I would very much like some input on how you would test diesel fuel for % bio fuel dilution. I know most of the engine OEMs approve of up to 5% mix (as long as bio fuel is within EN 14214.

Our problem is that there are different bio diesels available.

• From fish
  
• From plants
  
• Others (like coocking oil)
  

I have considered making an inhouse method with FT-IR, but it looks like a lot of work.

Nothing comes easy, my friend (at least not my way). You have a good idea on how to. I would run either FTIR or GC or GCMS scan on each individual compound that you suspect constitute the mixture. Having their "fin***prints" (peaks)it would then be easy to find them in mixture, if they are there. I doubt you can smell the difference, although it wouldn't surprise me if some dog shows up with "new" equipment that would do just that. I have been seeing few such persistent and boisterous dogs on this board lately.

Good Luck

There is method developed on a gc that can determine diesel and bio mixtures if that's any help. I works very well and each analysis takes about 3 minutes.

We have now set up an FTIR inhouse method for dilution up to 20% FAME. It was not to hard, since the FAMEs methylesters have a specific peak. It also turns out to work well on tracing % FAME in used engine oil.

Just curious - what are the detection limits of the GC and FTIR methods? Some applications are stating biodiesel must be less than 1%

With regard to the FTIR - do carboxylic acids (C=O) and hydroperoxides in fuels and ester in engine oil (C=O and C-O) interfer with the methyl ester peak.

Wondered if the unsaturation of the biodiesel could be used.