5,10,15,20-四(3-氯-4-磺酸苯基)卟啉的合成及其与银显色反应的研究

Synthesis of 5, 10, 15, 20-Tetra ( 3-Chloro-4-Sulfophenyl)-Porphyrin and Spectrophotometric Study of Its Reaction with Silver

报道了水溶性卟啉T(3-CP)PS_4的合成方法,研究了试剂与银离子的显色反应条件,测定了试剂的离解常数pKa_3,4为3.90。当Pb^(2+)和CTMAB存在时,配合物的最大吸收波长位于427.2nm处,表观摩尔吸光系数为3.23×10~5,配合比为1:1,稳定常数K=4.91×10~7,银含量在0～6μg/25ml范围内符合朗伯—比尔定律。本法可用于阳极泥和光谱底片中微量银的测定。

The synthesis process of meso-tetra ( 3-chloro-4-sulfophenyl ) -porphyrint; T(3-CP)PS4] was described in this paper. The ionization constant of T ( 3-CP ) PS4 was determined by means of spectrophotometry and the pKaa,4 is 3.90. The reaction conditions of the reagent with silver was studied and the color reaction was completed within 3 min at pH 11.5 by heating in boiling water bath. A highly sensitive method for spectrophotometric determination of micro amounts of silver in the presence of Pb2+ and CTMAB has been developed. The molar absorptivity is 3.23×105 L· mol-1 ·cm-1 at 427.2nm. Beer's law is obeyed for silver in the range of 0-6ug/25ml. The interference of foreign ions was also examined. This method can be used for the direct determination of trace silver in anode mud and glass photofilm with satisfactory results.