USE OF FLOW-INJECTION FLAME ATOMIC-ABSORPTION SPECTROMETRY FOR SLURRY ATOMIZATION - DETERMINATION OF COPPER, MANGANESE, CHROMIUM AND ZINC IN IRON-OXIDE PIGMENTS

A procedure for the determination of copper, manganese, chromium and zinc in slurries of commercial iron oxide pigments using flame atomic absorption spectrometry is described. The samples are suspended in water and introduced directly into the spectrometer using a flow injection manifold with air-compensation of the difference between the peristaltic pump flow-rate and the nebulizer uptake rate. In order to avoid matrix effects, calibration is achieved by using slurries prepared from previously analysed iron oxide samples. Excellent agreement was found between the results of the slurry procedure and those obtained by conventional acid-dissolution.