Whatman 0.45 μm ptfe membrane filters

To quantify the total content of Ce inside different plant species, seedlings were washed by agitation with HNO₃ 0.01 M for 15 min and rinsed with deionized water. The washed seedlings were oven-dried at 60 °C for three days, and 0.3 g of tissues were digested on a microwave oven (MARS Xpress, CEM, Matthews, NC, USA), using 9 mL of HNO₃ and 1 mL of hydrogen peroxide (H₂O₂) in Teflon cylinders at 180 °C. Plant extracts were diluted and filtered with Whatman 0.45 μm PTFE membrane filters. During the ICP–MS analysis, yttrium was the internal standard used for the analysis [36 (link)].

An amount of 0.3 g was sampled from the oven-dried plant fraction and digested on a CEM microwave oven (MARS Xpress, CEM, Matthews, NC, USA), using 9 mL of HNO₃ (65%) and 1 mL of hydrogen peroxide (H₂O₂) in Teflon cylinders at 180 °C, according to the USEPA 3052 method [63 ] After mineralization, plant extracts were filtered at room temperature under fume hood with Whatman 0.45 μm PTFE membrane filters, and finally diluted and analyzed. Determinations of the Ce total content were carried out using a ICP-MS NexION 350 (PerkinElmer, Waltham, MA, USA). The accuracy of the analytical procedure adopted for ICP-MS analysis was checked by running standard solutions every 20 samples. Yttrium was used as the internal standard.