However, instead of magnetic stirring, ultrasonic
energy (UA-SFODME) [14], vortex mixing (VA-SFODME) [15]
or the addition of a dispersive solvent (DLLME-SFO) [16] can also
be used. We tested these modes of SFODME for determination of
1 × 10−8 mol phosphate using 1-undecanol as the extraction solvent.
In this step, the main criterion was the extraction time.