2,4—二氯苯基荧光酮分光光度法测定微量铁

SPECTROPHOTOMETRIC DETERMINATION OF TRACE AMOUNTS OF IRON WITH DClPF

目的 :研究测定微量铁的新体系。方法 :分光光度法。结果 :在 pH为 9.4～ 10 2的缓冲介质中 ,在表面活性剂CTMAB存在下 ,Fe(Ⅲ )与 2 ,4—二氯苯基荧光酮 (DClPF)形成 1:3蓝紫色配合物 ,其最大吸收波长 6 10nm ,表观摩尔吸光系数ε=1 10× 10 5L/(mol·cm) ,Fe(Ⅲ )含量在 0～ 2 5 0 μg/L范围内符合比尔定律。 结论 :建立了测定Fe(Ⅲ )的分光光度新方法 ,该法操作简便 ,灵敏度高 ,可直接用于测定茶叶标样及蒙药中的微量铁 。

Objective:To study a new system of determining trace iron(Ⅲ). Methods: Spectrophotometry. Results: In a medium of pH 9.4～10.2, iron(Ⅲ) reacts with 2,4 dichlorophenylfluorone(DClPF) to form a 1:3 complex with maximum absorption at 610nm in the presence of CTMAB. The molar absorptivity is 1.10×10 5. Beer's law is obeyed in the range of 0～250μg/L. Conclusion:A new method for determining trace iron(Ⅲ) was established. This method has high sensitivity. Satisfactory results were obtained for the determination of trace iron(Ⅲ) in sample of tea and mongolian medicine.