Dear Sarath,

I think attached papers are useful for you. They are valuable articles about plant's GC-MS analysis. 

Kind regards, Homayoon. 

Hello,

which acquisition mode did you use? scan, SIM, MRM?

Did you perform measurements of standards?

It will depend on what you want to get from the extracts? Everything, or special analytes?

Hi Sarath,

take a look here. McLafferty's book gives you a very good introduction how to interpret MS spectra:

Article Interpretation of mass spectra / F. W. McLafferty, Frantisek Turecek

https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=2ahUKEwiig6LgjOHgAhVR3qQKHV4dAfQQFjAAegQICRAC&url=https%3A%2F%2Fwww.researchgate.net%2Fprofile%2FEduardo_Dellacassa%2Fpost%2FHow_to_analyze_the_unknown_metabolites_by_GC-MS_if_there_is_no_standard_and_no_databases_but_certain_characteristic_m_z_of_those_compounds_are_known%2Fattachment%2F59d631f679197b807798fb74%2FAS%253A368287646011392%25401464818025151%2Fdownload%2FMcLafertty%2BInterpretation%2BOf%2BMass%2BSpectral%2B4%2BTh%2BEdition%2B.pdf&usg=AOvVaw3T1yAw0mpQLlnCDZpl8D8u

Regards

Markus

Marcus gave you a very good advice. The first thing you have to do is to identify the compunds you have in your TIC chromatogram, and then, once identified, to think another method to, for instance, quatify these compounds and so on.

Hi, Nair

While analyses your samples. A list of compounds analyses that in samples with percentage to you. you should identification all of them.

Hi Sarath,

if you have screenshots of your mass spectra, you can send me the screenshots and I'll try to interpret the spectra as far as I can. ([email protected])

Do you have access to spectral libraries like NIST or Wiley? If yes, you can do a spectrum search and you can compare your measured spectra with the library spectra.

This will give you a first clue as to which substance class it might be. Usually, you get several suggestions, some of which differ only marginally. The only thing that helps is to get the compounds and inject them. If the compounds come at the same retention time and shows the same mass spectrum, then it is very likely also this compound. Furthermore, you can see from the mass spectra whether halogens (chlorine or iodine) are present. These give beautiful characteristic patterns. The nitrogen rule gives you a statement about the number of nitrogen atoms in your molecule. Sulphur is easily recognized by the M+2 peak. You can recognize alkanes e.g. by characteristic mass differences (14u) in the spectrum. Aromatics often show the mass 91 (tropylium cation). Mass 149 indicates e.g. phthalates. As you can see, one can read a lot out of a mass spectrum relatively quickly at first glance. However, what has been said now only applies to molecules with an odd number of electrons (radical cations, such as those produced by electron impact ionization, OE). Molecules with an even number of electrons (EE) fragment quite differently. This is rather interesting for ESI-MS. Otherwise only practice and experience will help. Practice makes perfect.

Regards

Markus

Hi Sarath,

plant extracts often contain typical classes of compounds. This could be:

- Terpenes (Mono-, Di, Tri-, Sesqui-)

- Alcohols

- Esters

- Phenols

- Amines

- Benzopyranes

- Aromatics

If I were you, I'd concentrate on these substance classes for now.

Regards

Markus

Dear Sarath,

I think attached papers are useful for you. They are valuable articles about plant's GC-MS analysis. 

Kind regards, Homayoon.