Determination of histamine in cheese by chronopotentiometry on a thin film mercury electrode

Simple electroanalytical method for histamine determination based on its irreverse oxidation by a constant current on a thin film mercury electrode was developed in this work. Experimental parameters of chronopotentiometric analysis, such as concentration of the supporting electrolyte, initial potential and dissolution current were optimised. The optimal experimental parameters included an initial potential of −0.4 V and oxidation currents in the range from 3 to 30 μA in 0.02 mol/l sulphuric acid. After the optimisation of experimental parameters, the linear response was obtained in the range 2–90 mg/l of histamine with achieved detection limit of 1.31 mg/l of histamine. The method was applied for the determination of histamine in various types of cheese. Prior sample analysis the procedure for sample preparation was developed and included ultrasonically-assisted extraction and chromatographic separation on a thin layer. To our knowledge, histamine has never previously been determined on mercury electrodes nor by applying chronopotentiometric analysis, thus developed electroanalytical method represents an important contribution to electroanalytical practise. By applying the developed method it is possible to perform simple and fast cheese analysis. Furthermore, in comparison to competitive chromatographic techniques, chronopotentiometric method allows the analysis of foodstuffs under moderate price.