I am interested to identify unknown flavonoids from plant extract. Does derivatization by trimethylsilylation followed by GC-MS analysis really help for this purpose?
To be able determine flavonoids by GC-MS you need to derivatise the OH groups by some method and trimethyl silylation with BSTFA and TMCS is a good procedure.
It is possible to analyze flavonoids by silanized derivatives in GC-MS. Just beware that under a common oven temperature program the flavonoids elution-time can be increased up after 65 minutes (due to the size of flavonoid molecules), so this is recommended to increase the helium flow at 1.5 or 2 ml / min or the runtime to 75 mins, at maximun temperature of 300° C.