What's the fastest way by analyzing omega-3 and omega-6

[mrpj]

What's the fastest application of analyzing omega-3 and omega-6 from biological samples?

GC-MS or GC-FID ?

[JGK]

What's the fastest application of analyzing omega-3 and omega-6 from biological samples?

GC-MS or GC-FID ?

Most official Methods such as AOCS, AOAC use GC-FID methods.

[mrpj]

Ah okay, I found this one: http://www.restek.com/pdfs/59584B.pdf when searching after "AOCS fatty acids".

Would there be any significant difference of using helium instead of hydrogen ?

[gserrano_84]

There would be no difference. Chromatographers are inclined towards hydrogen when looking for faster analysis time (H2 allows you to keep a good column efficiency even at relatively fast linear velocities). When using He, your optimal linear velocity is lower than that of H2, if you wanna keep a similar column efficiency.

As it was previously said, most official methods use GC-FID, as you don't really need GC-MS for FAMEs.

Also if you are looking for cis/trans FAMEs, there is no 'fast analysis', you'll have to use longer columns (100-m), if identifiying cis/trans is not important, you can use 15-m 0.10 ID columns (and hydrogen) for faster analysis time and good separations.

Gustavo
Supelco