5,10,15,20-四(2-羟基-5-磺酸苯基)卟啉光度法测定水中痕量锌的研究

Study on 5,10,15,20 -tetra(2-hydroxy-5-sulphophenyl)-porphine for the spectrophotometric determination of trace zinc in water

研究了5,10,15,20-四(2-羟基-5-磺酸苯基)卟啉与 Zn^(2+)的显色反应。最适 pH5.4。试剂及其锌配合物的最大吸收波长分别为412.6和420.5nm。试剂与 Zn^(2+)的配合比为1:1。表观摩尔吸光系数ε_(420.5)=3.5×10~5。可不经分离和富集直接光度测定自来水和某些天然水中的痕量锌。

A new water-soluble porphyrin,5,10,15,20-tetra(2-hydroxy-5-sulphophenyl)-porphine[T-(2-H-5-SP)P]for the spectrophotometric deter-mination of trace zinc has been studied.Thecomposition of the complex is Zn^(2+):T(2-H-5-SP)P=1:1,and the apparent molar absorptivity is3.5×10~5l·mol^(-1)·cm^(-1).The Soret band of thecomplex lies at 420.5 nm,which is well separatedfrom that of H_4P^(2+)(433.8 nm).The interferenceof foreign ions has been examined and theirtolerance limits by the APDC as masking reagentare also shown.Beer's law is obeyed for Zn^(2+) inthe range of 0～100 ppb.