Preconcentration of copper(II) on immobilized 8-quinolinol in a flow-injection system with an ion-selective electrode detector

A column containing 8-quinolinol, immobilized on porous glass, is used for preconcentration and medium exchange in a flow-injection system with a copper ion-selective electrode detector. The metal ions are bound to the chelating ion exchanger while the anions and inert sample components pass to waste without contacting the electrode. Acid is then injected to elute the ions into a neutralizing buffer passing the electrode. Matrix effects are thus reduced because all measurements are made in the same buffer. The detection limits are 10^?7 and 3 × 10^?8 M copper(II) for sample volumes of 5 and 25 ml, respectively. The maximum throughput is 12 and 5 samples h^?1 for the two stated injection volumes.