Spectrophotometric determination of acetone using vanillin.

A sensitive method is described for the spectrophotometric determination of acetone in water. Acetone reacts with vanillin in alkaline medium forming a yellow-orange dye with an absorption maximum at 430 nm. Beer's law is obeyed in the range from 0.5 to 5 p.p.m. of acetone in water. Molar absorptivity and Sandell's sensitivity were found to be 11.0 x 10(3) +/- 100 l mol-1 cm-1 and 0.005 micrograms cm-2, respectively. The important parameters for complete colour development were optimised and the method was used for the determination of acetone in biological samples. The method was also applied successfully to the determination of acetone in air after absorption in sodium hydrogen sulphite solution.