Jpc-journal of planar chromatography-modern tlc vol:7 issue:5 pages:349-353
A quantitative thin layer chromatographic (TLC) method on silica gel, with dichloromethane - methanol - 25% m/m ammonia (90 + 9 + 1.5, nu/nu) as mobile phase, has been developed for the analysis of bulk erythromycin. Detection by post-chromatographic color reaction was achieved by spraying with 0.15% m/nu xanthydrol in concentrated hydrochloric acid - acetic acid (90 + 7.5) and then heating the plate. Spots were quantitated by scanning at lambda = 525 nm, using troleandomycin as internal standard. The main component, erythromycin A, was separated from all related substances present in commercial samples except erythromycins B and E. Results for some commercial samples obtained by this TLC method correlated well with those obtained by a previously established LC technique. The TLC method separates erythromycin D from erythromycin A; this is not possible by LC. The application of this TLC method to biological samples of erythromycin is also reported.