Abstract: A new method for separation of chromium(Ⅲ) and chromium(Ⅵ)in food with 201×7-strong basic anion exchangeresin and their determination with ICP-MS was reported. After samples were digested by a microwave digestion procedure withconcentrated nitric acid and hydrogen peroxide, the liquid obtained was fall through the column of ion exchange, and the Cr(Ⅵ)was exchanged with strong basic anion exchange resin, the Cr(Ⅲ)was separated, and then the exchange resin was washed by thesolution of HNO3(5%)and L-ascorbic acid(0.005%), so the solution contain Cr(Ⅵ) was obtained. With the Sc using as internalelement, the method of internal calibration was used in the determination of Cr(Ⅲ) and Cr(Ⅵ). The recovery for spiking sampleis 98.6%～99.6%, the relative standard deviation is 2.1%～3.5%. This method is simple, rapid and accurate, and it also can beused in the testing of Cr(Ⅲ) and Cr(Ⅵ)in drinking water, and wastewater.

Key words: ICP-MS, food, Cr(Ⅲ), Cr(Ⅵ), ion-exchange method