Ion Pairs and Ion Pair Chromatography IPC

A major constraint of silica-bonded phases is the limited pH range of between 3 and 8. This may be troublesome for poorly retained hydrophilic strong acids or bases with pKa values outside this range. For this kind of compound the retention may be modified by the addition of moderately hydrophobic and oppositely charged surfactants. This technique is known as ion-pair chromatography (IPC) [47-49]. One of its shortcomings is poor reproducibility of retention. A further alternative for charged compounds is mi-cellar liquid chromatochrography (MLC), using longer chain surfactants, which form micelles. A disadvantage here are the rather broad peaks.

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