Please refer to :

https://www.ibl-international.com/media/catalog/product/f/i/file_108_104.pdf

Also , you can refer to LC/MS/MS methodology for determination of neurotransmitters in biological fluids..... it is an expensive method. But the above catalog shows many ELISA techniques that would be of benefit to your scientific protocol and less costy

However, i think from my readings that HPLC with electrochemical detector is required for such measurement of neurotransmitters " NE, DA, 5-HT" not HPLC/UV which is useful for amino acids extraction as far as i know from my lab. practice .

You can also find more methodologies with LC/MS/MS but as i told you it is expensive and not available easily.

GOOD LUCK

Sahar, you'll have no luck detecting these substances in plasma with UV. It's simply not sensitive enough. Neurotransmitters are in the ng/L-pg/L range. I suggest you buy an electrochemical detector. They are relatively inexpensive and can measure in this concentration range.

Much success!

Regards, Bob May

Thanks a lot Dr Robert. Actually, I am just answering the question of Barbara Nikolic asked in the top of the page. I adviced her the same that HPLC with UV is not the right choice but HPLC with electrochemical detector. Deep sorry if there is any misunderstanding.

Sorry, Sahar, you're right - I didn't read the thread properly!

You are most welcome Dr Robert. Many thanks for your generous and valuable scientific cooperation.

Dear Barbara,

I agree with Sahar and Robert, I think the main issue here is the UV detector. Electrochemical detection is a more sensitive option for catecholamines and indoleamines detection. Furthermore, plasma samples (I don´t know if you are using any kind of sample pre-treatment) constitute a much more complex matrix than brain extracts and this could be also contributing to your problems in detecting the peaks.

Best regards,

Manuel

Dear Barbara,

We are working on a protocol for plasma catecholamines in reptiles, and have been using the paper below as a base. I second all the people saying that electrochemical detection is the standard, but we have had some success with flurometric detection. We have had to use SPE columns as a pre treatment as discussed by Manuel as well.

I would be really interested in your findings from the lizard brain tissue, have you published these, I would live to read ?

Fujino, K., Yoshitake, T., Kehr, J., Nohta, H., Yamaguchi, M., 2003. Simultaneous determination of 5-hydroxyindoles and catechols by high-performance liquid chromatography with fluorescence detection following derivatization with benzylamine and 1,2-diphenylethylenediamine. J. Chromatogr. A 1012, 169–177. doi:10.1016/S0021-9673(03)01180-4

Thank you all for your answers! We managed to detect adrenalin from plasma (we lowered the pH of mobile phase), but we couldn´t detect serotonin (and still wondering why). From brain tissue we managed to detect catecholamines (adrenalin and noradrenalin in one peak, and dopamine in separate peak), serotonin, tyrosine and tryptophan. We did everything with UV-HPLC, but the results are not yet published.

Yes my dear Barbara, you are still working on HPLC-HPLC-UV which is not a right choice for brain neurotransmitters. So please if you want to continue properly without losing more time ,efforts and cost, try to find out any lab that possesses HPLC with electrochemical detector. Both Dr Robert and Dr Manuel had the same recommendation. "HPLC with electrochemical detector for brain neurotransmitterneurotransmitters and proper processing of brain homogenates" . Good Luck

i am also worried about that because my ecd is out of work and i was searching to find some good method of uv for the detection of neuotransmitters...but now again thinking to switch to ecd...