Kinetic determination of ultramicro amounts of As(III) in solution

Abstract

A new catalytic reaction is proposed and a kinetic method developed for the determination of ultramicro amounts of As(III) on the basis of its catalytic activity in the oxidation of ethylenediamine-N,N’-diacetic-N,N’ dipropionic acid (EAP) by KMnO4 in the presence of hydrochloric acid. Under optimal conditions, the sensivity of the method is 20 ng/cm3. The probable relative error is 7.6 – 14.5 % for the concentration range 50 – 200 ng/cm3 As(III). The effect of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method. The method has relatively good selectivity. Kinetic equations were proposed for the investigated process.

Keywords

• kinetic method
• As(III) determination
• ethylenediamine-N
• N’-diacetic-N
• N’-dipropionic acid