Ultraviolet Spectrophotometric Determination of 1,10-Phenanthroline

Abstract

A method for determining the 1,10-phenanthrohne content of technical 1,10-phenanthrohne is described. The sample is dissolved directly in alcohol. The difference in absorbance of this solution at 323 5 mμ and 820 mμ is an approximate measure of the amount of 1,10-phenanthroline present. By differential comparison of a sample solution of technical 1,10-phenanthrohne with a reference solution containing a known amount of pure 1,10-phenanthrohne, a more exact determination can be made. Results obtained with the method were in close agreement with those obtained by a colorimetric method based on the formation of a red to orange complex by the reaction of 1,10-phenanthrohne with ferrous ions. The standard deviation of the method based on five duplicate determinations is less than 0.2%.