ADV01-05_1-298

• 2 •

www.restekcorp.com

Quantitation of the hexachlorodibenzofurans on

Rtx

-5 or equivalent columns, like quantitation of the

dioxins, can be made difficult by coelutions of toxic

and non-toxic congeners. The new column resolves

furan congeners as effectively as dioxins. Figure 2 is

a chromatogram for the HCDF congener group in

reference material WMS-01; the congeners are very

well resolved (reference material courtesy of

Wellington Laboratories, Guelph, Ontario, Canada).

Figure 2—

Hexachlorodibenzofuran congeners resolved by an Rtx®-Dioxin2 column.

Chromatogram courtesy of Karen MacPherson and Eric Reiner, Ontario Ministry of the Environment, Etobicoke, Ontario, Canada.

Table 1 lists values for 1,2,3,4,7,8-hexachlorodiben-

zofuran in several reference materials. In analyses

on 5-type stationary phases, a number of non-toxic

hexafuran congeners can coelute with the toxic

1,2,3,4,7,8-HCDF congener, producing inflated val-

ues for 1,2,3,4,7,8-HCDF. In fact, it is generally

assumed that in fly ash the actual value for

1,2,3,4,7,8-HCDF is approximately 3-fold less than

the value obtained when using a 5-type column. This

Table 2

—Values for 2,3,7,8-tetrachlorodibenzofuran in biota reflect the Rtx®-Dioxin2 column’s

ability to resolve target compounds from potentially interfering chlorodiphenylethers (all values pg/g;

provisional (non-2,3,7,8-TCDF confirmed)).

Column

Certified

5-type

225-type

Rtx®-Dioxin2

Value

Biota-1

1.3

0.8

Biota-2

4.3

2.2

Sediment

Fly ash

240

EC-2 (DX-1)

n/a

89 ±44

NST 1974

4.7

n/a

3.3

is one of the reasons confirmation on a high-cyano

phase is necessary. As shown in Table 1, the value

for 1,2,3,4,7,8-HCDF on an Rtx

-Dioxin2 column is

approximately 3-fold less than what was quantified

using a 5-type column. The difference is explained

by the excellent separation in Figure 2: the lower,

more accurate value is due to elimination of coelu-

tions with non-toxic congeners. Values for other

congeners compare equally well.

An additional advantage of the Rtx

-Dioxin2 column

is its ability to separate the chlorodiphenylethers,

commonly found in biota extracts, from the furans.

Coelution of these materials is a common problem

on both 5% diphenyl / 95% dimethyl stationary

phases and cyanopropyl stationary phases, but chro-

matographic separation is necessary for accurate

quantification of the chlorofurans: the

chlorodiphenylethers form chlorofurans in the ion

source of the mass spectrometer, and therefore can-

not be separated spectrally from the target com-

pounds. Table 2 summarizes results from analyzing

several matrices for 2,3,7,8-tetrachlorodibenzofuran

(2,3,7,8-TCDF). The values for the biota extracts

demonstrate the importance of the

furan/chlorodiphenylether separation. Because nei-

ther the 5% diphenyl / 95% dimethyl-type column

nor the cyanopropyl-type column solves the coelution

problem, quantified values for 2,3,7,8-TCDF in biota

are high for both columns. The Rtx

-Dioxin2 column

separates these compounds, and the quantified values

for 2,3,7,8-TCDF, approximately one-half of the values

obtained on the other stationary phases for these par-

ticular samples, are more accurate values.

If you are involved in analyzing dioxins and furans,

and would like detailed information about Rtx

Dioxin2 columns, we can provide elution orders for

all of the commonly analyzed congeners, and chro-

matograms for each congener group in the WMS-01

reference material. Please contact our Technical

Service chemists at 800-356-1688 or 814-353-1300,

ext. 4, or contact your Restek representative.

Native HCDFs

373.8207 m/z

WMS-01

C13 labels

331.9386 m/z

1,2,3,4,7,8-HCDF-C13

1,2,3,6,7,8-HCDF-C13

2,3,4,6,7,8-HCDF-C13

1,2,3,7,8,9-HCDF-C13

GC_EV00703

Table 1—

An Rtx®-Dioxin2 column gives more accurate quantitation than 5-type columns for

1,2,3,4,7,8-hexachlorodibenzofuran in common matrices (all values pg/g).

Certified

5-type column

Rtx®-Dioxin2 column

Value

Biota-1

Biota-2

Sediment

290

210

Fly ash

570

200

EC-2 (DX-1)

780

630

714 ±276

NST 1974

Rtx®-Dioxin2 Columns (fused silica)

df (µm)

temp. limits

40-Meter

60-Meter

0.18mm 0.18

20°C to 320°C

10759

—

0.25mm 0.25

20°C to 320°C

—

10758

Additional columns for dioxins analysis

Rtx®-Dioxin,

60m, 0.25mm ID, 0.15µm, cat.# 10755, $715

Rtx®-Dioxin,

40m, 0.18mm ID, 0.11µm, cat.# 10756, $655

Rtx®-5,

60m, 0.25mm ID, 0.25µm, cat.# 10226, $705

Rtx®-5MS,

60m, 0.25mm ID, 0.25µm, cat.# 12626, $710

60m, 0.25mm ID, 0.25µm Rtx

-Dioxin2

(cat.# 10758)

Oven temp.:

130°C (hold 1 min.) to

205°C @ 45°C/min. to 305°C @

6°C/min. (hold 30 min.);

Dead time:

2.89 min.;

Carrier gas:

helium at

1.5mL/min., constant flow

Genuine

Restek

Replacement

Parts for

Agilent GCs

(lit. cat.# 59627D)

Restek chromatography

supplies and acces-

sories—designed by

chromatographers, for chromatographers.

This 50-page reference manual lists the consumer-

replaceable items, supplies, and accessories you need

to keep your Agilent GC running at top performance:

injector and inlet supplies, detector parts and supplies,

gas system components, tools, vials, syringes, and

much more. Many items have been designed to save

you time or improve your results, and are exclusive to

Restek. Many other items are manufactured

specifically to duplicate or exceed the performance of

the instrument manufacturer’s parts.

1,2,3,4,7,8-HCDF

1,2,3,6,7,8-HCDF

2,3,4,6,7,8-HCDF

1,2,3,7,8,9-HCDF