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8
Table I
Resolution of common chiral compounds on Restek’s cyclodextrin columns.
ns
= no separation of enantiomers
t
= peak tailing
b
= peak broadening
ad
= adsorption of nonderivatized drug compound
* = cis and trans linalool oxides analyzed@ 9.0 psi head pressure
Todemonstrate theabilitiesof the five
different types of chiral columns, we
analyzed twenty-five chiral com-
pounds commonly found in flavors,
fragrances, and pharmaceutical
analyses. The extent to which two
enantiomers are resolved (or any two
peaks)canbedeterminedby thereso-
lution equation and are known as
resolution factors, sometimes de-
noted R. An R value of 1.5 indicates
baseline resolution
.
Resolution fac-
tors for all chiral compounds on all
the
β
-cyclodextrincolumnswerecom-
pared to those obtained on the exist-
ing Rt-
β
DEXm (permethylated
cyclodextrin) column.
Table I
shows
thedegreeof enantiomericseparation
by resolution factor forall twenty-five
componentsoneachcolumn.Thecol-
umn that has the largest resolution
factor provides the best separation of
aparticular compound. These values
caneasilybecompared tohelpdeter-
mine which column is optimum for
specificchiral components.
Charts1–
6
illustrate thedegreeofenantiomeric
separationof eachcompoundoneach
chiral column.
Compounds
Formula
m.w.
Terpenes
1.
α
-pinene
C
10
H
16
136
2. limonene
C
10
H
16
136
Alcohols
3. 1-octen-3-ol
C
8
H
16
O
128
4. linalool
C
10
H
18
O
154
5.
α
-terpineol
C
10
H
18
O
154
6. terpinen-4-ol
C
10
H
18
O
154
7. isoborneol
C
10
H
18
O
154
8.
β
-citronellol
C
10
H
20
O
156
9. menthol
C
10
H
20
O
156
10. 2,3-butanediol
C
4
H
10
O
2
90
11. 1-phenylethanol
C
8
H
10
O
122
Ketones
12. carvone
C
10
H
14
O
150
13. camphor
C
10
H
16
O
152
14.
α
-ionone
C
13
H
20
O
192
Lactones
15.
γ
-nonalactone
C
9
H
16
O
2
156
16.
γ
-undecalactone
C
11
H
20
O
2
184
17.
δ
-decalactone
C
10
H
18
O
2
170
Esters
18. ethyl-2-methylbutyrate C
7
H
14
O
2
130
19. linalylacetate
C
12
H
20
O
2
196
Epoxides
20. styreneoxide
C
8
H
8
O
120
21. trans-linalooloxides C
10
H
18
O
2
170
21. cis-linalooloxides
Drugs
22. hexobarbital
C
12
H
16
O
3
N
2
236
23. mephobarbital
C
13
H
14
O
3
N
2
246
24. fenfluramine
C
12
H
16
F
3
N 231
25. fenfluramine TFAA der. C
14
H
15
F
6
NO 327
Column Resolution Factors
Rt-
β
DEX
sm
Rt-
β
DEX
se
Rt-
β
DEX
sp
Rt-
β
DEX
sa
Rt-
β
DEX
cst
Rt-
β
DEX
m
3.50
0.80
ns
ns
0.90
b
3.30
5.10
7.30
3.20
ns
2.70
b
1.40
1.10
ns
0.50
2.30
0.60
b
0.50
t
3.30
6.00
4.30
b
3.70
2.60
t
1.00
5.30
5.50
2.20
4.00
4.30
t
1.70
2.40
2.20
ns
ns
1.20
t
1.80
t
4.00
3.30
t
ns
ns
1.90
t
2.00
0.90
0.80
ns
1.00
t
ns
ns
1.10
1.10
2.20
ns
1.10
1.60
t
7.50
8.10
2.20
4.60
4.00
2.60
7.30
6.40
1.10
7.80
6.30
6.60
1.30
ns
ns
2.50
1.10
ns
1.80
2.10
t
1.30
b
4.30
2.50
t
ns
6.40
3.20
1.30
4.40
ns
3.20
4.70
5.00
3.40
4.40
5.90
1.00
2.90
2.90
1.70
3.70
4.50
ns
0.90
ns
ns
2.10
2.70
ns
1.30
3.50
1.10
b
ns
ns
ns
0.60
2.20
1.20
0.10
ns
ns
4.80
10.20
6.50
1.00
1.40
t
2.50
t
10.10
2.40
ns
1.50
4.30
b
6.80*
6.20
3.60
ns
1.00
3.50
b
4.20*
11.30
4.70
0.90
ns
8.90
6.30
8.40
3.80
0.60
ns
6.20
6.10
1.80
2.90
t
ad
ad
ns
ad
1.20
ns
ns
2.40
3.40
ns
