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Emerging Biomedical Analysis
Published in Lawrence S. Chan, William C. Tang, Engineering-Medicine, 2019
Orbitrap analyzer. The Orbitrap™ mass analyzer consists of a spindle-like central electrode that has a high voltage applied to it and is surrounded by an outer barrel-like electrode kept at ground (Scigelova et al. 2011). The electrodes are precisely shaped to maintain a radial and an axial electric field inside the Orbitrap. During the data acquisition, ions are accumulated in an RF-only bent quadrupole, which is called the C-trap, and ejected into the Orbitrap (Zubarev and Makarov 2013) (Fig. 5). Affected by the strong electric field inside of the Orbitrap, ions rotate around the central electrode and oscillate along the axis of the central electrode. The trajectory of ions is similar to a complicated spiral. Similar to FT-ICR MS, ion motions are recorded by the outer electrode as image currents, and converted to m/z by using Fourier transform. Currently, the Orbitrap mass analyzer is exclusively produced by Thermo Fisher Scientific.
Measurement of Partial Pressure at Vacuum Conditions
Published in Igor Bello, Vacuum and Ultravacuum, 2017
Fourier transform analysis is also applied to orbitrap mass analysis. Orbitrap is a mass spectrometer that is based on trapping of ions in a logarithmic electric field where ions orbit around an inner barrel electrode, while they drift back and forth along the electrodes. Their oscillation frequencies are unique for each specific mass-to-charge ratio (From Makarov, A., Anal. Chem., 72(6), 1156, 2000, doi:10.1021/ac991131p; Hu, Q. et al., J. Mass Spectrom., 40(4), 430, 2005, doi:10.1002/jms.856. PMID 15838939.
Detection Technology
Published in Rick Houghton, William Bennett, Emergency Characterization of Unknown Materials, 2020
Rick Houghton, William Bennett
An orbitrap mass analyzer is another type of cyclotron mass analyzer that uses an electrostatically charged spindle to trap ions, as opposed to the traditional Penning trap described with the Fourier transform mass analyzer. As the ions orbit the spindle, they oscillate along the spindle axis. Detector plates similar to those described with the Fourier transform mass analyzer collect information, which is processed by Fourier transformation to generate a spectrum.
Genotoxicity of quinone: An insight on DNA adducts and its LC-MS-based detection
Published in Critical Reviews in Environmental Science and Technology, 2022
Yue Xiong, Han Yeong Kaw, Lizhong Zhu, Wei Wang
Orbitrap is an ion trap mass analyzer that can be used as both analyzer and detector. Orbitrap is deemed suitable to detect a wide range of compounds including small molecules without the loss of selectivity or sensitivity, regardless of target or non-target analysis. By coupling with nano ESI, it greatly improved signal-to-noise ratios and sensitivity. Therefore, LC-nano ESI-Orbitrap is frequently reported in the detection of trace DNA adducts in human samples. Xiao et al. employed a nano-LC-Orbitrap MSn method to significantly improve LOQ of the major dG adducts for five cooked meat carcinogens in human prostate tissue, which ranged between 1.3 and 2.2 adducts per 109 nucleotides in 2.5 μg of DNA assayed (Xiao et al., 2016). Villalta developed a sensitive quantitation method for DNA adduct by using UPLC-ESI-Orbitrap MSn to detect a representative adduct of B[a]P carcinogenic named BPDE-N2-dG, with the LOD of 1 adduct per 1011 nucleotides (1 adduct per 10 human lung cells) in 40 μg of human lung DNA (Villalta et al., 2017).