Development and characterization of a novel semiautomated arrangement for electrochemically assisted injection in combination with capillary electrophoresis time-of-flight mass spectrometry

作者：Palatzky Peter; Matysik Frank Michael^*

来源：Electrophoresis, 2012, 33(17): 2689-2694.

DOI：10.1002/elps.201200088

• Capillary electrophoresis
• Electrochemically assisted injection
• Mass spectrometry
• Mass voltammetry
• Nitroaromatic compounds

Electrochemically assisted injection (EAI) is an attractive injection concept for CE that enables the separation of neutral analytes via electrochemical generation of charged species during the injection process. A new semiautomated EAI configuration was developed and applied in conjunction with CE-MS (EAI-CE-MS). The EAI cell arrangement consists of an integrated buffer reservoir for CEseparations and a compartment holding screen-printed electrodes. A drop of sample solution (50 mu L) was sufficient to cover the three-electrode structures. A piezo motor provided a fast and precise capillary positioning over the screen-printed electrode assembly. Using ferrocene methanol as a model system, the EAI arrangement was characterized regarding coulometric efficiency, precision, and sensitivity of electrospray ionization-time-of-flight-MS. The formation of the cationic oxidation product of ferrocene methanol enhanced the sensitivity of CE-MS determination by two orders of magnitude and the electrochemically formed product showed a migration time corresponding to its individual electrophoretic mobility. Preliminary studies of EAI-CE-MS in the field of the analysis of nitroaromatic compounds were carried out. The formation of corresponding hydroxylamines and amines paved the way for selective and sensitive CE-MS determinations without the need of adding surfactants to the electrophoresis buffer.

• 出版日期2012-9