DETERMINATION OF FORMALDEHYDE, GLYOXAL, GLUTARALDEHYDE, AND o-PHTHALALDEHYDE IN THE PRESENCE OF EACH OTHER IN DISINFECTANTS USING 2,4-DINTROPHENYLHYDRAZINE

Dialdehydes are predominantly used as disinfectants because these compounds exhibit a broad spectrum of antimicrobial activity. Among monoaldehydes, formaldehyde is used to a limited extent due to its higher toxicity. This work describes conditions for the simultaneous derivatization of formaldehyde, glyoxal, glutaraldehyde, and o-phthalaldehyde with 2,4-dinitrophenylhydrazine. The reaction is carried out in an acetonitrile–methanol mixture at 50°C in an ultrasonic bath using trifluoroacetic acid as a catalyst. The best separation of mixture components was achieved on a C18 column in gradient elution mode with acetonitrile and acetate buffer solution (pH 5.4) at a variable flow rate. The linearity range for formaldehyde was 2.51–20.0 mg/L, for glutaraldehyde 4.92–21.9 mg/L, for o-phthalaldehyde 1.98–6.94 mg/L, and for glyoxal 2.00–10.0 mg/L. The limits of detection for formaldehyde, glyoxal, glutaraldehyde, and o-phthalaldehyde were 0.453, 0.177, 0.967, and 0.760 mg/L, respectively. The developed method was successfully applied for the simultaneous determination of aldehydes in disinfectants.