Kinetic spectrophotometric determination of nanogram levels of manganese by use of the salicylaldehyde guanylhydrazone-hydrogen peroxide system

A kinetic method is described for determining trace amounts of manganese(II), based on its catalytic effect on the oxidation of salicylaldehyde guanylhydrazone by hydrogen peroxide. The reaction is followed spectrophotometrically by measuring the rate of change of absorbance at 505 nm. The calibration graph is linear in the range 8-80 mug/l. with a relative error of +/- 1%. The method has been applied to the determination of manganese in various samples.