Determination of aprotinin by titration with bovine trypsin with end-point detection by high-performance liquid chromatography

Abstract

A method for the determination of aprotinin (bovine pancreatic trypsin inhibitor, BPTI) is described. The procedure involves the formation of the BPTI-trypsin complex in the presence of an excess of BPTI, quantitative separation of the residual BPTI from the mixture by affinity chromatography and identification and evaluation of the residual BPTI by reversed-phase high-performance liquid chromatography. The method is precise with a mean coefficient of variation of 4.0 and 4.3% for intra- and inter-assay runs, respectively, and has a limit of determination of 3.0 µg of aprotinin. The proposed method can be applied to commercial samples, even in very dilute solutions, for the standardisation of aprotinin.