Bull. Spec. CORESTA Congress, Harare 1994, p. 184, S 9
Determination of small ionic compounds in tobacco and related materials by capillary electrophoresis
Philip Morris USA, Richmond, VA, USA
The separation and quantitation of organic compounds such as alkaloids and short-chain organic acids often encounter some difficulties due to their ionic characteristics. For example, two common problems in nicotine analysis, the adsorption in the liner (GC) and peak tailing (GC and HPLC), are the consequence of strong ionic interactions of nicotine with the injection port or the analytical column. Capillary electrophoresis (CE) is performed in a fused silica capillary with a high voltage applied across the length of the column. Solutes are separated based on electromigration, which is influenced by ion charge and mass. Under experimental conditions, a running buffer with pH 2-12 can be used to manipulate the ionic forms of the solutes, the UV absorbance of the target compounds and the separation. Nicotine is used as a model compound to demonstrate these advantages of CE. With optimization, a quick CE analysis of nicotine in aqueous tobacco extract can be achieved within 100 seconds. For ionic species lacking a chromophore (e.g., organic acids), several possibilities (including indirect photometric detection) are evaluated.