Indirect determination of formaldehyde by square-wave voltammetry based on the electrochemical oxidation of 3,5-diacetyl-1,4-dihydrolutidine using an unmodified glassy-carbon electrode.

A novel and indirect voltammetric procedure for the selective determination of formaldehyde is described. It is based on the oxidation of 3,5-diacetyl-1,4-dihydrolutidine (DDL) on an unmodified glassy-carbon electrode (GCE), generated by the selective reaction between formaldehyde and acetylacetone. A single oxidation peak of DDL at +0.8 V was observed, while formaldehyde is not electroactive under this condition, showing that this reaction can be used to indirect and selective detection of formaldehyde. Under the optimized conditions, a linear response between 0.4 and 40.0 mg L-1 and a detection limit of 0.13 mg L-1 were achieved, with a relative standard deviation of 0.7% (n = 10, 10 mg L-1). Due to the selectivity of this reaction to formaldehyde, this method is free from interference of other aldehydes. The procedure is a promising alternative for rapid formaldehyde determination in a wide range of samples.