ABSTRACT
The following flow chart provides a rough guide among the various liquid chromatographic techniques based on sample properties. Solvents that are commonly used in high-performance liquid chromatography frequently have inherent chemical instabilities that must be considered when designing an analysis or in the interpretation of results. In many cases, such solvents are obtainable with stabilizers added to control the instability or to slow the reaction. The following table provides a short list of ion pair chromatographic modifiers, for use in the separation ionic or ionizable species. The perchloric acid mentioned in the previous table on ion-pairing agents must be handled with great care since it can be a very powerful oxidizing agent. Cold perchloric acid at a concentration of 70 % or less is considered a very strong oxidizing agent. The selection of a particular phase and solvent system is an empirical procedure involving survey analyses.
