The determination of aminoglycoside antibiotics in serum: a comparison of a high performance liquid chromatographic method with a microbiological assay.

A high performance liquid chromatographic (HPLC) method for the determination of gentamicin and tobramycin in serum is compared with a microbiological method. The determination of gentamicin by chromatographic methods is complicated by the fact that gentamicin is a mixture of related compounds, giving rise to several chromatographic peaks. Good results were obtained when the sum of the peak heights of the chromatographic peaks corresponding with the gentamicin components are taken as a measure for the gentamicin concentration. Accuracy, precision and selectivity of the methods are discussed.