ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 25, Number 4
JKCSEZ 25(4)
August 20, 1981 

A simple semiquantitative procedure was developed for the determination of sub-ppm level of chromium(Ⅵ) in aquatic samples by using an analytical micro-column packed with diphenylcarbazide(DPC) gel beads. DPC gel beads were prepared by swelling XAD-2 resin(115∼150 mesh in dry condition) in ethanol for 10min, packing into a glass column(1.5 mm bore, 65nm length) and adsorbing 1ml of ethanol solution of 2×10-3M DPC for 20min at room temperature. When 0.5ml of ethanol solution containing chromium(Ⅵ) was passed through the DPC gel column for 40min, the original white color of the reagent gel turned to red-violet from the up-stream of the column. As the length of colored band was proportional to the total amount of chromium(Ⅵ) in the sample solution passed through the column, the concentration of chromium(Ⅵ) could be determined from the calibration line which had been prepared by using the standard solution. Chromium(Ⅵ) ion as small as from 0.1 to 0.8 ppm could be determined with ±5~±15% relative errors. Since other interfering cations were few, 100-fold excess of Fe(Ⅲ), 50-fold excess of Cu(Ⅱ) could be masked with EDTA. This method was successfully applied to the analysis of chromium(Ⅵ) in industrial effluents.