Discrimination between linear and non-linear models for retention indices of polycyclic aromatic hydrocarbons in the so-called Leeʹs scale

Detailed statistical analysis is presented to describe the retention indices of polycyclic aromatic hydrocarbons (PAHs) expressed in so-called Leeʹs scale as a function of boiling point, molecular weight and connectivity index. As a training set, experimental retention data of parent and alkylated PAHs obtained on SE-52 phase is used for correlation. On the basis of several statistical characteristics (multiple correlation coefficient, residual mean square, residuals, and the sequential probability ratio) quadratic with two variables and combined equations were chosen for describing the retention data on slightly polar stationary phases. As prediction sets, literature experimental retention indices expressed in so-called Leeʹs scale obtained on DB-5 slightly polar stationary phase are applied for comparison.