Trace Analysis of Hexavalent Chromium by Ion Chromatography-Mass Spectrometry

A recently developed method for the analysis of Cr(VI) with a direct isotope dilution (DID) quantification approach demonstrated the capability of the IC-MS/MS instrumentation, complementing the traditional ion chromatography separation with inductively coupled plasma mass spectrometry (ICP-MS) approach presented in method EPA 6800. The technique allowed to compensate for any loss of Cr(VI) occurring between collection and analysis time that can affect sample integrity and introduce possible biases in measured concentrations. The DID method achieved trace level analysis with an MDL of 2 ng/L.