Hypersil Elite

Hypersil Elite C13, 89 or SymmetryShield RPig, 70. However, if secondary interactions play a role, different selectivities will be found. This is especially true for packings with an embedded polar group. 

Zorbax SB Cl 8 Luna Nova-Pak Fluofix (EW Prodigy YMCC18 Hypersil BDS Prontosil Cl 8 Inertsil CDS 2 Prontosil AQ Repro-Sil CDS MP-Gel YMC AQ Purospher Nucleosil HD Discovery Cl 8 Repro-Sil AQ Supelcosil ABZ plus Jupiter Hypersil Elite Toso Haas TSK Inertsil QDS 3 Fluofix INW Ultrasep ES Discovery Cl 6 Nucleosil 50 Zorbax SB C8 Superspher LiChrosorb Superspher Select B Bondapak Nucleosil 100 LiChrosher Select B Supersorb QDS 2 LiChrospher Platinum Cl 8 Gromsil AB VYDAC Superisorb QDS 1 Platinum EPS Hypersil QDS Nucleosil Protect 1 Zorbax QDS... 

In general, one can be sure that the hydrophobidty of the stationary phase will play the major role, no matter what the analyte is. If the analyte bears basic functional groups, then the silanol activity will surely affect the retention. However, if the analyte does not contain basic functions, then the silanol activity is not very important see also Chapter 2.1.1. The same is true for the polar selectivity. The similarities and differences of stationary phases depend upon the nature of the analytes. For example, the stationary phases Hypersil Elite Cjg, 89, and Synergi MAX RP, 78, are practically identical with respect to hydrophobicity and polar selectivity, but the silanol activity at neutral pH is much lower for the Hypersil Elite Cjg column. Therefore, we would expect very similar separations on both columns if the silanol activity does not play a significant role, but more different separations if the opposite is true. On the other hand, if one is working on a new separation and would like to efficiently exploit the selectivity differences of different columns in an automated method development scheme, then the selectivity charts presented here will certainly be useful in the selection of columns of different selectivity properties. 

Figure 17c shows the section of Figure 17b that covers most Cg and Cig packings, with Zorbax Rx Cg, 24, Zorbax SB Cg, 29 and pBondapak Cjg, 30, in the upper left-hand corner. Figure 13d is a further expansion with Luna Phenylhexyl, 66, Supelcosil EC DB Cjg, 68 and Aqua Cjg, 69, in the upper left-hand corner, Hypersil Hypurity Elite, 63, on the left, and Shodex ODPerfect, 113, on the lower right. 

On the other hand, if we are working on a separation that is nearly complete, bnt reqnires a bit of fine-tnning that cannot be accomplished with mobile phase manipnlations, we wonld select a packing that is somewhat dissimilar bnt not too different. For example, if onr primary separation was done on a Pnrospher RP18e colnmn, 111, we conld select a Hypersil Hypurity Elite, 63, a Polaris Cjg-A, 65 or a SymmetryShield RPjg column, 70, as alternatives. These alternatives wonld change the selectivity of the separation somewhat, but not too drastically. 

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