Kinetic spectrophotometric determination of acetaldehyde

A method for determination of trace quantities of acetaldehyde based on its inhibition effect on the malachite green-sulfite reaction is described. Th e reaction is monitored spectrophotometrically by measuring the decrease in absorbance at 613 nm by a fixed time method of 60 seconds. The method allo ws the determination of acetaldehyde in the range of 0.2-10 mu g/ml The lim it of detection was 0.1 mu g/ml and the relative standard deviation for ten determinations of 2 mu g/ml acetaldehyde was 1.8%. The method is applied t o the determination of acetaldehyde in chemical industrial waste water with satisfactory results.