LaMotte SMART 2 - Manual (Page 125)

COD–STANDARD RANGE
MERCURY FREE DIGESTION • CODE 0073-SC
MERCURY DIGESTION • CODE 0076-SC
QUANTITY CONTENTS CODE
25 *COD Standard Range Mercury Free Tubes *0073-SC
or 25 *COD Standard Range Mercury Tubes *0076-SC
*WARNING: Reagents marked with an * are considered to be potential health
hazards. To view or print a Material Safety Data Sheet (MSDS) for these reagents go to
www.lamotte.com. To obtain a printed copy, contact LaMotte by e-mail, phone or fax.
COD Standard Range Mercury Free Tubes are not USEPA approved.
COD Standard Range Mercury Tubes are USEPA approved.
Equipment needed but not supplied:
QUANTITY CONTENTS CODE
1 COD Adapter 5-0087
1 COD Reactor, 12 tube, 110V 5-0102
or 1 COD Reactor, 12 tube, 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: 0–1500 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, a green complex is formed. The
concentration of the green complex is measured at 605 nm
and is directly proportional to the COD of the sample.
SAMPLE
HANDLING &
PRESERVATION: Collect samples in glass and test as soon as possible. If
samples must be stored, preservation is accomplished by the
addition of concentrated H
2
SO
4
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–Standard Range 1/4