5,10,15,20-四(3-溴-4-磺酸苯基)卟啉的合成及其光度法测定痕量锰的研究

Synthesis of 5,10,15,20-tetra(3-bromo-4-sulphophenyl)porphine and spectrophotometric study on the de■rmination of trace manganese

合成了5,10,15,20-四(3-溴-4-磺酸苯基)卟啉[T(3-BrP)PS_4],测定了试剂的离解常数,pK_(a_(1,2))=3.88,讨论了试剂与锰在 Cd^(2+)、邻菲啰啉和 CTMAB 存在下,于 pH9.2的显色反应。配合物的表观摩尔吸光系数,(?)_444=3.34×10~5L·mol^(-1)·cm^(-1)。锰含量在0～3.0μg/25mL 范围内服从比尔定律。用于茶溶液和草莓酒中痕量锰的测定,结果与 AAS 的一致。

A new water-soluble porphyrin,5,10,15,20-tetra(3-bromo-4-sulphophenyl) porphine [T(3-BrP)PS_4]has been synthesized and its ionization constant wasdetermined by using spectrophotometric method inaqueous solution(pK_(a_(1,2))=3.88).The color reaction ofthis reagent with manganese (Ⅱ) in the presence ofphenanthroline,cadmium and CTMAB has been stud-ied.The apparent molar absorptivity is 3.34×10~5L·mol^(-1)·cm^(-1) at pH9.2.In case sodium citrate is used asa masking agent,this method can be used to determinetrace manganese in foods.The results obtained arevery similar to those by atomic absorption spectropho-tometry.Beer's law is obeyed in the range of 0～3.0μg Mn(Ⅱ)/25mL.