Incorporation of electrodialysers into the conduits of flow injection–atomic absorption spectrometry systems. Determination of copper(ii) ions in multivitamin tablets after enhancement of mass transfer through a passive neutral membrane

Abstract

An electrodialyser unit was designed, incorporated into the conduits of a flow injection (FI) system and employed for the removal of suspended solids before detection by AAS. The combined electrodialyser–FI–AAS system was applied to the determination of copper(ii) in multivitamin and mineral tablets. The proposed system is fully computerised and is able to determine copper(ii) in samples at a frequency of 14 samples h^–1 with a sample interaction of 0.058%. The electrodialysis efficiency was 94%, which is a dramatic improvement over previous systems with passive neutral membranes. The calibration graph is linear between 1 and 60 mg l^–1. The detection limit is 1.44 mg l^–1. The results obtained for copper(ii) in multivitamin and mineral tablets with the proposed system compared favourably with those obtained with the standard manual AAS method.