Determination of zinc in pharmaceutical products using an electrodialyser incorporated into a flow system

An electrodialyser unit has been designed, incorporated into the conduits of a flow injection (FI) system, and employed for the removal of interferences in the determination of zinc(II) in multivitamin tablets. The proposed system is fully computerised and is able to determine zinc(II) at a frequency of 18 samples/h with a sample interaction of 0.0015%. The calibration graph is linear between 1 and 20 mg/L. The detection limit is 0. 998 mg/L. The results obtained for zinc(II) in multivitamin tablets with the proposed system compared favourably with those obtained with the standard manual AAS method.