Bestimmung von Cyaniden - behr Labor (EN)



CN 6


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Cyanides are salts of hydrocyanic acid. Cyanides are used in large quantities as intermediates in the org. Synthesis, in dyes, pesticides, in the surface treatment of metals, electroplating and the extraction of precious metals. Cyanides are a significant problem and a major threat to the waters in the effluents of such processing plants. Frequently, fish stocks have been destroyed in rivers for hundreds of kilometers in accidents involving cyanide-containing material. The danger is so great that even drinking water regulations require regular checking for cyanides.

We distinguish between total cyanide and readily releasable cyanides in the determination procedures.

Determination of cyanides - Total cyanide determination

Total cyanide determination

Functional principle of behrtest cyanide distillation

System for the determination of total cyanide: In the presence of copper(I)ions, the cyanide compounds are decomposed to hydrogen cyanide at boiling temperature.

Hydrogen cyanide is expelled with an exactly defined vacuum through-flow current and absorbed in sodiumhydroxide. The exactly set through-flow current is important and the behr-typical processing of the absorption vessel in terms of through-flow opening.

Determination takes place according to the following standards:

EPA 9010 B (Total and amenable cyanide: Distillation)

ISO 11262 (Cyanide in soil and solids)

DIN 38405-D 13 (Total cyanide in water)

DIN 38405-D14 (Cyanide in drinking and surface water)

DIN 38404-D7 (Cyanide in low contaminated water - ion chromatography)

The evaluation is performed by

photometer | titration | ion chromatography (DIN 38404-D7)

Total cyanide is the total of the simple and complex cyanides.

Available product variants:
Determination of cyanides - Easily releasable cyanide determination

Easily releasable cyanide determination

The separation process in acc. with DIN 38405-D 14 is applicable for drinking water, raw water for drinking water preparation, low contaminated soil and surface water. The mass concentration of cyanide compounds should not exceed 1 mg/l.

Procedure basis: The easily releasable cyanide is separated from the sample with the aid of a precisely metered vacuum airflow at room temperature and a pH value of 4 as hydrogen cyanide. Hydrogen cyanide is absorbed in the behrotest absorption vessel ASH/CY in potassium hydroxide and then after reaction with barbituic acid-pyridine

As easily releasable cyanide and all compounds that separate hydrogen cyanide at room temperature and a pH value of 4.

Available product variants: