restektn07 - page 297

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GC_FF00526
min.
Stabilwax®-DA 30m, 0.18mm ID, 0.18µm (cat.# 550752)
Inj.: 1µL splitless (hold 0.5min.) at conc. shown in peak list, in ethyl
acetate, 4mm ID splitless liner w/wool (cat.# 20814-202.1)
Inj. temp.: 240°C
Carrier gas: hydrogen
Make-up gas: nitrogen
Linear velocity: 28psi@ 240°C
Oven temp.: 70°C to 240°C at 12°C/min. (hold 3min.)
Det.: FID
PeakList Conc. (ppm)
1. ethyl octanoate 100
2. acetic acid 100
3. propionic acid 100
4. isobutyric acid 100
5. decanol 3 50
6. ethyl decanoate 50
7. ethyl laurate 50
8. cis-lactone 100
9. 2-phenylethanol 50
10. trans-lactone 100
11. methyl myristate 50
12. ethyl myristate 50
13. octanoic acid 100
14. ethyl palmitate 50
15. decanoic acid 100
16. dodecanoic acid 100
17. vanillin 100
PeakList Conc. (ppm)
1. caproic acid 100
2. ethyl laurate 100
GC_FF00525
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Stabilwax®-DA 30m, 0.18mm ID, 0.18µm (cat.# 550752)
Inj.: 1µL splitless (hold 0.5min.) at conc. shown in
peak list, in ethyl acetate, 4mm ID splitless liner
w/wool (cat.# 20814-202.1)
Inj. temp.: 240°C
Carrier gas: hydrogen
Make-up gas: nitrogen
Linear velocity: 28psi@ 240°C
Oven temp.: 80°C to 230°C at 5°C/min.
Det.: FID
Because alcoholic beverage samples often are injected via splitlessmode, it was impor-
tant to ascertain the stability of the Stabilwax®-DA column when exposed to aqueous
injections.We verified stability by performing a splitless injection of the alcoholic bev-
erage test mix, followed by five 1µL injections of water. We repeated this process 10
times, thenmade a final injectionof the testmix.The chromatogram for the final testmix
injection is shown in Figure 5. Even after repeated splitless injections of 100%water,
there is very little degradation in the peak shapes for the test mix components. Over the
courseof the study, thevariation in thepeak retention timeswas 0.08-0.22%RSD.These
data include retention times for the polar free fatty acids, which can be difficult to ana-
lyze under ideal conditions. The excellent stability of this stationary phase is demon-
strated by the reproducibility of the retention times.
AStabilwax® -DA column resolves the caproic acid / ethyl laurate critical pair to baseline.
Stabilwax® -DA columns arewell named: repeated injections of water produce very little degradation in the peak
shapes for alcoholic beverage test mix components.
Figure 4
Figure 5