METHOD AND APPARATUS FOR CONTINUOUS COLORIMETRIC DETERMINATION OF THE CYANIDE CONCENTRATION OF AQUEOUS SOLUTIONS.

摘要

According to the invention, cyanide concentrations of approximately 0.001 to 5 mg cyanide/1 are colorimetrically determined in a continuous manner by means of the known cyanidepicric acid color reaction. The solution containing free cyanide and/or cyanide releasable from cyanocomplexes is converted in a system enclosed in a gas-tight manner in the presence of chelate complexing agents, picric acid and alkaline buffer systems in 1-60 minutes at 50 DEG -120 DEG C. to the color complex and the absorbency is measured spectrophotometrically. The method avoids the extraction step which was previously necessary under 0.2 mg CN/1, avoids errors due to HCN gas evolution losses, is easy to manage, not prone to trouble and suitable for the continuous monitoring of waste-water streams or for controlling cyanide detoxification methods.