LaMotte MOLYBDENUM KIT - Manual (Page 2)

BEFORE TESTING:
A. Replace the black cap on *Mo Buffer (3997) with the plastic pipet assembly (0372).
B. Replace the black cap on Mo Titrant (3999) with the glass pipet assembly (0371).
PREPARATION OF *MO INDICATOR (4000-H)
*Mo Indicator (4000-H) must be prepared when you receive the kit.
If stored in a cool, dark place, it can be used for about 6 months.
1. Very carefully pour all of the *Denatured Alcohol (3998) into
the bottle containing the Sym-Dyphenylcarbazone (4001). Cap
and shake gently to mix.
2. Insert the dropper plug (28831) by fi rmly pressing into the neck
of the bottle until you hear a snapping sound. Recap bottle using
cap (28832).
3. Apply the Mo Indicator label (37088-4000-H) over top of the
label on the bottle.
NOTE: Consult MSDS.
SAMPLES LESS THAN 20 ppm MOLYBDENUM
1. Fill two clean test tubes (0970-S) to the 10 mL line with sample water.
2. Add 1.0 mL *Mo Buffer (3997) to each tube. Swirl to mix.
3. Holding bottle vertically, add 10 drops of *Mo Indicator (4000) to each tube.
Swirl to mix. Sample will turn pinkish-orange.
4. Use one tube as the “reference tube” and the other as the “sample tube.”
TO THE REFERENCE TUBE
5. Fill pipet (0371) with Mo Titrant (3999). While gently swirling the tube, add
Mo Titrant (3999), one drop at a time, until pink color changes to yellow, and no
further color change occurs. Hold pipet vertically.
TO THE SAMPLE
6. Fill pipet (0371) with Mo Titrant (3999). While gently swirling the tube, add Mo
Titrant (3999), one drop at a time, until pink color changes to yellow, matching
the reference tube. Count the number of drops added. Hold pipet vertically.
7. Multiply number of drops used in Step 6 by 2. Record as ppm Molybdenum.
# of drops x 2 = ppm Molybdenum (Mo)
To convert Molybdenum (Mo) reading to Molydbate (MoO
4
= ), multiply by
1.7. Record as ppm Molybdate.
To convert Molybdenum (Mo) reading to Sodium Molybdate
(Na
2
MoO
4
- 2H
2
O), multiply by 2.52. Record as ppm Sodium Molybdate.
SAMPLES GREATER THAN 20 ppm MOLYBDATE
1. Use the 1.0 mL pipet (0354) to add 1.0 mL of sample water to each test tube (0970-S).
2. Use the pipet (0372) to add 5 drops of *Mo Buffer (3997) to each tube. Swirl to mix.
3. Follow Steps 3 to 6 above.
4. Multiply number of drops used in Step 6 by 20. Record as ppm Molybdenum.
# of Drops x 20 = ppm Molybdenum (Mo)