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800-356-1688 •
2005vol. 3
American Society for Testing andMaterialsmethodD-6730-01was designed specifically for determining the individual hydrocar-
bons in spark ignition fuels and fuel blends containing oxygenates such as methyl
tert
-butyl ether (MTBE), ethyl
tert
-butyl ether
(ETBE),
tert
-butanol, and ethanol. To maximize the resolution of these complex mixtures, ASTM recommends a 100 meter x
0.25mm ID capillary columnwith a 0.5µm filmof 100%dimethyl polysiloxane stationary phase as the primary analytical column.
To control selectivity for the aromatic compounds, a short tuning column, typically 2-3meters, containing a 5% diphenyl / 95%
dimethyl polysiloxane stationary phase, is connected to the inlet of the primary column. Tomeet the demanding resolution and
retention criteria inASTMmethodD-6730-01, and inCanadianGeneral StandardsBoard (CGSB)methodology fordetailedhydro-
carbon analysis (DHA),Restek Innovations chemists have reformulatedourRtx®-1PONA column.
High-SpeedDetailedHydrocarbonAnalysis
53%FasterAnalysis, UsinganRtx®-1PONAColumnandHydrogenCarrierGas
By Barry Burger, PetroleumApplications Chemist
• C13elutedwithin70minutes.
• Excellent responseandpeak symmetry for polar oxygenates.
• Columnmeetsor exceeds all ASTMD-6730-01andCanadianGeneral StandardsBoardmethod requirements.
• Guaranteed column-to-column reproducibility.
A: Front end of DHA/oxygenates
setup blend
C5 efficiency: 586,825 plates
C5 k’: 0.476
tert
-butanol skew: 2.10
Resolution
tert
-butanol/
2-methylbutene-2: 5.39
B: DHA/oxygenates setup blend
1. ethanol
2. C5
3.
tert
-butanol
4. 2-methylbutene-2
5. 2,3-dimethylbutane
6. methyl
tert
-butyl ether (MTBE)
7. C6
8. 1-methylcyclopentene
9. benzene
10. cyclohexane
11. 3-ethylpentane
12. 1,2-dimethylcyclopentane
13. C7
14. 2,2,3-trimethylpentane
15. 2,3,3-trimethylpentane
16. toluene
17. C8
18. ethylbenzene
19.
p
-xylene
20. 2,3-dimethylheptane
21. C9
22. 5-methylnonane
23. 1,2-methylethylbenzene
24. C10
25. C11
26. 1,2,3,5-tetramethylbenzene
27. naphthalene
28. C12
29. 1-methylnaphthalene
30. C13
Column:
Rtx
®
-1PONA 100m, 0.25mm, 0.5µm (cat.# 10195) plus
Rtx
®
-5PONA tuning column (cat.# 10196), connected
via angled Press-Tight
®
connector (cat.# 20446)
Sample:
DHA/oxygenates setup blend
Inj.:
0.01µL, split (split ratio 150:1), 4mm ID cup inlet liner
(cat.# 20709)
A: front slice of DHA/oxygenates setup blend
B: DHA/oxygenates setup blend
Carrier gas:
hydrogen, constant flow (3.62cc/min.)
Linear velocity: 55cm/sec.
Inj. temp.:
250°C
Oven temp.:
A: 35°C
B: 5°C (hold 8.32min.) (elute C5) to 48°C@ 22°C/min.
(hold 26.32min.) (elute ethylbenzene) to 141°C@
3.20°C/min. (no hold) (elute C12) to 300°C@ 1°C/min.
Det.:
FID@ 300°C
GC_PC00774
Chromatogram courtesy of Neil
Johansen, Inc., Aztec, New
Mexico, in associationwith
Envantage Analytical Software,
Inc., Cleveland, Ohio.
Figure1
Rtx®-1PONA columnmeetsASTMD-6731-01 resolutionand retention specifications.
