Two reproducible and sensitive liquid chromatographic methods to quantify atenolol and propranolol in human plasma and determination of their associated analytical error functions

Two liquid chromatography (LC) methods with fluorimetric detection have been developed to measure atenolol and propranolol in human plasma. The same 5 μm Nucleosil RP-18 column, extraction procedure and mobile phase (containing acetonitrile, water, triethylamine and phosphoric acid, pH 3) were used. The linearity ranges were 25–800 ng/ml for atenolol and 3.13–100 ng/ml for propranolol. The coefficients of variation for validation assays were lower than 15% at the concentration assayed. The functions of the analytical error were linear: SD (ng/ml)=7.698+0.037C for atenolol and SD (ng/ml)=0.126+0.036C for propranolol.