Kratos Analytical, Urmston, Manchester, UK.
Liquid chromatography/fast-atom bombardment mass spectrometry was used to partially confirm the amino-acid sequence of the protein, beta-casein. The study demonstrates that the technique is capable of the rapid and accurate identification of peptide fragments from tryptic digests and that chromatographic integrity is maintained during the analysis. The power of the technique derives from the ability to determine both the retention time and the molecular weight of the eluting components. Each of the components yields a prominent pseudo-molecular ion (MH+), the majority exhibiting sufficient fragmentation to confirm their structure unambiguously.