The residue was dissolved
with 400 lL of a mixture of Milli-Q water/MeOH (50:50,
v/v) and placed in a 1.5 mL Eppendorf tube.
500 lL of hexane
was added and the mixture was centrifuged for 15 min at
24960g.
Finally, the underlying aqueous phase was separated and
10 lL injected into the ultra high performance liquid chromatograph
(UHPLC) system.