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Fatty acid profiling of Oil
Posted: Wed May 18, 2022 10:49 am
by rajanpatel
Hello everyone,
I am doing first time fatty acid profiling using gas chromatography. I have DB-WAX ( 30m X 0.320 mm ID, 0.5 um ; Temperature range 20 to 240℃ ) column. I have only nitrogen as carrier gas. Have anyone worked on fatty acid profiling using this column and carrier gas?
Thanks in advance.
Re: Fatty acid profiling of Oil
Posted: Wed May 18, 2022 1:16 pm
by Consumer Products Guy
I looked into "wax" polar columns for fatty acid profiling of fatty acid methyl esters from soap, fats, and oils, but I liked cyanopropylsilicone phases better.
Understand that wax columns like DB-wax are tons better than such phases used in the early 1980s.
A bigger issue might be getting realistic split in the inlet.
Re: Fatty acid profiling of Oil
Posted: Thu May 19, 2022 10:45 am
by rajanpatel
I looked into "wax" polar columns for fatty acid profiling of fatty acid methyl esters from soap, fats, and oils, but I liked cyanopropylsilicone phases better.
Understand that wax columns like DB-wax are tons better than such phases used in the early 1980s.
A bigger issue might be getting realistic split in the inlet.
So have you used nitrogen as carrier gas during fatty acid analysis?
Re: Fatty acid profiling of Oil
Posted: Thu May 19, 2022 12:59 pm
by Consumer Products Guy
So have you used nitrogen as carrier gas during fatty acid analysis?
Nope. We never tried nitrogen for GC other than make-up gas.
Re: Fatty acid profiling of Oil
Posted: Thu May 19, 2022 1:41 pm
by Chemiger
Hi, Never used Wax columns or Nitrogen for CG, however I have developed methods for Fatty Acids in Oil, can I ask is your method headspace or Liquid ?
I had real problems with this ended up having to develop a method using a HPLC.
Re: Fatty acid profiling of Oil
Posted: Sat May 21, 2022 11:01 am
by rajanpatel
Hi, Never used Wax columns or Nitrogen for CG, however I have developed methods for Fatty Acids in Oil, can I ask is your method headspace or Liquid ?
I had real problems with this ended up having to develop a method using a HPLC.
It is liquid sample. The sample is crude oil which is converted into fatty acid methyl easter. Also, for calibration I will use supelco 37 FAME mix (
https://www.sigmaaldrich.com/IN/en/prod ... o/crm47885).
I have UPLC/MS-MS also here. Can I do in that one also?
Re: Fatty acid profiling of Oil
Posted: Sat May 21, 2022 2:06 pm
by Consumer Products Guy
It is liquid sample. The sample is crude oil which is converted into fatty acid methyl ester.
I analyzed fatty acid methyl ester made from soap fatty acid salts for 4 decades. In general, these ranged from C8 to C18. We used boron trifluoride in methanol or less-expensive sulfuric acid-methanol for the esterification.
This is not rocket science, folks.
Re: Fatty acid profiling of Oil
Posted: Tue May 24, 2022 12:34 pm
by MSCHemist
I've done some basic fames profiles over the year but nothing too frequent. I use the mild methanolysis as you can just use regular methanol and concentrated HCl which I have on hand.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2817593/
Re: Fatty acid profiling of Oil
Posted: Wed May 25, 2022 7:55 am
by Chemiger
Hi, Never used Wax columns or Nitrogen for CG, however I have developed methods for Fatty Acids in Oil, can I ask is your method headspace or Liquid ?
I had real problems with this ended up having to develop a method using a HPLC.
It is liquid sample. The sample is crude oil which is converted into fatty acid methyl easter. Also, for calibration I will use supelco 37 FAME mix (
https://www.sigmaaldrich.com/IN/en/prod ... o/crm47885).
I have UPLC/MS-MS also here. Can I do in that one also?
Fatty Acid can be run on LC- MS I suppose you can run it on UHPLC/MS-MS
Cheers
Re: Fatty acid profiling of Oil
Posted: Tue May 31, 2022 10:54 pm
by Jake
DB-Wax, and the related DB-HeavyWax (higher maximum temps.) are our favorite columns for FAMEs. We do A LOT of FAME profiling. My lab is approaching having generated one million FAME profiles using various wax columns. The abundant number of more specialized cyanopropylsilicone phases are very good too, but no where near as robust in our hands as the Wax columns. We usually get over 10,000 injections before they're retired. We've never used N2 as a carrier either. Always hydrogen, with hydrogen generators.
Good luck!