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how to extract irgafos 168 from olive oil
Posted: Tue Mar 13, 2007 11:41 am
by 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
Posted: Tue Mar 13, 2007 2:55 pm
by 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.
Posted: Wed Mar 14, 2007 10:54 am
by eljoe
Thanks for replying.I don´t have access to GPC system. Would it be possible by spe?
Posted: Wed Mar 14, 2007 3:11 pm
by 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
Posted: Wed Mar 14, 2007 4:10 pm
by 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...
Posted: Wed Mar 14, 2007 4:59 pm
by 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
Posted: Thu Mar 15, 2007 4:48 pm
by 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
Posted: Thu Mar 15, 2007 5:10 pm
by 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