From Big Medical Encyclopedia

NITROPRUSSIATE REACTION — the chemical change which is the cornerstone of the numerous tests applied to detection of ketone bodies in urine and blood serum, and consisting in formation of complex connections of red-brown color at interaction in alkaline condition of a nitrozogruppa of Sodium nitroprussidum of hl. obr. with acetoacetic acid or acetone (to a lesser extent). Similar connections form with Sodium nitroprussidum and nek-ry amines (e.g., creatinine), however in acid medium amine complexes break up also the coloring caused by them disappears, and coloring of ketonic complexes not only does not disappear, but becomes more intensively.

N.'s use by the river — see. Ketone bodies .

M. G. Uzbekov.