The total catecholamine content of urine determined chemically by our modification of Euler and Floding's method.
1) The biochemical activity of catecholamine in stored urine was kept up by the addition to the urine of 6N sulfuric acid. This acid, which interferes with subsequent procedures when added in a relatively large amount, was added to the material in a quantity varying in proportion to the age of the child and not exceeding 10 ml.
2) Addition of EDTA (to the material) while catecholamine was being adsorbed to aluminum oxide in it, and washing with aceton under filtration and with chloroform of the material under filtration, facilitated the procedure of condensing and extraction the substance and prevented the appearance, during colorimetry, of a fluorescence from some other substance.
3) 0.1 ml of 0.25% Zinc sulfate used during fluorimetrical determination of Catecholamine contained in a material kept of pH 6.0 stabilized in intensity the fluorescence from the substance.
4) Catecholamine from urine, when preserved in our standard solution-adrenaline, mixed with 0.5 N-sulfuric acid in the ratio of 100 μg/ml and added with a small quantity of EDTA-, remained for a year or more without losing none of its potency.
5) The rate of Catecholamine which was recovered by our procedures was 60% ± 2%-rather low but so constant that 60% was taken as its standard recovery rate.