Comparing two herb samples using HPLC chromatography

[zuiko3000]

Hi all, I am new to this forum and I don't know if this question has been answered before so I apologize for any inconvenience. I remember working with HPLC chromatography when I used to study pharmacy many years ago and I might be wrong choosing this method to do the following:

I want to compare two herb samples, both have (Garlic, Nettle, Celery and Horsetail). The concentration of the components in the second sample is 1:1:1:1 but I would like to match the first one. I guess these herbs are going to have a lot of components (molecules) and there will be tons of peaks within the chromatography so … Should I pick the highest available component of every herb in order to compare both samples? Where can I get a HPLC chromatography done in USA? What should I do in order to find out the amount of Garlic, Nettle, Celery and Horsetail found in the first sample. I would appreciate your suggestions and comments.

Thank you very much in advance.

David

[danko]

David, Maybe my answer is too basic but I believe it’s kind of corresponding to the question in terms of advancement.
You need to separate the compounds of interest and quantitate them by utilizing the corresponding standards i.e. do some calibration with known amounts of the very same compounds.
Contract laboratories exist every ware in the world and I’m sure that includes USA. So maybe you are best of finding one such and talk to their specialists.

Best Regards

[djacqo]

Hi David,

If you are trying to quantify the amount of a particular herb, it might be difficult because you are correct that you will have multiple components and probably many peaks within the chromatogram. A challenge will be to identify molecules that are specific to each herb, as it may be likely there will be some peaks that are present in more than one herb.

After you find molecules to focus on, they need to be identified in the chromatogram with standards, which you would also use to determine concentrations in your samples by calibrating peak areas with known concentrations.

With any complicated extract, I would worry about coelution of other peaks with your peak of interest, which generates error in your measurement because they will add to the area. LC/MS/MS can eliminate a lot of this and make your method much more specific, but will certainly cost more.

There are many labs in the USA that can do work like this, including the one that I work in.

Best of luck,
Dave

[zuiko3000]

Thank you so much for all this information. So I am going to try to find out which herb has a unique element that can be used to identify it.

Thanks a lot for your help.

David