A new spectrophotometric method for the determination of la (iii)‎ with 3-hydroxy-4-(2-hydroxy-phenyl azo)‎ naphthalene-1-sulfonic acid

الملخص EN

A simple, rapid and sensitive spectrophotometric method has been proposed for the determination of La (III) using 3-hydroxy -4-(2-hydroxy-phenyl azo) naphthalene -1- sulfuric acid as a chromogenic reagent.

This method is based on the formation of a red-pink colored complex, upon the reaction of La (III) with the reagent in an alkaline medium (pH= 9.50), having a maximum absorbance at 459 nm.

Beer's law is valid in the concentration range 0.5-12 µg.ml-1 with a Sandell's sensitivity value of 0.0188 µg.cm-2 and molar absorptivity of 7376.12 L.mol-1.cm-1.

The stoichiometric composition of the chelate is 1:3.

The effect of the presence of different cations as interferon's in the determination of La (III) under the given optimum conditions were investigated.