基于紫外-可见光吸光度双组分模型评估大气水溶性有机碳含量  

Estimation of atmospheric water-soluble organic carbon content based on a two-component model of UV-vis absorbance

作　　者：何坦 操涛 吴杨 王典 蔡竟 宋建中[1] 曾祥英[1] 于志强[1] HE Tan;CAO Tao;WU Yang;WANG Dian;CAI Jing;SONG Jianzhong;ZENG Xiangying;YU Zhiqiang(State Key Laboratory of Advanced Environmental Technology,Guangdong Key Laboratory of Environment and Resources,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,Guangdong,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院广州地球化学研究所,先进环境装备与污染防治技术全国重点实验室/广东省环境资源利用与保护重点实验室,广东广州510640 [2]中国科学院大学,北京100049

出　　处：《地球化学》2025年第2期167-176,共10页Geochimica

基　　金：国家自然科学基金项目(41977188);广东省“珠江人才”计划本土创新科研团队项目(2017BT01Z134);广东省省级科技计划项目(2023B1212060049)联合资助。

摘　　要：大气水溶性有机碳(WSOC)在大气环境和气候变化中发挥重要作用。本研究将大气WSOC的复杂组成简化为A、B两个组分,构建了一个评估大气WSOC含量的模型。模型假设组分A中的分子具有强吸光性,而组分B中的分子弱吸光或不吸光,且两个组分分别具有唯一且恒定的紫外–可见光(UV-vis)吸收光谱。首先从10个城市大气颗粒物(PM_(2.5))样品中选取部分样品,采用WSOC含量和UV-vis吸光度数据对模型进行参数化,并基于参数化的UV-vis吸光度的双组分模型实现了样品WSOC含量的精准模拟(R^(2)=0.98,P<0.01)。与使用单波长(分别仅使用280 nm或365 nm)回归分析方法模拟大气WSOC含量相比,基于双组分模型的大气WSOC含量的模拟值与实测值之间的相关性分别提升了5%和53%,均方根误差(RMSE)分别降低了21%和71%。进一步使用10个城市的PM_(2.5)样品评估双组分模型,全部样品WSOC含量的计算值与实测值之间的相关系数(R^(2))为0.95(P<0.01),RMSE为0.80 mg/L。与单波长回归分析方法相比,使用双组分模型的大气WSOC含量的计算值与实测值之间的相关性分别提升了4%和28%,RMSE分别降低了13%和48%。总体而言,本研究构建的双组分模型为大气WSOC的定量分析提供了新的方法参考。Atmospheric water-soluble organic carbon(WSOC)plays an important role in the atmospheric environment and climate change.In this study,a model was developed to estimate the atmospheric WSOC content by simplifying the complex composition of the atmospheric WSOC into two components(A and B).The model assumes that molecules in component A exhibit strong ultraviolet-visible light(UV-vis)absorption,while molecules in component B demonstrate weak or negligible absorption,with each component characterized by a unique and constant spectrum.In this study,partial samples were first selected from 10 urban atmospheric particulate matter samples(PM_(2.5)),and then the model was parameterized with WSOC concentrations and corresponding UV-vis spectra of the selected samples.Based on the parameterized two-component model of UV-vis absorbance,an unbiased and accurate simulation of the WSOC content of the selected samples was achieved(R^(2)=0.98,P<0.01).Compared to the regression method fitted to absorbance at 280 nm or 365 nm alone,the correlation between the simulated and measured values of atmospheric WSOC content based on the two-component model improved by 5% and 53%,with root mean square error(RMSE)reduced by 21% and 71%,respectively.The two-component model was further evaluated using PM_(2.5)samples from 10 cities.The correlation between the calculated and measured WSOC contents of all the PM_(2.5)samples was 0.95(P<0.01),with an RMSE of 0.80 mg/L.Compared to the regression method fitted to absorbance at 280 or 365 nm alone,the correlation between the calculated and measured values of atmospheric WSOC content using the two-component model improved by 4% and 28%,respectively,with the RMSE reduced by 13% and 48%,respectively.Overall,the two-component model developed in this study offers a robust and innovative approach for the quantitative analysis of atmospheric WSOC,demonstrating significant improvements over traditional methods.

关 键 词：有机气溶胶 水溶性有机碳 紫外–可见光吸光度 双组分模型 

分 类 号：X142[环境科学与工程—环境科学]