Reflectoquant® Molybdenum Test Strips, Catalog No. 16979/1
1. Method
In acidic solutions, molybdenum reacts with
toluene-3,4-dithiol to form a green complex, the concentration of
which is determined reflectometrically.
2. Measuring Range and Number of Determinations
| Measuring Range1) |
Number of Determinations |
| 1.7 - 75.1 mg/l MoO42- |
50 |
1) for conversion factors see
section 8
for measurement of concentrations > 45.0 mg/l
Mo see section 6
3. Applications
Sample Material:
Boiler water, cooling water
4. Influence of Foreign Substances
This was checked - in the case of interfering
ions up to concentrations of 1,000 mg/l - in solutions containing 15
mg/l and 0 mg/l Mo. The concentrations of foreign substances given in
the table lie below the limit at which the determination is interfered
with:
Concentrations of Foreign Substances in mg/l
or %
| Cu2+ |
10 |
S2- |
1 |
| NO3- |
1,000 |
SiO32- |
1,000 |
| PO43- |
1,000 |
Total Hardness |
38% |
5. Reagents and Auxiliaries
Please Note the Warnings on Labels!
The analytical test strips are stable
at least up to the date stated on the pack when stored in the closed
tube at +15° to +25°·C.
Package Contents:
Tube containing 50 analytical test strips
Bar code strip
2 bottles of reagent Mo-1
Other Reagents:
EM Quant® Molybdenum Test, Cat.
No. 10049, measuring range 5-250 mg/l Mo
colorpHast® Universal indicator strips pH 0-14, Cat. No. 9590
Titristar® Sodium hydroxide solution 10% GR, Cat. No.SX0607U
Titristar® Sulfuric acid 25%, Cat. No. SX1243M
CertiPUR® Molybdenum standard solution ready for use, 1,000 mg/l Cat No. 1.70227
6. Preparation
- Check whether the molybdenum content is
within the measuring range
Use the EM Quant® Molybdenum
Test as a guide. Samples containing more than 45.0 mg/l Mo must be
diluted with distilled water.
- · The pH must be within the range
4-6. Check with universal indicator strips. If pH is lower than
4, add sodium hydroxide solution dropwise; if greater than 6, add
sulfuric acid dropwise.
7. Procedure
- Observe the instructions for the RQflex
Reflectometer.
The following applies to the Molybdenum Test:
Measurement procedure A. Stored reaction time:
60 sec.
- Rinse the test vessel several times with the
solution to be tested (15-35°C). Then fill to the 10-ml mark.
- Add 2 level red microspoons (in the cap of
the Mo-1 bottle) of reagent Mo-1 and swirl to dissolve.
- Remove 1 analytical test strip and immediately
reclose the tube.
- Press START button of the reflectometer and
at the same time place the test strip in the measurement solution so
that both reaction zones are completely wetted.
- As soon as the beeper sounds (5 sec before
end of reaction time), remove the test strip from the solution and
shake off excess liquid. then insert the test strip all the way into
the strip adapter with the reaction zones facing the display.
- Read off the result from the display. The
result is automatically stored.
Notes:
- If the test strip is inserted into the
adapter after the reaction time has expired, renewed depression of
the START key will result in a false-high reading of the molybdenum
concentration.
- After every 5 measurements and at the end of
each workday, the strip adapter must be cleansed thoroughly with
water or ethanol.
8. Conversions
units required = units given x conversion factor
| Units Required = |
Units Given x |
Conversion Factor |
| mg/l Mo |
mg/l MoO42– |
0.600 |
9. Method Control
To check analytical test strips, equipment and
procedure:
Dilute molybdenum standard solution to 10 mg/l
Mo and analyze as described in section 7.
|
MSDS
(Material Safety Data Sheet)
