Abstract:

Based on the catalytic effect of formaldehyde on the reaction between potassium periodate and methyl red, a new catalytic-kinetic photometric method for the determination of trace formaldehyde was developed in the present study. The factors affecting the rate of catalytic fading reaction were investigated. Under the optimal conditions, the formaldehyde concentration within a range of 2.25×10-4 to 1.35×10-2 μg/ml had a good linear relationship with absorbance at 516 nm, the detection limit was 4×10-5 μg/ml, and the relative standard deviation (RSD) was 0.1% for determining 0.0041 μg/ml formaldehyde solution (n = 11). The method had high sensitivity and selectivity. When it is applied in the detection of trace formaldehyde in yuba, the spike recoveries were between 93% and 106%.

Key words: catalytic-kinetic photometry, formaldehyde, yuba, methyl red