Determination of Chloride Ion Concentration

and CN ions, if present, can be eliminated by adding a high concentration of the sodium bromate oxidizing agent. 

Before and after sample measurements, the potentiometric measuring cell is calibrated with standard solutions in the range of 3 x 10 -0.1 M. The slope of the response curve should be about 54 5 mV/decade at 25 °C. Between measurements, the sample half-cell must be carefully washed and dried to avoid cross contamination. The cell voltage measured in the sample solution must be in the voltage range obtained for calibrating standards. 

For analyzing different samples, the sample preparation procedure needed to be carefully worked out. 

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