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11
Figure 13B
Lower temperature ramp rates provide maximum
resolution of chiral pairs.
Figure 13A
Trennzahl values increase with enantiomeric resolution factors as
temperature ramp rates decrease.
Rt-
β
DEXsa:
40°C (80°C for lactones) to 200°C@
2°C/min. (hold 1min.). Hydrogen carrier gas.
Rt-
β
DEXsa:
40°C to 200°C@ 2°C/min. (hold 1min.).
Hydrogen carrier gas.
Call 800-356-1688, ext.
4, for knowledgeable
technical support
Monday–Thursday,
8 a.m.–7 p.m.,
Friday, 8 a.m.–6 p.m.,
or Fax anytime at
814-353-1310.
restek
CORPORATION
1-octen-3-ol
linalool
α
-ionone
γ
-nonalactone
γ
-undecalactone
δ
-decalactone
1.5°C/min.
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
5.0
5.5
2.0°C/min.
2.5°C/min.
3.0°C/min.
30
25
20
15
10
5
0
1.5°C/min.
2.0°C/min.
2.5°C/min.
3.0°C/min.
TemperatureProgram
○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○
The resolution between the enantio-
mericpairscanbe improvedbyusing
slow temperature ramp rates. The
best temperature ramp rates are 1-
2°C/min. Trennzahl values improve
alongwithenantiomericresolutionas
the temperature ramp rate is de-
creased (
Figures 13A and B
).
Temperature Program Rate
Trennzahl Value
Temperature Program Rate
Resolution Factor
Remember, to optimize
chiral separation use:
1) Faster linear velocities
(80 cm/sec.) withhydrogen
carrier gas.
2) Slower temperature ramp
rates (1-2°C/min.).
3) Appropriateminimum
operating temperature
(40 or 60°C).
4) On-columnconcentrations
of 50ngor less.
