Im using BSTFA and getting good results. Check http://www.sigmaaldrich.com/etc/medialib/docs/Aldrich/General_Information/bstfa.Par.0001.File.tmp/bstfa.pdf

Each compound was treated in 1M HCl (dioxane–H2O, 1:1, 2 ml) at 100°C for 1.5 h. The reaction mixture was neutralized with silver carbonate and the solvent thoroughly driven out under N2 gas overnight. Furthermore, the residue in pyridine (1ml) was added to L-cysteine methyl ester hydrochloride (3.0 mg) in pyridine (0.1 ml) kept at 60°C for1.5 hr. Then butyl chloro tert dimethyl silane-trimethylchlorosilane (TCBDS-TMS) (0.6ml) was added to the reaction mixture and kept at again 60°C for 1.5hr. The supernatant (1.0 ml) was analyzed by GC/FID.

Thanks

I think you should use GC-MS (Not GC) for derived phenolic acid analysis.

yes.I mean is the same

BSTFA (sililation, +73 in MS) or TMSH (methyl ester compounds, +15 in GC-MS). I prefer the TMSH , but you need to check that it works for your compounds....

Thanks your attention