Potentiometric Determination of Cyanide in Effluents Having High Concentration of Chloride

The est~mat~on f cyanide IS generally done by titrimetry, colorimetry and polarography but each method has its own limitations. Argenlometric titration method IS not satisfactory at low cyanide concentralion at ppm levels. Distillation and colorimetry method is accurate but time consuming. Presence of large quant~t~es of chloride does not permit the use of ion selective electrodes. Other methods available are Double Pulse Polarography and Atomic Absorption Spectroscopy. They involve sophisticated costly ~nstruments and are d~tt~cult as tar as small scale industries are concerned. It has been observed that potentiometric t~tration method can be more easily adopted wlth falr accuracy even at ppm levels. The most Important advantage is that the estimations can be done at fast rate and does not require much of sophsticated ~nslruments or techn~que. Series of experiments were carried out with varying cyanide concentrat~ons and large excess of chloride ions. Detection limit by this method is 100 ppb and the results agree well w~ th those obtamed by the other methods. The results on actual samples and standards are presenled In thls paper.