DETERMINATION OF OXALATE IN VEGETABLE SAMPLES USING A LOW COST ELECTRODE BY POTENTIOMETRIC MICROTRITRATION METHOD
The purpose of this research was to build a potentiometricmicrotitration system by using homemade low cost electrodes (a pencil carbon electrode as a working electrode and a silver/silver chloride (Ag/AgCl) electrode as a reference electrode) for determination of oxalate. The analysis was based on a redox reaction of the oxalate (titrand) in sulfuric acid solution was titrated with a few microliter of 0.02 mol L-1 potassium permanganate solution (titrant). The conditions such as electroplating time of silver stripe in saturated potassium chloride solution, concentration and volume of sulfuric acid and temperature of titration system were studied. The results were 9 min of electroplating time, 2.0 mol L-1 and 1 mL of sulfuric acid and titration at room temperature. This proposed method was applied for the determination of oxalate in some vegetable samples. It provided some advantages of low cost of instruments and analysis, simple system and operation, low chemical consumption, low toxic waste and environmental friendly. It was found that the results obtained from the proposed method were good accuracy and precision.
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