High-pressure liquid chromatographic determination of plasma dobutamine concentrations

A sensitive and specific high-pressure liquid chromatographic method was developed for measuring dobutamine in human plasma samples. Nylidrin is employed as an internal standard. Following extraction and separation on a C18 reversed-phase column, the drug is detected by a fluorescence detector with an excitation wavelength of 195 nm and a 330-nm emission cutoff filter. The retention times of dobutamine and nylidrin are 5.2 and 19.2 min, respectively. The minimum level of sensitivity is 10 ng/ml. Reproducibility was +/- 5% over a 25--300-ng/ml range. Several drugs were screened for possible interference, but none interfered with the dobutamine analysis.