AL KA LIN ITY TEST KIT
EPA
COMPLIANTCOMPLIANT
MODEL DR-A • CODE 3467
QUAN TITY CON TENTS CODE
15 mL *Alkalinity Indicator #1, pH 8.3 *3870-E
15 mL Alkalinity Indicator #2, pH 4.5 3869-E
60 mL *Alkalinity Titration Reagent B *4493DR-H
1 Test Tube, 5-10-15 mL, glass, w/cap 0778
1 Direct Reading Titrator, 0-200 Range 0382
*WARNING: Reagents marked with an * are considered to be potential
health hazards. To view or print a Material Safety Data Sheet (MSDS) for
these reagents go to www.lamotte.com. To obtain a printed copy, contact
LaMotte by e-mail, phone or fax.
To order a complete set of refill reagents, order as R-3467. To order individual
reagents or test kit components, use the specified code number.
NOTE: Carefully read the instruction manual for the LaMotte Direct
Reading Titrator before performing the titration described below. The
Titrator is calibrated in terms of alkalinity expressed as parts per million
(ppm) calcium carbonate (CaCO3). Each minor division on the Titrator
scale equals 4 ppm CaCO3.
EPA AC CEPTED PRO CE DURE
To qualify as an EPA accepted test and to achieve greatest accuracy, the
normality of the *Alkalinity Reagent B should be checked periodically.
Standardize *Alkalinity Reagent B by titrating against 0.05N Na2CO3;
1 mL = 1.00 mg CaCO3. Should a variance of greater than 0.3 mL of
*Alkalinity Reagent B occur, discard and order a fresh bottle of
*Alkalinity Reagent B (Code 4493DR-H). A CaCO3 equivalent
standard of 100 ppm is also available (Code 6199-H). Refer to Standard
Methods, 16th edition, 403, 1985.
PHENOLPHTHALEIN (P) AL KA LIN ITY PRO CE DURE
1. Fill test tube (0778) to 5 mL line with sample water.
2 Add two drops of *Alkalinity Indicator # 1 (3870). Cap and mix. If
a red color develops, P alkalinity is present. Proceed to Steps 3-5.
If no red color develops, P alkalinity is not present. Proceed to Step
3 and then skip to Total Alkalinity Procedure Steps 6-9.
3. Fill Direct Reading Titrator with *Alkalinity Reagent B (4493).
Insert Titrator in center hole of test tube cap.
4. While gently swirling tube, slowly depress plunger until red color
disappears. Record test result where plunger tip meets titrator scale.
Record as P Alkalinity in ppm CaCO3.
EXAMPLE: Plunger tip is 3 minor divisions below 80 line. The
test result is 80 + (3 x 4) = 92 ppm, since each division is equal to
4 ppm.
5. If plunger tip reaches the bottom line on the titrator scale (200
ppm) before the endpoint color change occurs, refill Titrator and
continue titration. When recording test result, include original
amount of reagent titrated (200 ppm).
NOTE: Do not move the titrator plunger after P Alkalinity
endpoint has been obtained.
TO TAL (T) AL KA LIN ITY PROCEDURE
6. Without moving plunger, remove Titrator and test tube cap from
test tube containing sample from Step 4.
7. Add two drops Alkalinity Indicator #2. Cap and swirl to mix. A
blue color will appear. Insert Titrator in center hole of test tube cap.
8. While gently swirling tube, slowly depress plunger until blue color
changes to green. Record test result as T Alkalinity in ppm CaCO3.
Include total amount of titration reagent added. (See Step 5).
9. If only Total Alkalinity is to be tested, perform Steps 1, 7 and 8
only, using a full titrator for Step 8.
CAL CU LA TION OF AL KA LIN ITY RE LA TION SHIPS
Results obtained from Phenolphthalein and Total Alkalinity
determinations offer a means for the stoichiometric classification of
three principal forms of Alkalinity present in many water supplies.
Classification attributes the entire alkalinity to bicarbonate, silica,
phosphoric and boric acids. This classification system further assumes
incompatilibity of Hydroxide and Bicarbonate Alkalinities in the same
sample. Since calculations are on a stoichiometric basis, ion
concentrations in the strictest sense are not represented in the results.
According to this scheme:
A. Carbonate Alkalinity is present when Phenolphthalein is not zero
but is less than the Total Alkalinity.
B. Hydroxide Alkalinity is present if Phenolphthalein Alkalinity is
more than one-half the Total Alkalinity.
C. Bicarbonate Alkalinity is present if Phenolphthalein Alkalinity is
less than one-half the Total Alkalinity.
Mathematical conversion of the result is shown in the following table:
To tal, Car bon ate, Bi car bon ate and Hy drox ide Al ka lin ity
Re sult of
Ti tra tion
Re la tion ships Be tween Phenolphthalein,
Hy drox ide
Al ka lin ity as
CaCO
3
Carbonate
Alkalinity as
CaCO
3
Bicarbonate
Alkalinity as
CaCO
3
P = 0 0 0 T
P < ½T 0 2P
T - 2P
P = ½T 0 2P 0
P > ½T
2P - T 2(T - P)
0
P = T T 0 0
LaMOTTE COM PANY
Helping Peo ple Solve An a lyt i cal Chal lenges
®
PO Box 329 • Chestertown • Mary land • 21620 • USA
800-344-3100 • 410-778-3100 (Out side USA) • Fax 410-778-6394
Visit us on the web at www.lamotte.com
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