I am looking to verify the extent of epoxidation of fatty acid esters; more specifically the unreacted fraction. Could I conceptually use 2D-tocsy spectra to quantify the total protons next to the ester group vs epoxy cross peaks? Would that be (approximately) quantitative? I have only modest experience with 2D techniques, any tips would be welcome.
Hallo Rafael Dera,
nomally 2D-spectra are processed with sine or qsine function. After this the integral is not proportional to the concentration. If you use exponential function with line-broadering you get worse 2D-spectra. The 2D-spectra are normally not measured under quantitative conditions, too short D1 time. The TOCSY cross signal is also dependent on the coupling constant to the proton. The epoxide will have a differnet coupling constant to its next proton. The easiest way is always a 1D-1H-spectrum with Long relaxation- delay. For crude estimations it will work but not for quantitative results . If the coupling constant is nealy the same I think it will be not better than +/-10%. But you can try to measure both spectra and see the difference.
If you need to use 2D because of overlaps, you may consider this:
https://www.ncbi.nlm.nih.gov/pubmed/21247157
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials Chemistry