Fourier transform resonance imaging

Ion detection is carried out using image current detection with subsequent Fourier transform of the time-domain signal in the same way as for the Fourier transform ion cyclotron resonance (FTICR) analyzer (see Section 2.2.6). Because frequency can be measured very precisely, high m/z separation can be attained. Here, the axial frequency is measured, since it is independent to the first order on energy and spatial spread of the ions. Since the orbitrap, contrary to the other mass analyzers described, is a recent invention, not many variations of the instrument exist. Apart from Thermo Fischer Scientific s commercial instrument, there is the earlier setup described in References 245 to 247. 

FCS FT fMRI FTIR Fluorescence Correlation Spectroscopy Fourier Transform Functional Magnetic Resonance Imaging Fourier Transform Infrared Spectroscopy... 

MALDI-Fourier transform ion cyclotron resonance mass spectrometry MALDI-Q-ion mobility-TOFMS MALDI-Quadrupole-ion-trap-TOF mass spectrometry MALDI-TOF-imaging mass spectrometry MALDI Time-of-flight mass spectrometry Magnetic resonance imaging Matrix solution fixation Moxifloxacin... 

The MALDI-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (MALDI-FT-ICR-MS) and MALDI-Quadrupole-Ion-trap-TOF Mass Spectrometry (MALDI-QIT-TOF-MS) can be used on IMS. The FT-ICR-MS could provide the high resolution, expansive mass range and high sensitivity imaging MS data and good for determining the elemental composition of small molecules [60],... 

Ewert, U., Crepeau, R.H., Dunnmam, Curt.R., Xu,D., Lee, S.and Freed, J.H. (1991) Fourier transform electron spin resonance imaging, Chem. Phys. Letters 184, 25-33. 

The resonance frequency thus becomes a measure of the location of the sample along the x axis. For example, if we place a sample tube containing two capillaries of water in an ordinary NMR spectrometer and introduce the gradient Gx, apply a 90° rf pulse, and Fourier transform the FID, we obtain a spectrum of the sort shown in Fig. 14.1. The two broad lines show the relative positions of the capillaries in the x direction and constitute a one-dimensional image of the overall sample. Several important points can be deduced from Fig. 14.1 and Eq. 14.2 ... 

Fig. 6 Schematic of a FTICR MS instrument. This type of MS consists of an ion cyclotron resonance (ICR) analyzer cell that is situated in the homogeneous region of a large magnet. The ions introduced into the ICR analyzer are constrained (trapped) by the magnetic field to move in circular orbits with a specific frequency that corresponds to a specific mass-to-charge ratio (m/z). Mass analysis occurs when radiofrequency (rf) potential is applied (pulsed) to the ICR analyzer so that all ions are accelerated to a larger orbit radius. After the pulse is turned off, the transient image current is acquired and a Fourier transform separates the individual cyclotron frequencies. Repeating this pulsing process to accumulate several transients is used to improve the signal-to-noise ratio. (Courtesy of Bruker Daltonics, Billerica, MA.)...

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