Rapid Determination of Metformin Hydrochloride by Microchip Capillary Electrophoresis

Microchip capillary electrophoresis with contactless conductivity detection was applied to rapid determination of metformin hydrochloride (MFM) its tablets. Twenty tablets of MFM were de-sugarcoated and pulverised. A portion of 0.100 0 g of the powder was taken as sample and dissolved ultrasonically with water. After filtration the filtrate was diluted to 100 mL quantitatively and used for CE analysis. The microchip with cross manifolds should be cleaned before use as prescribed. 2.0 mmol·L-1 citric acid solution ［containing (φ) 5% ethanol and 0.1 mmol·L-1 sodium dodecyl sulfonate］ was used as separation medium. Time of sample introduction taken was 10.0 s, and separation voltage chosen was 1.3 kV. Separation and determination were fulfilled within 1 min. Linear relationship between values of peak heights and mass concentration of MFM was kept in the range of 10.0-110.0 mg·L-1, with detection limit (3S/N) of 1.0 mg·L-1. Three samples of the drug were analyzed by the proposed method and recovery was tested by standard addition method. Values of recovery found were in the range of 94.5%-103%, with values of RSD′s (n=6) ranged from 0.63% to 1.1%.