LaMotte SMART3 Colorimeter - Manual (Page 209)

MOLYBDENUM – HIGH RANGE
THIOGLYCOLATE METHOD • CODE 3699-03-SC
QUANTITY CONTENTS CODE
2 x 30 mL *Mo Buffer *3997-G
2 x 30 mL *Molybdenum Oxidizing Reagent *6485-G
2.5g *Molybdenum Indicator Powder *6486-S
1 Spoon, 0.05g, plastic 0696
2 Pipets, 1.0 mL, plastic w/cap 0354
*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.
Molybdenum occurs naturally in the earth’s crust as molybdenite and wolfenite,
and is an important element in many biochemical reactions, including nitrogen
fi xation. In industrial processes, such as the operation of boilers and cooling
towers, molybdenum, in the form of sodium molybdate, is used as a corrosion
inhibitor.
APPLICATIONS: Boiler and cooling water.
RANGE: 0.0–50.0 ppm Molybdenum
MDL: 0.6 ppm
METHOD: Calcium thioglycolate reacts with molybdenum to give a
yellow color with an intensity proportional to the amount
of molybdenum present.
SAMPLE HANDLING
& PRESERVATION:
Molybdenum samples may be stored in either plastic or
glass containers.
INTERFERENCES: Nickel levels less than 50 ppm do not interfere;
aluminum levels less than 10 ppm do not interfere;
chromate at higher concentrations interferes due to the
intense yellow color. Ferrous iron levels below 50 ppm do
not interfere, but low levels of ferric iron will cause a large
blank. Highly buffered samples may exceed the capacity
of the system possibly producing inaccurate results.
Samples with high levels of nitrite will eventually develop
a pale orange color. Scan the sample immediately to
avoid this inteference.
SMART3 Test Procedures 11.10 MOLYBDENUM, High Range
Test P
rocedures