Gas-liquid chromatographic determination of chloramphenicol in agricultural crops

A method is presented for the gas-liquid chromatographic determination of chloramphenicol in agricultural crops. Chloramphenicol is extracted with ethyl acetate, cleaned up by silicic acid column chromatography, acetylated with acetic anhydride and pyridine, and then measured by gas-liquid chromatography with electron capture detection. Two stationary phases, DEGS + phosphoric acid and Reoplex 400, were used. The sensitivity was ca 8 ng (40% full scale deflection). The efficicency of the analytical method was evaluated by analyzing crops fortified with chloramphenicol. The average recovery ranged from 72% in unpolished rice to 86% in Chinese radishes.