Optimal cut-times finding strategies for collecting a target component from overloaded elution chromatograms

The determination of accurate cut-times plays an important role in the design and implementation of preparative chromatography. Modeling and optimization studies involving preparative isolation of target components from multi-component mixtures overwhelmingly depend on the target amount collected, defined by specific cut-times. The task of finding these times can be quite challenging for complex chromatograms of experimental or theoretical origin. In this study, two new alternate strategies to find optimal cut-times are introduced. Using simple linear and complex overloaded chromatograms, the performances of these new methods are compared with that an established technique based on evaluating local purities. To demonstrate the methods, concentration profiles were generated theoretically using empirical functions and the equilibrium dispersive model. The methods are compared in terms of their accuracy, speed, robustness and also their ability to find multiple fractionation intervals.

► Finding accurate cut-times in preparative chromatography is very important.
► A generalized cut-times finding framework is proposed.
► We analyze different methods available for their advantages and associated pitfalls.
► Local purity based searches are extremely fast and simple.
► Optimization based algorithms are robust and flexible.