the poster assignment

The derivatization in Chromatography is techniques that prepare a sample by transferring sample components into similar chemical structure compounds but with new properties these compounds will enhance the capacity to be separated in column chromatography, as well the selectivity. There are a lot of methods for sample preparations, this poster will specify derivatization techniques based on chemical reactions. The specific functional groups in derivatives are responsible for separation properties of compounds.

The methods of derivatization can be divided into several categories: pre - and post - column methods and off - line and on - line methods [1].

In GC, The disadvantage of GC is that it cannot be used to separate non-volatile compounds, derivatization is used to cause a non-volatile compounds become volatile by transfer them into volatile compounds. This makes GC system capable of separation derivatives. Also, the detectivity is improved, and derivatives are thermally stable during separation in the GC column which increases efficiency [2].

The completion, reduction of interference, and stability are required for Derivatization reactions. The chemical reactions in Derivatization in GC are divided into four types: silylation, acylation, alkylation, and complexation.

In LC derivatizations can be induced by organic or electrochemical reactions, such as oxidation and reduction, or by displacement or addition reactions. The latter results from an electrophonic or nucleophilic attacks, which is determined by the reactivity of the substrate. Reduction and oxidation reactions are relatively non-specific and therefore less appropriate

References

[1,2] HAROLD M. MCNAIR, JAMES M. MILLER, Basic Gas Chromatography Second Edition, 2009,204, 202.