Determination of formaldehyde in fresh and retail milk by liquid column chromatography

A quantitative method is described for the determination of formaldehyde (CH2O) in milk by liquid chromatography. Aldehyde derivatization-extraction was carried out in situ with 2,4-dinitrophenylhydrazine in 2-phase reaction medium. Average recovery of added CH2O (0.1 microgram/mL) was 89.9 +/- 3.9% with an estimated detection limit of 0.009 mg/kg. The technique was used for the determination of CH2O in commercial 2% milk and in fresh milk of cows fed on a typical North American dairy diet. The average concentrations of CH2O in fresh and commercial milk were 0.027 and 0.164 mg/kg, respectively. Several methods for CH2O determination in milk are compared.