ColumnSelection, ctd.
The reagent used in themobilephase alters the chemical nature of the
analyteas perceived by the columnandmobilephase. This reagent
reduces the ability of water to solvate theanalytes andhydrogenbondwith
them, essentially forcing the charged complexes to remain longer in the
absorbed solvent layer of the stationary phase, and thus improve the
retention.
• The use of solvents as acetonitrileallow for dispersive interactionswith the
chaotropic anions.
• Solvents/reagents that are capable of hydrogen bonding interactions as
methanol shouldbe avoided as theymay cause ghost peaks or lead to total
retention loss in this analysis.
• The chaotropic agents are inorganic anionic salts added to the aqueous
portion of themobilephase.
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