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Plant (leafs) extraction

Posted: Mon Jun 04, 2018 9:28 pm
by sohaib1
Hello, the leafs are turning from green to pure white color. The leafs are still alive. I want to analyze these white leaves by GC-MS. Can you guys help me how to extract these leaves. Thank you very much for your help in advance

Re: Plant (leafs) extraction

Posted: Mon Jun 04, 2018 11:09 pm
by osp001
Are you trying to diagnose a disease or a nutrient deficiency? Mass spec probably won't help much.

Or are you looking for a specific compound?

Re: Plant (leafs) extraction

Posted: Tue Jun 05, 2018 7:32 am
by pumpedupchemist
You could try QuEChERS as a sample prep. For more information try this.

http://www.restek.com/pdfs/GNAN1097A.pdf

Re: Plant (leafs) extraction

Posted: Tue Jun 05, 2018 4:57 pm
by sohaib1
osp001 wrote:
Are you trying to diagnose a disease or a nutrient deficiency? Mass spec probably won't help much.

Or are you looking for a specific compound?


Well yes we want to know what caused this green to white color? The leafs are still alive. We are going to do ICP-MS on it. Nutrient analysis also. But we also want to run GC-MS on it so find if there is any chemical or compound responsible for the color that is why how can i extract the leaves to run it in GC-MS. Thank you

Re: Plant (leafs) extraction

Posted: Tue Jun 05, 2018 5:04 pm
by sohaib1
pumpedupchemist wrote:
You could try QuEChERS as a sample prep. For more information try this.

http://www.restek.com/pdfs/GNAN1097A.pdf


this is more related to food than leafs. we are just getting 3 samples of leaves. I just want to know basic extraction method to see if we can find a compound/chemical responsible to green to white color change. The weird part is the leafs are still alive. So it is not a fungus infection on the leafs.

Re: Plant (leafs) extraction

Posted: Tue Jun 05, 2018 5:48 pm
by Rndirk
Quechers wouldn't be a bad idea.

If the idea is to get as much as possible organics out of the sample, i think the easiest thing to do would be grind/cut the leaves to small pieces, extract with methanol, and inject.

I doubt you'll be able to draw any conclusions from comparing full scan MS spectra. I predict it'll be a forest of peaks...

What kind of MS will you be using?

Re: Plant (leafs) extraction

Posted: Wed Jun 06, 2018 5:46 pm
by sohaib1
Rndirk wrote:
Quechers wouldn't be a bad idea.

If the idea is to get as much as possible organics out of the sample, i think the easiest thing to do would be grind/cut the leaves to small pieces, extract with methanol, and inject.

I doubt you'll be able to draw any conclusions from comparing full scan MS spectra. I predict it'll be a forest of peaks...

What kind of MS will you be using?


I will be using GC-MS full scan
Yes the idea is to get what is inside the leaf. I know i will get a lot of peaks but thats what they want. They want to know of any of that is responsible for color change. How much methanol and plant should i be using. Do i just filter the extract after shaking for an hour?

Re: Plant (leafs) extraction

Posted: Wed Jun 06, 2018 6:04 pm
by Rndirk
sohaib1 wrote:
Rndirk wrote:
Quechers wouldn't be a bad idea.

If the idea is to get as much as possible organics out of the sample, i think the easiest thing to do would be grind/cut the leaves to small pieces, extract with methanol, and inject.

I doubt you'll be able to draw any conclusions from comparing full scan MS spectra. I predict it'll be a forest of peaks...

What kind of MS will you be using?


I will be using GC-MS full scan
Yes the idea is to get what is inside the leaf. I know i will get a lot of peaks but thats what they want. They want to know of any of that is responsible for color change. How much methanol and plant should i be using. Do i just filter the extract after shaking for an hour?


Yes, make sure to filter or centrifuge before injecting. 1h shaking sounds OK. I'd take like 10-20mL MeOH for 1g of leaves.

Re: Plant (leafs) extraction

Posted: Wed Jun 06, 2018 7:21 pm
by sohaib1
Rndirk wrote:
sohaib1 wrote:
Rndirk wrote:
Quechers wouldn't be a bad idea.

If the idea is to get as much as possible organics out of the sample, i think the easiest thing to do would be grind/cut the leaves to small pieces, extract with methanol, and inject.

I doubt you'll be able to draw any conclusions from comparing full scan MS spectra. I predict it'll be a forest of peaks...

What kind of MS will you be using?


I will be using GC-MS full scan
Yes the idea is to get what is inside the leaf. I know i will get a lot of peaks but thats what they want. They want to know of any of that is responsible for color change. How much methanol and plant should i be using. Do i just filter the extract after shaking for an hour?


Yes, make sure to filter or centrifuge before injecting. 1h shaking sounds OK. I'd take like 10-20mL MeOH for 1g of leafs.


OH ok thank you very much for your help

Re: Plant (leafs) extraction

Posted: Wed Jun 06, 2018 9:48 pm
by James_Ball
You can also do an overnight extraction by Soxhlet with Methylene Chloride which will extract any non-water soluble analytes.

Re: Plant (leafs) extraction

Posted: Thu Jun 07, 2018 1:54 pm
by sohaib1
James_Ball wrote:
You can also do an overnight extraction by Soxhlet with Methylene Chloride which will extract any non-water soluble analytes.


OH OK thank you very much for your help. I will try soxhlet as well thanks

Re: Plant (leafs) extraction

Posted: Thu Jun 07, 2018 3:52 pm
by sohaib1
James_Ball wrote:
You can also do an overnight extraction by Soxhlet with Methylene Chloride which will extract any non-water soluble analytes.


Hello James, after the soxhlet do i need to pass it through sodium sulfate and concentrate using nitrogen stream or rotovap.

How much plant and DCM should i be measuring in the soxhlet extraction. Thank you

Re: Plant (leafs) extraction

Posted: Thu Jun 07, 2018 9:17 pm
by James_Ball
sohaib1 wrote:
James_Ball wrote:
You can also do an overnight extraction by Soxhlet with Methylene Chloride which will extract any non-water soluble analytes.


Hello James, after the soxhlet do i need to pass it through sodium sulfate and concentrate using nitrogen stream or rotovap.

How much plant and DCM should i be measuring in the soxhlet extraction. Thank you


It would be good to dry the extraction with sodium sulfate to protect the column from water when doing GCMS. You can concentrate the sample as needed to achieve the detection limit you are looking for. If you concentrate a plant extract too much though, you will most likely need to do further cleanup steps to prevent overloading the instrument with the chlorophyll and sugars that might co-extract.

https://www.epa.gov/hw-sw846/sw-846-compendium

The 3600 series has cleanup options for different matrix and analyte combinations. The 3500 series has other extraction methods as well. Some are for water samples and some for solid samples. Not food related, but they are fairly rugged methods for samples that are not "clean" like drinking waters would be.

Re: Plant (leafs) extraction

Posted: Fri Jun 08, 2018 1:47 pm
by sohaib1
James_Ball wrote:
sohaib1 wrote:
James_Ball wrote:
You can also do an overnight extraction by Soxhlet with Methylene Chloride which will extract any non-water soluble analytes.


Hello James, after the soxhlet do i need to pass it through sodium sulfate and concentrate using nitrogen stream or rotovap.

How much plant and DCM should i be measuring in the soxhlet extraction. Thank you


It would be good to dry the extraction with sodium sulfate to protect the column from water when doing GCMS. You can concentrate the sample as needed to achieve the detection limit you are looking for. If you concentrate a plant extract too much though, you will most likely need to do further cleanup steps to prevent overloading the instrument with the chlorophyll and sugars that might co-extract.

https://www.epa.gov/hw-sw846/sw-846-compendium

The 3600 series has cleanup options for different matrix and analyte combinations. The 3500 series has other extraction methods as well. Some are for water samples and some for solid samples. Not food related, but they are fairly rugged methods for samples that are not "clean" like drinking waters would be.


OH OK thank you very much for your help James

Re: Plant (leafs) extraction

Posted: Tue Jun 19, 2018 9:13 am
by Gaetan Glauser
Hi,

The most probable reason for a plant turning from green to white (or another color) is degradation of chlorophyll due to leaf senescence. Leaves can live for quite a while in senescent conditions. In other words, it may be worth looking at which compound disappeared rather than which one appeared. Therefore, before running complex untargeted profiling by LC-MS or GC-MS, why not perform a quick quantification of chlorophyll A and B by UV spectrophotometry?