Sensitive Determination of Semicarbazide in Flour by Differential Pulse Voltammetry

Resumo

A sensitive method for semicarbazide determination was developed by differential pulse voltammetry. Comparing to traditional methods, such as HPLC‒mass spectrometry and HPLC–fluorescence detection, it provides several advantages including using low consumption of organic solvents and low cost of analysis. Accordingly, 2-nitrobenzaldehyde was used as an active reagent to react with semicarbazide. The reaction product, 2-nitrobenzaldehyde semicarbazone (2-NSEM), was quantified by differential pulse voltammetry. A linear relationship was obtained between the peak current and 2-NSEM concentration in the range from 0 to 100 μg/L (R² = 0.999). The limit of detection (LOD) was calculated to be 3 μg/kg (signal to noise ratio of 3), which is lower than LOD obtained by direct differential pulse voltammetry determination of semicarbazide. The developed method was successfully applied to determine semicarbazide in flour samples with satisfactory recoveries from 92 to 99% (relative standard deviation < 4.3%, n = 6) indicating this method to be potential and valuable for semicarbazide detection.