高浓度磷酸盐缓冲液中多巴胺电化学氧化过程的在线质谱分析  

On-line Analysis of the Electrochemical Oxidation of Dopamine in High Concentration Phosphate Buffer Solution by Electrochemical Mass Spectrometry

作　　者：林嘉美 王昊天 李慧[1] 余振东 宋丽丽[1] 朱玉玲 徐加泉 LIN Jia-mei;WANG Hao-tian;LI Hui;YU Zhen-dong;SONG Li-li;ZHU Yu-ling;XU Jia-quan(Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation,East China University of Technology,Nanchang 330013,China)

机构地区：[1]东华理工大学,江西省质谱科学与仪器重点实验室,江西南昌330013

出　　处：《质谱学报》2024年第1期103-110,I0003,共9页Journal of Chinese Mass Spectrometry Society

基　　金：江西省重点研发计划(20232BBG70004);江西省重点研发计划一般项目(20192BBG70008)。

摘　　要：研究高浓度缓冲盐体系中物质的电化学氧化还原过程,对于准确理解电化学反应机理具有重要意义。本研究研制了一款体积小、性能稳定、结构简单、制作方便的流动电解池,将其与大气压化学电离质谱联用,构建了一种可在线分析高浓度缓冲盐溶液中电化学过程的电化学-质谱分析装置,用于在线、实时研究缓冲盐溶液中多巴胺的电化学氧化过程。结果表明,通过热沉积方式可高效地在线去除缓冲溶液中的无机盐组分,有机组分可经大气压化学电离方式进行离子化,随后进入质谱检测。多巴胺电化学氧化质谱分析结果表明:在0 V氧化电位下,多巴胺不发生氧化,主要获得多巴胺的质子化信号m/z 154[M+H]^(+);当氧化电位为+0.3 V时,除多巴胺的质子化信号外,还可获得多巴胺失去4个e-的氧化产物多巴色素(dopachrome)质子化峰m/z 150[M+H]^(+),以及多巴色素与多巴胺通过分子间氢键形成的加合物信号m/z 303[M+H]^(+);当氧化电位升高至+0.6 V时,氧化产物m/z 150和303的丰度进一步提高。Electrochemical mass spectrometry is an important technique for studying the mechanism of electrochemical reactions.Mass spectrometry has the advantages of high detection sensitivity,high detection throughput and high specificity,which enables simultaneous acquisition of qualitative and quantitative informations for multiple components,making it highly valuable in the monitoring of electrochemical reaction products and the identification of intermediates.In general,electrolyte is necessary for electrochemical reaction.However,these electrolyte salts are detrimental to mass spectrometry analysis as they not only cause condensation in the mass spectrometry inlet,leading to blockage,but also impede the signal of the target analyte or form adduct ions with target analyte,resulting in a complex mass spectrum and increased analytical challenges.It is of great significance to develop a mass spectrometry method to real-time obtain trace organic components in high concentration buffer salt solutions.Therefore,a novel atmospheric pressure chemical ionization mass spectrometry(APCI-MS)method was developed for online analysis of trace organic components in high concentration buffer salt solutions,and a small volume flow electrolytic cell,stable performance,and simple structure were fabricated for on-line electrochemical reaction,which employed Pt,Pt and Ag/AgCl as working electrode,counter electrode and reference electrode,respectively.After combination of the APCI-MS and flow electrolytic cell,an electrochemical mass spectrometry device and method for on-line analysis of the electrochemical process in high concentration buffer salt solutions were constructed.As a proof of concept application,the device and method were used to on-line and real-time study the electrochemical oxidation process of dopamine in phosphate buffer salt solutions.The experimental results showed that the APCI-MS method can efficiently remove the inorganic salts in solutions on-line by on-line thermal deposition,while the organic components can be ioni

关 键 词：高浓度缓冲盐 电化学反应机理 多巴胺 电化学-质谱 

分 类 号：O657.63[理学—分析化学]