The catalytic kinetic method for the determination of trace formaldehyde (FA) base on a bromate-eosin Y system

A new simple and highly sensitive catalytic kinetic method for the determination of trace amount of FA in food sample has been established. The method was based on the catalytic effect of FA on the oxidation of eosin Y by potassium bromate in present of phosphoric acid. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of eosin Y at 518 nm. Under the optimized experimental conditions, the developed method allowed the determination of FA in the range of 0.03-0.6 μg mL(-1) with a good precision, and the limit of detection was down to 0.00988 μg mL(-1). The relative standard deviation of five replicate measurements for the determination of FA in concentration 0.12 μg mL(-1) was 1.8%. The proposed method was successfully applied to the determination of FA in food directly and satisfactory results were obtained.