Behaviour of resolution by changing solvent strength and selectivity in the 'PRISMA' model using reversed-phase HPLC...

The retention behaviour of 17 dansylated biogenic amines in 6 linear gradients at 13 solvent combinations, expressed by the selectivity points (Ps) according to the 'PRISMA' model, was investigated. The dependence between the retention times (tr) and different gradients was examined. Three dimensional resolution (Rs) maps for each peak-pair in the different gradients at the 13 selectivity points were constructed, and the affect of the gradients on separation were investigated. The study showed that the dependence between the gradients and tr values of dansyl amides can be expressed using quadratic functions with a high degree of accuracy. These functions are well suited for estimating the resolution in different gradients and Ps. The three dimensional Rs maps clearly demonstrated the changes between the different gradients and Ps. This was of considerable benefit when searching the optimum mobile phase by changing both the solvent strength (ST) and selectivity.