LaMotte COD Plus Colorimeter 1922-EX2 - Manual (Page 96)

MOLYBDENUM - HIGH RANGE
THIOGLYCOLATE METHOD • CODE 3699-02-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
0372
*WARNING: Reagents marked with a * are considered hazardous substances. Material
Safety Data Sheets (MSDS) are supplied for these reagents. For your safety read label
and accompanying MSDS before using.
Molybdenum occurs naturally in the earth’s crust as molybdenite and wolfenite,
and is an important element in many biochemical reactions, including nitrogen
fixation. 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
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.
COD PLUS TEST PROCEDURES 6/02 MOLYBDENUM - HIGH RANGE 1/2