导数伏安法测定肉类食品中的亚硝酸盐

Determination for Nitrites in Meat by Derivative Voltammetry

在盐酸介质中,痕量亚硝酸根对溴酸钾氧化中性红的反应有极强的催化作用,研究了最佳反应条件,发现在氨缓冲溶液中中性红具有良好的导数电流峰,通过悬汞电极跟踪催化反应过程中中性红浓度的变化,建立了测定痕量亚硝酸根的新方法。方法的线性范围为1.2×10^(-7)～5.0×10(^-4)μg·mL^(-1)。检出限为5.4×10^(-8)μg·mL^(-1),应用于肉类食品中亚硝酸根的测定,结果满意。

In a hydrochloric acid medium, trace amounts of nitrite ion showed a strong catalytic effect on the oxidation reaction between neutral red and potassium bromate.Furthermore, in an ammoniacal buffer solution, neutral red gave a sensitive derivative voltaic peak at E=-0.69V（vs.SCE）. It was found that the peak current difference △1 between the values of catalytic reaction （1） and non-catalytic reaction （10） kept a linear relationship with concentration of nitrite ion in the range of 1.2× 10^-7--5.0 × 10^-4μg·mL ^-1.Based on these pbenomenon,a sensitive method of determination of trace amounts of nitrite ion wa.s established.The detection limit of the method was found to be 5.4 × 10^-8 μg·mL^-1 Satisfactory results were obtained in its appli cation to the determination of nitrite in meat.