The determination of formaldehyde in beer and soft drinks by HPLC of the 2,4-dinitrophenylhydrazone derivative.

A simple procedure was developed for the determination of formaldehyde in samples of beer and soft drinks. A volume of sample was distilled and the aqueous distillate containing the formaldehyde collected directly in a solution of 2,4-dinitrophenylhydrazine. The resulting hydrazone was extracted and analysed by reversed-phase high-performance liquid chromatography with UV absorbance detection. Levels of formaldehyde found were in the low mg/kg range. Detection limits were less than 0.1 mg/kg of sample. Results were confirmed by mass spectrometry (probe) of the derivatives after fraction collection from the HPLC.