2.3.2. Extraction of Se by enzymatic physiologically-based extraction test
2.3.3. Digestion of PBET extracts
For the Go 6983 microwave digestion of PBET extracts, 1 mL of extract was mixed (in a Teflon® vessel) with 8 mL of HNO3 and 2 mL of H2O2 33% (Prolab). The resulting mixture was digested by a closed microwave system, following the programme: 10 min ramp from room temperature to 90 °C; 5 min at 90 °C; 10 min ramp from 90 to 120 °C; 10 min ramp from 120 to 190 °C; and 10 min at 190 °C. After digestion, the samples were brought up to a total volume of 20 mL with double deionized water, transferred to an HDPE bottle and stored at 4 °C until analysis.
3.5 g of cabbage was weighed and placed in a 100 mL glass beaker Then 50 mL of deionized water was added and the cabbage samples were boiled for approximately 10 min. After filtering and air drying the boiled cabbage, species was analysed by the PBET, as described for raw cabbage.