Quantification of a decapeptide anticoagulant in rat and monkey plasma by high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic method was developed to quantify a decapeptide anticoagulant in rat and monkey plasma. The compound and internal standard, a nonapeptide analogue, were extracted from plasma with an amino solid-phase extraction column with an extraction efficiency in the range 75-90%. A C18 analytical column was used to separate the analytes by gradient elution followed by ultraviolet detection at 215 nm. Quantification of the decapeptide over the concentration range 0.1-10.1 micrograms/ml resulted in an assay relative error and relative standard deviation both less than 10%. The anticoagulant decapeptide was stable in both rat and monkey plasma frozen at -20 degrees C.