Automated capillary gas chromatographic assay using nitrogen-phosphorus ionization detection for the determination of...

A highly sensitive and specific capillary gas chromatographic method for the determination of the antianginal drug bepridil in plasma is described. The capillary gas chromatograph and nitrogen-selective detector combination provides excellent sensitivity for clinical samples. The lowest concentration of bepridil which can be measured accurately and precisely in a 1-ml plasma sample is 1 ng/ml. Standard curves are linear over the concentration range 1-60 ng/ml. Accuracy and precision of the assay, expressed as relative deviation from the true value and relative standard deviation (inter-run) are less than 15% at all concentrations in the linear range. No interfering peaks are observed. Using an automatic injector and a laboratory computer system, sixty samples can be analyzed routinely in one day. The present assay has been successfully cross-validated with a published high-performance liquid chromatographic assay.