O Alkalinity

SPECIFICATIONS

Method           : Titration

Range              : Not Specific period

Testing time    : Not Specific period

Calculations    : 10 mL sample size

                          P-alkalinity as ppm CaCO₃ = (100) x (mL of SO226 used in Step 6.)           

                          50 mL sample size

                          P-alkalinity as ppm CaCO₃ = (20) x (mL of SO226 used in Step 6.) 

INTERFERENCES (All Alkalinity)

1.      Phosphates, polymer, silica, organic acids and ammonia may contribute to alkalinity and could cause a sliding endpoint.

2.      High sulfate levels yield turbidity that can mask the endpoint color.

3.      Suspended solids containing fine particles of CaCO₃ and Mg(OH)₂ can cause a fading endpoint.

4.      Free chlorine can interfere by destroying the indicator. Add 3 drops of CRD-4 (SO120) before adding the indicator.

The table below lists the recommended sample size for different types of water. Others sizes may be used depending on the expected alkalinity level.

Type of Water	Sample Size
Boiler water	10 mL
Open cooling system	50 mL
Others	50 mL

PROCEDURE

1.      Rinse the graduated cylinder with the sample to be tested.

2.      Measure the appropriate size of unfiltered sample and pour it into a casserole.

3.      Add 2 drops of P-Indicator (SO222).

Note: If the sample does not turn pink, the P-alkalinity is zero.

If the sample turns pink, proceed to the next step.

4.      Fill the buret up to the zero mark with N/50 Sulfuric Acid (SO226)

5.      Open the buret valve and add N/50 Sulfuric Acid (SO226) to the casserole in a steady stream of drops while stirring the sample.

As soon as one drop turns the entire sample colorless, IMMEDIATELY close the valve.

Check the buret scale and record the number of mL of SO226 that was used to cause the color change. Do not refill the buret. Use the same sample to test for M-alkalinity.

Check the buret scale and record the number of mL of SO226 that was used to cause the color change. Do not refill the buret. Use the same sample to test for M-alkalinity

O Alkalinity

Titration Analytical Procedure

-          Sample : 10 mL/20 mL/50 mL/100 mL

-          Add Indicator (460-SO222) two drops, Swirl to mix (Colour : Red).

-          Titration with Titrant (460-SO226) until colour change from Red to Colourless.

-          Add Indicator (460-SO260) seven drops, Swirl to mix (Colour : Blue).

-          Titration with Titrant (460-SO226) until colour change from Blue to Red.

-          Sample water used = 10   mL,  The result (ppm CaCO3)  = Titrant used x 100

Sample water used = 20   mL,  The result (ppm CaCO3)  = Titrant used x 50

Sample water used = 50   mL,  The result (ppm CaCO3)  = Titrant used x 20

Sample water used = 100 mL,  The result (ppm CaCO3)  = Titrant used x 10