Chromatography of pyruvic acid and of acetoacetic acid as their 2:4-dinitrophenylhydrazones

Abstract

Paper chromatography of the 2,4-dinitrophenylhydrazone of pyruvic acid shows 2 sharply separated spots with RF values 0.36 (A) and 0.57 (B). Acetoacetic acid dinitrophenylhydrazone has an Rp value of 048 and is only formed in the ordinary analytical procedure when acetoacetic acid is present in high concn. in the blood. In most cases, owing to decomposition, acetone 2,4-dinitrophenylhydrazone with the RF value 0.94 is formed exclusively. Attention is directed to the possibility of error in mistaking the spot B due to pyruvic acid for the spot due to acetoacetic acid.