Carbonates cause large uncertainties in determining the concentrations of organic carbon (OC) and elemental carbon (EC), as well as EC’s light absorption characteristics, in arid locations, such as Central Asia. To investigate this influence, a comparison between acid (HCl)-treated and original total suspended particle (TSP) samples was conducted in Dushanbe, Tajikistan. According to the results, the OC and EC concentrations were overestimated by approximately 22.8 ± 33.8 and 32.5 ± 33.5%, with the actual values being 11.9 ± 3.0 and 5.13 ± 2.24 μg m^–3, respectively. It was found that carbonates had a larger influence from May to October than during the other months, which was significantly correlated with the amount of TSPs on the filter. Furthermore, the mass absorption cross-section of EC (MAC_EC) increased from 4.52 ± 1.32 to 6.02 ± 1.49 m² g^–1; this indicated that carbonates can significantly decrease MAC_EC, thus causing an underestimation of approximately 23.9 ± 16.7%. This is the first study that quantifies the influence of carbonates on the light-absorbing abilities of EC.

中文翻译：

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碳酸盐对测定有机碳和黑碳的重大影响：以中亚塔吉克斯坦为例

碳酸盐在确定干旱地区（例如中亚）的有机碳（OC）和元素碳（EC）的浓度以及EC的光吸收特性方面引起很大的不确定性。为了研究这种影响，在塔吉克斯坦杜尚别进行了酸（HCl）处理和原始总悬浮颗粒（TSP）样品之间的比较。根据结果​​，OC和EC浓度被高估了约22.8±33.8和32.5±33.5％，实际值分别为11.9±3.0和5.13±2.24μgm ^–3。发现碳酸盐在5月至10月的影响大于其他几个月，这与过滤器上TSP的含量显着相关。此外，EC（MAC _EC）从4.52±1.32增加到6.02±1.49 m ² g ^–1；这表明碳酸盐可以显着降低MAC _EC，从而导致低估约23.9±16.7％。这是第一个量化碳酸盐对EC的光吸收能力的影响的研究。