|
|
 |
|
Fatty acid extraction
from a glycerolipid mixture |
|
|
|
|
|
Belfrage, P. &
Vaughan, M. (1969) Simple liquid-liquid partition system for
isolation of labeled oleic acid from mixtures with glycerides.
J. Lipid. Res. 10: 341-344. |
|
|
|
|
|
Sample in aqueous medium (250 ml). |
|
|
|
Add 1.57 ml methanol, 1.39 ml chloroform,
and 1.11 ml n-heptane (total 4.06 ml; 1.41:1.25:1 by vol). |
|
|
|
Add 1.25 ml of 0.05 M potassium
carbonate buffer (pH 10.0). |
|
|
|
Vigorous vortexing. |
|
|
|
Centrifuge 1000
rpm, 15 min. |
|
|
|
Volume in the upper
phase: 3.06 ml (alkaline methanol/water). Contains the free fatty
acid. |
|
Volume in the lower
phase: 2.56 ml (chloroform and heptane). Contains the neutral
glycerides. |
|
|
|
|
|
|
|
|
|
Dole
assay |
|
|
|
|
|
Sample in aqueous
medium (200 ml). |
|
|
|
Add 2.5 ml 2-propanol/heptane/0.5
M H2SO4. |
|
|
|
Add a small amount
of silica gel and vortex. |
|
|
|
Add 1.5 ml water
and 1.5 ml heptane. |
|
|
|
Vortex to resuspend
the silica. |
|
|
|
Wait until the silica
settles down. |
|
|
|
Load 1 ml of the
top phase (heptane) onto a silica column (total volume is 2 ml). |
|
|
|
Wash the column
with 1 ml diethyl ether. |
|
|
|
The eluate contains
the free fatty acid. |
|
|
|
|
|
|
|
|
|
Back
to Protocols |
|
|
