Chromatography Forum

Hi, I was wondering if anyone has any dosing methodology for 9-Octadecenedioic acid on HPLC, or if they have any ideas?

Reverse phase analysis using a C8 or C18. Water and MeCN should work but some buffer might be a good idea. What detector are you using or have access to? For UV, 205 or 210nm might work if the analyte level is high enough, and any mobile phase additive used has an acceptable cut-off. Alternatively you can tag the molecule with a chromophore/fluorophore by derivatization. There are many ways to derivatize, but two that come to mind are with phenacyl bromide or 2-Nitrophenylhydrazine. See also: https://www.thermofisher.com/us/en/home ... amine.html

A aerosol detector like a CAD or ELSD would be other options that might work without derivatization. For mass spec detection fatty acids can be detected using electrospray ionization in negative polarity mode.

Hi, I was wondering if anyone has any dosing methodology for 9-Octadecenedioic acid on HPLC, or if they have any ideas?

At 10% level? At 10 ppm? In what matrix? What other chromatography equipment is available?

I'm sure that you have your reason to use HPLC for this determination but I think that best option is derivatization and quantify it with GC as an ester.

I agree that HPLC-ELSD also can be an option:

https://assets.fishersci.com/TFS-Assets ... 211_v7.pdf