EMPLOY OF SILICA GEL ORGANICALLY MODIFIED AND IONICALLY IMPRINTED FOR SELECTIVE ON-LINE PRECONCENTRATION OF COPPER IONS

EMPLOY OF SILICA GEL ORGANICALLY MODIFIED AND IONICALLY IMPRINTED FOR SELECTIVE ON-LINE PRECONCENTRATION OF COPPER IONS. The present work purposes the preparation of a silica gel sorbent organically modified with 2-aminoethyl-3-aminobutylmethyldimethoxysilane (AAMDMS) and imprinted with Cu2+ ions by means surface imprinting technique and its use for selective on-line sorbent preconcentration of Cull ions with further UV-VIS spectrophotometric determination by flow injection analysis. The Cu2+-imprinted silica gel, when compared with non imprinted silica gel and silica gel, showed from the binary mixture Of Cu2+/Ni2+ relative selectivity coefficient (k') of 6.84 and 5.43 and 6.64 and 19.83 for the mixture Cu2+/Pb2+, thus demonstrating higher selectivity of Cu2+-imprinted silica gel towards Cull ions. Under optimized condition, the on-fine preconcentration method provided detection limit of 3.4 mu g L-1 and linear range ranging from 30.0 up to 300.0 mu g L-1 (r = 0.995). The accuracy of method was successfully assessed by analyzing different kind of spiked water samples with recovery values ranging from 92.2 up to 103.0%.