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Room temperature ionic liquid based carbon paste electrode
|Galyna Shul 1, Ewa A. Rozniecka 1, Marcin Opallo 1, Juliette Sirieix-Plenet 2, Laurent Gaillon 2|
1. Polish Academy of Sciences, Institute of Physical Chemistry, Kasprzaka 44/52, Warszawa 01-224, Poland
The carbon paste electrodes (CPEs) have been employed in a variety of applications such as analysis of numerous organic and inorganic compounds. Typically, the body of CPE is composed of graphite particles and non-conducting non-polar organic liquid like Nujol, silicone oil or high liquid hydrocarbon [1, 2]. One of the way of CPE modification is the dissolution of a redox probe in a binder . Recently, we have presented electroactive CPE prepared with the redox probe solution in the organic polar solvent as the binder . The structure of CPE, where small aggregates of graphite particles and polar organic phase in contact with an aqueous solution, give possibility to formation of three-phase junction: graphite particle / polar solvent / aqueous solution.
We will present new type of elecroactive CPE with conducting binder (room temperature ionic liquid, RTIL). It exhibits electrochemical signal connected with electrode reaction of the redox probe (tert-butylferrocene) dissolved in RTIL. The efficiency of the electrode process is much larger than that of similar CPE modified with the redox probe solution in less viscous organic polar solvent. It could be connected with the presence of conducting organic phase, and as a consequence with the enlargement of reaction zone from the three-phase junction to two-phase junction: graphite particle / RTIL. Moreover, the midpeak potential depends on the hydrophobicity of the anion present in the aqueous solution indicating significant contribution of anion injection into the ionic liquid following the electron transfer. In addition, this electrode exhibits sensitivity towards the concentration of anion in the aqueous phase.
 R. N. Adams, Anal. Chem., 30 (1958) 1576.
Presentation: Short communication at SMCBS'2005 Workshop, by Galyna Shul
See On-line Journal of SMCBS'2005 Workshop
Submitted: 2005-07-27 09:01 Revised: 2009-06-07 00:44