Determination of Formaldehyde by Differential Pulse Voltammetry with Pretreated Au Electrode

Gold electrode was treated by scanning in the potential range of -0.8 to 0.8 V in 0.1mol·L-1 NaOH solution. The electrochemical behavior of formaldehyde at this pretreated Au electrode was studied. Two oxidation peaks of formaldehyde at the pretreated Au electrode, were observed at the potentials of -0.45 V and 0.31 V (vs.SCE). Based on these findings, a sensitive method for determination of formaldehyde by differential pulse voltammetry was proposed. Linear relationship between values of peak current at -0.56 V and concentration of formaldehyde was obtained in the range of 1.0×10-6-1.0×10-3mol·L-1, with detection limit (3S/N) of 8.0×10-7mol·L-1. The proposed method was applied to the determination of formaldehyde in water samples, giving values of recovery and RSD′s (n=5) in ranges of 95.5%-103.7% and 3.9%-4.1%, respectively.