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6
Rt-
β
DEXsm and
Rt-
β
DEXse
○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○
Cisand trans linalool oxides, linalool,
and linalyl acetate are commonly
found together in lavender oils, and
resolutionof all enantiomers isdesir-
able. The Rt-
β
DEXsm separates the
linalool oxides,but itdoesnot resolve
linalyl acetate. Conversely, Rt-
β
DEXseseparates linalool and linalyl
acetate,butdoesnot resolveall of the
linalool oxides. Combining both to-
gether in a dual column systemwill
provide resolution for all of these
enantiomers (
Figure 7
).
Rt-
β
DEXsp
○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○
Rt-
β
DEXsp is a specialized column
that best resolves menthol. It would
be useful in addition to the Rt-
β
DEXsm or Rt-
β
DEXse column for
analyzing complete profiles of mint
oils (
Figure 8
).
Rt-
β
DEXsa
○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○
TheRt-
β
DEXsahasasignificantlydif-
ferentselectivity than theotherchiral
columns. It provides thebest separa-
tion of 1-octen-3-ol, carvone, cam-
phor, 1-phenylethanol,
β
-citronellol,
and rose oxides (
Figure 9
).
Figure 7A
Cis and trans linalool oxide
enantiomers separated on an
Rt-
β
DEXsm column.
Figure 7B
Linalool and linalyl acetate
enantiomers are resolved on
the
Rt-
β
DEXse column.
Figure 8
Menthol enantiomers are best resolved on the
Rt-
β
DEXsp column
.
min. 20
30
linalool oxides
30
min. 20
linalool
linalyl acetate
menthol
min. 30
Figure 9A
1-octen-3-ol and carvone
enantiomers are best resolved
on
an Rt-
β
DEXsa column
.
Figure 9B
An Rt-
β
DEXsa column provides
baseline chiral resolution for
β
-citronellol
.
Figure 9C
An Rt-
β
DEXsa column
separates racemic cis and
trans rose oxides.
1-octen-3-ol
carvone
(-)(S)
(+)-cis
(+)(R)
(+)-trans
30
40
min. 20
52
53
min. 51
25 26
min. 24
27
(+)-trans
(+)-cis
(-)-cis
R
S
R
S
(+)
(-)
(+/-)
(-)
(+)
(-)-cis
(-)-trans
30m, 0.32mm ID, 0.25µmRt-
β
DEXsp (cat.# 13110)
Oven temp.:
60°C (hold 1min.) to 200°C@
2°C/min.;
Carrier gas:
hydrogen; 80cm/sec. set @
40°C;
Detector:
FID set @ 220°C
(-)-trans
30m, 0.32mm ID, 0.25µm
7A: Rt-
β
DEXsm (cat.# 13104)
7B: Rt-
β
DEXse (cat.# 13106)
Oven temp.:
40°C (hold 1min.)
to 230°C@ 2°C/min. (hold 3
min.);
Carrier gas:
hydrogen;
80cm/sec. set @ 40°C;
Detector:
FID set @ 220°C
30m, 0.32mm ID, 0.25µm
Rt-
β
DEXsa (cat.# 13108)
Oven temp.:
40°C (hold 1min.)
to 230°C@ 2°C/min. (hold 3
min.);
Carrier gas:
hydrogen;
80cm/sec. set @ 40°C;
Detector:
FID set @ 220°C
