 和 6.4 ± 2.5 ‰。主要相同来源的稳定 C 和 N 同位素指纹的比较表明，德里的 PM _2.5和 PM ₁₀的大部分主要来自化石燃料燃烧 (FFC)、生物质燃烧 (BB)（C-3 和 C-4 型植被） 、二次气溶胶 (SA) 和道路灰尘 (SD)。 δ ¹³ C 与其他 C（OC、TC、OC/EC 和 OC/WSOC）成分以及 δ ¹⁵ N 与其他 N 成分（TN、NH ₄ ⁺和 NO ₃ ^- ）的相关性分析也支持了来源识别同位素特征。