simple reversed-phase adsorption chromatography with c8-bonded silica is not able to separate these compounds very well because of ( i ) the very small retention of the more basic compounds in circumstances where the acidic compounds are well separated , ( ii ) bad peak shapes and ( iii ) low column efficiences , although the last drawback can be circumvented by the addition of inorganic anions to the eluent .
C0021966
i
C0003075
anions