Selective spectrophotometric determination of trace amounts of chromium(VI) using a flow injection system with a microcolumn of zirconium(IV) oxide modified silica gel
Abstract
Zirconium(IV) oxide coated on a silica gel surface was found to be very effective for extracting CrVI from aqueous solutions at a pH of about 3. A microcolumn packed with this material was inserted into a flow injection system for the separation and preconcentration of CrVI. By this process, a concentration level of 2 ppb was detected with a relative standard deviation of 2.4%. Because of the high selectivity of the immobilized substrate, it was possible to determine CrVI in the presence of larger amounts of other ions. The analysis was also carried out on natural water spiked with CrVI, and compared with a standard method.