Indirect determination of cyanide in waste waters by formaldehyde chronopotentiometry

Abstract

An indirect method for the determination of cyanide at concentrations between 0.01 and 0.1 µg ml^–1 is described. The method is based on the displacement observed in the quarter-wave potential of the chronopotentiometric graph of formaldehyde, in 0.1 M NaOH using a gold electrode, on increasing the concentration of cyanide. The method exhibits a relative error of 2% and a relative standard deviation of 1%. It has been applied to the determination of cyanide in waste waters.