Determination of chloramphenicol in pharmaceutical preparations by the cadmium ion-selective electrode, spectrophotometry and atomic-absorption spectrometry.
New simple methods are described for the determination of chloramphenicol and its esters in pure powders, suppositories, injections, eye-drops, capsules and oral suspensions. These are based on reduction with cadmium metal whereby 6 equivalents of cadmium ions per mole and the corresponding amino-derivative are released. Four portions of the reduction products are used for (i) measurement of the cadmium ions by atomic-absorption spectrometry at 228.8 nm; (ii) potentiometric titration with EDTA, with use of the cadmium ion-selective electrode; (iii) visual titration with EDTA, with Eriochrome Black T as indicator, (iv) diazotization and coupling with N-(1-naphthyl)ethylenediamine and measuring the resultant colour at 550 nm. The results obtained by these procedures are in good agreement, and compare favourably with those of the official methods.
Hassan
S S
SS
Research Microanalytical Laboratory, Department of Chemistry, Faculty of Science, Ain Shams University, Cairo, Egypt.
Eldesouki
M H
MH