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Chemistry LibreTexts

Section 2: Electrospray

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  • Learning Objectives

    At the end of this assignment, you should be able to:

    • Explain how the m/z values and spacing of peaks in an ESI charge envelope is used to determine molecular weight.
    • Calculate the charge state and mass of a protein from its ESI-MS spectrum.
    • Explain how a quadrupole ion trap mass analyzer works.

    Calculating the molecular weight of a protein from its electrospray ionization mass spectrum (ESI-MS)

    References and Resources

    1. G.L. Glish and R.W. Vachet, “The basics of mass spectrometry in the twenty-first century,” Nat. Rev. Drug Discov., 2003, 2, 140-150.
    2. C. Hendrickson, “Electrospray Ionization (ESI)”,
    3. C.S. Ho, et al. “Electrospray ionization mass spectrometry: principles and clinical applications,” Clin. Biochem. Rev. 2003, 24, 3-12.
    4. J.R. Yates, “A century of mass spectrometry: from atoms to proteomes,” Nat. Methods, 2011, 8, 633-637.
    5. J. Yergey, et al. “Isotopic distributions in mass spectra of large molecules,” Anal. Chem. 1983, 55, 353-358.
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