Indirect complexometric determination of manganese(II) using tartaric acid as a masking agent

Department of Chemistry, Srinivas Institute of Technology, Mangalore-574 143, Karnataka, India

E-mail : kagochara@gmail.com

Department of Chemistry, Mangalore University, Mangalagangothri-574 199, Mangalore, Karnataka, India

Department of Chemistry, Dr. M. V. Shetty Institute of Technology, Moodbidri-574 225, Karnataka, India

Manuscript received online 30 November 2013, revised 16 January 2014, accepted 16 April 2014

A complexometric method for the determination of manganese in the presence of other metal ions based on the selective masking ability of tartaric acid towards manganese is described. Manganese(II) present in a given sample solution is complexed with a known excess of EDTA and surplus EDTA is titrated against lead nitrate solution at pH 5–6 using xylenol orange as the indicator. A known excess of 10% solution of tartaric acid is then added. The mixture is then shaken well and the EDTA released from Mn-EDTA complex is titrated against the standard lead nitrate solution. Reproducible and accurate results are obtained for 1.10 to 33.0 mg of manganese(II) with relative error ≤ 0.51% and standard deviations ≤ 0.12 mg. The interference of various ions are studied. This method was applied to the determination of manganese(II) in its alloy composition.