四(3-甲氧基-4-羟基苯基)铽卟啉分光光度法测定微量铅

Spectrophotometric Determination of Trace Lead Using Meso-tetra-(3-methoxy-4-hydroxyphenyl-Tb³⁺ Porphyrin

摘要: 以Meso-四(3-甲氧基-4-羟基)铽卟啉T-(3-MO-4-HP)P-Tb为微量铅的显色剂，在pH值为4.95的HAc-NaAc缓冲溶液中，双-2-乙基己基硫代琥珀酸钠(AOT)微乳液存在下，沸水浴加热4 min显色反应完全.在最大吸收波长478 nm处，配合物的摩尔吸光系数ε为7.49×10⁵ L/(mol·cm)，铅含量在0.0~0.2 μg/mL范围内符合朗伯比尔定律.方法的灵敏度高、选择性好，用于水样中痕量铅的测定，结果满意.

Abstract: A spectrophotometric determination of trace Lead using T-(3-MO-4-HP) P-Tb as a chromogenic reagent has been systematically studied. The results showed that the chromogenic reaction was complete under the following conditions: pH = 4.95 of a HAc-NaAc buffer solution, AOT microemulsion, and a heating of 4 min in a boiling water bath. At the maximum absorption wavelength of 478 nm, the molar absorption coefficient was 7.49×10⁵ L/(mol·cm). Beer's law was obeyed in the concentration range of 0.0~0.2 μg/mL for lead II. This method is of high sensitivity, good selectivity, and can be applied to the determination of trace lead(II) in water sample with satisfactory results.