Chiral gels temperature dependence

The effect of the temperature is also important for chiral resolution on these CSPs. Pirkle etal. [81] reported inversion of the elution order when the temperature was changed from high to low and vice versa. The temperature effect observed was dependent on the content and polarity of the organic modifier in the mobile phase. The injection amount, the silica gel particle size, the spacer between the chiral selector and silica gel, and the column dimensions may be used as optimization parameters for chiral resolution. Recently, Baeyens et al. [80] carried out the chiral resolution of pirprofen on Whelk-Ol columns with internal diameters of 2.1 and 4.6 mm. The authors reported the best resolution on the 4.6 mm column (Figure 7.5). The optimization of chiral resolution on Pirkle-type CSPs is presented in Scheme 7.12. 

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