This work demonstrated a novel amperometric method to measure the concentration of histamine directly without using any enzymatic reaction or a complicated derivation scheme. Based on the strong chelating property between histamine and cupric (II) ions, cupric oxide would be dissolved by the histamine and a cupric-histamine complex would be formed on the electrode surface, subsequently, an oxidative current resulted from the regeneration of the surface cupric oxide was used to reflect the concentration of the histamine in the sample. Under the optimal conditions with operating potential at 200 mV in a 100 mM phosphate buffer, pH 10.0, containing 50 mM acetate, a suitable dynamic range of histamine from 1 to 750 μM with a sensitivity of 15 nA/μM (R = 0.999) and a detection limit of 0.33 μM was achieved on a typical FIA system. Subsequently, the performance of this scheme was integrated with high-performance liquid chromatography as an electrochemical detector. In optimal conditions, the linear range is estimated from 10 to 2500 μM (0.5–125 nmol per injection), which is an adequate range for the determination of the freshness quality of a seafood. Finally, the feasibility of this scheme in real sample application was demonstrated by evaluating the histamine level in a fresh saury fish and a defrost one, respectively.

这项工作展示了一种新颖的安培法，无需使用任何酶促反应或复杂的推导方案即可直接测量组胺的浓度。基于组胺和铜离子之间的强螯合性能，氧化铜将被组胺溶解，并在电极表面形成铜-组胺络合物，随后，表面铜的再生产生了氧化电流氧化物被用来反映样品中组胺的浓度。在最佳条件下，在100 mM磷酸盐缓冲液（pH 10.0，含50 mM乙酸盐）中的工作电位为200 mV的情况下，组胺的动态范围合适，为1至750μM，灵敏度为15 nA /μM（R = 0.999），并且在典型的FIA系统上，检出限为0.33μM。随后，该方案的性能与高效液相色谱法作为电化学检测器相结合。在最佳条件下，线性范围估计为10到2500μM（每次注射0.5-125 nmol），这是确定海鲜新鲜度的适当范围。最后，通过分别评估新鲜秋刀鱼和除霜鱼中组胺的含量，证明了该方案在实际样品应用中的可行性。