LaMotte AM-21 Water Pollution Detection Outfit - Manual (Page 48)

The LaMotte Total Dissolved Solids Outfit is furnished with two
ready-to-use resin columns. Each resin column can be used for twenty water
samples, after which it should be discarded. Keep a record of the number of
times the resin column is used.
5. Suspend the resin column (1079) in the second test tube (0778).
6. Use 1 mL pipet (0354) to add 3-4 mL of deionized water (5115) to the
resin column.
7. Use the 1 mL pipet (0354) to add 5 mL of sample water. Discard all of
the solution that has passed through the column then continue adding
the water sample until at least 10 mL has been collected.
8. Water that has passed through the resin column is now poured into the
first test tube (0778) and the volume adjusted to exactly 10 mL.
9. Add 3 drops of Methyl Orange Indicator with Halidex (2299). Cap and
mix.
10. The second Titrator (0384) is filled with *TDS Reagent B (4803). The
*TDS Reagent B (4803) is added until the red color changes to yellow,
swirling to mix after each addition. Read the test result directly from the
scale where the large ring on the Titrator meets the Titrator barrel. This
is result “B.”
11. Add result “A” to result “B.” The sum is equal to the total dissolved
solids in parts per million expressed as calcium carbonate.
Care of Resin Column
At the conclusion of any test, the resin column should be treated with
Distilled Water (5115) as in step 6, then stoppered and capped until used
again.
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