FIELD: chemistry.
SUBSTANCE: method is based on detecting In (III) ions through differential pulse polarography on a stationary mercury-drop electrode in a background electrolyte of the following composition 3M HNO3+0.8M H2C4H4O6+0.5M HCl. A voltage versus current curve is plotted in a voltage interval from -0.65 V to 0.80 V with cathode potential sweep rate of 5 mV/s. Content of In (III) ions is determined from the height of the peak at potential -0.72 V relative a silver chloride electrode. According to the invention, the lower limit for detecting In (III) ions is equal to 1.0 mg/l, and the duration for analysing one sample, including sample preparation, is not more than 6 minutes.
EFFECT: high accuracy of detection.
7 dwg
