ADV01-05_1-298

• 4 •

www.restekcorp.com

800-356-1688

For years column manufacturers have proclaimed

that packed GC columns have gone the way of the

dinosaurs. While packed columns do not fill every

need, in some situations their use is dictated by

methodology, and, for some analysts, they are the

column of preference. Restek innovations have

brought new life to the “expired” packed column in

all three aspects of column technology: the support,

the phase, and the tubing. Silcoport

™

support pro-

vides unsurpassed inertness for trace analyses. Our

bonded phase packings are a revolution in packed

column technology. They significantly shorten con-

ditioning times, greatly reduce column bleed, and

prolong column lifetimes. SilcoSmooth

™

tubing

combines the inertness of glass with the durability

of stainless steel.

The great sensitivity of modern detection systems

and a progressing need to reduce detection limits

place challenging demands on a chromatography

column. Silcoport

™

diatomaceous earth support is

the modern solid support that we developed to

meet these demands. Unlike conventional DMDCS

by Neil Mosesman, GC Columns Product Marketing Manager

Packed Column Technology

Has New Life

With Restek Innovations

✔

Optimized tubing and support ensure unsurpassed inertness for trace analyses.

✔

Bonded phases shorten conditioning times, greatly reduce bleed, and prolong

column lifetimes.

deactivation, we use a proprietary fused silica deac-

tivation technology and a special mixture of deacti-

vants to ensure the greatest inertness (Figure 1)

without changing the polarity of the stationary

phase. Each batch of support is carefully tested to

confirm a uniform particle size distribution that

ensures columns with maximum efficiency.

By applying our experience in stationary phase syn-

thesis in conjunction with our unique Silcoport

™

packing deactivation process we create completely

bonded packing materials. To encompass a wide

range of applications, we offer Rtx

-1 and Rtx

-5,

bonded methyl silicone phases, and Stabilwax

, a

bonded Carbowax

phase. Each phase is completely

cross-linked on Silcoport

™

support. In side-by-side

comparisons with conventional nonbonded methyl

silicone phase columns, Rtx

-1 and Rtx

-5 columns

have lower bleed, improved peak shape, and longer

useful lives (Figure 2). Evaluations with an Rtx

-1

column show retention times are repeatable after

only 30 minutes of conditioning.

If your analysis involves reactive compounds, you

probably have used fragile, inflexible glass

columns, but now you can do better. Made from

ultra-smooth, seamless 304 stainless steel, and

treated with our innovative Silcosteel

deactivation

process, SilcoSmooth

™

tubing combines the inert-

ness of glass with the strength and flexibility of

stainless steel. SilcoSmooth

™

tubing can replace

glass tubing in virtually any application. For analy-

ses of ppb levels of sulfur-containing compounds,

use Sulfinert

™

tubing packed with Rt-XLSulfur

™

packing. For undemanding applications we can

make columns from conventional tubing: stainless

steel, Hastelloy

, nickel, copper, or Teflon

In combination, Silcoport

™

support, our bonded

phase packings, and SilcoSmooth

™

tubing make

packed column GC a viable alternative in many

applications in which the technique had been

endangered. If you use packed columns, and think

that you have to live with limitations, call us. We

can provide the column that will give you the sepa-

ration you need, but with convenience, inertness,

and column lifetimes you never expected from a

packed column.

Non-Bonded

Methyl Silicone

Bleed interferes

with analysis

18 17 16 15 14

11 10 9 87654 1

Bonded Rtx

-1

Low bleed after 170

cycles to 350°C!

GC_PC00369

Ordering Information

| Bonded Packed Column Stationary Phases:

Stainless Steel Tubing

SilcoSmooth

™

Tubing

Liquid Phases Bonded

OD ID cat.#*

on 100/120 Silcoport

™

(ft.)

(in.)

(mm)

(m)

(in.)

(mm)

3% Rtx

-1

2.1 80441-

2 80401-

10% Rtx

-1

2.1 80442-

2 80405-

20% Rtx

-1

2.1 80443-

2 80409-

3% Rtx

-5

2.1 80444-

2 80477-

10% Rtx

-5

2.1 80445-

2 80478-

20% Rtx

-5

2.1 80446-

2 80479-

5% Rtx

-Stabilwax

2.1 80447-

2 80415-

10% Rtx

-Stabilwax

2.1 80448-

2 80416-

20% Rtx

-Stabilwax

2.1 80449-

2 80417-

Rtx

-1 SimDist 2887

25"

2.1 80450

25"

80000

3 4 5 6 7 8 9 10 11

14 15 16

17 18

30 min.

Figure 2

Bonded packed columns exhibit longer life-

times than nonbonded columns.

1. C5

2. C6

3. C7

4. C8

5. C9

6. C10

7. C11

8. C12

9. C14

10. C16

11. C18

12. C20

13. C24

14. C28

15. C32

16. C36

17. C40

18. C44

Rtx

-1 SimDist 2887 25" x

Silcosteel

column (cat.# 80000)

1.0µL direct injection of 1-12%

(w/w) each component cat.# 31647

(1% each listed analyte in CS

) and

cat.# 31675 (5% each, neat) meet

requirements of ASTM D2887-01.

Oven temp.:

35°C to 350°C @

10°C/min. (hold 5 min.)

Inj. & det. temp.:

350°C

Carrier gas:

helium @ 25mL/min.

FID sensitivity:

256 x 10

-11

AFS

Figure 1

A trace level analysis of pesticides, including labile endrin and DDT, demonstrates the

inertness of Silcoport

™

support.

GC_EV00370

1. aldrin

2. 4,4'-DDE

3. endrin

4. 4,4'-DDD

5. 4,4'-DDT

6. endrin aldehyde

7. endrin ketone

1.5% Rt-608Pkd 2m, 2mm ID (cat.# 80221-)

Concentration:

50pg each analyte on-column

Oven temp.:

200°C isothermal

Inj. & det. temp.:

250°C

Det.:

ECD

Column flow:

nitrogen, 30cc/min.

min.

*Please include configuration suffix number (refer to our catalog, lit. cat.# 59662).