S. Bessman
1957
Citations
0
Influential Citations
5
Citations
Journal
Methods in Enzymology
Abstract
Publisher Summary Preparation of oxaloacetic acid involve addition of sodium diethyloxalacetate in the disodium ethylenediaminetetraacetate (Na 2 -EDTA). When solution is complete, the mixture is placed in a liter separatory funnel and concentrated sulfuric acid is added dropwise until acid to congo red paper. Diethyloxalacetate separates as a heavy oil. Sufficient ether is added with shaking to bring all the oil into an upper organic phase, and it is then separated. The flask is stoppered and placed in the refrigerator for 7 to 10 days. It should be shaken two or three times daily. The thick crystalline precipitate of oxalacetic acid which forms is collected in a sintered glass funnel and washed with ice-cold HC1. The assay of oxaloacetic acid is complicated by its rapid rate of spontaneous decomposition, which is catalyzed by a multitude of substances, many of which might be present as tissue components. The lability of oxalacetic acid is utilized for its assay, either as evolved CO 2 in the presence of a catalyst or as the dinitrophenylhydrazone of pyruvic acid after catalytic decarboxylation. The two methods can be combined to give an estimate of purity of the compound.