Simple methods for the qualitative identification and quantitative determination of macrolide antibiotics

Pyrolysis—gas chromatography is shown to be a rapid straightforward method for the qualitative differentiation of the macrolide antibiotics erythromycin, oleandomycin, troleandomycin, spiramycin and tylosin. Organic salts do not interfere and identification of erythromycin and troleandomycin in commercial products is viable. Spectrophotometric quantitation of these same five antibiotics after reaction with concentrated sulphuric acid is studied at about 470 nm. Reaction conditions such as acid concentration, time and temperature are provided. The sugar moieties of the antibiotics are proposed as the reactive sites. Detection limits are about 0.2–1.0 ng ml −1 and analysis of pharmaceutical products should be possible.