LaMotte PHOSPHONATE TEST KIT FI-DR - Manual (Page 2)

PRO CE DURE
For most accurate results, a blank test should be run on a sample of the
water containing no phosphonate. Any result from this blank test should
be subtracted from the result recorded in Step 6.
1.
Fill the test tube (0778) to the 10 mL line with sam ple wa ter.
2. Add 1 drop of Sodium Thiosulfate (6155) and 5 drops of *Fluoride
Inhibitor (3929).
3. Use the 0.1 g measuring spoon (0699) to add one level measure of
Xylenol Orange (6165). Swirl to dissolve.
4. Best results are obtained in the pH range 2.5-3.0. This adjustment is
made by adding *Hydrochloric Acid (6130) drop by drop to the
sample and using the pH paper (2958) to test the solution. After each
addition of *Hydrochloric Acid (6130) dip a strip of pH paper, torn
from the roll, into the test solution for 5 seconds. Compare the
resulting color with the color standards on the side of the pH paper
container. Add *Hydrochloric Acid (6130) until the color of the pH
paper matches the pH 2.8 color standard. The sample will be yellow.
5. Replace the regular cap on the bottle of Thorium Nitrate (6158PS)
with the dispenser cap (0601). Fill the Direct Reading Titrator (0378)
with this reagent. Insert the Titrator into the center hole of the
titration tube cap.
NOTE: Replace the regular cap on the Thorium Nitrate bottle for
storage.
6. While gently swirling the titration tube, slowly press the plunger to
titrate until the solution changes from yellow to pink. Read the test
result directly from the scale where the large ring on the Titrator meets
the Titrator barrel. Record the result in ppm phosophonate.
LaMOTTE COM PANY
Helping Peo ple Solve An a lyt i cal Challenges SM
PO Box 329 • Chestertown • Mary land • 21620 • USA
800-344-3100 • 410-778-3100 (Out side U.S.A.) • Fax 410-778-6394
Visit us on the web at www.lamotte.com
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