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by Barry Burger, Petrochemical and Packed GC Innovations Chemist
High-Speed Analysis of
Petrochemicals
Using OPN Res-Sil™ C GC Packings
✔ Unique selectivity for saturated and unsaturated hydrocarbons.
✔ Innovative bonding chemistry for batch-to-batch reproducibility, excellent thermal
stability, and long life.
✔ Wide range of bonded phases available.
✔ Equivalent to Waters Durapack® packings.
For over 25 years the process GC and petrochemi-
cal industries have used bonded silica packings
such as Waters Durapak® packings for analysis of
C1 to C4 hydrocarbons. These phases provide
unique selectivity by modifying silica with a covalent
attachment of either n-octane or cyano-propyl
(OPN) functional groups. These phases have many
advantages over conventional gas liquid chromatog-
raphy packings because they yield faster separa-
tions, higher thermal stability, shorter conditioning
times, and longer lifetimes. In the past, these pack-
ings had inconsistent reproducibility and limited
availability. Restek’s research team has solved these
age old problems by developing Res-Sil™ C pack-
ings for consistent batch-to-batch performance and
immediate delivery.
Unique Selectivity for Process GC and High-
Speed Analysis of Petrochemicals
Speed of analysis is crucial for process GC, and in
laboratory gas analyzers using multiple columns
and valve switching for separation of complex gas
mixtures. The Res-Sil ™ C bonded packings are ideal
for resolution of the saturated and unsaturated C4
hydrocarbons that are difficult to separate. The
chromatogram in Figure 1 demonstrates the unique
selectivity for separation of cis-2-butene before 1,3-
butadiene using the OPN on Res-Sil™ C packing.
This unique selectivity, when combined with other
columns in series, provides petroleum and petro-
chemical method developers with a powerful tool
for fast determination of C1 to C5 hydrocarbons.1
Innovative Research and Stringent QA
Provide Batch-to-Batch Consistency
Historically, one of the problems with bonded phas-
es such as Carbowax ®, n-octane, and OPN on
Porasil ® packing has been batch-to-batch variations
in the amount of liquid stationary phase added to
solid silica support. Restek’s product development
team pulled together chemists with experience in
GC packings and HPLC phase development to inno-
vate a new synthesis procedure. Utilizing new syn-
thesis pathways, the amount of bonded liquid phase
is precisely controlled in every batch, resulting in
reproducible retention times and separations. Each
production batch of Res-Sil™ C packing is quality
assurance tested with a complex hydrocarbon mix-
ture to meet demanding retention time and reten-
tion index specifications. Column bleed also is eval-
uated at the recommended maximum temperature
of 150°C, as part of the QA test to ensure that
retention shifts and high baselines are not
observed.
A Full Line of Bonded GC Phases
Restek offers a wide range of bonded packings for
packed GC columns, including Rtx® -1 and
Stabilwax® phases, Carbowax® and n-octane phases
on Res-Sil™ C packing, and OPN on Res-Sil™ C
packing. Each of these packings has low bleed,
conditioning time of less than 30 minutes, long life-
time, and consistent batch-to-batch reproducibility.
Every batch of Restek’s bonded phases is tested for
bleed, efficiency, retention index and retention time
reproducibility. In addition, Restek offers a full
range of packed and micro-packed GC columns,
available with specially-deactivated Silcosteel ® tub-
ing for improved inertness and efficiency.
1. N.C Saha, S.K. Jain, and R.K. Dua. J. of
Chromat. Sci. 1978: 16, pp.323-328.
Reference not available from Restek.
Figure 1
OPN on Res-Sil™ C packing demonstrates unique selectivity for cis-2-butene and
1,3-butadiene.
Retention
Indices
1. methane 100
2. ethane/ethylene 200
3. acetylene 260
4. propane 300
5. propylene 321
6. propadiene 345
7. isobutane 386
8. butane 400
9. butene-1 422
10. isobutylene/ trans-2-butene 434
11. cis-2-butene 443
12. 1,3-butadiene 454
13. isopentane 488
14. pentane/3-methyl-1-butene 503
15. pentene-1 522
16. trans-2-pentene 533
17. cis-2-pentene 540
18. 2-methyl-2-butene 549
1
3
5 2
6
7 8
9
10
11
12
13
14
15 16 17 18
min. 0 5 10
4
OPN on Res-Sil™ C Packing, 80/100 mesh, 12' x 2mm ID x 1/8" OD in SilcoSmooth™
tubing (cat.# 80437). 20µL on-column injection of refinery gas.
Concentration: 0.1-6 absolute mole %
Oven temp.: 50°C
Inj. & det. temp.: 200°C
Carrier gas: He
Flow rate: 30mL/min
Standard courtesy of AC Analytical Controls, Bensalem, PA.
GC_PC00373
Res-Sil™ C Packing Materials
Description
Temp.
Limit (°C) Mesh
Min.
Qty. cat.# price/g
Res-Sil™ C 300 60/80 10g 25400
300 80/100 10g 25028
Res-Sil ™ B 300 60/80 10g 25401
300 80/100 10g 25080
1% TCEP on Res-Sil™ B 175 80/100 10g 25081
OPN on Res-Sil™ C 150 80/100 10g 25042
n-Octane on Res-Sil™ C 150 80/100 10g 25030
2% Carbowax® 1540 on Res-Sil™ C 150 80/100 10g 25044
Restek’s packed columns deliver the
1 -2-3 punch!
1. Bonded stationary phases mean short condi-
tioning times, low bleed levels, and unsur-
passed column lifetimes.
2. SilcoSmooth™ tubing provides the inertness
of glass and the durability of stainless steel.
3. Silcoport ™ diatomaceous earth provides
unsurpassed inertness for trace analyses.