My headspace device is under maintenance and I have urgent VOCs samples. I extracted the samples using LLE (hexane) and injected them into GCMS with a delay time of 5.5 min. Temp programing (40 C°, 1 min then 8/min to 300 C° 4 min hold. But no peaks were shown in the chromatogram. I can understand that some compounds will be eluted during the delay time, but what about late eluted peaks? Any tips? Thanks in advance
In order to understand the problem I have several questions.
Split or splitless?
scan range?
Internal STD?
Are you using the same column?
Best regards
Eleuterio Umpierrez Thanks for your answer. I am running with splitless mode and at a scan range from 35 to 260. No internal standard.
Thanks again
Dear Noel W Davies , I am analyzing a standard sample at a concentration of ppb with a splitless mode. So, I rule out that poor concentration is the cause. Nevertheless, thank you.
In my opinion, the problem is poor concentration. If I use the needle injection technique, I use the SPEME liner and SAFE as the sample preparation technique. The chromatograms will be different from the headspace ones anyway
Thank you Krzysztof Wojtycza for your reply. Could you please tell me what SAFE stands for?
Depending which method you have being using for VOCs is if the L/L is useful or not.
If you were looking for ppb components, L/L is not an option and you should use SPME with the proper fiber and the optimal conditioning, in order to reach ppb in the GC/MS
Dear Eleuterio Umpierrez thanks for your reply. I am actually aware of SPME but I was investigating the applicability of LLE.
Solvent Assisted Flavour Evaporation (SAFE)
doi.org/10.1007/s002170050486
doi.org/10.1021/acs.jafc.1c01475
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