Hach DR/850 Procedures Manual page 450

ZINC,
continued
Interferences
Pollution Prevention and Waste Management
The following may interfere when present in concentrations
exceeding those listed below.
Interfering Substance
Aluminum
Cadmium
Copper
Iron (ferric)
Manganese
Nickel
Organic material
Highly buffered samples or
extreme sample pH
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.
Interference Level and Treatments
6 mg/L
0.5 mg/L
5 mg/L
7 mg/L
5 mg/L
5 mg/L
Large amounts may interfere. Perform the mild digestion
(Section 2) to eliminate this interference.
May exceed the buffering capacity of the reagents and
require sample pretreatment (see pH Interference in
Section 1). Adjust pH to 4-5.
450