The chromatographic behavior of charged analytes in ion interaction chromatography (IIC) is theoretically investigated. The chemical modifications of the stationary and mobile phases in the presence of ion interaction reagent (IIR) are theoretically shown to change the partition coefficient for charged molecules. The most reliable literature experimental results concerning retention behavior of charged molecules in IIC were used to test the new theory. Retention equations are compared with those that can be obtained from the most important retention models in IIC. The present exhaustive retention model, which is well-founded in physical chemistry, goes further than the previous ones whose retention equations can be viewed as limiting cases of the present theory. The present extended thermodynamic approach reduces to stoichiometric or electrostatic retention models if the surface potential or pairing equilibria are respectively neglected. Moreover, it is able to quantitatively explain experimental evidences that cannot be rationalized by the existing retention models.

SummaryThe chromatographic behavior of zwitterions in Ion-interaction chromatography (IIC) is, investigated theoretically for the first time. The modification of the stationary phase in the presence of Ion-interaction reagent (IIR), and adsorption competition bel',,veen test analytes and IIR for inner layer sites are shown theoretically to change the partition coefficient for zwitterions.Experimental results from the literature concerning retention behavior of zwitterions in IIC, were used to test the new thermodynamic theory. Very reasonable estimates of (i) AG ~ values for the IIR adsorption onto the stationary phase (ii) total ligancl concentration, and (iii) dipolar moments validate the present thermodynamic model for the I IC of zwilterionic analytes.Retention equations are compared to those which can be obtained, if the net charge of the analyte is zero, from the most important retention models in IIC. None of them is able to explain, even in a qualitative way the retention behavior of zwitterions in IICwhereas, the present model is quantitatively able to do this.

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SummaryThe chromatographic behavior of neutral molecules in ion-interaction chromatography (IIC)is investigated theoretically. The physical and chemical modification of the stationary phase in the presence of Ion Interaction Reagent (IIR) in the eluent, and adsorption competition bef,,veen test analytes and IIR for inner layer sites are shown theoretically to change the partition coefficient of neutral molecules.The most reliable, literature experimental results, concerning retention behaviour of neutral molecules in IIC, were used to test the new theory. The wide variabih b, among them was elucidated on the basis of the exhaustive retention model developed. Retention equations were compared to those which can be obtained, if the charge of the analyte is zero, from the most important retention model in IIC.

We synthesized the Cu(II) and Zn(II) complexes of the 2,7,12,17-tetrapropionic acid of 3,8,13,18-tetramethyl-21H,23H porphyrin (coproporphyrin-I) and successfully employed them as sensitizers in dye-sensitized solar cells. Copper(II) coproporphyrin-I exhibits a power conversion efficiency of 3.8% measured under irradiation of AM 1.5G full sunlight (100 mW cm À2).