Search results for "Quadrupole ion trap"
showing 10 items of 26 documents
Application of ultra-high pressure liquid chromatography linear ion-trap orbitrap to qualitative and quantitative assessment of pesticide residues
2014
Abstract The analysis of pesticides residues using a last generation high resolution and high mass accuracy hybrid linear ion trap-Orbitrap mass spectrometer (LTQ-Orbitrap-MS) was explored. Pesticides were extracted from fruits, fish, bees and sediments by QuEChERS and from water by solid-phase with Oasis HLB cartridges. Ultra-high pressure liquid chromatography (UHPLC)–LTQ-Orbitrap mass spectrometer acquired full scan MS data for quantification, and data dependent (dd) MS 2 and MS 3 product ion spectra for identification and/or confirmation. The regression coefficients ( r 2 ) for the calibration curves (two order of magnitude up to the lowest calibration level) in the study were ≥0.99. Th…
Applicability of hybrid linear ion trap-high resolution mass spectrometry and quadrupole-linear ion trap-mass spectrometry for mycotoxin analysis in …
2012
Abstract Recent developments in mass spectrometers have created a paradoxical situation; different mass spectrometers are available, each of them with their specific strengths and drawbacks. Hybrid instruments try to unify several advantages in one instrument. In this study two of wide-used hybrid instruments were compared: hybrid quadrupole-linear ion trap-mass spectrometry (QTRAP ® ) and the hybrid linear ion trap-high resolution mass spectrometry (LTQ-Orbitrap ® ). Both instruments were applied to detect the presence of 18 selected mycotoxins in baby food. Analytical parameters were validated according to 2002/657/CE. Limits of quantification (LOQs) obtained by QTRAP ® instrument ranged …
Characterization of methyl orange and its photocatalytic degradation products by HPLC/UV–VIS diode array and atmospheric pressure ionization quadrupo…
2002
Abstract HPLC/UV–VIS diode array and HPLC/MS techniques were successfully applied to the analysis of sulfonated molecules present in samples coming from the photocatalytic degradation of the azo dye indicator, methyl orange. The substrate was chosen as a simple model for the study of reactions involving the more complex commercial products used for the dyeing of textile fibers. Unexpected MS fragmentation path was observed, due to the very stable methyl orange molecular structure. The chromatographic information were combined with the obtained MS, MS/MS data and the UV–VIS diode array spectra and allowed to rationalize the molecular structures attributable to the various degradation product…
The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results
2007
The highest precision in direct mass measurements is obtained with Penning trap mass spectrometry. Most experiments use the interconversion of the magnetron and cyclotron motional modes of the stored ion due to excitation by external radiofrequency-quadrupole fields. In this work a new excitation scheme, Ramsey's method of time-separated oscillatory fields, has been successfully tested. It has been shown to reduce significantly the uncertainty in the determination of the cyclotron frequency and thus of the ion mass of interest. The theoretical description of the ion motion excited with Ramsey's method in a Penning trap and subsequently the calculation of the resonance line shapes for differ…
Theory of simultaneous dipole and quadrupole excitation of the ion motion in a Penning trap
2012
Abstract Penning traps confine ions of atoms and molecules as well as other charged particles by a combination of static electric and magnetic fields to the central region of the trap, where these objects can be studied. Most experiments employ pulses of dipolar radio-frequency radiation followed by pulses of quadrupolar radio-frequency radiation to manipulate the motional state of the trapped particles. Instead of a sequential procedure an excitation of the ion motion by the simultaneous application of dipolar and quadrupolar rf-fields is also conceivable. This paper investigates the theory of simultaneous excitation under very general assumptions, with inclusion of possible damping terms.…
Quadrupole excitation of stored ion motion at the true cyclotron frequency
1995
Abstract The motion of an ion in a Penning trap has been investigated in the presence of an azimuthal quadrupole radio frequency field and a damping force provided by buffer gas collisions. Analytical expressions are derived which describe the line shape of the cyclotron resonance as well as the properties of the mass-selective cooling mechanism for heavy ions. Excellent agreement is observed between theoretical results and experimental data obtained with the tandem Penning trap mass spectromer ISOLTRAP at ISOLDE (CERN).
The elliptical Penning trap: Experimental investigations and simulations
2008
Abstract The application of an additional azimuthal quadrupolar electrostatic field to a Penning trap leads to a field configuration referred to as an elliptical Penning trap. The resulting changes of the radial ion motions have been investigated experimentally and by use of simulations. The eigenfrequencies, i.e., the magnetron frequency ω ˜ − and the reduced cyclotron frequency ω ˜ + , are found to be shifted with respect to those of the standard Penning trap ω − , ω + , respectively. As the shift of the magnetron frequency ω ˜ − is larger than that of the reduced cyclotron frequency ω ˜ + their sum ω ˜ + + ω ˜ − is also a function of the ellipticity and no longer equal to the cyclotron f…
Comparison of liquid chromatography using triple quadrupole and quadrupole ion trap mass analyzers to determine pesticide residues in oranges.
2005
Liquid chromatography-triple quadrupole/mass spectrometry (LC-TQ/MS) and liquid chromatography-quadrupole ion trap/mass spectrometry (LC-QIT/MS) for determining bupirimate, hexaflumuron, tebufenpyrad, buprofezin, pyriproxyfen, and fluvalinate in fruits have been compared. The differences in the mass spectra obtained by triple and ion trap quadrupoles are discussed, showing how both of them provide interesting features. The evaluation of the two instruments was carried out by ethyl acetate extraction of oranges spiked with the studied pesticides at LOQ and 10 times the LOQ. Results obtained by LC-TQ/MS correlated well with those obtained by LC-QIT/MS. Recoveries were 70-94% by LC-TQ/MS and 7…
Instabilities of ion motion in a linear Paul trap
2006
Abstract We have investigated the stability properties of a linear radio frequency ion trap with cylindrical electrodes. Inside the region of stability for an ideal trap we found a number of instabilities similar to those experimentally observed in three-dimensional traps. They arise from higher order contributions to the ideal quadrupole trapping potential. The static potential for axial confinement shifts the radial ion oscillation frequencies and leads to additional instabilities.
Antiproton confinement in a Penning-Ioffe trap for antihydrogen.
2007
Antiprotons ((p) over bar) remain confined in a Penning trap, in sufficient numbers to form antihydrogen ((H) over bar) atoms via charge exchange, when the radial field of a quadrupole Ioffe trap is added. This first demonstration with (p) over bar suggests that quadrupole Ioffe traps can be superimposed upon (p) over bar and e(+) traps to attempt the capture of (H) over bar atoms as they form, contrary to conclusions of previous analyses.