3.3.2. Folch LLE Procedure [1]

Briefly, for each 100 μL plasma sample, an aliquot of ice-cold 1.4 mL chloroform/MeOH (2:1, v/v) was added directly to the sample in a glass tube. The sample was vortexed and incubated on ice for 30 min. After the addition of 0.4 mL water, the sample was vortexed and incubated on ice for an additional 10 min. The sample was centrifuged at 2000× g for 5 min at 4 °C. The bottom (organic) layer was transferred to a new glass tube. The aqueous layer was re-extracted with 1 mL of chloroform/MeOH (2:1, v/v) following the above procedure. The organic layers were combined and dried with N₂ at 30 °C.