Determination of formaldehyde by its catalytic influence on the oxidation of substituted p-phenylenediamines by hydrogen peroxide
(EN)
Santiris, N. C.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Santiris, N. C.
(EN)
Two kinetic-spectrophotometric methods for the determination of formaldehyde are presented, based on its ''catalytic'' effect to increase the rate of the oxidation of 2,5-diaminotoluene and 4-aminodiphenylamine by hydrogen peroxide. The effects of factors such as pH, reagents' concentration and temperature are examined. Both methods show good reproducibility and excellent selectivity to formaldehyde against other aldehydes. The detection limits are estimated to be 11 and 50 mu g mL(-1) for the 2,5-diaminotoluene and the 4-aminodiphenylamine methods respectively. Their sensitivities at optimum conditions have been found to be 0.0306 and 0.0181 Amin(-1)mu g(-1)mL respectively which are about the double of the corresponding values for the p-phenylenediamine and N,N-dimethyl-p-phenylenediamine methods, presented in previous work. Furthermore, the proposed methods were applied to the determination of formaldehyde emitted from urea-formaldehyde bonded wood based panels and the results were compared to those obtained from the official pararosanilin method.
(EN)
