High performance liquid chromatographic measurement of bisoprolol in plasma

A simple high performance liquid chromatographic method has been devised for the measurement of bisoprolol in plasma or serum. The sample (200 μL) is vortex mixed for 30 s with 2 M Tris solution (50 μL), aqueous internal standard (benzimidazole, 2.0 mg/L, 50 μL) and methyl t‐butyl ether (200 μL). After centrifugation (9950 × g, 2 min), a portion of the resulting extract is analysed on a microparticulate (5 μm) silica column using 1 mM camphorsulphonic acid in methanol as the mobile phase. Detection is by fluorescence at an excitatioh wavelength of 215 nM. The lower limit of accurate measurement for the assay is 10 μ/L (CV% = 8.9, n = 9) with a lower limit of detection of 5 μg/L. There is minimal interference from either commonly prescribed drugs or endogenous compounds.