Influence of experimental parameters on chromatographic behavior of neutral, molecules in ion interaction chromatography

The chromatographic behavior of aprotic neutral molecules in Ion Interactio n Chromatography (IIC) was investigated both theoretically and experimental ly on a styrene-divinylbenzene based Cls stationary phase. The chemical mod ification of the stationary phase in the presence of Ion Interaction Reagen t (IIR) in the eluent, and adsorption competition between tested analytes a nd IIR for inner layer sites are theoretically shown to change the partitio n coefficient for neutral molecules. Experimental evidence confirms that their retention decreases with increasi ng ion-interaction reagent (IIR) concentration in the eluent. The influence of the mobile phase ionic strength on neutral molecules retention was inve stigated and the dependence of retention modulus on organic modifier concen tration in the eluent was elucidated.