Trimethylsilyl deriv most general silyl

Table 1 lists the common names, abbreviations and structures of silyl derivatives used in chromatography. I here has been a substantial expansion in the range of silyl reagents that have been considered for use in GC analysis since the late 1970 s [1,7]. Many of the derivatives have not, however, found routine application, and TMS derivatives have maintained their popularity. The following section describes the general properties of the most commonly used reagents for trimethylsilylation. Subsequent sections will then deal with the preparation and applications of silyl derivatives other than TMS. 

Some of the most widely used reagents for the esterification of acids are fisted in Table 2. The general method for the silylation of mono- and polyfunctional carboxylic acids by forming for trimethylsilyl (TMS) or the more stable tert-butyldimethylsilyl (TBDMS) derivatives is similar to that for the silylation of other hydroxy-containing compounds (see Hydroxy Compounds Derivatimtion for GC Analysis, p. 1165). 

Trimethylsilyl (TMS) derivatives are those most commonly used for organic acids, other silyl derivatives, for example the dimethylsilyl and chloro-methyldimethylsilyl, being used for specialized applications. The term silyl tends to be used rather loosely in the literature and interchangeably for trimethylsilyl, but silylation can imply the introduction of any silyl group into a molecule, generally in substitution for an active hydrogen but occasionally for a metal ion, while trimethylsilylation indicates the specific introduction of TMS groups. 

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