Linear Scanning Polarographic Determination of Metformin Hydrochloride

It was found that in a PBS of pH 6.85 and by the linear scanning polarography,a sensitive adsorption wave of metformin was observed at the potential of -1.165 V (vs.SCE).Linear relationship between values of the 1st derivative of values of peak current and mass concentration of metformin was obtained in the range of 0.41-41.0 mg·L-1 with detection limit (3S/N) of 0.28 mg·L-1.Precision was tested with standard solution of metformin hydrochloride of 41.0 mg·L-1 for 6 determinations,value of RSD found was 0.72%.The proposed method has been used in the determination of content of metformin hydrochloride in its tablets.