Performance Evaluation of a High-field Orbitrap Mass Analyzer

• Published in: Journal of the American Society for Mass Spectrometry 2009-08, Vol.20 (8), p.1391-1396
• Main Authors: Makarov, Alexander, Denisov, Eduard, Lange, Oliver
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Bioinformatics; Biotechnology; Chemistry; Chemistry and Materials Science; Exact sciences and technology; Field strength; Focus: The Orbitrap; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mass spectrometers and related techniques; Mass spectrometry; Organic Chemistry; Performance evaluation; Physics; Proteins; Proteomics; Resolution; Space charge; Spectrometric and optical methods; Tolerances
• ISSN: 1044-0305; 1879-1123
• DOI: 10.1016/j.jasms.2009.01.005

A new design of the Orbitrap™ mass analyzer is presented. Higher frequencies of ion oscillations and hence higher resolving power over fixed acquisition time are achieved by decreasing the gap between the inner and outer Orbitrap electrodes, thus providing higher field strength for a given voltage. Experimental results confirm maximum FWHM resolving power in excess of 350,000 at m/z 524 and 600,000 at m/z 195, isotopic resolution of proteins above 40 kDa, and a single-shot dynamic range of 25,000. It was also found that mass shifts in the new design depend very little on space charge inside the analyzer. This performance was achieved using higher voltages and by careful balancing of construction tolerances and operation parameters, which appeared to vary in narrower ranges of tuning than for a standard Orbitrap analyzer. This work is devoted to experimental characterization of a novel, high-field Orbitrap mass analyzer with a decreased gap between electrodes.