聚乙烯醇存在下银-邻菲罗啉-荧光桃红体系分光光度法测定微量银

Spectrophotometric Determination of Trace Silver with System fo Silver-1, 10-Phenanthroline-phloxine in the Presence of Nonionic Surfactant Polyvinyl-alcohol

本文研究了非离子表面活性剂聚乙烯醇存在下,银-邻菲罗啉-荧光桃红(phlo)体系的显色反应。实验表明,体系的最佳酸度是PH6.1～6.5,其最大吸收峰位于565nm,摩尔吸光系数是6.8×10~4 1mol^(-1)cm^(-1),配合物组成为Ag:phen:phlo=1:2:1。银量在0～30μg/25ml范围内遵守比耳定律。干扰离子的影响可采用EDTA掩蔽,用本法测定一些矿样中的银,结果满意。

In this paper colorimetric reaction of Ag^+-1, 10-phenanthroline and phloxine in the presence of nonionic surfaetant polyvinyl alcohol has been studied. The experimental result shows that the complex compound gives a maximun absorption at 565nm. The optimum pH is 6.1-6.5. The apparent molar absorption is 6.8×10~4L·mol·-1 cm^(-1). The molar ratio of Ag:phen: phlo has been found to be 1:2:1. Beer's law is obeyed within the range of 0-30μg Ag per 25ml.The interference of diverse ions can be masked by EDTA, It's able to directly determine trace silver in water solution. The given results are satisfactory when using proposed method for spectrophotometrie determination of silver in some minerals.