meso-四-(3,5-二溴-4-羟基苯)卟啉分光光度法测定铅

Application of Meso-Tetra-(3,5-Dibrcmo-4-Hydroxyphenyl) Porphyrin to the Spectro-photometric Determination of Lead

meso-四(3,5-二溴-4-羟基苯)卟啉[T(DBHP)P],一种新的溴代卟啉可用作测定铅的试剂.当8-羟基喹啉存在时,铅可在碱性介质中迅速与T(DBHP)P反应生成配合物.该配合物的Soret带位于479nm,摩尔吸光率为2.4×10~5 L/(mol·cm).在25ml溶液中0～11μg铅符合比耳定律.本法的选择性显著高于未溴代的meso-四(4-羟基苯)卟啉[T(4-HP)P]法.用本法通过碘化物-MIBK萃取后测定了铁矿和金属锌中的铅,结果良好.

Meso-Tetra- (3,5-dibromo-4-hydroxyphenyl) porphyrin [T(DBHP)P],a bromo-substituted porphyrin was found to be a very useful reagent for the spectrophotometric determi nation of lead.Lead reacts rapidly with T(DBHP)P in alkaline medium in the presence of 8-hydroxyquinoline.The Soret band of the complex lies at 479 nm, with a molar absorptivity of.4x10^5l.mol^(-1)·cm^(-1).Beer's law is followed for 0~11μg of lead in 25ml of solution.The selectivity of this porphyrin is much better than that of the unsubstituted porphyrin, T(4-HP)P.A method using T(DBHP)P has been applied for the determination of lead in standard samples of iron ore and zino spelter after an extraction with iodide-MIBK in 0.6M hydrochloric acid solution.