Introduction to Gas ChromatographySilylation and Silylation Reagents
No one but Pierce offers the combination of variety, quality and reliability.
Derivatization The chemical literature contains an abundance of data on derivatization, most of which is relevant to particular compounds, classes of compounds and derivatization reagents. Two books are recognized as standards in the field of analytical derivatization. The first book, Handbook of Analytical Derivatization Reactions by Daniel R. Knapp (see page 36), provides a general collection of analytical derivatization methods for chromatography and mass spectroscopy (MS) that involves formation of covalent derivatives prior to analysis. The second book, Silylation of Organic Compounds by Alan F. Pierce2, “is a significant factor in the transfer of silylation reactions from the relatively esoteric field of organosilicon chemistry to the status of perhaps the most widely practiced of derivatization methods.”3
Compounds or compound mixtures are derivatized before analysis for the following reasons:
1. To make a compound that otherwise could not be analyzed by a particular method suitable for analysis4.
2. To improve the analytical efficiency of the compound5,6
3. To improve the detectability of the compoundSuitability
Often compounds cannot be analyzed because they are not in a form that is suitable for the particular analytical technique. Examples include nonvolatile compounds for GC analysis,8,9,10
insoluble compounds for HPLC analysis, and materials that are not stable using the conditions of the technique.11 The derivatization procedure modifies the chemical structure of the compounds, allowing analysis by a desired technique.12Efficiency
Direct analysis can be difficult when compounds interact with each other or with the column. These interactions can lead to poor peak resolution and/or asymmetrical peaks that make proper peak integration difficult or impractical. This interference can be reduced with conversion to derivatized products.13,14 Compounds that exhibit co-elution can often be separated by using the appropriate derivatization methods.