well I guess as usual extract eg ASE, clean up eg size exclusion chromatography, slica mini column, derivatisation, GC-MS, sounds straightforward....

In the end which extraction and which clean up you do depends on what methods you already have established....

Thanks for the reply. After a few hours on the internet, I decided to do a cheaper way by using QuEChERS extraction at pH less than 2 to keep it in acetonitrile, add appropriate dispersive cleanup and absorb fat with C18 or product from Agilent and use GC/QQQ on a polar column so no derivatization is needed.

sure that will give a cheap rapid semiquantitative result.