I am analyzing VOCs in the air and have a question about choosing a column for good separation of VOCs. I use GC-FID and inject 1 uL (split ratio: 1:10).
It depends of injection and concentration technics, detector is also important: if you have MS then cappilary column is better because of lower gas flow to vacuum.
For 1 ul injection - capillary column is the right choice: there is no need in large capacity column and also packed column has lower resolution then capillary one .
Although the comments look sensible, it seems that you speak about some solvent extract or a preconcentration method. 1 microliter of air seems not enough for VOCs at low concentrations.
FID is quite a sensitive detector. However, I wonder whether you are in a routine analysis where you know the identity of each peak or you are in an exploratory analysis where you are not sure of the kind of substances you have. FID is an appropriate choice only for the former, unless you are not interested in determine each substance.
My choice of analysis is capillary column due to its good separation, resolution, faster analysis and smaller quantity of injection volume. We used capillary column with MS.
Good luck...
Jean-François Gal I currently have Agilent 122-1032 - GC Column DB-1 30m, 0.25mm, 0.25µm available and use solvent extraction method. Is that column usable and what the injection volume is?
It is a general purpose column which can work with most weakly polar analytes, although more specialized column may be found.
I did not use GC/MS recently for VOC analysis. I just looked at vendors recommendations.
* Thermo: TraceGOLD TG-VMS column
A Rapid Method for the Analysis of Air Toxics Based on US EPA TO-15 (thermofisher.com); https://assets.thermofisher.com/TFS-Assets/CMD/Application-Notes/an-10729-gc-ms-air-toxics-us-epa-to-15-an10729-en.pdf
* VF-624 MS 60m capillary column
5991-3927EN_6pg.indd (agilent.com)
https://www.agilent.com/cs/library/applications/5991-3927EN_HR.pdf
Recent papers on VOC analysis are also a good source of information.
Good luck
J-F
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