I can't find a compound that should be in a standard mix

I'm working with a  5977B MSD with an 8890 GC.  I've been trying to identify all of the compounds in the Sigma Terpene Mix B (https://www.sigmaaldrich.com/US/en/product/supelco/crm40937).  I'm able to identify all of them fine except for phytol.  I just can't seem to find it.  I'm also pretty sure that it's a mix of isomers, so there should be multiple peaks.

For a while I thought that I had found them, there are two significant peaks, one is coming up as palmitic acid and another as stearic acid.  They're both long hydrocarbon chains like phytol, but when I do a serial dilution of the mix they remain at more-or-less constant concentrations, so I think they are present as a result of some processing I'm doing.  They also come up later in the run (which from other reading I have done appears to be when phytol should come out.

I've searched in NIST for what the spectra should look like and have tried extracting ions in their chromatographs, but that doesn't seem to help (although it does pull up the palmitic acid and stearic acid).  There are other compounds that are highlighted, but they don't appear to be good matches either.

I didn't know if anyone had any suggestions for additional ways I could try to find this stubborn compound.  Thanks.

Parents Reply
  • Geraniol and Phytol would behave very similarly chemistry wise. Do you see good peak for Geraniol? Have you tried deconvolution in MH Qual? Standard that you have mentioned here is in MeOH. Maybe its MeOH that is not allowing you to get the other compounds derivatize properly as MeOH will eat away all the TMS. Which column are you using currently? 

    Palmitic is C16 and Stearic is C18 while the Phytol is C20. C16 and C18 are not coming from your C20. 

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