Additional filter portionswere submitted to acidic digestion
in closed PFA 60 mL reactors by using a HF:HNO3:HClO4
mixture, with subsequent evaporation, and final re-dissolution
with HNO3 (Querol et al., 2001). The contents of around 40
major and trace elements were determined in the resulting
solutions by inductively coupled plasma atomic emission
spectroscopy (ICP-AES) and/or inductively coupled plasma
mass spectroscopy (ICP-MS).