Linear solvent strength gradient model

The linear solvent strength (LSS) model combined with QSRR calculations has been applied for the prediction of retention in gradient RP-HPLC. It was established that total dipole moment (jd), electron excess charge of the most negatively charged atom (<5Mm) and water-accessible molecular surface area (Awas) exert the highest impact on the retention ... 

In this section a phenomenalogical approach to the description of solvent gradients will be adopted based largely on the linear solvent strength model prt osed by Snyder [552-555]. This is the least complicated of the models available and provides a reasonable approximation for typical experimental conditions. Mathematically more rigorous approaches have been developed by Jandera and Churacek [551,556], schoenmakers et al. [520,534,557] and Tomellini et al. [558]. 

T. Baczek and R. Kaliszan, Combination of linear solvent strength model and quantitative structure-retention relationships as a comprehensive procedure of approximate prediction of retention in gradient liquid chromatography. J. Chromatogr.A 962 (2002) 41-55. 

L.R. Snyder, J.W. Dolan, High-Performance Gradient Elution. The Practical Application of the Linear-Solvent-Strength Model. Hoboken, NJ Wiley-Interscience, 2007. 

Vd is the so-called gradient dwell volume [i.e., the volume of the mobile phase contained in the instrument parts (mixer, filter, and tubing) between the pump and the column]. In an ideal case, linear concentration gradients in RPLC correspond to linear solvent strength (LSS) gradients according to the model developed by Snyder and Dolan " hence, Eq. 4 describes the retention data in LSS gradient elution. 

Snyder, L.R. Dolan, J.W. The linear-solvent-strength model of gradient elution. Adv. Chromatogr. 1998, 38, 115-187. 

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