ADV06-15_1-412

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2007.01

Chemical/Petrochemical

Using Silcosmooth™ Columns and a Modified ASTM D-3606-06e1 Method

By Barry L. Burger, Petroleum Chemist

Resolving Aromatics in Spark Ignition Fuels

• Easy quantification of aromatics, using 2-butanol as an internal standard.

• Complete resolution of benzene from ethanol.

• Fully conditioned column set – ready to use out of the box.

Our robust two column set for this modified D-

3606-06e1 application completely resolves benzene

from ethanol. Column A is a 2.46m x 1/8” OD x

2mm ID Silcosmooth™ (Silcosteel® treated) stain-

less steel column packed with 10% Rtx®-1 on

80/100 Silcoport™W, which separates the compo-

nents by boiling point. After the elution of n-

octane (C8) from Column A, the column is back-

flushed to prevent the heavier compounds from

entering Column B, the main analytical column.

Column B is a unidirectional 6.15m x 1/8” OD x

2mm ID Silcosmooth™ stainless steel column

packed with separate beds of 15% Carbowax®

1540 on 80/100 Chromosorb® WAW and 20%

TCEP on 80/100 Chromosorb® PAW. To demon-

strate the performance of the column set, we

installed it in an Agilent 6890 GC equipped with a

flame ionization detector (FID). Helium was used

as the carrier gas at a flow rate of 25mL/min. in the

constant flow mode. Figure 1 shows the aromatic

compounds are fully resolved, and can easily be

quantified, using 2-butanol as an internal standard.

This column set is fully conditioned, and is ready

to use right out of the box. Only a brief (10 min.)

carrier gas purge at ambient temperature, followed

by a 30 min. hold at 165°C, is required.

If your laboratory has been struggling with ASTM

method D-3606-06e1 for reformulated fuels con-

taining ethanol, Restek’s new column set is the

solution.

Figure 1

Complete resolution of benzene from ethanol,

using a Silcosmooth™ two column set and modified

ASTM D3606-06e1 method.

GC_PC00897

D3606 Application Columns (2 column set)

*Please add column configuration suffix number from our catalog

to cat.# when ordering–see our catalog or website.

9.2-Meter

cat. #*

” Silcosmooth

™

2.0mm

80487-

$450

Having coking or fouling problems?

See what Silcosteel®-AC can do for you.

www.restekcoatings.com

Column:

Column A: 10% Rtx

1 on 80/100 Silcoport™W,

2.46m x 1/8” OD x 2mm ID Silcosteel

treated stainless steel

Column B: 20% TCEP on 80/100 Chromosorb

PAW / 15% Carbowax

1540 on

80/100 Chromosorb

WAW, 6.15m x 1/8” OD x 2mm ID Silcosteel

treated

stainless steel

Sample:

ethanol (10%), benzene (1.5%) toluene, (10%), and 2-butanol (10%) in carbon disulfide

Inj.:

1.0µL on-column

Inj. temp.:

200°C

Carrier gas:

helium, constant flow

Flow rate:

25.0mL/min.

Oven temp.:

135°C

Det.:

FID @ 200°C

1. ethanol

2. benzene

3. 2-butanol

4. toluene

Laboratories analyzing benzene and toluene in spark ignition fuels reformulated to contain ethanol must use a modified ASTM D-

3606-06e1 method to prevent the co-elution of ethanol and benzene. This method modification also is a requirement of the US EPA.

The benzene range of determination is between 0.1 and 5 volume percent, and the toluene range is between 2 and 20 volume percent.