ANOMALOUS RETENTION BEHAVIOR OF PEPTIDES ON POROUS GRAPHITIZED CARBONCOLUMN

The retention behaviour of fourteen peptides was determined on a porou s graphitized carbon (PGC) column, using acetonitrile-water mixtures a s eluents. The majority of peptides showed irregular retention behavio ur, their retention decreased with increasing concentration of acetoni trile in the lower concentration range, reached a minimum and increase d again with increasing concentration of acetonitrile in the higher co ncentration range. Both quadratic and bilinear equations described wel l the irregular retention of peptides on the PGC column, however, the coefficients of correlation were slightly higher for the quadratic fun ction, Calculations indicated that the impact of hydrophobicity, steri c and electronic parameters on the retention of peptides on a PGC colu mn is similar, that is a PGC column shows mixed retention mechanisms i n which hydrophobic, steric, and electronic forces are equally involve d. (C) 1997 Elsevier Science B.V.