Silylation reagents - MSTFA

N-methyl-N-trimethylsilyl-trifluoroacetamide
m.w. 199.1, Bp 70°C (75mm Hg), density d20°/4° = 1.11
MSTFA: R' = CF₃, R" = CH₃
the most volatile trimethylsilyl amide available
very strong TMS donor which does not cause any noticeable fouling of the FID burning chamber even after long-time measuring series
The already good solution characteristics can be improved by addition of submolar quantities of protic solvents (e.g. TFA for extremely polar compounds such as hydrochlorides) or pyridine (e.g. for carbohydrates).

recommended application: carboxylic acids, hydroxy and ketocarboxylic acids, amino acids, amines, alcohols, polyalcohols, sugars, mercaptans and similar compounds with active hydrogen atoms. Even amine hydrochlorides can be silylated directly.
advantages: complete reaction with high reaction rates, even without a catalyst (1 to 2% TMCS or TSIM)
the by-product of the reaction (N-methyltrifluoroacetamide) features high volatility and short retention time.