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- Posts: 8
- Joined: Mon Jan 18, 2021 5:13 pm
I am working on leaf wax composition. These are the parameters/features I used on GC-MS:
Machine: Agilent 8890 GC 7010B Triple Quadrupole GC/MS
Column: 30 m x 250 μm x 0.25 μm DB1-MS
Carrier gas: Helium
Flow rate: 1 ml/min
One microliter of the sample was injected into the column at an initial oven temperature of 50 °C for 2 minutes, then increased for 1 minute at 40 °C/min to 200 °C and then raised for 10 minutes at 3 °C/min to 320 °C.
I cannot define the compounds that have more than 33-carbon because the spectra are not good enough after the peak belonging to a 33-carbon compound. The leaf I use has 44, 46, and 48-carbon wax esters (I could see them in FID).
I need to define the compounds between 33 - 44 carbon chemicals. In order to see clear peaks after 33-carbon compounds, I have tried wax ester methods; however, still I cannot see chemicals with longer than 33-carbon chains.
The adjusted parameters for wax esters:
Transfer line temperature: 310 C
MS ion source: 220 C
Scan range: 40-850
Scan time: 720 ms
Solvent delay: 5 min
Injector temp: 325 C
Splitless mode with 2 min splitless time
One microliter of the sample was injected into the column at an initial oven temperature of 50 °C for 3 minutes, then increased for 1 minute at 50 °C/min to 180 °C and then raised for 10 minutes at 3 °C/min to 320 °C.
Could you please advise me what I should change/edit/remove to be able to see peaks of the compounds with more than 33-carbon and define them?
Thanks in advance!