I’m interested in measuring the amount of salicylates in various plants.
How could I do that?
Any chemists? Pharmaceutical company drug developers? Anybody?
I operate a GC (Gas Chromatograph) all day at work, so when I see this question, I think “Yes, I could do that” The problem is that is that it wouldn’t be cheap, and still might not tell you what you want to know.
The price would sort of depend on how many samples you were planning on analyzing. The more samples, the more we can spread out our method development costs. Just as a rough guess, I would think for 10-20 samples it would run about $200 each.
The other possible problem is that I would be writing a report that would list each of the tested for salicylates individually. For example Salicylic Acid 10 mg/Kg, Methyl Salicylate 3 mg/Kg, Ethyl Salicylate 14mg/Kg… The problem might arise that you are looking for a summation of all the salicylates, and I could only tell you about the ones we looked for.
There might be a fast and easy (Therefore cheap) wet chemistry or perhaps UV/Vis spectrographic method that would serve. But as my Organic textbooks are at home, it will be much later before I can look and see.
GC would work or you could go with an HPLC method.
Before going down either road, you might check the literature to see if anyone has already published values for the plants you’re interested in.
Couldn’t you first hydrolyse all of the esters to the free acid and just quanitfy that? negative-ion electrospray LC/MS works well for carboxylates. Of course, throw in the stable-isotope labeled internal standard and the price goes up.
Wow - I saw this sinking like a rock yesterday and almost gave up on responses!
I have looked up salicylates in general, because my wife is salicylate-sensitive (she’s deathly allergic to aspirin, and her allergist figured out that other substances similar enough - salicylates - when too prevalent in food make her stomach hurt).
So I’m trying to breed my own vegetables - low-salicylate versions of vegetables which seem to be ‘borderline’ - for instance squash.
Thanks.
I’d actually suggest an enzyme linked immunosorbant assay (ELISA), which is much easier than HPLC, and doesn’t require as much equipment for the laboratory impaired. ELISAs are also pretty easy to run if you have never done one before.
These guys apparently sell a kit, which should be most everything you need.
I was thinking about this on the way home last night. You are right, hydrolyse them to the free acid. Then methylate them to improve the chromotagraphy.
I don’t think you would need to tie up an expensive LC/MS for this. GC/FID would be fine. However, we are still talking about $100-200 per sample.
Immuno assay is probably the best solution. Both on price and do-it-yourself ease.
Agreed on all counts; 5yearlurker gets a cookie…
Except I realize that not everyone apparently has access to pipettes…