Colorimetric determination of manganese

The colour developed, when freshly formed manganese dioxide dissolves in alkaline tellurate solution is found to be suitable for the colorimetric determination of manganese. The colour obeys Beer's law within the concentration range 1.886.10^-4 - 7.54.10^-4M. The colour is developed by oxidizing Mn(II) (in presence of 2.5M alkali) with the equivalent amount of H₂O₂ in the presence of 4 moles of telluric acid per mole Mn(II).