Determination of 2′-acetyl erythromycin and erythromycin in plasma by HPLC using manual and robotic sample preparation

Abstract

A simple and specific HPLC method with coulometric detection was developed for the determination of 2′-acetyl erythromycin and erythromycin in human plasma. Methyl tert-butyl ether was used as the extraction solvent after alkalization of plasma samples. The plasma extracts were chromatographed on a reverse phase column using 4-component mobile phase. The manual sample preparation procedure was modified so that it could also be applied to the robotic system (Zymate™ Laboratory Automation System). The linear range was 0.25–7.0 µg/ml. The quantitation limit for 2′-acetyl erythromycin and erythromycin was 0.05 µg/ml. Equivalent manual and robotic sample preparation methods were used to analyze a large number of plasma samples.