how to extract irgafos 168 from olive oil

[eljoe]

Hi,

Can anyone help on a process to extract Tris (2,4-di-tert-butylphenyl) phosphite (irgafos 168) from olive oil. The objective is to quantify contamination coming from packaging. I have a gc-fid method that works fine for quantification in hexane. If I use this solvent to dilute the oil how can I remove the oil without removing my compound of interest ( which is non-polar).
Thanks in advance
joel

[AICMM]

I would think this is a perfect candidate for gel permeation chromatography clean up. The EPA has a method for GPC clean up in SW-846 that I would suggest you review. These can be home-built for a fairly reasonable sum of money, the most expensive part being the pump.

Best of luck.

[eljoe]

Thanks for replying.I don´t have access to GPC system. Would it be possible by spe?

[Peter Apps]

K. Grob et al published something fairly recently about just injecting oils to the GC inlet and thermally desorbing the compounds out of it. Sorry, I do not reall any more details and I do not have a copy or a link.

Peter

[Consumer Products Guy]

If your active is stable to saponification, saponify with caustic, then extract your analyte into hexane. The soaps formed from your triglyceride would be hexane insoluble. From your analyte composition, I wonder if direct HPLC-UV would be a better option...

[GOM]

Hi,

I was going to suggest transesterification, if it is stable to acid, and hexane extract. The esters would chromatograph nicely and should elute well away from your analyte. But I think that CP Guy's saponification idea is more elegant.
Regards,
Ralph

[CE Instruments]

I have vague memories of a Grob method from years ago but cannot find a reference. Thermo have published Application Note 10049, Trace Determination of Organo-Phosphorous Pesticides in Olive Oil by GC Analysis through PTV Backflush / FPD
Fausto Munari, Stefano Pelagatti, Andrea Cadoppi – Thermo Electron Corporation, Milan, Italy. Requires PTV with backflush valve This should be downloadable from the Thermo.com web site.Link

[CE Instruments]

Knew I had seen it some where

From a product manager bulletin in 1993 I have two papers detailing the analysis of Organo Phosphorus pesticides in Oils inc Olive oil using a standard split splitless but with a special glass liner and recovery tank. Parts were actually detailed for the GC 8000 split/splitless (same as current Trace) , wonder if they are still available

Original reference from 1992 Morchio, De Andreis, Verga, Riv. Ital Sostanze Grasse 69:147 for capillary columns with reference to liner design in 1982 for packed columns. Grob added a thin film pre-column to protect the analytical column and repeated the work above showing better reproducability. I have a photocopy of the paper but no reference. Anyone desperate for a copy can pm me and I will scan it