Lab Science News - Science, chemistry and environmental news from laboratory experts

Posts Tagged ‘EPA Method 7199’

Hexavalent Chromium in Aqueous Samples Containing Color and Chemical Interferences

Friday, February 4th, 2005

Hexavalent-Chromium-in-Aqueous-Samples-Containing-Color-and-Chemical-InterferencesBackground
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.

(more…)