5 mL n-hexane was added and the mixture was stirred for two minutes before being centrifuged at 2000 rpm for five minutes. After this, 3 mL supernatant was collected in a 10 mL glass beaker and allowed to evaporate at room temperature. The oily residue was removed and 10 microL added to 400 microL methanol and 100 microL trans-esterification reagent (TMSH, trimethylsulfonium hydroxide, 0.2 mol/L in methanol, Macherey-Nagel), which converts fatty acid from acylglycerol to methyl esters.