Polaris Amid

Those possessing enhanced shape-selectivity (oCjyo) reduced retention (fepg), as typified by polar embedded phases, e.g., Suplex pkj, 100, HyPURITY ADVANCE, Polaris Amide Cjg, BetaMax Acidic (column nos. 100, 46, 76, and 9, respectively) - group C. 

Fig. 12. Differences in stationary phase seiectivity on the analysis of degraded Ketoprofen using identical chromatographic conditions. Note the change in elution order for peaks marked (A) and (B) on the polar embedded phase - Polaris Amide Cl8.

Polaris Cjg A, Polaris Cg-Ether, Polaris Cjg Amide, Polaris NH... 

If polar and apolar interactions are necessary for separation (e.g., components with amino and acidic groups), phases may be encountered that show sufficient hydrophobicity but which are also capable of polar interactions because of additional polar groups on the surface, e.g., Spherisorb ODS 2, LiChrospher, Polaris C18-A, Ascends RP-Amide, Purosphere, Uptisphere UP5MM, Nucleodur Sphinx RP, Atlantis d Cjg, SynergiFUSION RP, and Acclaim PA. The fine adjusting for a better selectivity can be most effectively achieved by means of the pH of the eluent and by variation of the acid/base used [8]. A possible lack of robustness of the method has to be accepted in such systems. 

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