Determination of boronophenylalanine in biological samples using precolumno-phthalaldehyde derivatization and reversed-phase high-performance liquidchromatography

A reversed-phase high-performance liquid chromatographic method for the det ection of boronophenylalanine is described. Determination was obtained by p recolumn reaction of o-phthalaldehyde with a mixture of standard amino acid s containing boronophenylalanine and separating the corresponding o-phthala ldehyde derivatives, using a Kromasil C-18, 250 x 4.6 mm, 5-mu m particle s ize column, a step gradient with two buffers, a flow rate of 1.2 ml/min, a column temperature of 23 degrees C, and fluorimetric detection (excitation and emission wavelengths of 330 and 430 nm, respectively). The use of such a method for assaying boronophenylalanine in biological samples was tested in neutralized perchloric acid blood and cerebral tissue extracts of rats t reated with intracarotid administration of 300 mg/kg of body weight boronop henylalanine. Results of these experiments showed that the present HPLC met hod represents a valid alternative to currently available analytical techni ques for assaying. boronophenylalanine based on boron determination in term s of reproducibility, recovery, or sensitivity. Therefore, it is suggested that the present method may routinely be used in all preclinical and clinic al studies in which quantification of circulating and tissue concentrations of boronophenylalanine is critical for the application of boron neutron ca pture therapy. (C) 2000 Academic Press.