RestekCorporation • (800)356-1688 • (814) 353-1300 •
food& flavor
Figure1
TheRtx
®
-65TG column exhibits excellent resolution of butter fat triglycerides in under 35minutes at 365°C.
injection port and increased solute band broadening in the
stationary phase.
Triglyceridesare separatedaccording tocarbonnumberormolecular
weightonnon-polar,methylsiliconecolumns (AOACandAOCS
Methods use this typeof column).However, no resolution is
achieved for differences inunsaturationwithin theunsaturated
fatty acids.Therefore, triglycerides such asPOP, SOS, andPOS
would all appear as a singlepeak. Triglyceride separationby
degreeof unsaturation, aswell as carbonnumber requires ahighly
polar stationaryphase.While polar stationaryphases such as 50%
phenyl/50%methyl offer thenecessary selectivity, they tradition-
allyhave suffered from relatively low thermal stability. Phenyl/
methyl polysiloxanes generally exhibit lowermaximumoperating
temperatureswhen comparedwithmethyl silicones.
30m, 0.25mm ID, 0.10µmRtx
®
-65TG (cat.# 17008)
0.2µL direct injection of 1% butter fat in isooctane.
Oven temp.:
80°C (hold 1min.) to 240°C@ 30°C/min. to 365°C@ 4°C/min. (hold 5min.)
Det. temp.:
380°C
Carrier gas:
hydrogen
Linear velocity:
70cm/sec.
FID sensitivity:
16 x 10
-11
AFS
SPI injector:
high-performance capillary insert 60°C, 300°C/min. to 400°C (hold 5min.)
1. PPP
2. PPS
3. PPO
4. PSO
5. POO
6. SSO
7. OOS
8. OOO
min. 0
40
10
20
30
1
2
3
6
8
7
4
5
T26
T28
T32
T34
T36
T38
T40
T42
T44
T46
T48
T52
T54
T50
SeparateTriglycerides byCarbonNumberandDegree of
UnsaturationUsing anRtx
®
-65TGColumn
The chemists at Restekhave combined innovative polymer
synthesiswith advanced deactivation techniques to create a
highly polar, uniquely selective stationary phasewith the
extended thermal stability required for triglyceride analysis. This
produces columns that last longer and exhibit less bleed at
temperatures as high as 370°C. TheRtx
®
-65TG column (65%
phenyl/35%methyl polysiloxane) is selective for resolving
triglycerides according to degree of unsaturation aswell as
carbonnumber.
Figure 1 shows butter fat triglycerides runon a 30m, 0.25mm,
0.10µmRtx
®
-65TG column using a septum-equipped program-
mable injector (SPI). TheSPI injector reducesmolecularweight
