LaMotte SMART 2 - Manual (Page 113)

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 shellfish 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 Chromium
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.
Smart2 TEST PROCEDURES 2.04 Chromium-Hexavalent 1/2