Combining the power of HPLC and GC
Both GC and LC are widely used in today’s analytical lab. Each technique has its advantages. In recent years
HPLC has increased in range of application mostly because shorter sample preparation.
Yet GC still offers the best sensitivity and separation power.
The coupling of LC to GC offers the best of both world:
- Simple sample preparation
- Sample enrichment
- High resolution of compounds
- High sensitivity
In LC-GC technique, the sample is separated using typically NPLC (Normal Phase Liquid Chromatography).
The LC allows selective isolation of groups of compounds then transfer to the GC by mean of on-column large volume injection.
Following a long tradition of chromatography innovation and experience,
Brechbühler AG now commercializes Thermo’s LC-GC System.
Brechbühler brings exciting enhancement to the technique as well as its knowledge and excellent customer support.
Technique
The principle of the LC-GC coupling is simple
After separation on the LC column the fraction of interest is transferred via the transfer valve onto the GC column by large volume injection technique. The fraction transferred is analyzed by the GC or GC/MS. A backflush of the LC column can be performed at any time. Because of large volume injection the sensitivity is greatly improved
Automation at your fingertip
The dedicated software makes the LC-GC 9000 a routine instrument. Once the method is setup, a sequence of sample can be programmed. The software controls all the instruments (Phoenix pump, Trace GC, PAL Autosampler and Exachrom acquisition system).
Mode of operation
Standard mode:
one transfer per LC run
Multitransfer mode:
Several transfer per LC Run. The pumps are placed on Hold after each transfer for the duration of the GC run. This mode can be used for LCxGC experiments
Peak detection transfer:
The transfer is triggered by the detection of a peak on the UV detector.
For complex matrices
LC-GC coupling has been successfully used in the following fields:
- Food samples
- Flavor & Fragrance samples
- Petrochemical and industrial samples
- Environmental samples
- Pharmaceutical samples
- Biological samples.
Any sample in complex matrices.
There are many applications published using LC-GC techniques.
For more information on the technique please refer to Dr.. K. Grob & Maurus Biedermann work.
Another good starting point is a paper by Luigi Mondelo: On-line Coupled LC–GC: Theory and Applications
