LaMotte SMART3 Colorimeter - Manual (Page 131)

CHROMIUM, HEXAVALENT
DIPHENYLCARBOHYDRAZIDE METHOD
CODE 3645-SC
QUANTITY CONTENTS CODE
10 g *Chromium Reagent Powder *V-6276-D
1 Spoon, 0.1 g, plastic 0699
50 Filter Paper 0465-H
1 Funnel, Plastic 0459
*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.
Chromium may be present in water containing waste from industries such as metal
plating. It is considered to be a toxic chemical and, if present in an amount of over
0.5 ppm, is evidence of contamination from untreated or incompletely treated
industrial waste.
Chromium is one of a class of heavy metals found in the bottom mud of polluted
bodies of water. Certain shellfi sh are capable of concentrating this element,
endangering the health of its ultimate consumer, human or animal.
APPLICATION: Drinking, surface, & saline waters; domestic and
industrial wastewaters.
RANGE: 0.00–1.00 ppm Chromium
MDL: 0.01 ppm
METHOD: Hexavalent chromium reacts with 1,5
diphenylcarbohydrazide under acidic conditions to
form a red-purple color in proportion to the amount of
chromium present.
SAMPLE HANDLING &
PRESERVATION:
Analysis for chromium should be made as quickly as
possible after sample collection since storage in glass
or plastic containers may result in low chromate values.
INTERFERENCES: High concentrations of mercurous and mercuric ions
may impart a blue color to the chromium determination.
Iron and vanadium in concentrations above 1 mg/L may
result in a yellow color. However, the vanadium color
becomes negligible 10 minutes after the addition of
diphenylcarbohydrazide.
SMART3 Test Procedures 11.10 CHROMIUM, Hexavalent
Test P
rocedures