Catalytic-Spectrophotometric Determination of Trace Amounts of Manganese(II) by Catalysis of the Oxidation of Ferroin with Periodate

A catalytic spectrophotometric method for determination of ultra-trace quantities of manganese(II) id described. The method is based on the catalytic effect of manganese(II) on the oxidation reaction of ferroin by potassium periodate in acidic media. The reaction is monitored spectrophotometrically at 510 nm by a slope method and Mn(II) is determinable in the range of 1-1000ngmL-1. The limit of detection is as low as 0.94ngmL-1. The proposed method was applied to the determination of manganese in milk.