TEST METHOD FOR DISSOLVED OXYGEN (D.O) IN INDUSTRIAL WATER
(LR: 0.02-0.2, HR: 0.5-5.0 & above mg/L as O2)
BACKGROUND OF THE TEST:
Since dissolved oxygen (D.O) certain concentration in water is one of the
essential elements for nature such as in lakes, rivers etc. So D.O test plays an
important role for such applications. Also for boiler feed water, D.O should be
NIL or should have very minimum levels.
Nuclotrasis offers user friendly test method with ease of handling the
relevant reagents and other equipment using modified wrinkle method. In
the procedure, the sample is first treated with manganous and alkali azide
solutions leading to manganese oxide precipitates formation. Then addition
of sulfuric acid causes the precipitates to re-dissolve along with the oxidation
of iodide ions to iodine by manganese oxide hydroxide. As the amount of
iodine produced are equals to dissolved oxygen in the sample, so by
calculating the concentration of iodine through thiosulfate ions reducing
iodine back iodide ions, concentration of dissolved oxygen (D.O) is
determined.
In the provided kit, two options for analyzing D.O are given. Option-I is for
low range (LR) D.O analysis such as in boiler feed water (BFW) and option-II
is for high range (HR) D.O such as in natural or wastewater.
REAGENTS/EQUIPMENTS/APPARATUS:
• Provided 5 mL & 10 mL marked glass vial (Item Code: 02-01)
• NUCLOTRASIS D.O TEST REAGNET-I (Item Code: 01-13-1)
• NUCLOTRASIS D.O TEST REAGNET-II (Item Code: 01-13-2)
• NUCLOTRASIS D.O TEST REAGNET-III (Item Code: 01-13-3)
• NUCLOTRASIS D.O TEST INDICATOR SOLUTION(Item Code: 01-13-4)
• NUCLOTRASIS D.O LR-TITRANT SOLUTION (Item Code: 01-13-5)
• NUCLOTRASIS D.O HR-TITRANT SOLUTION (Item Code: 01-13-6)
SAMPLE COLLECTION & PREPARATION
• Make sure to immediately analyze the sample after collection of
sample.
• Ensure to collect sample in a suitable and designated bottle for a
specific sample.
•
• Thoroughly rinse the sample bottle with current sample and fill
the sample by allowing slight overflow and immediately tighten
the cap.
• Prevent agitation of the sample and exposure to air as the test is
sensitive to the air.
TEST PROCEDURE:
1. Use the provided glass reagent bottle, rinse the bottle thoroughly
with sample to be analyzed and fill to overflow. Insert stopper and
ensure that small amount of sample spills over.
2. Remove the stopper and add five (5) drops each of NUCLOTRASIS
D.O TEST REAGNET-I and REAGENT-II. Then again add more
sample water to just spill over and tighten the stopper on bottle.
3. Now invert the reagent bottle for several times. If D.O is present in
the sample, sample color will eventually get orange-yellow and
flocculent precipitates will be formed.
4. Now let the sample stand for some minutes until precipitates settle
down.
5. After approximately two (2) minutes, upper half of the bottle
becomes limpid, add ten (10) drops of NUCLOTRASIS D.O TEST
REAGNET-III (Item Code: 01-13-3)
6. Again stopper the bottle and invert for several times until solution
becomes transparent. Now the sample is ready for titration. Also
note that more yellow the solution color is, more is the D.O present.
7. We recommend selecting the titrant solution based on your
expected/desired DISSOLVED OXYGEN residuals from low range
(LR) and high range (HR) tables below and use LR titrant for low
range test such as in boiler feed water (BFW) or use HR titrant for
high range such as in natural or wastewater.
8. Now carefully transfer 10 mL aliquot of the treated sample from
glass reagent bottle into calibrated cylinder provided with the kit.
Immediately cap both reagent bottle and cylinder with respective
caps.
9. Add one 1-2 drops of NUCLOTRASIS D.O TEST INDICATOR
SOLUTION (Item Code: 01-13-4) into the cylinder and mix. Blue
color will be developed if D.O is present in the sample and the
intensity of blue color developed will be proportional to
concentration of D.O present.
10. Now start adding NUCLOTRASIS D.O LR-TITRANT SOLUTION (Item
Code: 01-13-5) or NUCLOTRASIS D.O HR-TITRANT SOLUTION
(Item Code: 01-13-6) drop wise with gentle mixing and while
counting the number of drops added until the colorless solution is
obtained.
11. Note the total number of drops added and multiply with
multiplication factor mentioned in either table-I or table-II based on
selected sample range.
12. Report the final reading as required by the system.
REFERENCES:
1. Standard Methods for the Examination of Water and Wastewater
Table-II: For Dissolved Oxygen HR (0.5-5 & above ppm)
Range
(mg/L as O2)
Sample volume
(mL)
Multiplication
Factor
0.5-5.0 & above 10 0.5
Table-I: For Dissolved Oxygen LR (0.02-0.2 & above ppm)
Range
(mg/L as O2)
Sample volume
(mL)
Multiplication
Factor
0.02-0.2 10 0.02
PRODUCT INFORMATION FLYER