ATAS GL has successfully applied this approach in the Direct Thermal Desorbtion (DTD) unit.
Now we introduce its second generation: LINer EXchanger.
- Can be used on any GC,
- Micro Headspace technique permits the analysis of trace contaminants in a wide range of different matrices,
- Uses standard 11mm septa and is compatible with the Merlin Microseal,
- True septum purge (removes septum bleeding, reduced risk of carry over)
- Liquid injection can be done while the automatic head is closed,
- Uses standard OPTIC liners,
- No liner transport adapter required,
- Based on the OPTIC 3,
- Little if any sample preparation is required,
- Can be automated by FOCUS / CombiPAL,
- Selective desorption of components of interest without pyrolyzing of the matrix,
- Low consumable costs,
LINEX, an automated liner exchanger, is designed to be used for Direct (in-injector) Thermal Desorbtion (DTD).
It can be quickly, in a matter of minutes, mounted on any standard OPTIC injector. Any of the standard OPTIC liners can be handled by LINEX either in manual or automated mode.
In the automated mode liners are transported between the 98-position tray and injector by ATAS GL FOCUS sampling robot equipped with a pneumatic gripping arm.
With LINEX, the multi-sample analysis sequence works in a simple way: head of the injector is opened and a liner containing sample is introduced.
The head is closed and the liner is purged with carrier gas.
Next, the injector is heated and the sample is transferred onto the column.
At the end of the analysis the empty liner is moved back to the tray and the cycle is repeated.
The use of the newly developed LINEX is a most promising approach for analysis of solid and enriched gaseous samples with the fully automated OPTIC GC or OPTIC GC/MS system.
There is also a possibility to apply the approach for the analysis of samples with a difficult matrix using the so-called DMI technique.
With DMI a minimum sample preparation is required.
What is DMI:
- Ability to analyse sample by directly introducing the matrix or extract into the injector - little if any sample prep is involved
- Liquid or dirty solid samples contained in a microvial which is inserted in an injector liner
- Desorption from sample directly onto head of the GC capillary column - fewer steps involved, less opportunities for analyte losses
- Solvents can be removed by venting under controlled conditions
- Compounds of interest can be transferred onto the column using the lowest possible final temperature - limits pyrolyzing of matrix
- Involatiles from the matrix are kept in the microvial which is disposed of after use - liner can be re-used
Applications done on LINEX:
- Qualitative and quantitative determination of the organic wood preservative component N-cyclohexyl-diazeniumdioxide (HDO) in treated timber means of direct thermal desorption-gas chromatography-mass spectrometry (DTD-GC-MS).
- Trace-level determination of pesticides in food using difficult matrix introduction.
- Fatty Acid Profile in vegetable oils.
- Analysis of car exhaust.
- Nicotine in Tobacco.
- Chemical Analysis of Spores and Pollen.
- Limonene in shampoo.
- Benzene and toluene in crude oil.
- Caffeine in instant coffee.
Capping and De-Capping station for LINEX:
In many cases the GC injector liner should be sealed (capped) from both sides to either protect the sample, placed or collected into the liner, from deteriorating influence of the environment or keep the liner clean after conditioning.
The liner should than be de-capped just before it is placed into the GC injection port. The ATAS GL Capping-De-Capping (CDC) Station is designed to automate this procedure.