TEST INSTRUCTIONS - Geotech Environmental Equipment

COD–LOW RANGE
MERCURY FREE DIGESTION CODE 0072-SC
MERCURY DIGESTION CODE 0075-SC
QUANTITY CONTENTS CODE
25 *COD Low Range Mercury Free Tubes *0072-SC
or 25 *COD Low Range Mercury Tubes *0075-SC
*WARNING: Reagents marked with an * are considered hazardous substances. To
view or print a Material Safety Data Sheet (MSDS) for these reagents see MSDS CD
or our web site. To obtain a printed copy, contact us by e-mail, phone or fax.
COD Low Range Mercury Free Tubes are not USEPA approved.
COD Low Range Mercury Tubes are USEPA approved.
Equipment needed but not supplied:
QUANTITY CONTENTS CODE
1 COD Adapter 5-0087
1 COD Reactor, 12 vial, 110V 5-0102
or 1 COD Reactor, 12 vial, 230V 5-0102-EX2
1 Measuring Pipet, 1.0 mL 2-2110
1 Pipet Bulb 2-2164
Chemical Oxygen Demand (COD) is a measure of the amount of organic
matter in water which is susceptible to oxidation by chemical oxidants. COD
can be empirically related to the Biological Oxygen Demand (BOD) and
organic carbon content of a specific source of water. This correlation must be
determined experimentally for each source of water.
APPLICATION: Domestic and industrial wastes.
RANGE: 5–150 mg/L COD
METHOD: Dichromate in the presence of silver salts, at high
temperature in a closed system, oxidizes most organic
compounds to 95-100% of the theoretical amount. This
process is called digestion. As dichromate oxidizes the
organic compounds, the amount of yellow color is reduced.
The remaining yellow color is measured colorimetrically at
the 420 nm and is directly proportional to the COD of the
SAMPLE
HANDLING &
PRESERVATION:
sample.
Collect samples in glass and test as soon as possible. If
samples must be stored, preservation is accomplished by the
addition of concentrated H2SO4 to adjust the pH below 2.
Samples with suspended solids should be homogenized in a
blender (100 mL for 30 seconds) and then stirred gently
with a magnetic stirrer.
Smart2 TEST PROCEDURES 03.05 COD–LR 1/4