Trimethylsilyl fluoroacetamide

Various fluoroacetamide derivatives have been used as trimethylsilylating reagents and, of these, N,0-bis(trimethylsilyl)trifluoro-acetamide (5) is the best known. It has approximately the same donor... 

Gas chromatographic separation of amphenicols is further complicated by the need for derivatization of their polar functional groups. Silyl derivatives formed by treating sample extracts with N,O-bis(trimethylsilyl)acetamide (49), trimethylsilyl N,N-dimethyl carbamate (47), N,O-bis(trimethylsilyl)tri-fluoroacetamide/trimethylchlorosilane (99 1) mixture (32, 51), or mixture of... 

After evaporation to dryness the fractions are derivatized by heating with bis-trimethylsilyl tri-fluoroacetamide (BSFTA) at 90°C for one hour. 

N,0-bis(trimethylsilyl)tr1-fluoroacetamide + trimethyl-silyldiethylamine + trimethyl-silylchlorosilane, . 76 agroclavine... 

The most commonly used reagents for trimethylsilylation are i is-trimethylsilyltri-fluoroacetamide and iV-methyl-O-trimethylsilyltrifluoro-acetamide, which are perhaps more readily recognised by the abbreviations BSTFA and MSTFA, respectively. Typically, the sample is dried and dissolved in dry pyridine or acetonitrile and the reagent. The reaction mixture is heated for 30 min at 70-90°C, dried in vacuo and dissolved in heptane before GC-MS analysis. Further practical details can be obtained by consulting Hedden [3]. 

GC-MS or GC-MS/MS has been widely used to analyze hormone steroids in the environmental samples [19,39,97,98,120-122]. Due to their polarity, steroids are derivatized by various derivatization agents such as BSTFA, N-(ferf-butyldimethylsilyl)-N-methyltri-fluoroacetamide (MTBSTFA), or a mixture N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) trimethylsilylimidazole (TMSl) dithioerythritol (DTE) (1000 2 2, v/v/w) prior to GC separation. The selected ion masses for quantification in each case vary depending on the derivatization reaction performed. Table 25.2 lists the selected ion masses for TMS derivatives of steroids. 

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