Kinetic spectrophotometric method for rapid determination of trace formaldehyde in foods

A simple and sensitive kinetic-spectrophotometric method was developed for the determination of ultra trace amount of formaldehyde in food samples. The method was based on the oxidation of rhodamine B (RhB) by potassium bromate in sulfuric acid medium (formaldehyde as catalyst). The reaction was monitored by measuring the decrease in absorbance of the dye at 515 mn after 6 min. The developed method allowed the determination of formaldehyde in the range of 10-100 mu gL(-1) with good precision, accuracy and the detection limit was down to 2.90 mu g L-1. The relative standard deviations for the determination of 10 and 60 mu g L-1 of formaldehyde were 3.0% and 1.9% (n = 10), respectively. The method was found to be sensitive, selective and was applied to the determination of formaldehyde in foods with satisfactory results. (c) 2007 Elsevier B.V. All rights reserved.