2.3.2. Metal analysis
To measure Cd accumulation, the tissues (gill and kidney) were first
dried at 60 °C for 24 h until a constant mass was reached. Samples were
then transferred into glass tubes and digested in a 1:2 perchloric acid
and nitric acid (Merck) mixture at 120 °C. After complete digestion (visual
inspection), samples were cooled and diluted with distilled water
to be within the range of standards that were prepared from stock standard
solutions of Cd (Merck). All samples were completely clear and not
filtered. Cd concentrations, expressed as μg Cd g−1 of dry mass, were determined
by atomic absorption spectrophotometry (Unicam 939, Kassel,
Germany).