Determination of copper(II) and iron(III) in some anaerobic adhesive formulations using high-performance liquid chromatography

Abstract

The determination of copper(II) and iron(III) in some anaerobic adhesive formulations has been investigated using reversed-phase high-performance liquid chromatography. A typical anaerobic adhesive formulation was first dissolved in dichloromethane before being extracted with 0.1 M HCl. After centrifugation, the aqueous layer was passed through a C₁₈ Sep-Pak cartridge and the eluate mixed with 8-hydroxyquinoline (oxine) in order to form the corresponding Cu^II-and Fe^III-oxine complexes. These complexes were then extracted into dichloromethane and the organic phase was passed through a silica Sep-Pak cartridge. After drying the cartridge, the complexes were eluted with methanol and injected on to a C₁₈ reversed-phase column using a mobile phase of acetonitrile (made 1 × 10^–2M in oxine) and 0.1 M acetate buffer, pH 6.0 (made 0.1 M in KNO₃)(1 + 1). Detection of the metal complexes was achieved using a spectrophotometric detector operated at 400 nm. Limits of detection of the order of 100–250 p.p.b. of Cu^II and 250–600 p.p.b. of Fe^III can typically be achieved.