Question

Your unknown will be either palmitic acid, margaric acid, myristic acid, or triolein. How would you be able to differentiate these by GC-FID?

Answer 1

As we know FID is flame ionization detector that measures analytes in a gas stream.

FID measurements are usually reported as "as methane", meaning as the quantity of methane which would produce the same response.

palmitic acid is nothing but hexadecanoic acid, has molecular formula C₁₆H₃₂O₂

margaric acid is nothing but heptadecanoic acid, has molecular formula C₁₇H₃₄O₂

myristic acid is nothing but tetradecanoic acid, has molecular formula C₁₄H₂₈O₂

and triolein has molecular formula C₅₇H₁₀₄O_6.

_{Now, As per above discussion more number of carbon and hydrogen more will be the response.}

_{So, triolein will give more response than other compounds then} margaric acid next palmitic acid and then myristic acid.