Modified Pisano Method for Estimating Urinary Metanephrines

Abstract The Pisano method [Clin. Chim. Acta 5, 406 (1960)] for estimating urinary metanephrine, used in the screening of hypertensive persons for pheochromocytoma, has been modified by replacing ion-exchange chromatography with differential solvent extraction. An internal standard is incorporated to correct for procedural losses. Interference from some related compounds is negligible. Normal-range values obtained for various age groups by the present method compare well with those obtained by Pisano’s procedure, but are higher than values reported for more specific methods.