Any help on a method for Tenofovir (an HIV drug)_LOD 10ng

[adugyasidennis]

Please, can anybody help me with a method to analyse Tenofovir with a detection limit of 10ng/ml on HPLC/UV detector? I don't have a mass spec and would want to do a study on Tenofovir. The plasma concentration for this drug, i have found to be 30ng/ml to 75ng/ml. Please any help on a sensitive method? I am ready to share a baseline report with any interested person to see how i can be helped.
Thank you.

[Kreall]

The only way o get so low LOD without MS is to try derivatization amino group with flourescnce compound like fluorescamine, AQC (6-aminoquinolyl-N-hydroxysuccinimidyl carbamate), OPA and so on. You take plasma, get ultrafiltration, change pH to >8, add derivatiosation coumpund with Internal Standard like purine for this analysis.

Phe-Hex column (for armomatic derivatiosator) or C18 with good endcapping, gradient with ACN and water phase (pH <2) I think should be sufficient.

[adugyasidennis]

I am very grateful for the quick response i have received to the post i made. I am quite a beginner with HPLC and most of the terminologies. I am however catching up with reading and practice to set up a unit within our research centre to undertake bioanalytic studies.
I only have a UV/VIS detector. Can that pick detect the fluorescent compounds? I would welcome a step-by-step guide and wouldn't mind a collaboration to set-up a method if you have the time. I would love to try your beautiful idea when i get to know exactly what I need to move.

I thought i had a solution when i saw the two papers by;
1. Sensitive determination of tenofovir in human plasma samples using reversed-phase liquid chromatography by Setenac et al, 2003
2. Simultaneous quantification of emtricitabine and tenofovir in human plasma using high-performance liquid chromatography after solid phase extraction by Naser et al, 2005

These two papers reported LOD of 10ng/ml which I thought will solve my problems but i am receiving a lot of non-specific peaks. For this reason I am looking for a simple separating method and extraction for tenofovir.
Thank you

[Kreall]

I didnt expect that Tenofovir has such high absorption in UV light. The HPLC shouldnt be hard to develop with those two papers, the only hard thing is develop a optimum method for SPE for extraction of active substance from plasma. If you want I can guide you with some explanatiion via mail.

[adugyasidennis]

Please I am ready for any guidance. My email is adugyasidennis@gmail.com if what i used for this platform does not work for you.
Very grateful.
Dennis