Hach DR/850, Procedures Manual, Page: 450 / 460

450
Interferences
The following may interfere when present in concentrations
exceeding those listed below.
Pollution Prevention and Waste Management
ZincoVer 5 reagent contains potassium cyanide. Cyanide
solutions are regulated as hazardous wastes by the Federal
RCRA. Cyanide should be collected for disposal as reactive
(D003) waste. Be sure that cyanide solutions are stored in a
caustic solution with pH >11 to prevent the release of hydrogen
cyanide gas.
In the event of a spill or release, clean up the area by following
these steps:
a) Use a fume hood or supplied-air or self-contained breathing
apparatus.
b) While stirring, add the waste to a beaker containing a
strong solution of sodium hydroxide and calcium
hypochlorite or sodium hypochlorite (household bleach).
c) Maintain a strong excess of hydroxide and hypochlorite.
Let the solution stand for 24 hours.
d) Neutralize and flush the solution down the drain with a
large excess of water.
Interfering Substance Interference Level and Treatments
Aluminum 6 mg/L
Cadmium 0.5 mg/L
Copper 5 mg/L
Iron (ferric) 7 mg/L
Manganese 5 mg/L
Nickel 5 mg/L
Organic material Large amounts may interfere. Perform the mild digestion
(Section 2) to eliminate this interference.
Highly buffered samples or
extreme sample pH May exceed the buffering capacity of the reagents and
require sample pretreatment (see pH Interference in
Section 1). Adjust pH to 4-5.
ZINC,
continued