Improving selectivity in high-performance liquid chromatography

Improving selectivity in high-performance liquid chromatography 

As part of their research in optimizing chromatographic methods, M.C. Breitkreitz and co-workers employed a mixture design to search for the MP composition that would give the best selectivity for a 10-component mixture separation (Breitkreitz et al., 2005). The organic solvents acetonitrile (ACN), methyl alcohol (MeOH) and tetrahydrofuran (THF) were used as water modifiers. Initially, the solvent strength of ACN in water was varied to produce a desirable separation power for all the solutes. Once this composition had been experimentally determined, the water contents of the other two solvents were predicted based on empirical relationships. In this manner, the pure components used to specify the design were, in fact, binary mixtures ACN H20, MeOH H20 and THF H20. 

Solvent proportions used in the first design of the HPLC study and the separation responses obtained 

Linear, quadratic and special cubic models were fitted to the data. The linear model shows lack fit, whereas the quadratic and special cubic do 

ANOVA results for the reduced quadratic model fitted to the data of Table 7A.12 

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A. 7. Improving selectivity in high-performance liquid chromatography... 

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