This method is intended for the separation and quantification of trivalent and hexavalent chromium ions in complex water systems including: refinery wastewater, power industry wastewater Flue Gas Desulphurization (FGD) wastewater, and contaminated groundwater at parts per billion (ppb) levels using IC-ICP-MS (Ion chromatograph (IC) coupled to an Inductively Coupled Plasma Mass Spectrometer (ICPMS) system). Samples are run with minimal sample preparation and do not require digestion. The chromium species Cr(III) and Cr(VI) can be detected at 0.1 ppb and quantitated at < 1 ppb. The linearity range for the method is from 1 ppb to 50 ppb. Quantitation of the total chromium value is suggested prior to analysis by this method to avoid overloading the column. Higher concentrations can be determined by volume dilution.