Impex Produkter NANOCOLOR COD 160 Hg-free Chemical Oxygen Demand User Manual
- June 3, 2024
- Impex Produkter
Table of Contents
Impex Produkter NANOCOLOR COD 160 Hg-free Chemical Oxygen Demand
Method
Photometric determination of decrease in chromate concentration after oxidation with potassium dichromate / sulfu ric acid / silver sulfate without use of mercury salts
Contents of reagent set
- 20 cartridges for chloride elimination
- 20 test tubes COD 160 Hg-free
- 1 test tube with blank value “NULL”
Hazard warning
Cartridges contain silver sulfate 10–100 %, test tubes contain sulfuric acid 80–98 %, blank value “NULL” con-tains sulfuric acid 51–80 %.H314 Causes severe skin burns and eye damage. P260, P280, P301+330+331, P303+361+353, P304+340, P305+351+338, P501 Do not breathe vapors. Wear protective gloves / eye protection. IF SWALLOWED: rinse mouth. Do NOT induce vomiting. IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water / shower. IF INHALED: Remove person to fresh air and keep comfortable for breathing. IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. Dispose of contents / container to regulated waste treatment. For further information ask for a safety data sheet. When shaking COD test tubes use safe ty bottle (REF 91637).
Interferences
Chloride contents up to 2000 mg/L are eliminated by cartridge pretreatment,
and thus do not interfere. For chloride contents > 2000 mg/L the test sample
must be diluted with COD-free water (REF 918993). Alterna-tively, the chloride
interferences can be eliminated by the use of several cartridges (REF 963911).
For the de-termination of the chloride content we recommend a preliminary test
with QUANTOFIX® Chloride (REF 91321). The method can not be applied for the
analysis of sea water.
Note
The cartridge contents are sensitive to heat and light. Thus, it is
recommended to open the cartridge packag-ing just before use. Avoid contact
with the cartridge content. In case of contact with skin, rinse thoroughly
with water. Light color changes of the cartridge content do not interfere with
the determination.
Procedure
Requisite accessories: reaction tubes 16 mm OD (REF 91680), alternatively beaker, piston pipette with tips, NANOCOLOR® heating block
Pretreatment
Open packaging and take out cartridge. Dip cartridge into test sample and draw up plunger slowly until about 5 mL of sample solution are in-side the cartridge. Shake cartridge well for 30 s. Afterwards, press out sample solution carefully; reject the first drops (ca. 0.5 mL) and fill the remaining contents (clear solution) into an empty reaction tube by slowly pouring the solution down the inner side of the tube.
Digestion at 148 °C
Open COD test tube, hold it at an angle and slowly add 2.0 mL of the pretreated sample solution from the reaction tube 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). Pla ce tube into the heating block. Start heating programme. After 2 h remove test tube from heating block, allow to cool down to room temperature and shake gently several times. Clean outside of test tube and measure. Adjust photometer to zero by using blank value “NULL”.
Short time COD at 160 °C
Open COD test tube, hold it at an angle and slowly add 2.0 mL of the pretreated sample solution from the reaction tube 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). Pla ce tube into the heating block. Start heating programme. After 30 min remove test tube from heating block, allow to cool down to room temperature and shake gently several times. Clean outside of test tube and measure. Adjust photometer to zero by using blank value “NULL”. 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 NANOCOLOR® photometers and PF-12 see manual, test 0-26. The same method is called up as for the mercury-containing COD 160 (REF 985026).
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 160 (REF 92526) or Multistandard Sewage outflow 1 (REF 925011)
Storage:
Store the test kit in a cool (2–8 °C) and dry place. Avoid exposing the
test kit to sunlight.
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