Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 4, pp. 620−627.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © L.G. Shaidarova, A.V. Gedmina, I.A. Chelnokova, G.K. Budnikov, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84,
No. 4, pp. 582−590.
OF SYSTEMS AND PROCESSES
Selective Determination of Paracetamol and Acetylsalicylic Acid
on Electrode Modiﬁ ed with a Mixed-Valent Film
of Ruthenium Oxide–Ruthenium Cyanide
L. G. Shaidarova, A. V. Gedmina, I. A. Chelnokova,
and G. K. Budnikov
Kazan State University, Kazan, Tatarstan, Russia
Received April 16, 2010
Abstract—Catalytic activity exhibited by a mixed-valent ﬁ lm of ruthenium oxide– ruthenium cyanide deposited
on the surface of a glassy-carbon electrode in electrooxidation of paracetamol and acetylsalicylic acid was used
to develop a high-sensitivity selective method for determination of these compounds in the case of their joint
presence under ﬂ ow-injection conditions.
Because of the increased amount of pharmaceutical
preparations containing paracetamol (PC, N-(4-
hydrophenyl)acetamide and acetylsalicylic acid (AC,
2-acetyloxybenzoic acid) and threat of their falsiﬁ cation,
development and implementation of new, more perfect
and rapid methods for determination of these organic
compounds is an important and topical task.
PC and AC are commonly determined by various
methods, such as titrimetry, spectrophotometry,
voltammetry, and high-performance liquid chromato-
graphy [1–5]. Most of these techniques are complicate
by the necessary sample preparation and include
extraction or a preceding chemical reaction. The results
obtained when determining PC by the titrimetric and
spectrophotometric methods are affected by presence
of ascorbic or acetylsalicylic acid in a medicinal
preparation, which impairs the metrological
characteristics of determination in their joint presence.
Use of direct voltammetric methods for determination
of PC and AC on metallic and graphite electrodes is
hindered by the lacking reproducibility of their results.
In addition, determination of simultaneously present PC
and AC by voltammetry is hindered by the fact that their
electrooxidation potentials are close. Use of chemically
modiﬁ ed electrodes (CMEs), including those operating
on electrocatalysis principles, makes it possible to
overcome these difﬁ culties. As immobilized catalysts
for determination of PC and AC are commonly used
boron-doped diamond , nanoparticles of gold  and
nickel oxide , metal-polymeric ﬁ lms , and carbon
nanotubes . However, use of CMEs fails to always
improve the reproducibility of the analytical signal.
Combination of voltammetry on CMEs and ﬂ ow-
through methods of analysis frequently improves the
metrological characteristics of determination of organic
We studied the electrooxidation of PC and AC on
a glassy carbon (GC) electrode covered with an inorganic
ﬁ lm of a mixed-valent ruthenium oxide–ruthenium
cyanide (RuO–RuCN) and developed a selective method
for determination of PC and AC on a modiﬁ ed electrode
of this kind under conditions of a ﬂ ow-injection analysis
We recorded cyclic voltammograms using a PI-50-
1.1 potentiostat with a PU-1 programming unit in a three-