Preconcentration with membrane cell and adsorptive polarographic determination of cyanides in air Original Research Article

The present paper describes a procedure that cyanides in air were preconcentrated in a membrane cell and their content was determined by adsorptive polarography. In a pH 8.4 buffer solution the cyanide ion can form a quaternary complex with Co(II), α,α′-dipyridyl and ethanolamine. The complex can be adsorbed at the mercury electrode and yields a sensitive oscillopolarographic wave at −1.45 V. Over the range 1.0×10−8–1.0×10−7 M, the peak currents are linearly proportional to the concentration of the cyanide. The detection limit is 6.0×10−9 M. First the cyanides in the air samples were preconcentrated in the membrane cells using 0.10 M NaOH solution, then their content was determined by complex-adsorptive polarography.