LaMotte SMART3 Colorimeter - Manual (Page 134)

APPLICATION: Drinking, surface, & saline water; domestic and industrial
waste.
RANGE: 0.00–1.00 ppm Chromium
MDL: 0.01 ppm
METHOD: The trivalent chromium is converted to hexavalent
chromium by permanganate under acidic
conditions. 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
interfere.
CHROMIUM, Hexavalent, Trivalent, Total SMART3 Test Procedures 11.10
Test P
rocedures