In response to a draft scientific review released in September 2010, the EPA has issued guidance to all public water systems (PWS) recommending enhanced monitoring and sampling programs specifically for hexavalent chromium [also known as chromium-6 or Cr(VI)] in drinking water.

Read more about monitoring for hexavalent chromium in drinking water…

Background
Today there are two common colorimetric techniques using a Diphenylcarbazide (DPC) solution for determining Hexavalent Chromium (Cr+6) in RCRA site water samples. EPA Method 7196, a colormetric method, analyzes the untreated or filtered sample as is. EPA Method 7199, an ion chromatographic method, separates the Cr+6 ion from interferences and is then followed by post column reaction with DPC. Therefore, colored matrices or matrices containing chemical interferences may be better analyzed by ion chromatography as shown in the following example.

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