摘要
运用紫外光谱滴定技术结合差分光谱与二维相关光谱分析,对溶解性黑炭(DBC)的质子化过程进行定性和定量研究。结果发现:热解温度为280, 360, 440℃的DBC在消光光谱200~250 nm间有特征吸收峰,但DBC特征峰并未随pH变化出现发色团去质子化和结构改变;运用差分光谱分析发现,3个热解温度下DBC均于波长280, 355, 385 nm处形成特征差分吸收峰,且吸收峰强度与H+浓度成正相关(p<0.05);二维紫外相关光谱分析表明,DBC的质子化主要发生于羧基及含酚官能团上。以上结果表明,紫外差分光谱滴定法可以定量分析DBC的质子化,DBC发生质子化的主要位点与腐殖酸类似,均为羧基及酚羟基。
The quantitative and qualitative study of the protonation process of dissolved black carbon(DBC)were carried out by combining ultraviolet(UV)spectral titration technique combining with differential spectroscopy and two-dimensional correlation spectroscopy analysis.It was found that DBC with pyrolysis temperatures of 280,360 and 440°C had characteristic absorption peaks in the extinction spectral range of 200-250 nm,but the characteristic peaks of DBC did not show deprotonation of chromophores and structural changes with pH changes.Differential spectroscopy analysis revealed that the DBC at the three pyrolysis temperatures formed characteristic differential absorption peaks at 280,355 and 385 nm,and the intensity of the absorption peaks was positively correlated with the Ht concentration(p<0.05).Two-dimensional UV correlation spectroscopy showed that the protonation of DBC mainly occurred at the carboxyl group and phenol-containing functional groups.The above results indicated that the UV differential spectroscopy titration method could quantitatively analyze the protonation of DBC,and the main sites of protonation of DBC were carboxyl and phenolic hydroxyl groups,where were similar to those of humic acid.
作者
张竑
穆玉宁
杨晨宇
苏友波
蒋明
张继来
傅开道
张乃明
陈文华
ZHANG Hong;MU Yuning;YANG Chenyu;SU Youbo;JIANG Ming;ZHANG Jilai;FU Kaidao;ZHANG Naiming;CHEN Wenhua(College of Resources and Environment,Yunnan Agricultural University,Kunming 650500,China;Lab of Soil Fertilization and Pollution Remediation Engineering,Yunnan Province,Kunming 650201,China;Institute of International Rivers and Ecological Security,Yunnan University,Kun-ming 650091,China;School of Resources and Environment,Baoshan University,Baoshan 678000,China)
出处
《分析试验室》
EI
CAS
CSCD
北大核心
2024年第4期469-475,共7页
Chinese Journal of Analysis Laboratory
基金
国家自然科学基金青年项目(42107300)
云南省基础研究专项(202101AU070100)资助。
关键词
生物碳
溶解性黑炭
质子化
紫外吸收光谱
biochar
dissolved black carbon
protonation
ultraviolet absorption spectrum
