Chromium-6+ analysis with the San++

Chromium is found naturally in rocks, plants, soil, humans and animals, but can also enter the environment via e.g. wastewater from metal finishing and plating industries and discharges from chromate-treated waters. The most common forms that occur are Chromium-3+ and Chromium-6+. Cr6+ is very toxic and can cause serious health problems at very low concentrations in drinking water. To detect these very small amounts of Cr6+ an analysis method with a very high sensitivity is needed.

CFA long flow cell

Skalar has developed a very sensitive routine analysis method for determination of Cr6+ on their San++ continuous flow analyzer, using a Long Capillary Flow Cell (LCFC). The photometric determination is based on the reaction of diphenylcarbazide with hexavalent chromium in an acid medium, producing a red-purple color that is measured at 550 nm. Skalar’s procedure for Cr6+ analysis is in accordance with ISO 23913-Cr6+ 2006 and ASTM D 1687-02, Cr6+ .

Typical performance data and analysis results of Skalar’s Cr6+ application on the San++ analyzer using the LCFC can be found below.

San++ analysis data Cr6+

Range: 0.1- 20 μg/L

Method Detection Limit (MDL): 0.02 μg/L

Coefficient of Variation (CV) (%): 0.23%

Regression (r): 0.9999

Calibration curve (0.1 - 20 μg /L Cr6+):

Graph 2

Cr6+ calibration (0.1 - 20 μg /L Cr6+):

Cr6 run

The Skalar San++ method is capable of detecting Cr6+ down to concentrations as low as 0.02 μg/l, whilst still yielding superb reproducibility and stability.The determination of Total Chromium is also available on the San++ continuous flow analyzer.

If you require more information on the above application or other Skalar analyzers, please do not hesitate to contact us.