14
c.c. Parrish
Evaporate extract to near dryness.
Add 0.5 ml of hexane or pentane, then 1 ml of (14%) BFjMeOH.
Flush headspace with nitrogen gas.
Seal tube with a cap containing a Teflon liner and vortex.
Heat at 80°C for 1 hour (the solution goes monophasic during this period).
Add 0.5 ml of chloroform-extracted double-distilled water and vortex thoroughly.
Add 2 ml of hexane and flush with nitrogen.
Cap and centrifuge at 1,000 rpm (125 x g) for 1 minute.
Withdraw the upper organic layer and concentrate to 1 ml under nitrogen.
Pass through a column of anhydrous sodium sulfate (Na2SO., packed into a Pasteur
pipette) previously rinsed with chloroform and hexane; make up to 1-10 ml in
hexane.
Inject 1 fl.1 into the gas chromatograph to obtain up to 100 ng for the major peak.
FIGURE 1.6. Fatty acid derivatization procedure for 2-20 mg of extract, based on Morrison
and Smith (1964). For smaller amounts of extract, the volumes should be decreased
proportionately.
c.c. Parrish
Evaporate extract to near dryness.
Add 0.5 ml of hexane or pentane, then 1 ml of (14%) BFjMeOH.
Flush headspace with nitrogen gas.
Seal tube with a cap containing a Teflon liner and vortex.
Heat at 80°C for 1 hour (the solution goes monophasic during this period).
Add 0.5 ml of chloroform-extracted double-distilled water and vortex thoroughly.
Add 2 ml of hexane and flush with nitrogen.
Cap and centrifuge at 1,000 rpm (125 x g) for 1 minute.
Withdraw the upper organic layer and concentrate to 1 ml under nitrogen.
Pass through a column of anhydrous sodium sulfate (Na2SO., packed into a Pasteur
pipette) previously rinsed with chloroform and hexane; make up to 1-10 ml in
hexane.
Inject 1 fl.1 into the gas chromatograph to obtain up to 100 ng for the major peak.
FIGURE 1.6. Fatty acid derivatization procedure for 2-20 mg of extract, based on Morrison
and Smith (1964). For smaller amounts of extract, the volumes should be decreased
proportionately.