Gel-permeation high-performance liquid chromatography (HPLC) and reversed-phase HPLC were used to separate a mixture of peptides, produced at pilot-plant scale by peptic hydrolysis of bovine haemoglobin. Volatile buffers were employed in both HPLC techniques in order to get an easy recovery of peptides for further applications. The method is more rapid than low-pressure gel filtration. Amino acid analysis and fast atom bombardment mass spectrometry confirmed the purity, and allowed accurate molecular weights to be determined, for isolated peptides. These data demonstrate that such efficient techniques, usually used to resolve hydrolysates obtained in batch with pure substrates and highly specific enzymes, can be employed to resolve complex enzymatic hydrolysates of crude protein.