ADV06-15_1-412

Analyze Hydrocarbons on OPNIRes-Sil™ CBondedGC Packing

Superior Replacement for Porasil" Packings

By Barry Burger, Petroleum Chemist

• Unique separations of saturated and unsaturated hydrocarbons.

• Innovative bonding chemistry for batch -to-batch reproducibility, excellent thermal stability, and long life.

• Other bonded phases available.

For years , Porasilv C and Porasil'" B, modified with covalentl y att ached liquid

phases such as

OPN

(cyanopropyl) or n-octane function al groups, offered

important advantages, relative to conventional GC packings, in analyses of

CI-C4 hydrocarbons: faster separations, high er thermal stability, shorter con

d itioning times, and lon ger lifetimes. Porasil '" C / Porasile B products were

discontinued in the 1980s, however, and inventories have been depleted, for c

ing those that use these packings to search for comparable materials.

Restek chemists solved th e problem by develop ing Res-SiFMC and Res-Sil?" B

bonded pa ckings. These packings afford all of the advantages of the Porasil's

C and Porasil's B materials, with th e added advantage of con sistent batch-to

batch performanc e - and the y are readil y available for immediate delivery.

Compared to diatomaceou s earth media, Res-SiF MC has a small surface area,

good inertness, low friability, and less reactivity.

Unique Selectivity for ProcessGC and High -Speed Analysis

Speed of analysis is crucial in process GC, and in laboratory gas analyzers in

wh ich multiple columns and valve switching are used to separate complex gas

mixtures. Res-SiFMC bonded packi ngs are ideal for resolving th e difficult-to

sepa rate saturated and unsaturated C4 hydrocarbons under th ese demanding

conditions. Figure 1 illustr ates th e un ique selectivity of

OPN

on Res-Sil?" C

packing for eluting cis-2-butene before 1,3-butadiene. When used in series

with other columns, th is unique material provides petroleum and petro

chemic al method developers with a powe rful tool for fast determination of

C l-C4

hydrocarbons."

Stringent QA Assures Batch-to-Batch Consistency

Historically, one of the problems with bonded ph ases on Porasil 's media has

been batch-to-batch variations in the amount of liquid stat ionary phase

incorporated on the silica support. Thro ugh our new synthesis pathways, we

precisely control the amount of bonded liquid phase on Res-SiF M C in every

batch of packing, assuring reproducible retention tim es and separation s. Each

batch of packing is tested with a complex mixture of hydrocarbons, to confirm

it meets demanding retention time and retention index specifications. We

evalu ate column bleed at the recommended maximum temperature, ISO°C, to

en sure that there are no ret ention shifts or high baselin es.

In addition to

OPN

Res-Sil"

C packing, we bond n-octane and

Carbowax" IS40 phases to

Res-Sil" C.

Each of th ese pac kings offer s a condi

tioning time of less th an 30 minutes, low bleed, long lifetime, and cons istent

batch-to-batch rep roducibility. For details about n-octane or Carbowax's on

Res-SiFM C, and for bonded ph ase packings on Silcoport" deactivated

diatomaceous earth, refer to our current chromatography supplies catalog.

We test every batch of every Restek bonded phase packing for bleed, efficien

cy,

retention index, and retention time reproducibility. In addition, we make a

broad range of packed and micropacked columns in specially-deactivated

Silcosteelv tubing, for superior inertness and efficiency.

If you have been looking for a replacement for a Porasile C or Porasil s B pack

ing, we invite you to contact us. Your search should end here.

Reference

1 Saha, N.C., S.K.Jain,and R.K.Dua.

Chromatogr. Sci.

16: 323-328 (1978).

Reference not available fromRestek.

2006

vol.

• 7 •

Figure 1

OPNon Res-5W

C packing has

unique selectivity for cis-2-butene and

1,3-butadiene.

1 2

4 5

Peak

methane

2. ethane/ethylene

3. acetylene

4. propane

5. propylene

6. propadiene

7. isobutane

8. butane

9. butene

10. isobutylene/

trans-2-butene

cis-2-butene

12. 1,3butadiene

13.

isopentane

14. pentane/

3-methyl/l-butene

15. pentene-l

16. trans-2-pentene

17. cis-2-pentene

18. 2-methyll2-butene

Ret.

Index

100

200

260

300

321

345

386

400 .

422

434

443

454

488

500

503

522

533

540

549

min.

Reference standard courtesyof DCGPartnerships, Ltd., Pearland,TX.

12'x 2mmID x lI8" OD

Silcosteel"

column packedwith OPNon

Res-Sill C 80/100 mesh.

20fJLon-column injectionof refinery gas

OvenTemp.:

50°C

In],

temp.:

200°C

Del. temp.:

200°C

Flow rate:

30mL/min., He

Res-SiI'M CPackings

Res-Sir C,

80/100

mesh, 10g*

25028

OPNon

Res-Sil~

C, 80/ 100 mesh, 10g*

25042

n-Octane

on_~es-Sil

80/100

mesh,10g* 25030

Carbowax"

1540 on Res-Si!'" C,

80/100

mesh, 10g*

25044

Website :

www.chromtech.net.au

E-mail :

info@chromatech.net.au

TelNo : 03 9762 2034 . . . in AUSTRALIA