A. Afkhami et M. Rezaei, Sensitive spectrophotometric determination of formaldehyde by inhibition of the malachite green-sulfite reaction, MICROCHEM J, 63(2), 1999, pp. 243-249
A simple, sensitive, and selective method for rapid determination of ultrat
race quantities of formaldehyde based on its inhibitory effect on the malac
hite green-sulfite reaction is described. The reaction is monitored spectro
photometrically by measuring the decrease in absorbance at 613 nm at a fixe
d time of 61 s. The method allows the determination of formaldehyde in the
range 14-700 ng/ml. The limit of detection was 7 ng/ml and the relative sta
ndard deviation for 10 determinations of 140 ng/ml formaldehyde was 1.2%. T
he method is applied to the determination of formaldehyde in chemical indus
trial wastewater and phenol formaldehyde resin. (C) 1999 Academic Press.