1070-4272/05/7804-0606 + 2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 4, 2005, pp. 606!608. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 4, 2005,
Original Russian Text Copyright + 2005 by Alekseev, Nersesova, Khalyapina.
AND INDUSTRIAL ORGANIC CHEMISTRY
Determination of Benzylpenicillin, Ampicillin, and Carbenicillin
by Paper Chromatography
V. G. Alekseev, A. F. Nersesova, and Ya. M. Khalyapina
Tver State University, Tver, Russia
Received June 16, 2004
Abstract-A mobile phase was developed for selective determination of benzylpenicillin, carbenicillin,
and ampicillin in drugs by paper chromatography.
Antibiotics of the penicillin group are widely used
in the medical practice for treatment of infectious dis-
eases. Numerous agents of this group are used today
[1, 2]. The molecular structures of penicillins are as
follows [3, 4]:
where R = PhCH
(carbenicillin), or PhCH(NH
These antibiotics significantly differ in perfor-
mance, spectrum of the antimicrobial effect, and price.
In particular, carbenicillin (CC) differing from benz-
ylpenicillin (BP) only in the presence of one more
carboxy group is 9310 times more expensive than BP.
Thus, a risk arises that an expensive drug can be adul-
terated by replacement with a cheaper drug of the same
group. In this case, the drug identification is of crucial
importance [5, 6]. Therefore, an urgent problem is the
development of selective methods for analysis of anti-
biotics, as their adulteration is more frequent . Ti-
trimetric [8, 9], spectrophotometric , and
ionometric (with membrane ion-selective electrodes
[14, 15] and biosensors ) methods, as well as flow
injection analysis , can be successfully used for
quantitative determination of penicillin of a known
chemical structure, but are unsuitable for identifica-
tion of particular penicillins. According to recent stud-
ies, high-performance liquid chromatography (HPLC)
can be successfully used for selective determination
of penicillins [18, 19]. However, this procedure re-
quires expensive apparatus. Thin-layer chromatography
(TLC) and paper chromatography (PC) are simpler but
also efficient methods; they are widely used in the
analytical chemistry of drugs .
The possibility of using TLC and PC for the deter-
mination of penicillins was examined in numerous
studies . As eluents were used alcohols, ethers,
esters, ketones, and their mixtures with addition of
acetic or formic acid, or of aqueous buffer solutions
(phosphate, carbonate, citrate). It should be noted,
however, that many studies were performed with out-
dated drugs (heptylpenicillin, propionylpenicillin, eth-
ylmercaptomethylpenicillin, etc.). Furthermore, the re-
sults obtained by different authors are inconsistent and
sometimes even contradictory.
The goal of this study was to develop a procedure
for qualitative determination of three penicillin drugs
widely used today: BP, ampicillin (AP), and CC, us-
ing such a simple and cheap method as paper chro-
Experiments were performed with antibiotics in the
form of powders in vials: benzylpenicillin sodium salt
(Biokhimik, Saransk, Mordovia, Russia), ampicillin
sodium salt (Krasfarma, Krasnoyarsk, Russia), and
carbenicillin disodium salt (Ferane, Moscow, Russia).
Acetone, ethanol, 2-propanol, 1-butanol, diethyl ether,
ethyl acetate, carbon tetrachloride, chloroacetic acid,
and crystalline iodine were of analyticaly pure grade.
Borate buffer solution (pH 9.18), a 0.01 M solution
of sodium tetraborate, was prepared from a reference