Chromatography Forum

Greetings from Costa Rica to all,



I am writing again, however in this occasion I have a question, I am trying to choose a method for analysis of fatty acids by HPLC.

I have being requested to develop a method for analysis of fatty acids in shrimp and shrimp’s food. In order to do this, I have HPLC equipment with UV detector. My interest is focused in fatty acids of 16 to 24 carbon molecules (?).

I would like to know your recommendations, whether the derivation with p-bromophenacyl is convenient for this type of samples or a simple methylation will be enough?

Looking forward your comments.

Many thanks in advance.

Searching derivatization techniques for the carboxylic acid moiety from a tertiary amino acid that are usufull for HPLC UV detection and thanks to the lead given by JMB, I find a site with a lot of information about lipid analytycal chemistry that you will sure find usefull in your task: the lypid lybrary( Scottish Crop Research Institute William W. Christie, http://www.lipidlibrary.co.uk/ ) in particular the article PREPARATION OF ESTER DERIVATIVES OF FATTY ACIDS FOR CHROMATOGRAPHIC ANALYSIS(http://www.lipidlibrary.co.uk/topics/ester_93/index.htm ).

Simple methylation is not adecuate for HPLC with UV Detection.

http://www.lipidlibrary.co.uk/topics/fa_hplc/index.htm has a nice chromatogram of mixture of fatty acids in the form of the phenacyl esters by reversed-phase HPLC in a precambric HPLC column.
As the author states "improved stationary phases are now available. It should therefore be easy to reproduce such separations with modern columns of conventional dimensions, but ......."
I hope you'll find the information usefull

If you want the article "Separation of Long Chain Fatty Acids as Phenacyl Esters by High Pressure Liquid Chromatography" by Borch, R.F.
I can share the pdf , send me your e-mail

thank you very much for your reply cristobal, I am a litle concern if this procedure is good for my sample because thsi is a very comlex matrix, I would like to know about the tips for this derivatation, I ssupose that the sample need to be very dry conditions, but what about time?
Other of my problem.

you can e mailme to:
oscar.cortes@scancotec.com