ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 3, pp. 407!411. + Pleiades Publishing, Ltd., 2008.
Original Russian Text + S.V. Kurbatova, O.V. Kharitonova, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 3, pp. 420!424.
OF SYSTEMS AND PROCESSES
Influence of Eluent Composition on the Retention Factor
of Azoles in Reversed-Phase High-Performance
S. V. Kurbatova and O. V. Kharitonova
Samara State University, Samara, Russia
Received April 18, 2007
Abstract-The linear dependence of the retention factor of indole, imidazole, triazole, and tetrazole deriva-
tives on the acetonitrile content of the mobile phase was studied.
Chemistry of five-membered heterocycles and their
derivatives attracts researchers’ attention mainly due
to their high physiological activity and their use as
models in solving some problems of theoretical organ-
ic chemistry [1, 2]. It is known that many derivatives
of diazoles and triazoles exhibit adrenoblocking,
antimicrobial, and others kinds of pharmacological
activity. In addition, many important natural com-
pounds such as histamine, histidine, allantoin, etc.
contain the imidazole group.
Azoles of various structures are relatively widely
used as models in theoretical determination of the
quantitative structure3property relationships (QSPR)
and quantitative structure3activity relationships
(QSAR) . These compounds show promise in de-
termination of the quantitative structure3retention
factor relationships described in detail in [5, 6]. It
should be noted that the dependence between the
structure and retention factor of nitrogen-containing
heterocycles was studied mainly for gas chromatog-
raphy. At the same time, high-performance liquid
chromatography (HPLC) is a convenient and promis-
ing tool not only for determination of structures and
many physicochemical properties of compounds, but
also in simulation of biochromatographic processes
occurring after introduction of physiologically active
compounds into a living body. In many cases, the
sorption mechanism of the physiological action of
a pharmaceutical or biologically active substance is
suggested. Therefore, determination of sorption prop-
erties of these compounds by chromatographic meth-
ods is of interest. HPLC allows variation of the chro-
matographic conditions, in particular, of the type and
composition of the eluent, in a wide range .
In this study we examined the influence of the
eluent composition on the retention factor of deriva-
tives of nitrogen-containing five-membered hetero-
cycles under conditions of reversed-phase HPLC.
The experiments were performed on a Biotronik
Chromatographic system with a BT 8100 HPLC
Pump and an ultraviolet detector. A 40 150 mm
column was used. Elution was per-
formed in the isocratic mode using an acetonitrile3
water mixture (1 : 1, 5 : 3, and 3 : 1, v/v) as the eluent.
Prior to analysis the eluent was degassed with
a UZDN-2T device and filtered. The flow rate of the
eluent was 0.3 ml min
. Substrate solutions were
prepared by dissolution of dry pure heterocyclic com-
pounds in appropriate solvents. The volume of the
injected sample was 20 ml. Sodium nitrite was used as
The UV detector operated at 254 nm. The analysis
was performed at 20oC.
The retention factor k was calculated by the follow-
k = t<
is the retention time of the examined com-
pound and t
is the retention time of the unsorbable
compound (min) .
Five replicate runs were performed for each point.
It is known that chromatographic retention depends
on many factors. Among them the main factors are