四-(对-三甲铵苯基)卟啉分光光度法测定微量银

SPECTROPHOTOMETRIC DETERMINATION OF TRACE SIDVER WITH α,β,Υ,δTETRAKIS(4-TRIMETYLAMMONIUMPHENYL)PORPHYRIN

本文对以四-(对-三甲铵苯基)卟啉与Ag(I)显色反应的条件进行了研究。实验证明:在邻菲罗啉及CPB存在的碱性条件下,Ag(I)与TAPP反应生成银配合物(λ_(mxx)=427.2nm)。加入铅溶液使过量的TAPP转变为铅配合物(λ_(mxx)=464nm)从而消除试剂干扰。银配合物的表观摩尔吸光系数3.06×10~5,银含量在0～10μg/25ml范围内服从比耳定律。

A sensitive method for the spectrophotometric determination of silver with α, β,γ,δ tetrakis(4—trimethylammoniumphenyl)porphyrin(TAPP)has been developed. Ag(I)reacts with TAPP in the presence of O—phenanthroline hydrate and CPB to form silver complex over the pH range 12.2～12.9 and the TAPP remaining is converted into its lead complex by adding a small excess of lead(Ⅱ)after the silver complex was formed.The sorer band of the silver complex lies at 427.2nm which was well separated from that of the lead complex(464nm).Apparent molar absorptive of the silver complex is 3.06×l0~5.Beer's Law is obeyed for 0～10μg/25ml of silver.