Sensitive Determination of Hexavalent Chromium in Drinking Water Using a Compact Ion Chromatography System

Instrument Type: IC

This record demonstrates that the method in AU179 can be run successfully using an Integrion Ion Chromatography (IC) system. AU179 describes modification of the conditions described in EPA Method 218.6, including use of the column in the 2 mm format and a smaller reaction coil to increase method sensitivity. The modified method, which is now US EPA Method 218.7, uses a Dionex IonPac AS7 column (2 × 250 mm), a 1000 μL injection volume, and postcolumn reaction (using a 125 μL reaction coil) followed by visible absorbance detection at 530 nm.

AU179: Sensitive Determination of Hexavalent Chromium in Drinking Water

Instrument Type: IC

The work shown here describes modification of the conditions described in EPA Method 218.6, including use of the column in the 2 mm format and a smaller reaction coil to increase method sensitivity. The modified method uses Dionex IonPac AS7 column (2 × 250 mm), a 1000 μL injection volume, and post column reaction (using a 125 μL reaction coil) followed by visible absorbance detection at 530 nm. This method permits an MDL for chromate of 0.001 μg/L. This results in a quantitation limit of 0.003 μg/L, which is more than sufficient for analysis at the proposed California PHG level of 0.02 μg/L.