This document specifies a method for the determination of hexavalent chromium [Cr(VI)] and trivalent chromium [Cr(III)] in water by liquid chromatography with inductively coupled plasma mass spectrometry (LC-ICP-MS) after chelating pretreatment. This method is applicable to the determination of Cr(VI) and Cr(III) dissolved in wastewater, surface water, groundwater, or drinking water from 0,20 μg/l to 500 μg/l of each compound as chromium (Cr) mass. Samples containing Cr at concentrations higher than the working range can be analysed following appropriate dilution of the sample.