Rapid and Sequential Determination Chromium (Ⅲ)-Chromium (Ⅵ) by Flow Injection Analysis-Atomic-Absorption Spectrometry

A rapid and sensitive method for the sequential determination of Cr(Ⅲ)-Cr(Ⅵ) based on FIA-AAS has been develpoed. A micro-column of activated alumina was used in the FIA manifold to separate and pre-concentrate Cr(Ⅲ) from Cr (Ⅵ) in aqueous solution before detection at 357. 8nm.Linear calibration for Cr(Ⅲ) and Cr(Ⅵ) was established over the concentration range 0-1000μg/L. The satisfactory results were obtained for the waste water determination of electrodepositon and switch plants. The relative standard deviations were 2.8% for Cr(Ⅲ) and 1.8% for Cr(Ⅵ) and the recoveries were 105% for Cr(Ⅲ) and 113% for Cr (Ⅵ) respectively.