Sterols
GC
XTI®-5
Sterols (Cholesterol)
GC
XTI®-5
FOODS, FLAVORS, & FRAGRANCES
8
Phone: 800-356-1688 or 814-353-1300
Fats & Oils
CholesterolandOtherDietarySterols
Cholesterol is a lipid with a completely different
structure than a fatty acid. Cholesterol is present
only in foods of animal origin.Because cholesterol
contentmust be includedonnutritional label pan-
els,accuratequantitation is important forproducts
suchasbutter,eggs,andbakedgoods.CapillaryGC
is recommended in AOACMethods 970.51E and
976.26 for the determination of cholesterol con-
tent.Cholesterol, andother sterols,must be recov-
ered from the unsaponified fraction of an ether
extract. The sterols can be converted to the
trimethylsilyl (TMS) or butyl ester derivatives and
analyzed on an
Rtx®-5
capillary column, or they
can be analyzed underivatized on a highly inert
XTI®-5
column.An
XTI®-5
columnoffers low reac-
tivityandhigh thermal stability for accuratequan-
titation with very short analyses times. For more
complex mixtures of sterols,
including
coprostanone and cholesterol, amore polar
Rtx®-
225
column shouldbeused (page 9).
also
available
Custom lengths and film thicknesses are available. Call technical
service at 800-356-1688 (ext. 4), or contact your Restek repre-
sentative.
ordering
note
Toorder oneof the columns highlightedon page8or 9, please see
the followingpages:
Rtx
®
-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Rtx
®
-225 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
XTI
®
-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
min.
2
4
6
8
10
2
3
Peak List:
1. 5-
α
-cholestane
2. coprosterol
3. cholesterol
1
30m, 0.25mm ID, 0.50µm XTI
®
-5 (cat.# 12238)
1.0µL split injection, 250ng on-column
Oven temp.:
330°C
Inj. & det. temp.:
300°C
Carrier gas:
helium
Linear velocity:
30cm/sec. set@40°C
FID sensitivity:
8 x 10
-11
AFS
Split ratio:
100:1
GC_FF00132
min.
2
4
6
8
10
2
3
4
5
6
7
8
9
1
30m, 0.25mm ID, 0.50µm XTI
®
-5 (cat.# 12238)
1.0µL split injection.
On-column conc.: 250ng
Oven temp.:
330°C
Inj. & det. temp.:
300°C
Carrier gas:
helium
Linear velocity:
30cm/sec. set@40°C
FID sensitivity:
8 x 10
-11
AFS
Split ratio:
100:1
GC_FF00133
Peak List:
1. 5-
α
-cholestane
2. coprosterol
3. cholesterol
4. brassicasterol
5. ergosterol
6. campesterol
7. stigmasterol
8.
β
-sitosterol
9. lanosterol
for
more
info
Request ApplicationsNote Analysis of Cholesterol andOther
Dietary Sterols (cat.# 59581).
