BergamotFlavor
GC
Rt-
β
DEXse™
Peach/VanillaFlavor
GC
Rt-
β
DEXsa™
FOODS, FLAVORS, & FRAGRANCES
24
Phone: 800-356-1688 or 814-353-1300
Chiral Separations
Flavor chemists can use chiral chromatography to
monitor the ratios of various enantiomeric com-
pounds.
γ
-lactones, for example, canbemonitored
todetermine if apeach flavorhasbeenadulterated.
Ethyl-2-methylbutyrate and 2-methylbutyrate are
important contributors to apple flavor, and both
are naturally present in predominantly the (S)
form in apple juices.The enantiomers of these two
compounds can be resolved on an
Rt-
β
DEXsm™
column.
30m, 0.32mm ID, 0.25µmRt-
β
DEXsa
™
(cat.# 13108)
Oven temp.:
60°C (hold 2min.) to 100°C@15°C/min.
to 220°C@3°C/min.
Carrier gas:
helium, 60cm/sec. set@60°C
Det.:
MS@220°C
0
9.5
19
28.5
38
1. (R)-
γ
-octalactone
2. (S)-
γ
-octalactone
3. (R)-
γ
-decalactone
4. (R)-
γ
-undecalactone
5. (S)-
γ
-undecalactone
1 2
3
4 5
min.
GC_FF00162
30m, 0.32mm ID, 0.25µmRt-
β
DEXse
™
(cat.# 13106)
Oven temp.:
40°C (hold 1min.) to 200°C@4°C/min.
Carrier gas:
helium, 60cm/sec. set@40°C
Det.:
MS@220°C
1. (S)-limonene
2. (R)-limonene
3. (R)-linalool
4. (S)-linalool
5. (R)-linalyl acetate
6. (S)-linalyl acetate
min.
8
13
18
1
2
3
4
5
6
GC_FF00163
for
more
info
Request Chiral Column Technical Guide (cat.# 59889).
tech
tip
To optimize chiral separations, use:
1) Faster linear velocities (80cm/sec.) with hydrogen carrier gas.
2) Slower temperature ramp rates (1–2°C/min.).
3) Appropriateminimum operating temperature (40 or 60°C).
4) On-column concentrations of 50ng or less.
