Assay of gentamicin in serum by high-pressure liquid chromatography

A procedure is described that uses high-pressure liquid chromatography for assay of gentamicin in serum. The technique involves extraction of gentamicin from serum by using a CM-Sephadex column and analysis by reverse-phase, ion-pair chromatography. Continuous-flow, post-column derivatization with o-phthaladehyde is used to form fluorescent products for detection. The possible scope of this method for analysis of other aminoglycoside antibiotics is illustrated by application to sisomicin and netilmicin.