[Determination of trace manganese by non-organic solvents extraction catalytic spectrophotometry in Mn(II)-H2O2-EBT-PEG-2000 system].

A new non-organic solvents extraction catalytic spectrophotometric method for the determination of trace amounts of manganese was studied. The method is based onthe manganese (II) catalyzing hydrogen peroxide to oxidate o f eriochrome black T in hydroxide-ammonium chloride buffer medium. The reaction time and the degree of indicating reaction are controlled by non-organic solvents extraction equilibrium using polyethylene glycol-2000. The absorbance of polyethylene glycol-2000 phase is measured at 539 nm in weak acidic medium. The calibration graph is linear for 0.0080-0.55 microg x mL(-1) Mn (II), and the detection limit is 3.0 x 10(-9) g x L(-1). The method can be applied to the determination of trace manganese in tea and aluminum alloy with satisfactory results.