Chemical Forums
Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: Username14 on March 12, 2016, 01:57:55 PM
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Hi,
I recently completed a univerity lab in which we used both GC-MS and LC-MS to analyse a sample. We focused on three main cannabinoids in the sample - delta-9-THC, CBD and CBN. We used methanol as a solvent, and then repeated the practical using hexane as a solvent.
My questions are: What are the advantages of using methanol over hexane or vice versa?
Would one solvent be better than the other? Or is one solvent better for GC-MS and the other better for LC-MS?
Thanks :)
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You must attempt a problem or give your thoughts before we can help you. It is a Forum Rule.
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The only thing that I can think of is the different polarities, because Methanol is polar and Hexane is non polar. I know that the cannabinoids are non polar also, and so would be dissolved by Hexane. But whilst trying to find out if I would be correct in saying the Hexane is better suited for the extraction of cannabinoids, I found out that Methanol is amphiphilic and so would also dissolve non polar molecules. So now I'm really unsure.
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Okay ... since you did it once with each solvent, did you see a difference? If you saw a difference, does the difference coincide with your theories about the differences in the two solvents? If not, you may have to determine other differences between the two solvents.
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Okay ... since you did it once with each solvent, did you see a difference? If you saw a difference, does the difference coincide with your theories about the differences in the two solvents? If not, you may have to determine other differences between the two solvents.
For the GC-MS results, the concentrations were consistently higher for the samples using Methanol as a solvent, but for the LC-MS results the concentrations were higher with Hexane as a solvent.
But I don't understand what might have caused the difference