The ION Chromatograhic Determination of Cr(III)-Cr(VI) Using an EDTA ELUANT

Abstract
Recent work in our laboratory has involved the use of ethylene diaminete traacetic acid as an eluant for the ion chromatographic determination of transition metals. We have continued this investigation into the use of EDTA by developing a potential method for the determination of Cr(III) and Cr(VT) in the same solution at the ppm level. The method involves the separation of the species as anions—the monovalent Cr(III)-EDTA anion and the divalent dichromate ion—followed by the detection of the species using a variable wavelength UV detector. The detection limits are approximately 2 ppm and the precision and stability of the system are within 6% RSD over the course of a working day. The linear operating range is in excess of two orders of magnitude.