61-67
DIGESTION
Method 8000
OXYGEN DEMAND, CHEMICAL (COD)
(0 to 1,500 and 0 to 15,000 mg/L)
For water, wastewater and seawater
Reactor Digestion Method*; USEPA approved for reporting
(0 to 1,500 mg/L range)†
1. Homogenize a
100 mL sample for 2
minutes in a blender.
Note: For samples with
high solid content,
blending ensures
distribution of solids
and improves accuracy
and reproducibility.
Note: Pour
homogenized sample
into a 250-mL beaker
and stir with magnetic
stirrer.
Note: If samples cannot
be analyzed immediately,
see Sampling and
Storage following these
steps.
2. Turn on the COD
Reactor. Preheat to
150
o
C. Place the
plastic shield in front
of the reactor.
Caution: Ensure safety
devices are in place to
protect analyst from
splattering should
reagent leaking occur.
3. Remove cap of a
COD Digestion
Reagent Vial of the
desired range:
Sample COD Digestion
Concentration Reagent
Range (mg/L) Vial
Type
0 to 1,500 High Range
0 to 15,000 High Range Plus
Note: The reagent
mixture is light
sensitive. Keep unused
vials in the opaque
shipping container, in a
refrigerator if possible.
The amount of light
striking the vials during
testing will not affect the
results.
*Jirka, A.M.; Carter, M.J. Analytical Chemistry, 1975, 47(8), 1397.
†Federal Register, April 21, 1980, 45(78), 26811-26812.
Caution
Some of the chemicals and apparatus used in this procedure may be
hazardous to the health and safety of the user if improperly handled or
accidentally misused. Please read all warnings and the safety section of
this manual. Appropriate eye protection and clothing should be used
for adequate user protection. If contact occurs, flush the affected area
with running water. Follow instructions carefully.
2 minutes
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