THICK-FILM VOLTAMMETRIC SENSORS FOR TRACE COPPER-BASED ON A CATION-EXCHANGER-MODIFIED SURFACE

Strip-type, preconcentrating/voltammetric sensors, prepared by incorpo rating a cation-exchange resin within screen-printed carbon inks, are described. Such single-use strips combine the efficient electrostatic accumulation of heavy metals with the use of ''mercury-free'' surfaces . The uptake of copper(II) from dilute solutions (under open circuit c onditions) is followed by voltammetric measurements in a separate blan k solution. Various experimental variables have been optimized to yiel d low detection limits (e.g. 0.5 mu g 1(-1) with 10 min accumulation) and good reproducibility (relative standard deviation, 2%). The applic ability to assays of drinking water is demonstrated.