slam

I think , super cretical fluid extraction method is most ideal 

in general I hope the following att. can help u

Dear Dr. Abdelmageed

Thank you.

Good luck.

Headspace analysis - GC and GCMS

For Isolation

Supercritical carbon dioxide extraction

Headspace sorptive extraction

For Analysis & quantitative determination

Near-Infrared Spectroscopy (NIRS)

Continuous Wave-Free Precession NMR

HPLC, GLC, IR, GCMS, NMR etc can be used.

Dear Rajeswara: any extraction using solvents even water are non-destructive methods to separate volatile and non-volatile secondary metabolites from plants. By other side to isolate them using chromatographic techniques are also non destructive methods.  Are these your questions?.

Ms. Olga Lock

Thank you. Generally plant parts are detached or harvested from plants for extracting or isolating phytochemicals i.e. leaves, flowers, fruits, seeds, bark, roots etc. Once these parts are separated from the plant they die. This is destructive sampling. My question is, do we have any techniques to estimate quantitatively either volatile or non-volatile chemical compounds present in the plant parts or whole plant without separating them from the plant? For example, instruments are available to measure leaf surface temperature, photosynthetic rate etc. on intact leaves. Do we have such equipment or techniques for estimating quantity of phytochemicals and extracting them from intact plant parts?

Best wishes?

In USP or any pharmacopeia you can find some methods to quantify , for example alkaloids, flavonoids, quinones, tannins, in some specific plants, specially if the plants are used as drug and have commercial value. In RG I have added an experiment how to quantify rutin from Ruta graveolens using chromatographic methods.  

Headspace sorptive extraction and then GC-MS

I think if there is, it could be portable spectroscopy techniques. 

Dear all

Thank you very much for your valuable contributions.

Best wishes.

I agree that Supercritical carbon dioxide extraction and Headspace sorptive extraction is generally recommended for non destructive analysis of samples. 

However, I do have a question for all those who are recommending HPLC- MS and GC-MS. These are to analyze/ quantify the extracts right? I think the question here is for the isolation. Can you elaborate on that? Thanks.

Dear Dr. Shalini

Thanks for your contribution and the aprropriate doubt you expressed.

For any extraction or isolation of secondary metabolites we resort to collection (harvesting) of plant parts, bring them to the laboratory and then subject the fresh/dried samples to different extraction/isolation techniques.

Plants synthesise  (metabolize) and catabolize (utilize) secondary metabolites in a continuous manner. If we can develop a procedure or techniques to isolate the desired secondary metabolites from intact plant parts without collecting/harvesting them, we will be providing an opportunity to the plant to synthesize these secondary metabolites and accumulate them in due course of time. In other words we will be able to harvest the secondary metabolites from time time without destroying plant parts. Something like milching a cow.

There are of course problems in such an approach but it is worth giving a try. 

Dear Rao Sir

Thank you for your clarification. 

However, I was not asking about the importance of non destructive methods to isolate sec. Metabolites. I agree with you on the advantages and the difficulties of the same. I just wanted to request a clarification on how HPLC-MS or GC-MS can be an nondestructive way to isolate metabolites since they are analytical techniques used after the extraction process, if I am not mistaken. Since, a few people have replied to your question with only these analytical techniques as the answer and no pre-preparative step.

Dear Dr. Shalini

You are right. HPLC-MS and GC-MS are not non-destructive isolation techniques.