Chiral GCMS

mnitabach

Basenotes Dependent
Nov 13, 2020
Is it correct that the ( - ) ß LAEVO isomer of citronellol always elutes before ( + ) ß DEXTRO isomer, and that, the 2 peaks are like 2 forks of one peak, - the resolution is not complete?
 

Alex F.

Super Member
Nov 29, 2019
I haven't done any chiral analysis of the enantiomers of β-citronellol. (It's used as an indicator to determine whether certain EOs are genuine or not.) So this is not from direct personal experience.

Is it correct that the ( - ) ß LAEVO isomer of citronellol always elutes before ( + ) ß DEXTRO isomer
Not always. The order of the elution depends on the coating of the column. If there is no documentation or reliable literature available, you'll have to determine which one elutes first yourself.
  • (-), then (+): Restek, A Guide To The Analysis Of Chiral Compounds By GC, 1997.
  • (+), then (-) (using Lipodex E) Ravid, Uzi et al: Determination of the Enantiomeric Composition of Citronellol in Essential Oils by Chiral GC Analysis on a Modified γ-Cyclodextrin Phase. 1992. DOI:10.1002/ffj.2730070413.

the 2 peaks are like 2 forks of one peak, - the resolution is not complete
If the peaks aren't separated down to the baseline, then it's not "baseline resolved". For a baseline resolution of citronellol, you'll have to puchase a special column - not all chiral columns can do that. (See for example A Guide To The Analysis Of Chiral Compounds By GC, Restek, 1997.)
 

mnitabach

Basenotes Dependent
Nov 13, 2020
I haven't done any chiral analysis of the enantiomers of β-citronellol. (It's used as an indicator to determine whether certain EOs are genuine or not.) So this is not from direct personal experience.


Not always. The order of the elution depends on the coating of the column. If there is no documentation or reliable literature available, you'll have to determine which one elutes first yourself.
  • (-), then (+): Restek, A Guide To The Analysis Of Chiral Compounds By GC, 1997.
  • (+), then (-) (using Lipodex E) Ravid, Uzi et al: Determination of the Enantiomeric Composition of Citronellol in Essential Oils by Chiral GC Analysis on a Modified γ-Cyclodextrin Phase. 1992. DOI:10.1002/ffj.2730070413.


If the peaks aren't separated down to the baseline, then it's not "baseline resolved". For a baseline resolution of citronellol, you'll have to puchase a special column - not all chiral columns can do that. (See for example A Guide To The Analysis Of Chiral Compounds By GC, Restek, 1997.)
Thank you for this detailed answer!
 

Latest News

Top