Total arsenic content of nine species of Antarctic macro algae as determined by electrothermal atomic absorption spectrometry

摘要

Total arsenic in nine species Antarctic macro algae has been measured, by electrothermal atomic absorption spectrometry using a Pd/Mg(NO_3)_2 matrix modifier, to determine their capacity to accumulate the element. Macro algae were collected in February during the 2000 austral summer season at Jubany Station (Argentinean scientific station) around Potter Cove, King George Island. An optimized two-step microwave (MW) program was used to digest the samples. Dried samples were treated with HNO_3, H_2O_2, and HF, left overnight, then subjected to the first MW cycle. After cooling HNO_3 and HClO_4 were added and samples were subjected to the second MW cycle of digestion treatment. The effect of power and time on As recovery was examined. The analytical features of the method were: detection limit, 0.24 μg g~(-1) (dry mass); precision (RSD), 4.2–5.7%; recovery 91–105%. A wide range of As-retention capacity (41.0–447 μg g~(-1) dry mass) was observed among the different species. The highest levels of As were found in Phaeurus antarcticus (447 μg g~(-1) dry mass). This organism satisfies several prerequisites to be considered for consideration as a biomonitor in future studies.