LaMotte SMART3 Colorimeter - Manual (Page 255)

PHOSPHATE – HIGH RANGE
VANADOMOLYBDOPHOSPHORIC ACID METHOD
CODE 3655-SC
QUANTITY CONTENTS CODE
4 x 30 mL *VM Phosphate Reagent *4410-G
1 Pipet, 1.0 mL, plastic 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.
Phosphate treatments in boiler and cooling water and other industrial water
systems are run at levels up to 100 ppm orthophosphate. These high levels permit
the use of a simpler, high range test.
APPLICATION: Boiler, cooling, and industrial water.
RANGE: 0.0–70.0 ppm Phosphate
MDL: 0.5 ppm
METHOD: Orthophosphate reacts in acid conditions
with ammonium vanadomolybdate to form
vanadomolybdophosphoric acid. This yellow color is
proportional to the concentration of orthophosphate and
is read colorimetrically.
SAMPLE HANDLING
& PRESERVATION:
If the analysis cannot be performed the same day of
collection, the sample should be preserved by the
addition of 2 mL of concentrated sulfuric acid or 40 mg
mercuric chloride per liter and refrigerated at 4°C.
INTERFERENCES: Silica interferes only if the sample is heated. Arsenate,
fl uoride, thorium, bismuth, sulfi de, thiosulfate, and
thiocyanate cause negative interference.
SMART3 Test Procedures 11.10 PHOSPHATE, High Range
Test P
rocedures