Discrimination between linear and non-linear models describing retention data of alkylbenzenes in gas-chromatography

Summary Detailed statistical analysis is presented to describe the retention indices of alkylbenzenes as a function of their physical (boiling point, modrefraction) and topological (connectivity and complexity indices) properties. With the help of several statistical characteristics (examination of residuals, F test, partial F test, termination criteria, correlation indices) a discrimination is made among different models. A nonlinear equation was chosen which describes the retention data on slightly polar phases with the practically attainable precision. A comparison with literature sources shows that this equation provides the smallest residual error and, hence, it can be applied for prediction purposes. A correlation was found between the preexponential factor in the simple exponential model and the polarity of stationary phases on the Tarján scale.