A modified method for the estimation of total carbonyl compounds in heated and frying oils using 2-propanol as a solvent

Abstract  A modified method without using benzene for quantitative determination of total carbonyl compounds in heated and frying fats and oils has been developed. The analysis is done by the reaction of 2,4-dinitrophenylhydrazine (2,4-DNP) with aldehydes and ketones in 2-propanol. The optimal wavelength to determine the total carbonyl compounds is 420 nm where the 2,4-dinitrophenylhydrazone (2,4-DNPH) derivatives from saturated and unsaturated aldehydes and ketones had the same molar absorption coefficient. The modified method for the estimation of total carbonyl compounds in heated and frying oils using 2-propanol instead of benzene as a solvent had a good correlation with the conventional method.