Cyanide
Cyanide
Cyanide_PP_Other_PPZ_Eng_Ody.fm Page 3 of 8
Pollution Prevention and Waste Management
Special Considerations for Cyanide Containing Materials
Samples analyzed by this procedure may contain cyanide, which is regulated as
reactive (D003) waste by the federal RCRA. It is imperative these materials be
handled safely to prevent the release of hydrogen cyanide gas (an extremely
toxic material with the smell of almonds). Most cyanide compounds are stable
and can be safely stored for disposal in highly alkaline solutions (pH >11) such
as 2 N sodium hydroxide. Never mix these wastes with other laboratory wastes
which may contain lower pH materials such as acids or even water.
In the event of a spill or release, special precautions must be taken to prevent
exposure to hydrogen cyanide gas. The following steps may be taken to destroy
the cyanide compounds in the event of an emergency:
• Use a fume hood or supplied air or self contained breathing apparatus.
• While stirring, add the waste to a beaker containing a strong solution of
sodium hydroxide and calcium hypochlorite or sodium hypochlorite
(household bleach).
• Maintain a strong excess of hydroxide and hypochlorite. Let the solution
stand for 24 hours.
• Neutralize and flush the solution down the drain with a large excess of
water. Note: if the solution contains other regulated materials such as
chloroform or heavy metals, it may still need to be collected for hazardous
waste disposal. Never flush hazardous wastes down the drain.
Interferences
Interfering
Substance
Interference Levels and Treatments
Chlorine
Large amounts of chlorine in the sample will cause a milky white precipitate after the addition of the CyaniVer® 5
Reagent. If chlorine or other oxidizing agents are known to be present, pretreat the sample before testing using
the procedure in this table for oxidizing agents.
Metals
Nickel or cobalt in concentrations up to 1 mg/L do not interfere. Eliminate the interference from up to 20 mg/L
copper and 5 mg/L iron by adding the contents of one HexaVer Chelating Reagent Powder Pillow
(Cat. No. 243-99) to the sample and then mixing before adding the CyaniVer 3 Cyanide Reagent Powder Pillow in
step 3. Prepare a reagent blank of deionized water and reagents to zero the instrument in step 13.
Oxidizing
Agents
1. Adjust a 25-mL portion of the alkaline sample to pH 7–9 with 2.5 N Hydrochloric Acid Standard Solution
(Cat. No. 1418-32). Count the number of drops of acid added.
2. Add two drops of Potassium Iodide Solution (Cat. No. 343-32) and two drops of Starch Indicator Solution
(Cat. No. 349-32) to the sample. Swirl to mix. The sample will turn blue if oxidizing agents are present.
3. Add Sodium Arsenite Solution (Cat. No. 1047-32) drop-wise until the sample turns colorless. Swirl the sample
thoroughly after each drop. Count the number of drops.
4. Take another 25-mL sample and add the total number of drops of Hydrochloric Acid Standard Solution counted
in step a.
Subtract one drop from the amount of Sodium Arsenite Solution added in step c. Add this amount to the sample
and mix thoroughly. Continue with step 3 of the cyanide procedure.
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