在pH 1.2邻苯二甲酸氢钾-盐酸缓冲溶液中,新型卟啉吡啶季铵盐显色剂-溴化5-［4-N-(对甲氧基)苄铵基吡啶基］-10,15,20-三(4-N-吡啶基)卟啉与锌(Ⅱ)形成1∶1配合物。在此显色反应中,新型卟啉试剂具有显色和表面活性剂的双重功能。此配合物的最大吸收波长为424 nm,表观摩尔吸光率为4.96×105L·mol-1·cm-1,锌(Ⅱ)质量浓度在800 μg·L-1以内符合比耳定律。方法用于3个水样中锌(Ⅱ)的测定,方法的回收率和测定值的相对标准偏差(n=5)在96.0%~97.1%和0.43%~0.63%之间。

A new chromogenic reagent, 5-［4-(p-methoxy) benzyl ammonium pyridinium］-10,15,20-tris(4-N-pyridinium) porphyrin bromide was used to react with Zn(Ⅱ) in potassium acid phthalate-HCl buffer medium of pH 1.2 to form a coordination complex with molar ratio of 1 to 1. Absorption maximum of the complex lies at the wavelength of 424 nm with its molar absorptivity of 4.96×105L·mol-1·cm-1. Linear relationship between values of absorbance and mass concentration of zinc was kept in the range within 800 μg·L-1. In the reaction, this new reagent not only acted as a chromogenic reagent but also as a surfactant. Three water samples were analyzed by the present method, giving values of recovery and RSD′s (n=5) in the ranges of 96.0%-97.1% and 0.43%-0.63% respectively.