BHAandBHT
GC
Rtx®-50
TocopherolsandTocotrienols
GC
Rtx®-20
FOODS, FLAVORS,
& FRAGRANCES
17
Preservatives
Phone: 800-356-1688 or 814-353-1300
Foods containing fats and oils are prone to lipid
oxidation,which canpromoteoff-flavors and limit
shelf-life. To inhibit lipid oxidation, antioxidants
can be added to the product. Phenolic antioxi-
dants, including butylated hydroxyanisole (BHA),
butylated hydroxytoluene (BHT), propyl gallate
(PG), and tert-butyl hydroquinone (TBHQ), are
used inavarietyof products.Phenolicantioxidants
are regulated by the FDA and can be added to the
product at levels up to 200ppm based on the fat
content. Another approach is to use “natural”
antioxidants, such as tocopherols and tocotrienols.
These compounds inhibit lipidoxidation andpro-
mote general health in the consumer.
Phenolicantioxidants canbeanalyzedbyGCusing
intermediatepolarity
Rtx®-50
or
Rtx®-20
capillary
columns.Coelutions that canoccurwith less polar
columns canbeavoided.Usingdirect injectionand
a flame ionization detector, BHA andBHT can be
separated in less than 10minutes. Using an
Rtx®-
20
column, tocopherols from the unsaponified
fraction of animal and vegetable fats and oils can
be analyzed in their free formwithout derivatiza-
tion. Baseline resolution is possible, with analyses
times of less than10minutes.
Rtx
®
-20, 30m, 0.53mm ID, 0.5µm (cat.# 10340)
Sample:
1mg/mL each component in isooctane
Inj.:
1.0µL split (split ratio 20:1),
4mm inlet liner (cat.# 20814)
Inj. temp.:
320°C
Carrier gas:
hydrogen, constant flow
Flow rate:
5.2mL/min.
Oven temp.:
270°C to 290°C@ 2°C/min.
290°C to 320°C@ 10°C/min. (1min. hold)
Det.:
FID@ 320°C
GC_FF00634
1.
δ
-tocopherol
2.
β
-tocopherol
3.
γ
-tocopherol
4. dl-
δ
-tocotrienol
5.
α
-tocopherol
6. dl-
β
-tocotrienol
7. dl-
γ
-tocotrienol
8. hexadecyl hexadecanoate
9. dl-
α
-tocotrienol
Rtx
®
-50, 30m, 0.53mm ID, 0.50µm (cat.# 10540)
Sample:
50ppm each inmethanol
Inj.:
1.0µL direct injection, gooseneck splitless inlet liner, 4mm (cat.# 20798)
Inj. temp.:
280°C
Carrier gas:
helium, constant pressure
Linear velocity:
60cm/sec.@ 50°C
Oven temp.:
50°C to 240°C@15°C/min. (hold 3min.)
Det.:
FID@280°C
GC_FF00630
1. BHA
2. BHT
for
more
info
Request ApplicationNoteHPLCAnalysis of PreservativesUsing
UltraAqueous andPinnacle II
™
Columns (cat.# 59398).
