Quantitative relationship between the retention of peptides on a reversed-phase alumina support and their physicochemical parameters

The retention time of 16 peptides was determined on polyethylene-coated alumina stationary phase using mixtures of acetonitrile (MeCN) and acidic and basic phosphate buffers as mobile phases. The majority of peptides showed nonlinear retention behaviour, their retention decreased with increasing concentration of MeCN in the lower concentration range, reached a minimum and increased again with increasing concentration of MeCN in the higher concentration range. Quadratic equations described well the atypical retention behaviour of peptides, the significance level being always over 95%. Principal component analysis indicated that the steric parameters of peptides exerted the highest influence on their retention on polyethylene-coated alumina stationary phase.