同轴式电化学电喷雾质谱离子源研究蒽电化学衍生十二胺.pdf

物理化学学报(Whai」
2616
Acta Phys.-Chim.SIin.2012,28(11),2616-2624
November
Article
doi;0.3866/PKU.WHXB201208133
www.whxb.pku.edu.cn
同轴式电化学电喷雾质谱离子源研究蒽电化学行生十二胺
凌星丁传凡
(复旦大学化学系,上海200433)
摘要:提出一种同轴式电化学电喷雾质谱离子源,用于电化学与质谱分析在线联用.离子源结构简单,造价低
廉,容易制作.离子源内的电化学反应器工作在两电极模式,利用自制的悬浮在电喷雾高压上的无线电化学工
作站探制,使用二苯基蒽或三乙胺的乙腈溶液作为分析物,全面测试了离子源的性能,包括电势控制精度、电
化学转化率、响应时间和抗污能力等.测试溶液添加浓度约10 mmol L的银盐作为电解质和去极剂,将溶液
电阻降至250Q,提高了在线联用的电势控制精度.所测二苯基蔥溶液流动时的伏安曲线与常规三电极体系的
循环伏安曲线基本一致.在36uL?min'的流速下,离子源的响应时间不超过5s,三乙胺的电化学转化率高达
77%.利用此离子源,研究了蒽的电化学衍生反应,衍生试剂为十二胺.蔥作为一种非极性物质,不能为常规电
喷雾质谱检测.而利用电化学电喷雾质谱离子源,蔥首先发生电化学氧化反应,进而与衍生试剂作用生成各种
极性物质,被电喷雾质谱检测.依据质谱检测到的主要反应产物的相对分子质量与结构提出了行生反应的机
理,有助于理解蔥的复杂电化学行为
关键词:电化学;电喷雾;质谱;在线联用;衍生
中图分类号:O646
Online Electrochemistry/ Electrospray Mass Spectrometry with a Coaxial
Probe for Investigation of Electrochemical Derivatization of Anthracene
with Dodecylamine
LING Xing
DING Chuan-fan
(Department ofchemistry, Fudan University, Shanghai 200433, P R. China)
Abstract: In the present study, a coaxial probe was used for online electrochemistry/electrospray mass
spectrometry(EC/ES-MS). The probe can be constructed quickly using readily available materials at low
cost. A wireless potentiostat floating at the electrospray high voltage was used to control the probe in a
two-electrode configuration. sing an acetonitrile solution containing diphen anthracene or triethylamine
we examined the performances of the probe, including the accuracy of potential control, the conversion
efficiency, the response time, and the tolerance to fouling. A silver() salt solution(10 mmol. L) in
acetonitrile was used as the electrolyte and depolarizer. This decreased the solution resistance of the
probe to approximately 250 and enabled precise potential control during online operations. Good
correspondence was observed between the hydrodynamic and cyclic voltammograms
diphenylanthracene. At 3.6 ul.min the response time of the probe was as low as 5 s and the conversion
efficiency for triethylamine was 77%. Using the coaxial probe, we investigated the electrochemical
derivat zation of anthracene w t odec lamine. As a non- olar compound, anthracene usually cannot be
detected by ES-MS. However, with the EC/ES-MS the anthracene was first oxidized electrochemically
and then derivatized online by reactions with dodec lamine The derivatization produced polar compounds
Received: April 17, 2012; Revised: August 10, 2012; Published on Web: August 13, 2012
Corresponding author. Email: cfding(fudan.edu. cn; Te]: +86-21-55664549
The project was supported by the National Key Technology R&D Program of China(2009 3 )and China Postdoctoral Sciencc
Foundation (20110490652)
国家科技支撑计划(2009BAK60B03)和中国博土后科学基金(20110490652)资助项目
(C Editorial office of Acta Physico-chimica Sinica