Fourier transform ion cyclotron resonance FTICR mass spectrometers

Figure 2.19. Schematic of a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer (a) and a cylindrical cell (b). Reprinted from A. Westman-Brinkmalm and G. Brinkmalm (2002). In Mass Spectrometry and Hyphenated Techniques in Neuropeptide Research, J. Silberring and R. Ekman (eds.) New York John Wiley Sons, 47-105. With...

An overview of commercial ICP mass spectrometers from different companies (quadrupole based ICP-MS with and without collision/reaction cell, double-focusing sector field instrumentation with single and multiple ion collectors, time-of-flight (ToF), ICP-ion trap-MS and non-commercial ICP-Fourier transform ion cyclotron resonance (FTICR) mass spectrometers is given in Figure 5.2. By using ion traps and FTICR mass spectrometers in ICP-MS isobaric interferences of atomic ions... 

The most common types of MS/MS instruments available to researchers in food chemistry include triple quadrupole mass spectrometers and ion traps. Less common but commercially produced tandem mass spectrometers include magnetic sector instruments, Fourier transform ion cyclotron resonance (FTICR) mass spectrometers, and quadrupole time-of-flight (QTOF) hybrid instruments (Table A.3A.1). Beginning in 2001, TOF-TOF tandem mass spectrometers became available from instrument manufacturers. These instruments have the potential to deliver high-resolution tandem mass spectra with high speed and should be compatible with the chip-based chromatography systems now under development. 

In a commercially available device based on Penning traps - the Fourier transform ion cyclotron resonance (FTICR) mass spectrometer - the ions are constrained spatially or rather ions can be... 

Ion-molecular reactions are used to resolve isobaric interferences, as discussed, in ICP-MS with a collision/reaction cell or by utilizing ion traps. The mass spectra of Sr, Y and Zr (Fig. 6.10a) without O2 admitted into the collision cell and (Fig. 6.10b) with 10 Pa Oj are different. By introducing oxygen, selective formation of YO and ZrO, but not SrO, is observed. This behaviour of different oxide formation is relevant for an interference free determination of Sr. Ultrahigh mass resolving power ICP mass spectrometry (at m/Am 260 000) selectively removes unwanted ions prior to transfer to the FTICR analyzer cell by gas-phase chemical reactions, e.g., for separation of Ca from " Ar+ obtained with a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer equipped with a 3 tesla superconducting magnet. ... 

Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometers that are pioneering die study of proteins in cells (proteomics), and a state-of-the-art Molecular Sciences Conqmting Facility with a siqierconqiuter having a peak performance of 11 teraflops. More than a thousand scientists from outside PNNL use the EMSL fiicilities annually, many of them accessing its csqiabilities remotely, and many of them studying environmental problems. 

Hybrid linear ion trap-Fourier transform ion cyclotron resonance (FTICR) mass spectrometer, 7T (LTQ-FTICR,Thermo), or equivalent instrument, equipped with an electrospray/nanospray (ESI/ NSI) source and ECD accessory, operated under the control of Xcalibur software package (Thermo Fisher Scientific, San Jose, CA Instrument Configuration, Instrument Setup, Sequence Setup, and Qual Browser modules appropriately created and used) with Bioworks available to preprocess raw data files for database search. ECD may be replaced with ETD and the respective manufacturer s own version of the above software should be used, when alternative instrument is selected. 

Alkali metal ion/molecule association reactions have been exploited in various mass spectrometric methods since the early 1970s. Initial studies were to determine metal ion affinities of simple compounds, with use of Fourier transform ion cyclotron resonance (FTICR) mass spectrometers. Alkali ions offer unique and interesting potential in analytical chemistry and studies of chemical dynamics. Consequently, the use of metal ions as reagents for Cl mass spectrometry has been developed. The major advances in the apphcation of MS as a routine analytical instmment using the complex ion/molecule chemistry came arotmd in the past decades. They include atmospheric pressure chemical ionization (APCI), proton transfer reaction mass spectrometry (PTR-MS), selected ion flow tube mass spectrometry (SIFT-MS), ion attachment mass spectrometry (lAMS) and ion molecrtle reaction mass spectrometry (IMM-MS). 

Fig. 5 Fourier-Transform Ion Cyclotron Resonance (FTICR) mass spectrometer with electrospray ionization (ESI) source used for IRMPD ion spectroscopy at the FELIX facility. The hexapole ion guide is also used to accumulate ions from the ESI source before being pulse-injected into the ICR ceil. The inside of the excite electrodes of the ICR cell are polished so that they act as a multipass reflection ceil for the IR beam fiom FELIX (or an OPO) achieving approximately 10 passes through the ion cloud. Adapted from [142]...

Other types of mass spectrometer may use point, array, or both types of collector. The time-of-flight (TOF) instrument uses a special multichannel plate collector an ion trap can record ion arrivals either sequentially in time or all at once a Fourier-transform ion cyclotron resonance (FTICR) instrument can record ion arrivals in either time or frequency domains which are interconvertible (by the Fourier-transform technique). 

Resolution does not affect the accuracy of the individual accurate mass measurements when no separation problem exists. When performing accurate mass measurements on a given component in a mixture, it may be necessary to raise the resolution of the mass spectrometer wherever possible. Atomic composition mass spectrometry (AC-MS) is a powerful technique for chemical structure identification or confirmation, which requires double-focusing magnetic, Fourier-transform ion-cyclotron resonance (FTICR) or else ToF-MS spectrometers, and use of a suitable reference material. The most common reference materials for accurate mass measurements are perfluorokerosene (PFK), perfluorotetrabutylamine (PFTBA) and decafluorotriph-enylphosphine (DFTPP). One of the difficulties of high-mass MS is the lack of suitable calibration standards. Reference inlets to the ion source facilitate exact mass measurement. When appropriately calibrated, ToF mass... 

Currently PCR and mass spectrometry are performed by two separate instruments. However, there is no reason why PCR followed by simple automated cleanup and mass spectrometry cannot be incorporated into a single integrated instrument. Essentially every configuration of the modern ESI mass spectrometer has been used successfully for the analysis of PCR products, from the highest to the lowest resolution involving. Fourier transform ion cyclotron resonance (FTICR), triple quadrupole, quadrupole-time of flight (Q-TOF), and ion trap.22-24 MS discriminates between two structurally related PCR products by MW difference. Mass accuracy is needed to differentiate the... 

In addition to the diversity of ionisation techniques available, mass spectrometers offer a selection of mass analyser configurations. Of note are single (MS) and triple quadrupole (MS—MS) instruments, ion trap analysers (MS)n, time-of-flight (ToF) analysers, sector field analysers, and Fourier transform-ion cyclotron resonance (FTICR) instruments. 

The same group studied the lithium cation basicities of a series of compounds of the general formula R R R PO, i.e. phosphine oxides, phosphinates, phosphonates and phosphates, by using Fourier Transform Ion Cyclotron Resonance (FTTCR) mass spectrometry. A summary of their results is shown in Figure 4. The effect of methyl substitution on LCA as well as the correlation between LCA and PA was also investigated by Taft, Yanez and coworkers on a series of methyldiazoles with an FTICR mass spectrometer. They showed that methyl substituent effects on Li binding energies are practically additive. 

The technique of laser desorption (LD) has been widely used in mass spectrometry (J, 2) to desorb and to ionize high molecular weight or other nonvolatile samples, most often using time-of-flight (3. 4 ) or Fourier transform ion cyclotron resonance (FTICR) ( 5. 6 ) mass spectrometers for mass analysis. In this technique, highly focussed laser irradiation, most often with a power density of at least 10° W/cm, is used to desorb and ionize a solid sample that has been inserted into the high vacuum system of the mass spectrometer. 

These types of detectors have a limited resolving power in discriminating between small mass differences. In such cases, double focusing mass spectrometers are used. Fourier-transform ion cyclotron resonance (FTICR) analyzers interfaced with ESI or MALDI are used in the high molecular weight polymer characterization [44]. 

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