A new sensitive catalytic method for determination of ultratrace manganese(II) based on oxidation of N,N-diethylaniline by potassium periodate.

Abstract

A highly sensitive catalytic method for determining ultratrace amounts of manganese(II) has been described. The method is based on the catalytic oxidation of N, N-diethylaniline by potassium periodate in weakly acidic media. The catalyzed reaction was followed spectrophotometrically at 470 nm by the fixed time method. By adjustment of variables affecting the reaction, manganese(II) in the concentration range of 10 - 80 pg ml-1 could be determined. Most of coexisting ions did not interfere with the determination, while interfering ions, copper(II), vanadium(V) and chromium(III), were allowed to coexist up to 500 times the amounts of manganese(II). The relative standard deviation at 40 pg ml-1 of manganese(II) was 3.0% (n=6). The accuracy of the method was confirmed by standard materials. The present method was successfully applied to the determination of trace manganese(II) in natural waters.