LaMotte COD Plus Colorimeter 1922-EX2 - Manual (Page 86)

DISSOLVED OXYGEN
WINKLER COLORIMETRIC METHOD • CODE 3688-SC
QUANTITY CONTENTS CODE
30 mL *Manganese Sulfate Solution
*4167-G
30 mL *Alkaline Potassium Iodide Azide
*7166-G
30 mL *Sulfuric Acid 1:1
*6141WT-G
1 Sample Tube, screw cap
29180
1 Cap
28570
*WARNING: Reagents marked with a * are considered hazardous substances. Material
Safety Data Sheets (MSDS) are supplied for these reagents. For your safety, read label
and accompanying MSDS before using.
Dissolved oxygen is vital to the survival of aquatic organisms. Naturally
present, dissolved oxygen enters the water when plants photosynthesize. Wind
and wave action also cause oxygen from the air to dissolve into water.
Dissolved oxygen is consumed by aquatic animals and by the oxidation, or
chemical breakdown, of dead and decaying plants and animals. The
concentration of dissolved oxygen in natural waters can range from 0 to 14
ppm and is effected by temperature and salinity.
APPLICATION:
This method is applicable for the determination of dissolved
oxygen in drinking water, all surface waters and wastewater.
RANGE: 0.0 – 11.0 ppm Dissolved Oxygen
METHOD: This method uses the azide modification of the Winkler
Method with a colorimetric determination of the yellow
iodine produced from the reaction with the dissolved
oxygen.
INTERFERENCES: The presence of other oxidizing agents may cause positive
interferences. Reducing may cause negative interferences.
Nitrite interferences are eliminated with the azide
modification.
COD PLUS TEST PROCEDURES 6/02 DISSOLVED OXYGEN 1/3