Validation of methods for the determination of aluminium in fish gills by INAA and ICP-MS

Instrumental neutron activation analysis (INAA) and inductively-coupled plasma mass spectrometry (ICP-MS) were assessed as methods for the determination of aluminium and other elements in gills of freshwater fish dying in the mixing zones of rivers with different acidities. Both methods suffered from considerable contamination problems, requiring samples to be handled on clean benches with super-pure reagents. Nuclear interference was determined experimentally by irradiating stoichiometric phosphorus compounds, with and without a cadmium shield. The observed interference of 1 ug of aluminium from 50 mg of phosphorus required no correction in most cases. INAA was validated for this application.