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Volume 46, Number 1
(January - February 2001) |
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Volume 46, Number 1
(January - February 2001) |
Spectrophotometric Determination of Ampicillin and Amoxycillin with Ce(IV) and Arsenazo III
by Franciszek Buhl and Barbara Szpikowska-Sroka
Institute of Chemistry, University of Silesia, 9 Szkolna Str., 40-006 Katowice, Poland
Key words: Ce(IV), arsenazo III, spectrophotometry, ampicillin, amoxycillin
A simple and sensitive spectrophotometric method for the determination
of ampicillin and amoxycillin in a system: Ce(IV), reductant, arsenazo
III was carried out. Colorimetric method for the determination of the analyte
is based on reduction of cerium(IV) ions with ampicillin and amoxycillin.
The cerium(III) ions formed were complexed with arsenazo III and spectrophotometrically
determined.Beer`s law is obeyed in the concentration range from 2.5 to
25 mg and from 2 to 10 mg
in 25 ml for ampicillin and amoxicillin respectively. The absorbance was
measured at lmax
= 655 nm at pH 3.2-3.6 in 1 cm cuvettes. The molar absorptivity of the
colour system was found to be 2.7 x 105
l mol-1cm-1
for ampicillin and 5.2 x 105 l mol-1
cm-1 for amoxycillin. The method has been
successfully applied for the determination of ampicillin and amoxycillin
in pharmaceuticals.
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