A SIMPLE OFF-LINE SAMPLE SPOTTER FOR COUPLING HPLC WITH MALDI MS

This article describes a simple, off-line coupling of microbore high p erformance liquid chromatography (HPLC) and matrix-assisted laser-deso rption ionization (MALDI) for semiautomated mass spectrometry (MS) ana lysis of peptide and protein mixtures. The device used by the authors comprises a modified pen plotter programmed to apply the HPLC effluent directly to a membrane that is attached to the MALDI sample target st age. They analyzed the effluent using an automated MALDI MS routine. T he authors also present data that demonstrate the retention of chromat ographic resolution by this interface and the determination of molecul ar weights with good sensitivity. Peptide structural information can b e provided by postsource decay fragmentation or in situ digestion of e ach spot on the membrane.