A simple and rapid cleanup of urinary catecholamines is possible by us
e of alumina filled in small plastic pipette tips. The whole isolation
procedure takes only few minutes and in comparison with the classical
''batch'' method is not only more rapid but it offers also higher rec
overies and a better reproducibility. For cleanup of plasma catecholam
ines the liquid-liquid extraction procedure using diphenylborate compl
exation and extraction into organic solvent with quarternary amine has
been simplified by omitting octanol in the organic phase.