Factor analysis of experimental design in chromatography

Summary

Experimental design and factor analysis have been applied to the optimization of the separation of two series of compounds. The behavior of the nonhomogeneous series of test compounds appears to be ideal whereas the second series of congeneric substituted naphthalenes exhibit non-ideal behavior. Factor analysis maps exhibit the projection of the experiment design, on the first factorial plan, as a ternary graph for the ideal model. In this instance the linear combination of the eluents is preserved through the factor analysis projection. For the non-ideal model, the projections of the experiment design do not restore the ternary graph. Competitive interactions with ternary or quaternary eluents are clearly apparent. The simultaneous application of experimental design and factor analysis improve the optimization procedure. With the ideal model, the separation optimum can be reached directly through factor analysis maps. With the non-ideal model, the projection of eluents and their contribution to the inertia explained by the factorial axes can define a new experimental domain where maximum selectivity is obtained.