CryoTrapFor Agilent Technologies 7890/6890/6850 GC Systems

CryoTrap

Bad peak shapes and interferences of low boiling compounds are often observed in case of using a sample introduction other than liquid injection, such as headspace, thermal desorption or sampling loop for gas analysis.

In order to improve peak shape and peak resolution in the chromatogram it is required to refocus high

volatile components in the front of the column before chromatographic separation. Otherwise incorrect peak

identification and peak integration may occur.

The JAS double chamber CryoTrap is a powerful tool of high quality to efficiently trap volatile compounds in

the front part of a capillary column. It combines the latest advances in CryoTrap technology including low

thermal mass, efficient insulation and maximum heating power - features that ensure a fast heating and an

economical cooling. Various appropriate coolants can be used to cool the trap (liquid carbon dioxide, liquid

nitrogen and pressurized air). An extremely fast but controlled heating of the trapping zone up to 700°C/ min

allows a rapid re-vaporization of the trapped components for subsequently GC analysis – replacing a

high speed injection. As a result low boiling compounds occur as sharp peaks with a high resolution in

the chromatogram. JAS CryoTrap can be actuated either due to control software embedded into Agilent

ChemStation or by GC keyboard.

JAS CryoTrap is provided to be fully integrated in

Agilent 6890 and 7890 GCs. It can be positioned

inside the GC oven, either at the left hand side wall of

the GC oven or below the valve cabinet. The devise

requires one heated zone (150W) and one pneumatic

inlet slot of the GC. In case of Multi Dimensional GC

applications, JAS CryoTrap can also be mounted

outside the GC oven and connected to a second GC

by means of an optional heated transfer line.

Features

Features

The main advantageous features of JAS CryoTrap system are:

Flexible In order to meet your analytical needs JAS CryoTrap can be installed at various positions (two locations inside the GC oven and one location outside). Additionally, three different cooling options (liquid CO2, liquid N2 and pressurized air) provide complete flexibility to guarantee the most effective analytical conditions.

Efficient By means of a double chamber design the JAS CryoTrap features an effective insulation reducing the coolant consumption to a minimum.

Easy to Use Dedicated and optimized alignment of tuning parameters provides excellent performance at any oven temperature

Economical JAS CryoTrap is controlled either by Agilent ChemStation software or by GC keyboard. The use of the Trap is easy and may be embedded into every GC method.

Fig. 1

JAS CryoTrap

Column in Column in

Column out

OUT

Liquid coolant

IN

Gaseous coolant

Column out

HeatingCatridge

Cooling Phase Heating Phase

Operating Mode

1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00

1000000

2000000

3000000

4000000

5000000

6000000

7000000

8000000

9000000

1e+07

1.1e+07

1.2e+07

1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00

5000000

1e+07

1.5e+07

2e+07

2.5e+07

3e+07

3.5e+07

4e+07

4.5e+07

5e+07

2

Time (min)

Abu

ndan

ce

Abu

ndan

ce

Ace

ticac

id

Furfu

ral 3-

Met

hylh

ydan

toin

Without CryoTrap

GC-Method: 40°C for 6 min, with 20°C/min to 300°C

Time (min)

Ace

ticac

id Furfu

ral

3-M

ethy

lhyd

anto

in

CO

With CryoTrap

GC-Method: 40°C for 4 min, with 15°C/min to 300°C

The outer wall of the JAS CryoTrap is made of stainless steel. In order to resist thermal fluctuation a tube of a

specific material for optimal heat carriage is inserted into the CryoTrap body.

The analytical column is guided through the CryoTrap chamber. Due to appropriate coolants the trap is cooled

down to the effective temperature and components transferred from the inlet system to the analytical column

are trapped before chromatographic separation. Re-vaporization for subsequent GC analysis is caused by

means of rapid but controlled heating of the trapping zone. Temperature and time of trapping process can be

optimized depending on the analytes and may easily be adjusted using the control software. A fast heating

rate is important in order to obtain sharp peaks of volatile components. As a result peak broadering and

interferences are minimized and quantitative evaluation becomes more precise.

Chromatograms of a wood sample are illustrated for comparison. Figure 3a shows the bad quality of

peak resolution for high volatile components, like acidic acid or furfural, in case no Cryo Trap is used. An

identification and integration of these peaks with reasonable certainty is not possible. Figure 3b demonstrates

the necessity of using a CryoTrap in order to improve the peak resolution of low boiling compounds.

Fig. 2

Functionality of JAS CryoTrap

Fig. 3a

Analyses of high volatile compounds in wood samples

Fig. 3b

2.5e+07

Benz

ene

1.5e+07

2e+07

TD-GC/MS: Thermal desorpt ion(200→320°C wi th CryoTrap)

5000000

1e+07

HC

l

Hydrochloric acid8000000 Ion 36.00 (35.70 to 36.70):

Carbon dioxidem/z=44

m/z=36

3000000

Ion 44.00 (43.70 to 44.70):

Acetic acidm/z=601500000

Ion 60.00 (59.70 to 60.70)

/1500000

Ion 100.00 (99.70 to 100.70)

m/z=100 2-propenoic acid (methyl ester)

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

TD-GC/MS: Thermal desorption(200→320°C without Cryo Trap)

1400000

Abundance

Column: UA5 (30m, x 0.25mm x 0.25μm)PyrolyzerFurnace: 200ºC→320ºC (20°C/min)Carrier gas: He 1ml/minSplit ratio: 1:50GC oven: 40→ 20ºC/min→320ºC (1min)Injector: 320ºC

1100000

1400000

These are residual volatiles which can be separated by cryo-trapping during desorption.

800000

500000

1 00 00 10 00

200000

1.00 5.00 10.00Time (min)

Operating Mode

Figure 4:

Comparison of thermal desorption analysis (200– 320°C)

with (4a) and without (4b) Cryo Trap (TD-GC/MS system)

4a

4b

Thermal desorption often results in broad initial

peaks including numerous individual components.

While reducing of the initial column temperature or

using thick film columns will just narrow this initial

band width, cryo-focussing is the most efficient and

cost effective way of ensuring peak separation.

Figure 4a and b illustrate the separation

improvement of the volatile fraction by means of

cryo-trapping. Qualitative and quantitative data

quality will be enhanced tremendously.

Specifications

Specifications of JAS CryoTrap

Description Double chamber CryoTrap design with combined inlet/exhaust port

Order Numbers for GC 6890: for GC 7890:

JAS 65600 JAS 66600 - for air cooling JAS 66601 - for liquid N2 JAS 66602 - for liquid CO2

Instrument Dimensions Length: 105 mm Width: 20 mm (o.d.) / 1 mm (i.d.)

Compatibility Agilent GC 7890/6890/6850

Power Int. Power Supply 24V, Input 150 VA

Maximum Temperature Agilent GC 6890: 500°C Agilent GC 7890: 450°C

Cooling Temperature Liquid N2: -160°C Liquid CO2: -60°C

Pressurized Air: ambient temperature or oven start temperature

Heating Rate 1-700°C/min

In case of Multi Dimensional GC application the JAS CryoTrap is positioned outside the oven to trap

components eluting from the first separation column.

Using liquid nitrogen as cooling agent a dewar vessel with a dip tube is required (minimum 1 bar head

pressure for full perfomance mandatory). In case of liquid carbon dioxide as cooling agent a cylinder with

a dip tube and a variable restriction is required.

Carl-Zeiss-Str. 49

47445 Moers

Germany

Phone: +49 2841 9871 100

Fax: +49 2841 9871 222

e-Mail: info@jas.de

Internet: www.jas.de

joint analytical systems GmbH

About joint analytical systems

Since 1995 JAS is a major partner and Value Added Reseller of Agilent Technologies. We are an innovative-driven organization that offers customized solutions for GC, GCxGC, µGC, GC-AED, GC-MS, GC-QQQ, LC, LC-MS, LC-QQQ and Q-TOF LC-MS applications.

JAS serves key industries such as

Chemical•Environmental•FoodandFlavor•Forensic•MechanicalEngineering•Petrochemical•Pharmaceutical•

JAS Products for GC

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