Answer / t reddy

consider ur performing combination drug.... if both the drugs hydrophilic means.

in c8 column the rt will be high compare to c18 and resolution between two peaks also will increase in c8.

i think peak shape won't affect based on this factor.

Reason - c8 is less hydrophobic than c18... because of less carbon.... c18 is more hydrophobic so the interaction between hydrophilic drug and high hydrophobic column(c18) is less, drug will elute quickly and RT will be less than c8 column and resolution also.

NOTE - this is just a possibility, u can still get the good Rt with c8 also by changing the various factors like mobile phase composition, flow rate, temperature etc

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