LaMotte EC-5 User Manual

TOTAL DISSOLVED SOLIDS (TDS)

L

Mott

DIRECT READING TITRATOR METHOD

MODEL TDS-DR · CODE 4801-DR

QUANTITY CONTENTS CODE

60 mL *TDS Reagent A *4802DR-H
60 mL *TDS Reagent B *4803DR-H
15 mL *Methyl Orange Indicator, 0.1%

w/Halidex
2 Direct Reading Titrators, 0-1000 Range 0384
2 Test Tubes, 5-10-15 mL, glass, w/caps 0778
1 Pipet, 1.0 mL, plastic 0354
60 mL Demineralizer Bottle 1151
2 Resin Columns 1079

**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 individual reagents or test kit components, use the specified code
number.

Read the LaMotte Direct Reading Titrator Manual before proceeding. The
Titrator is calibrated in terms of Total Dissolved Solids (TDS) expressed as parts
per million calcium carbonate (CaCO3). Each minor division on the Titrator
scale equals 20 ppm.

Two identical Direct Reading Titrators are furnished in this kit. Use one
Titrator to dispense TDS Reagent A; use the second to dispense TDS Reagent
B. Do not interchange the Titrators.

The Demineralizer Bottle is the source of all the demineralized water used in
this test. Read the instruction sheet before proceeding.

CARE OF THE RESIN COL UMN

At the conclusion of each test, treat the resin column with demineralized water
as described in Step 6. Stopper and cap the moist column between uses.

*2299-E

PRO CE DURE

PART A

1. Fill a test tube (0778) to 10 mL line with sample water.

2. Add 3 drops *Methyl Orange Indicator, 0.1% w/Halidex (2299). Cap and

mix. Solution will turn yellow.

3. Fill a Direct Reading Titrator (0384) with *TDS Reagent A (4802DR).

Insert Titrator into the center hole of the test tube cap.

4. While gently swirling the test tube, slowly press the Titrator plunger to

dispense *TDS Reagent A until the yellow color changes to pink. Read the
test result directly from the scale where the large ring on the Titrator meets
the Titrator barrel. Record as Result A. Discard the test sample and any
TDS Reagent A remaining in the Titrator.

PART B

In the second part of the TDS test, the sample water is passed through an ion
exchange column, which exchanges the various cations (Na, Ca, Mg, etc.) for
hydrogen ions, which are then titrated with *TDS Reagent B. Two ready-to-use
resin columns are furnished in this kit. Each column may be used for twenty
water samples before being discarded. Keep a record of the number of times a
column is used.

5. Suspend a resin column (1079) in the second test tube (0778) by inserting

the tip of the column into the center hole of the test tube cap.

6. Add a small amount of Demineralized Water (3 or 4 mL) to the resin

column.

7. Use the 1.0 mL pipet (0354) to add 5 mL of sample water to the column.

8. When all of this water has passed through the column, remove the cap and

discard the solution collected in the tube.

9. Replace the cap and the resin column and continue adding sample water

to the column, using the pipet, until exactly 10 mL has been collected in
the test tube. Remove the cap and column.

10. Add 3 drops of *Methyl Orange Indicator, 0.1% w/Halidex (2299). Cap

and mix. Solution will turn red.

11. Fill the second Titrator with *TDS Reagent B (4803DR). Titrate the

sample until the red color changes to yellow. Read the test result directly
from the scale where the large ring on the Titrator meets the Titrator
barrel. Record as Result B.

12. Add Result A and Result B. Record as ppm total dissolved solids as

CaCO3.

LaMOTTE COM PANY

Helping Peo ple Solve An a lyt i cal Challenges

PO Box 329 • Chestertown • Mary land • 21620 •USA

800-344-3100 • 410-778-3100 (Out side USA) • Fax [phone]

Visit us on the web at www.lamotte.com

®

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