Ternary solvent system resolution

Improved Resolution in High Performance Liquid Chromatography Analysis of Polynuclear Aromatic Hydrocarbons Using Ternary Solvent Systems... 

Experimental design methodology was applied for the optimization of the elution program for the RP-HPLC resolution of a mixture of nine phenols, with a ternary solvent system (water-AcOH-MeCN). Important factors were the initial isocratic elution, the gradient running time and the gradient curvature . ... 

Liquid chromatography On silica or polar bonded phases (nitro, cyano), the separation of vitamin D metabolites occurs according to the number and position of hydroxyl groups in the molecule. Binary mobile phases are usually based on hexane-2-propanol mixtures. Improved resolution of normally co-eluting D2 and D3 hydroxylated metabolites is afforded by ternary solvent systems containing dichloromethane as a third component. However, the D2 and D3 parent compounds remain unresolved in any normal-phase system. 

Another means of controlling eluent strength is the use of ternary or quaternary solvent mixtures instead of the more common binary approach. Each solvent has its own unique properties that can be used to improve the separation of difficult-to-resolve analytes or to shorten the analysis time without sacrificing resolution. Although gradients and more complex solvent matrices are more difficult to model than binary isocratic systems, software exists for such purposes and can assist in method development. 

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