Do anyone know a reverse phase protocol to separate fatty acids on HPLC using a PDA detector? I know that a GC is usually used in the litterature for the analysis on those compounds, but I dont have this equipement in my laboratory.

Thanks

Fatty acids can be done using reverse phase with a RI detector. To use UV/PDA you would have to make derivitives.

Thermo Hypersil-Keystone have an apllication for the analysis of n-alkyl carboxcylic acids using a BETASIL Phenyl, 5µm, 150x4.6mm Column. The conditions are as follows:
Mobile Phase:A=0.1% H3PO4, B=MeCN
Gradient:
Time %B
0 25
20 75
Flow:1ml/min
Detector: UV @ 210nm

Thanks for your answers,
Do you make derivatives with your BETASIL protocol, or you are able to see the fatty acids at 210nm without any modification?

Do you know a simple derivatization method with a commercial reactive that allow the observation within the UV range? All I have seen in the litterature is derivatives observables with a fluorescence detector.

A derivative that can be seen in the fluorescence detector also has UV absorbance

The most commonly utilized derivatization chemistry for determination of carboxylic acids is the p-bromophenacyl ester derivatization reagent. Information about this chemistry can be found in a number of references. The following link gives the details for a specific application: http://www.cardinal.com/PTS/pdf/HPLC%20Determination%20of%20Free%20Fatty%20Acids%20Roman%20et%20al%20Cardinal%20Health%20PTS.PDF If this link doesn't work, enter "fatty acid bromophenacyl ester" into the Google search box. You should be able to find a number of relevant links based on such a search.