The assembly of elements (ii) and (iii) is
crucial since it defines, as depicted in Fig. 1C, the internal chamber
where the extraction solvent is located. Later on, the appropriate
solvent is introduced in the unit and the membrane (Fig. 1B(iv))
is placed over the unit and fixed to it by displacing the external
element (Fig. 1B(v)). The final unit has an internal chamber of ca.
50L