Determination of titanium(IV) and chromium(VI) with 2,7-dichlorochromotropic acid and 1,5-diphenylcarbazide on the solid phase

Abstract

Possibility of the selective determination of Ti(IV) and Cr(VI) by diffuse reflection spectroscopy after their simultaneous adsorption from one sample on a two layer substrate is studied. Titanium(IV) is adsorbed on a fiber filled with a cation exchanger (PANV KU 2) and determined with 2,7 dichlorochromo tropic acid; chromium(VI) is adsorbed on a fiber filled with an anion exchanger (PANV AV 17) and deter mined with 1,5 diphenylcarbazide. Conditions are selected for the simultaneous adsorption of titanium and chromium in the batch and dynamic modes. Conditions are optimized for the determination of titanium with 2,7 dichlorochromotropic acid on PANV KU 2. The selectivity of titanium and chromium determination in the presence of foreign ions is studied. Calibration graphs are linear in the ranges 5-40 and 2-20 ng/mL for Ti(IV) and Cr(VI), respectively; the detection limits are 4 and 2 ng/mL. The possibility of determining Ti(IV) and Cr(VI) in one sample at their ratios from 5 : 1 to 1 : 4 is shown.