MACHEREY-NAGEL 963029 Chemical Oxygen Demand Instructions
- June 3, 2024
- MACHEREY-NAGEL
Table of Contents
MACHEREY-NAGEL 963029 Chemical Oxygen Demand
Method
Photometric determination of chromium(III) concentration after oxidation with
potassium dichromate / sulfuric acid
Contents of reagent set:
20 test tubes COD 1500 Hg-free
Hazard warning:
Information regarding safety can be found on the box’ label and in the safety
data sheet. You can download the SDS from www.mn-net.com/SDS.
Interferences
Chloride interferes: 100 mg/L Cl– ≜ approx. 22 mg/L COD. Samples
containing more than 1000 mg/L Cl– should be diluted prior to determining the
COD. Moreover, chloride contents up to 2000 mg/L can be eliminated using
NANOCOLOR® cartridges for chloride elimination (REF 963911). For determination
of the concentration of chlorides we recommend a preliminary test with
QUANTOFIX® Chloride (REF 91321).
The method cannot be applied for the analysis of sea water.
Procedure
Requisite accessories: NANOCOLOR® heating block, piston pipette with tips
Decomposition at 148 °C
Open test tube, hold it diagonally and slowly add 2.0 mL test sample to
contents without mixing so that two sepa ra te lay ers are formed; screw cap
securely on to test tu be, hold tube by the cap, place tube into the safety
bottle and shake (Cau tion, test tube becomes hot), then pla ce tube into the
heating block.
After 2 h remove test tube from heating block, after about 10 min (test tube
is still warm) shake once and allow to cool to room temperature.
Clean outside of test tube and measure.
Short time COD at 160 °C
Open test tube, hold it diagonally and slowly add 2.0 mL test sample to
contents without mixing so that two sepa ra te lay ers are formed;
screw cap securely on to test tu be, hold tube by the cap, place tube into the
safety bottle and shake
(Cau tion, test tube becomes hot), then pla ce tube into the heating block.
After 30 min remove test tube from heating block, after about 10 min (test
tube is still warm) shake once and allow to cool to room temperature.
Clean outside of test tube and measure.
- In contrast to the digestion at 148 °C, the short time COD is characterized by a higher digestion temperature and reduced reaction time. Therefore we recommend to compare the results of the short time COD from time to time (150 ± 5 °C / 2 h ± 10 min).
Measurement
For MACHEREY-NAGEL photometers see manual, test 0-29.
Photometers of other manufacturers:
For other photometers check whether measurement of round glass tubes is pos
sible. Verify factor for each type of instrument by measuring standard
solutions.
Analytical quality control:
NANOCONTROL COD 1500 (REF 92529)
Disposal
Information regarding disposal can be found in the safety data sheet. You can download the SDS from www.mn-net.com/SDS.
Storage
Store the test kit in a cool and dry place. Avoid exposing the test kit to
sunlight.
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>