Chromate (hexavalent)
 
 
Visual Kits
Range MDL Method Kit Catalog No. Refill Catalog No.
0-1 & 1-10 ppm 0.05 ppm Diphenylcarbazide K-2810 R-2810
0-30 & 30-300 ppm 5 ppm Diphenylcarbazide K-2810D R-2810D
0-60 & 60-600 ppm 10 ppm Diphenylcarbazide K-2810A R-2810A
0-120 & 120-1200 ppm 20 ppm Diphenylcarbazide K-2810B R-2810B
0-1200 & 1200-12,000 ppm 200 ppm Diphenylcarbazide K-2810C R-2810C
Instrumental Kits
Range Method Kit Catalog No.
0.20-3.50 ppm Diphenylcarbazide K-2803
0.70-13.00 ppm Diphenylcarbazide K-2823

Method

References: APHA Standard Methods, 21st ed., Method 3500-Cr B (2005). ASTM D 1687-02, Chromium in Water, Test Method A.


Hexavalent chromium salts are used in numerous industrial processes. They are also used extensively as corrosion inhibitors in open and closed cooling water systems.

 

With the chromate test method, hexavalent chromium reacts with diphenylcarbazide under acid conditions to form a red-violet color. Results are expressed as ppm (mg/L) CrO4.