Abstract
Compared to continuous extraction, pulsed extraction (PE) of ions formed by matrix-assisted laser desorption/ionization (MALDI) in time-of-flight (TOF) mass spectrometers significantly improves mass resolution. Parameters such as extraction voltage, delay time, and correction pulse must be varied, however, to achieve optimum mass resolution over a broad mass range because the PE method is mass dependent. We previously reported a novel method, mass correlated acceleration (MCA), which we have now combined with a reflectron MALDI TOF mass spectrometer to further enhance mass resolution over a broader mass range. Unlike the PE method, MCA is not mass dependent and high resolution mass spectra can be achieved with a single tuning of instrument parameters. The ions may be brought into focus simultaneously, i.e., the multi-channel recording advantage can be more fully realized. The MCA dual-stage ion source design includes an extraction pulse region and an acceleration region that contains a time-dependent waveform correlated with mass. We demonstrate the validity of this novel technique with applications in peptide mixture analysis and protein digests of lysozyme and bovine serum albumin.
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Kovtoun, S.V., English, R.D. & Cotter, R.J. Mass correlated acceleration in a reflectron MALDI TOF mass spectrometer: an approach for enhanced resolution over a broad mass range. J Am Soc Mass Spectrom 13, 135–143 (2002). https://doi.org/10.1016/S1044-0305(01)00346-4
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DOI: https://doi.org/10.1016/S1044-0305(01)00346-4