Modeling of solute retention and separation optimization procedures - PowerPoint PPT Presentation

Modeling of solute retention and separation optimization procedures for research and educational purposes in LC with Microsoft Excel Macros S.Fasoula A , Ch. Zisi A , H. Gika B , A. Pappa-Louisi A , P. Nikitas A A Department of Chemistry, Aristotle University of Thessaloniki, Greece B Department of Chemical Engineering, Aristotle University of Thessaloniki, Greece

A few words… ² A package of Excel VBA macros has been developed for modeling multilinear gradient retention data obtained in single and double gradient elution mode by changing organic modifier(s) content and/or eluent pH. ² The direct application of Microsoft Excel in optimization procedures was very limited up to day because up to the version 2007, Excel did not equip with enhanced optimization features. ² This situation has been altered in the new versions, 2010 and 2013, in which the Solver add-in provides optimization capabilities when the cost function is not differential , like the cost functions adopted in LC gradient elution.

Steps for a computer-assisted optimization procedure under multilinear gradient elution Step 3 Optimization Step 2 Prediction Determination of the optimal Step 1 gradient Test the capability Fitting conditions of the retention model by predicting Fitting initial retention data gradient data to a under different retention model to gradient conditions determine its adjustable parameters

Optimization Platform an example Fitting-Prediction Platform an example Fitting-Prediction Platform

To sum up… « The proposed package of Excel VBA macros is a very helpful tool for modeling and optimizing separation of a mixture under multilinear single or double gradient elution conditions by changing organic modifier and/or eluent pH. « This package and the accompanied spreadsheets are easy-handled and user-friendly, so no specialized knowledge of programming is a prerequisite for their use . « The Excel VBA macros can be straightforwardly modified in order to include new models and gradient conditions extending the capabilities of the proposed package. S. Fasoula, Ch. Zisi, H. Gika, P. Nikitas, A. Pappa-Louisi, J. Chromatogr. A, 1395 (2015)109-115