Hello, my name is Lee and I am studying Biochemistry in England. I have a free choice module in drug analysis and have a coursework question on derivatisation i.e how can non-volatile carboxylic acids and alcohols be derivatised and why is derivatisation useful in GC. Any help would be app. as my Biochem. text books are a bit lacking and I have not got time to dig out Drug Analysis texts. Thankyou.

A quick answer why derivatization is useful in GC is that it allows GC analysis of materials that could not otherwise be tested by GC. Derivatization may be used to increase the volatility of an analyte (if a compund is not sufficiently volatile, it may not elute from the column) or eliminate functional groups that could interact with the system (often manifested by peak tailing). For example, by eliminating the hydrogen bonding of compounds such as alcohols and carboxylic acids, you tend to increase volatility and reduce interactions of the analyte with active sites in the GC. In addition, there are compounds that are not thermally stable under GC conditions. Derivatization of the reactive functional group(s) may increase stability enough to allow a GC assay. There are several books on derivatization procedures for GC. Some information is also available from chromatography supply company catalogs such as Supelco (http://www.sigma-aldrich.com) or from manufacturers of derivatization reagents such as Pierce Chemical (http://piercenet.com). Hope this helps.

Thanks Russ-that's a big help.