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Updated: Jul 18, 2026

Simultaneous Affinity Enrichment of Two Post-Translational Modifications for Quantification and Site Localization
Published on: February 27, 2020
Simultaneous mass analysis of positive and negative ions using a dual-polarity time-of-flight mass spectrometer
Shang-Ting Tsai1, Chiu Wen Chen, Ling Chu Lora
1Genomics Research Center, Academia Sinica, 128, Academia Road, Section 2, Nankang District, Taipei 115, Taiwan, ROC.
Abstract:
Positive and negative ions produced from matrix-assisted laser desorption/ionization (MALDI) were simultaneously measured using a newly developed dual-polarity time-of-flight mass spectrometer. This instrument is effective not only for express and comprehensive mass analysis but also for studying the ionization mechanisms of biomolecules. It comprises two identical time-of-flight mass analyzers located symmetrically about a MALDI ion source. The ion optics are arranged to be able to extract positive and negative ions synchronously with equal efficiency to each corresponding mass analyzer. Mass spectra of various proteins with molecular weights as large as that of myoglobin monomer and dimer were obtained. The spectral patterns obtained in this work are approximately mirror images with opposite polarities.
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