LaMotte AST Series Professional Soil Test Outfits - Manual (Page 31)

PROCEDURE
Read the Direct Reading Titrator instructions on page 6 before
proceeding. The Titrator is calibrated in ppm chloride. Each minor
division on the Titrator scale equals 20 ppm.
1.
Fill a clean test tube (0701) to 15 mL line with deionized water.
2. Use the 1 g spoon (0697) to add 3 measures of soil sample. Add 0.5
mL of Charcoal Suspension (5638). Cap and shake for 5 minutes.
3. Use funnel (0459) and filter paper (0465) to filter soil (see How to
Use a Funnel and Filter Paper, page 10). Collect the soil filtrate. It
will be used as the extract for the chloride test.
NOTE: The extract may be slightly turbid. This will not interfere
with the test result.
4. Fill the test tube (0778) to 10 mL line with soil extract.
5. Add 3 drops of *Chloride Reagent #1 (4504). Cap and mix.
Solution should turn yellow.
6. Fill the Titrator (0384) with *Chloride Reagent 2S (7624). Insert
Titrator into center hole of test tube cap.
7. While gently swirling the tube, slowly press plunger to titrate with
*Chloride Reagent 2S until yellow color changes permanently to
brick-red. Read result where plunger meets the scale. Record as ppm
Chloride.
8. If the Titrator reaches the bottom mark on the scale before the color
change occurs, refill and continue titration. Include original amount
(1000 ppm) in final result.
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