Determination of Trace Formaldehyde in Alcoholic Beverage by Chromotropic Acid Spectrophotometry

A simple spectrophotometric method was developed for the determination of trace formaldehyde in alcoholic beverage samples. The method was based on the reaction between formaldehyde and chromotropic acid in the medium of sulfuric acid and aqueous hydrogen peroxide. The reaction was monitored by measuring the absorbance of the product at 575 nm after 30 min in the boil water bath. A detection limit of 0.033 mugldr mL-1 was achieved. The relative standard deviation for the determination of 0.235 and 1.2 mugldr mL-1 of formaldehyde were 1.95% and 0.93% (n = 5), respectively. The method was found to be sensitive, selective and was applied to the determination of formaldehyde in alcoholic beverage with satisfactory results.