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Sample records for ion trap mass

  1. Ion Trap Mass Spectrometry

    SciTech Connect

    Eiden, Greg C.

    2005-09-01

    This chapter describes research conducted in a few research groups in the 1990s in which RF quadrupole ion trap mass spectrometers were coupled to a powerful atomic ion source, the inductively coupled plasma used in conventional ICP-MS instruments. Major section titles for this chapter are: RF Quadrupole Ion Traps Features of RF Quadrupole Ion Trap Mass Spectrometers Selective Ion Trapping methods Inductively Coupled Plasma Source Ion Trap Mass Spectrometers

  2. Mini ion trap mass spectrometer

    DOEpatents

    Dietrich, D.D.; Keville, R.F.

    1995-09-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  3. Mini ion trap mass spectrometer

    DOEpatents

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  4. Halo ion trap mass spectrometer.

    PubMed

    Austin, Daniel E; Wang, Miao; Tolley, Samuel E; Maas, Jeffrey D; Hawkins, Aaron R; Rockwood, Alan L; Tolley, H Dennis; Lee, Edgar D; Lee, Milton L

    2007-04-01

    We describe a novel radio frequency ion trap mass analyzer based on toroidal trapping geometry and microfabrication technology. The device, called the halo ion trap, consists of two parallel ceramic plates, the facing surfaces of which are imprinted with sets of concentric ring electrodes. Radii of the imprinted rings range from 5 to 12 mm, and the spacing between the plates is 4 mm. Unlike conventional ion traps, in which hyperbolic metal electrodes establish equipotential boundary conditions, electric fields in the halo ion trap are established by applying different radio frequency potentials to each ring. The potential on each ring can be independently optimized to provide the best trapping field. The halo ion trap features an open structure, allowing easy access for in situ ionization. The toroidal geometry provides a large trapping and analyzing volume, increasing the number of ions that can be stored and reducing the effects of space-charge on mass analysis. Preliminary mass spectra show resolution (m/Deltam) of 60-75 when the trap is operated at 1.9 MHz and 500 Vp-p. PMID:17335180

  5. Microscale ion trap mass spectrometer

    DOEpatents

    Ramsey, J. Michael; Witten, William B.; Kornienko, Oleg

    2002-01-01

    An ion trap for mass spectrometric chemical analysis of ions is delineated. The ion trap includes a central electrode having an aperture; a pair of insulators, each having an aperture; a pair of end cap electrodes, each having an aperture; a first electronic signal source coupled to the central electrode; a second electronic signal source coupled to the end cap electrodes. The central electrode, insulators, and end cap electrodes are united in a sandwich construction where their respective apertures are coaxially aligned and symmetric about an axis to form a partially enclosed cavity having an effective radius r.sub.0 and an effective length 2z.sub.0, wherein r.sub.0 and/or z.sub.0 are less than 1.0 mm, and a ratio z.sub.0 /r.sub.0 is greater than 0.83.

  6. An electrostatic autoresonant ion trap mass spectrometer

    SciTech Connect

    Ermakov, A. V.; Hinch, B. J.

    2010-01-15

    A new method for ion extraction from an anharmonic electrostatic trap is introduced. Anharmonicity is a common feature of electrostatic traps which can be used for small scale spatial confinement of ions, and this feature is also necessary for autoresonant ion extraction. With the aid of ion trajectory simulations, novel autoresonant trap mass spectrometers (ART-MSs) have been designed based on these very simple principles. A mass resolution {approx}60 is demonstrated for the prototypes discussed here. We report also on the pressure dependencies, and the (mV) rf field strength dependencies of the ART-MS sensitivity. Importantly the new MS designs do not require heavy magnets, tight manufacturing tolerances, introduction of buffer gases, high power rf sources, nor complicated electronics. The designs described here are very inexpensive to implement relative to other instruments, and can be easily miniaturized. Possible applications are discussed.

  7. Universal collisional activation ion trap mass spectrometry

    DOEpatents

    McLuckey, S.A.; Goeringer, D.E.; Glish, G.L.

    1993-04-27

    A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

  8. Universal collisional activation ion trap mass spectrometry

    DOEpatents

    McLuckey, Scott A.; Goeringer, Douglas E.; Glish, Gary L.

    1993-01-01

    A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

  9. Miniaturized Linear Wire Ion Trap Mass Analyzer.

    PubMed

    Wu, Qinghao; Li, Ailin; Tian, Yuan; Zare, Richard N; Austin, Daniel E

    2016-08-01

    We report a linear ion trap (LIT) in which the electric field is formed by fine wires held under tension and accurately positioned using holes drilled in two end plates made of plastic. The coordinates of the hole positions were optimized in simulation. The stability diagram and mass spectra using boundary ejection were compared between simulation and experiment and good agreement was found. The mass spectra from experiments show peak widths (fwhm) in units of mass-to-charge of around 0.38 Th using a scan rate of 3830 Th/s. The limits of detection are 137 ppbv and 401 ppbv for benzene and toluene, respectively. Different sizes of the wire ion trap can be easily fabricated by drilling holes in scaled positions. Other distinguishing features, such as high ion and photon transmission, low capacitance, high tolerance to mechanical and assembly error, and low weight, are discussed. PMID:27373557

  10. Proton Transfer Reaction Ion Trap Mass Spectrometer

    SciTech Connect

    Prazeller, Peter; Palmer, Peter T.; Boscaini, Elena; Jobson, B Tom T.; Alexander, M. Lizabeth

    2003-06-11

    Proton transfer reaction mass spectrometry is a relatively new field that has attracted a great deal of interest in the last few years. This technique uses H₃Oþ as a chemical ionization (CI) reagent to measure volatile organic compounds (VOCs) in the parts per billion by volume (ppbv) to parts per trillion by volume (pptv) range. Mass spectra acquired with a proton transfer reaction mass spectrometer (PTR-MS) are simple because proton transfer chemical ionization is ‘soft’ and results in little or no fragmentation. Unfortunately, peak identification can still be difficult due to isobaric interferences. A possible solution to this problem is to couple the PTR drift tube to an ion trap mass spectrometer (ITMS). The use of an ITMS is appealing because of its ability to perform MS/MS and possibly distinguish between isomers and other isobars. Additionally, the ITMS duty cycle is much higher than that of a linear quadrupole so faster data acquisition rates are possible that will allow for detection of multiple compounds. Here we present the first results from a proton transfer reaction ion trap mass spectrometer (PTR-ITMS). The aim of this study was to investigate ion injection and storage efficiency of a simple prototype instrument in order to estimate possible detection limits of a second-generation instrument. Using this prototype a detection limit of 100 ppbv was demonstrated. Modifications are suggested that will enable further reduction in detection limits to the low-ppbv to high-pptv range. Furthermore, the applicability of MS/MS in differentiating between isobaric species was determined. MS/MS spectra of the isobaric compounds methyl vinyl ketone (MVK) and methacrolein (MACR) are presented and show fragments of different mass making differentiation possible, even when a mixture of both species is present in the same sample. However, MS/MS spectra of acetone and propanal produce fragments with the same molecular masses but with different intensity ratios

  11. Proton Transfer Reaction Ion Trap Mass Spectrometer

    SciTech Connect

    Prazeller, Peter; Palmer, Peter T.; Boscaini, Elena; Jobson, B Tom; Alexander, M. Lizabeth

    2003-07-07

    Proton Transfer Reaction Mass Spectrometry (PTR-MS) is a relatively new field that has attracted a great deal of interest in the last several years. This technique uses H3O+ as a chemical ionization (CI) agent for measuring volatile organic compounds (VOCs) in the parts per billion by volume (ppbv) - parts per trillion by volume (pptv) range. PTR-MS mass spectra are simple because the ionization method of proton transfer is “soft”, resulting in little or no fragmentation. Unfortunately, the simplicity of the mass spectra can cause problems in peak identification due to isobaric interferences. A possible solution to this problem is to couple the PTR drift tube to an ion trap mass spectrometer (ITMS). ITMS is appealing because of the ability to perform MS/MS and possibly distinguish between isomers and other isobars. Additionally, the ITMS duty cycle is much higher than that of a linear quadrupole so faster data acquisition rates can be realized for detection of multiple compounds. We present here the first results from a Proton Transfer Reaction Ion Trap Mass Spectrometer (PTR-ITMS). The aim of this study was to investigate ion injection and storage efficiency of a simple prototype interface in order to estimate possible detection limits of a second generation instrument. Using this prototype a detection limit of 100 ppbv was demonstrated for the PTR-ITMS. Modifications are suggested that will enable further reduction in detection limits to the low ppbv to pptv range. Furthermore the applicability of MS/MS to differentiate between isobaric species was determined. MS/MS spectra of the isobaric compounds methyl vinyl ketone (MVK) and methacrolein (MACR) are presented and show fragments of different mass making a differentiation possible even when a mixture of both species is present in the same sample. MS/MS spectra of acetone and propanal produce fragments with the same molecular weight but different ratios, allowing quantitative distinction only if one species

  12. Electron source for a mini ion trap mass spectrometer

    DOEpatents

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  13. Electron source for a mini ion trap mass spectrometer

    DOEpatents

    Dietrich, D.D.; Keville, R.F.

    1995-12-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  14. Ion trap simulation program, ITSIM: A powerful heuristic and predictive tool in ion trap mass spectrometry

    NASA Astrophysics Data System (ADS)

    Bui, Huy Anh

    The multi-particle simulation program, ITSIM version 4.0, takes advantage of the enhanced performance of the Windows 95 and NT operating systems in areas such as memory management, user friendliness, flexibility of graphics and speed, to investigate the motion of ions in the quadrupole ion trap. The objective of this program is to use computer simulations based on mathematical models to improve the performance of the ion trap mass spectrometer. The simulation program can provide assistance in understanding fundamental aspects of ion trap mass spectrometry, precede and help to direct the course of experiments, as well as having didactic value in elucidating and allowing visualization of ion behavior under different experimental conditions. The program uses the improved Euler method to calculate ion trajectories as numerical solutions to the Mathieu differential equation. This Windows version can simultaneously simulate the trajectories of ions with a virtually unlimited number of different mass-to-charge ratios and hence allows realistic mass spectra, ion kinetic energy distributions and other experimentally measurable properties to be simulated. The large number of simulated ions allows examination of (i) the offsetting effects of mutual ion repulsion and collisional cooling in an ion trap and (ii) the effects of higher order fields. Field inhomogeneities arising from exit holes, electrode misalignment, imperfect electrode surfaces or new trap geometries can be simulated with the program. The simulated data are used to obtain mass spectra from mass-selective instability scans as well as by Fourier transformation of image currents induced by coherently moving ion clouds. Complete instruments, from an ion source through the ion trap mass analyzer to a detector, can now be simulated. Applications of the simulation program are presented and discussed. Comparisons are made between the simulations and experimental data. Fourier transformed experiments and a novel six

  15. Ion trap array mass analyzer: structure and performance.

    PubMed

    Li, Xiaoxu; Jiang, Gongyu; Luo, Chan; Xu, Fuxing; Wang, Yuanyuan; Ding, Li; Ding, Chuan-Fan

    2009-06-15

    An ion trap array (ITA) mass analyzer--a novel ion trap mass analyzer with multiple ion trapping and analyzing channels--was designed and constructed. Its property and performance were investigated and reported in this paper. The ITA was built with several planar electrodes including two parallel printed circuit board (PCB) plates. Each PCB plate was fabricated to several identical rectangular electric strips based on normal PCB fabrication technology and was placed symmetrically to those on the opposite plate. There is no electrode between any two adjacent strips. Every strip was supplied with an rf voltage while the polarity of the voltage applied to the adjacent two strips was opposite. So the electric potential at the central plane between two adjacent strips is zero. Multiple identical electric field regions that contain the dominant quadrupole plus some other high-order fields were produced between the two PCB plates. The multiple identical electric field regions will have the property of ion trapping, ion storage, and mass analysis functions. So an ITA could work as multiple ion trap mass analyzers. It could perform multiple sample ion storage, mass-selected ion isolation, ion ejection, and mass analysis simultaneously. The ITA was operated at both "digital ion trap mode" and "conventional rf mode" experimentally. A preliminary mass spectrum has been carried out in one of the ion trap channels, and it shows a mass resolution of over 1000. Additional functions such as mass-selected ion isolation and mass-selected ion ejection have also been tested. Furthermore, the ITA has a small size and very low cost. An ITA with four channels is less than 30 cm(3) in total volume, and it shows a great promise for the miniaturization of the whole mass spectrometer instrument and high-throughput mass analysis. PMID:19441854

  16. Fundamental studies of ion injection and trapping of electrosprayed ions on a quadrupole ion trap mass spectrometer

    NASA Astrophysics Data System (ADS)

    Quarmby, Scott Thomas

    The quadrupole ion trap is a highly versatile and sensitive analytical mass spectrometer. Because of the advantages offered by the ion trap, there has been intense interest in coupling it to ionization techniques such as electrospray which form ions externally to the ion trap. In this work, experiments and computer simulations were employed to study the injection of electrosprayed ions into the ion trap of a Finnigan MAT LCQ LC/MS n mass spectrometer. The kinetic energy distribution of the ion beam was characterized and found to be relatively wide, a result of the high pressures from the atmospheric pressure source. One of the most important experimental parameters which affects ion injection efficiency is the RF voltage applied to the ring electrode. A theoretical model was fit to experimental data allowing the optimum RF voltage for trapping a given m/z ion to be predicted. Computer simulations of ion motion were performed to study the effect of various instrumental parameters on trapping efficiency. A commercially available ion optics program, SIMION v6.0, was chosen because it allowed the actual ion trap electrode geometry including endcap holes to be simulated. In contrast to previous computer simulations, SIMION provided the ability to start ions outside the ion trap and to simulate more accurately the injection of externally formed ions. The endcap holes were found to allow the RF field to penetrate out of the ion trap and affect ions as they approached the ion trap. From these simulations, a model for the process by which injected ions are trapped was developed. Using these computer simulations, techniques of improving trapping efficiency were investigated. Most previous techniques perturb ions which are already in the ion trap and therefore cannot be used to accumulate ions; the ability to accumulate ions is a necessity with ionization sources such as electrospray which form ions continuously. One such novel technique for improving trapping efficiency

  17. Differentially pumped dual linear quadrupole ion trap mass spectrometer

    SciTech Connect

    Owen, Benjamin C.; Kenttamaa, Hilkka I.

    2015-10-20

    The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

  18. Laser desorption in an ion trap mass spectrometer

    SciTech Connect

    Eiden, G.C.; Cisper, M.E.; Alexander, M.L.; Hemberger, P.H.; Nogar, N.S.

    1993-02-01

    Laser desorption in a ion-trap mass spectrometer shows significant promise for both qualitative and trace analysis. Several aspects of this methodology are discussed in this work. We previously demonstrated the generation of both negative and positive ions by laser desorption directly within a quadrupole ion trap. In the present work, we explore various combinations of d.c., r.f., and time-varying fields in order to optimize laser generated signals. In addition, we report on the application of this method to analyze samples containing compounds such as amines, metal complexes, carbon clusters, and polynuclear aromatic hydrocarbons. In some cases the ability to rapidly switch between positive and negative ion modes provides sufficient specificity to distinguish different compounds of a mixture with a single stage of mass spectrometry. In other experiments, we combined intensity variation studies with tandem mass spectrometry experiments and positive and negative ion detection to further enhance specificity.

  19. Collisional activation with random noise in ion trap mass spectrometry

    SciTech Connect

    McLuckey, S.A.; Goeringer, D.E.; Glish, G.L.

    1992-07-01

    Random noise applied to the end caps of a quadrupole ion trap is shown to be an effective means for the collisional activation of trapped ions independent of mass/charge ratio and number of ions. This technique is compared and contrasted with conventional single-frequency collisional activation for the molecular ion of N,N-dimethylaniline, protonated cocaine, the molecular anion of 2,4,6-trinitrotoluene, and doubly protonated neuromedin U-8. Collisional activation with noise tends to produce more extensive fragmentation than the conventional approach due to the fact that product ions are also kinetically excited in the noise experiment. The efficiency of the noise experiment in producing detectable product ions relative to the conventional approach ranges from being equivalent to being a factor of 3 less efficient. Furthermore, discrimination against low mass/charge product ions is apparent in the data from multiply charged biomolecules. Nevertheless, collisional activation with random noise provides a very simple means for overcoming problems associated with the dependence of single-frequency collisional activation on mass/charge ratio and the number of ions in the ion trap. 45 refs., 7 figs.

  20. "Fast Excitation" CID in Quadrupole Ion Trap Mass Spectrometer

    SciTech Connect

    Murrell, J.; Despeyroux, D.; Lammert, Stephen {Steve} A; Stephenson Jr, James {Jim} L; Goeringer, Doug

    2003-01-01

    Collision-induced dissociation (CID) in a quadrupole ion trap mass spectrometer is usually performed by applying a small amplitude excitation voltage at the same secular frequency as the ion of interest. Here we disclose studies examining the use of large amplitude voltage excitations (applied for short periods of time) to cause fragmentation of the ions of interest. This process has been examined using leucine enkephalin as the model compound and the motion of the ions within the ion trap simulated using ITSIM. The resulting fragmentation information obtained is identical with that observed by conventional resonance excitation CID. ''Fast excitation'' CID deposits (as determined by the intensity ratio of the a{sub 4}/b{sub 4} ion of leucine enkephalin) approximately the same amount of internal energy into an ion as conventional resonance excitation CID where the excitation signal is applied for much longer periods of time. The major difference between the two excitation techniques is the higher rate of excitation (gain in kinetic energy) between successive collisions with helium atoms with ''fast excitation'' CID as opposed to the conventional resonance excitation CID. With conventional resonance excitation CID ions fragment while the excitation voltage is still being applied whereas for ''fast excitation'' CID a higher proportion of the ions fragment in the ion cooling time following the excitation pulse. The fragmentation of the (M + 17H){sup 17+} of horse heart myoglobin is also shown to illustrate the application of ''fast excitation'' CID to proteins.

  1. Coulomb crystal mass spectrometry in a digital ion trap

    NASA Astrophysics Data System (ADS)

    Deb, Nabanita; Pollum, Laura L.; Smith, Alexander D.; Keller, Matthias; Rennick, Christopher J.; Heazlewood, Brianna R.; Softley, Timothy P.

    2015-03-01

    We present a mass spectrometric technique for identifying the masses and relative abundances of Coulomb-crystallized ions held in a linear Paul trap. A digital radio-frequency wave form is employed to generate the trapping potential, as this can be cleanly switched off, and static dipolar fields are subsequently applied to the trap electrodes for ion ejection. Close to 100% detection efficiency is demonstrated for Ca+ and CaF+ ions from bicomponent Ca+-CaF+ Coulomb crystals prepared by the reaction of Ca+ with CH3F . A quantitative linear relationship is observed between ion number and the corresponding integrated time-of-flight (TOF) peak, independent of the ionic species. The technique is applicable to a diverse range of multicomponent Coulomb crystals—demonstrated here for Ca+-NH 3+ -NH 4+ and Ca+-CaOH +-CaOD + crystals—and will facilitate the measurement of ion-molecule reaction rates and branching ratios in complicated reaction systems.

  2. Laser desorption lamp ionization source for ion trap mass spectrometry.

    PubMed

    Wu, Qinghao; Zare, Richard N

    2015-01-01

    A two-step laser desorption lamp ionization source coupled to an ion trap mass spectrometer (LDLI-ITMS) has been constructed and characterized. The pulsed infrared (IR) output of an Nd:YAG laser (1064 nm) is directed to a target inside a chamber evacuated to ~15 Pa causing desorption of molecules from the target's surface. The desorbed molecules are ionized by a vacuum ultraviolet (VUV) lamp (filled with xenon, major wavelength at 148 nm). The resulting ions are stored and detected in a three-dimensional quadrupole ion trap modified from a Finnigan Mat LCQ mass spectrometer operated at a pressure of ≥ 0.004 Pa. The limit of detection for desorbed coronene molecules is 1.5 pmol, which is about two orders of magnitude more sensitive than laser desorption laser ionization mass spectrometry using a fluorine excimer laser (157 nm) as the ionization source. The mass spectrum of four standard aromatic compounds (pyrene, coronene, rubrene and 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (OPC)) shows that parent ions dominate. By increasing the infrared laser power, this instrument is capable of detecting inorganic compounds. PMID:25601688

  3. Development of a quadrupole ion trap mass spectrometer

    NASA Astrophysics Data System (ADS)

    Hebert, Joseph Ellis

    Because of its potential to be made portable the quadrupole ion trap (QPIT) is a prime candidate for specialized applications such as atmospheric studies, other field measurements, or measurements anywhere a laboratory instrument would be prohibitively inconvenient. To utilize the QPIT in such ways it is necessary to design and construct custom built instruments. A QPIT mass spectrometer was constructed as the foundation for such future development. Two ionization schemes were employed. Direct electron bombardment was used for in situ ion production, and UV photoionization was used to produce ions external to the trap. Calibration measurements determined that the system performed as theory dictated. It was also demonstrated that the system was capable of sampling the atmosphere and detecting the presence of an atmospheric contaminant. Finally, DC bias foils were invented as a novel approach to mass isolation in the trap. The use of DC bias foils was demonstrated to be an exceptionally easy and inexpensive method of controlling the contents of the QPIT.

  4. Laser-based studies with an ion-trap mass spectrometer: Ion tomography and analytical applications

    NASA Astrophysics Data System (ADS)

    Alexander, M. L.; Cisper, M. E.; Hemberger, P. H.; Nogar, N. S.; Williams, J. D.; Syka, J. E. P.

    The iron trap mass spectrometer (ITMS) is an ion storage device which consists of two hyperbolic endcaps and a hyperbolic ring electrode. This forms a trapping cavity having a volume of several cm(sup 3). An RF potential applied to the ring electrode produces a time-varying potential which can be used to trap and/or manipulate ions under controlled conditions. This device has been used in ion trapping studies for a number of years. More recently, a commercial version has been produced and sold which allows for mass-selective ejection of trapped ions, with subsequent detection by an electron multiplier. In this mode, it operates as a compact, high efficiency, high resolution mass spectrometer. The instrument has found applications in GC/MS, in tandem mass spectroscopy and in portable mass spectral analysis. In this manuscript, we present a survey of recent results incorporating laser desorption, ionization, or photodissociation with ITMS. In one instance, we describe the use of laser photodissociation to map the spatial distribution of trapped ions in the ITMS. In this tomographic study, we have parameterized the effects of trapping potential, buffer gas pressure, supplementary RF-potential, and laser intensity. In separate studies, laser desorption was used to generate gas phase ions in the ITMS from a solid probe, by irradiation of both neat and matrix-dissolved samples. The latter experiment produced both high molecular weight ions and significant numbers of negative ions.

  5. Frequency-scanning MALDI linear ion trap mass spectrometer for large biomolecular ion detection.

    PubMed

    Lu, I-Chung; Lin, Jung Lee; Lai, Szu-Hsueh; Chen, Chung-Hsuan

    2011-11-01

    This study presents the first report on the development of a matrix-assisted laser desorption ionization (MALDI) linear ion trap mass spectrometer for large biomolecular ion detection by frequency scan. We designed, installed, and tested this radio frequency (RF) scan linear ion trap mass spectrometer and its associated electronics to dramatically extend the mass region to be detected. The RF circuit can be adjusted from 300 to 10 kHz with a set of operation amplifiers. To trap the ions produced by MALDI, a high pressure of helium buffer gas was employed to quench extra kinetic energy of the heavy ions produced by MALDI. The successful detection of the singly charged secretory immunoglobulin A ions indicates that the detectable mass-to-charge ratio (m/z) of this system can reach ~385 000 or beyond. PMID:21932813

  6. Characterization of protonated phospholipids as fragile ions in quadrupole ion trap mass spectrometry

    PubMed Central

    Garrett, Timothy J.; Merves, Matthew; Yost, Richard A.

    2011-01-01

    Some ions exhibit “ion fragility” in quadrupole ion trap mass spectrometry (QIT-MS) during mass analysis with resonance ejection. In many cases, different ions generated from the same compound exhibit different degrees of ion fragility, with some ions (e.g., the [M+H]+ ion) stable and other ions (e.g., the [M+Na]+ ion) fragile. The ion fragility for quadrupole ion trap (QIT) mass spectrometry (MS) for protonated and sodiated ions of three phospholipids, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, PC (16:0/16:0), 1,2-dipalmitoyl-sn-glycero-3-phophoethanolamine, PE (16:0/16:0), and N-palmitoyl-D-erythro-sphingosylphosphorylcholine, SM (d18:1/16:0), was determined using three previously developed experiments: 1) the peak width using a slow scan speed, 2) the width of the isolation window for efficient isolation, and 3) the energy required for collision-induced dissociation. In addition, ion fragility studies were designed and performed to explore a correlation between ion fragility in QIT mass analysis and ion fragility during transport between the ion source and the ion trap. These experiments were: 1) evaluating the amount of thermal-induced dissociation as a function of heated capillary temperature, and 2) determining the extent of fragmentation occurring with increasing tube lens voltage. All phospholipid species studied exhibited greater ion fragility as protonated species in ion trap mass analysis than as sodiated species. In addition, the protonated species of both SM (d18:0/16:0) and PC (16:0/16:0) exhibited greater tendencies to fragment at higher heated capillary temperatures and high tube lens voltages, whereas the PE (16:0/16:0) ions did not appear to exhibit fragility during ion transport. PMID:22247650

  7. Ion Sponge: A 3-Dimentional Array of Quadrupole Ion Traps for Trapping and Mass-Selectively Processing Ions in Gas Phase

    PubMed Central

    2015-01-01

    In this study, the concept of ion sponge has been explored for developing 3D arrays of large numbers of ion traps but with simple configurations. An ion sponge device with 484 trapping units in a volume of 10 × 10 × 3.2 cm has been constructed by simply stacking 9 meshes together. A single rf was used for trapping ions and mass-selective ion processing. The ion sponge provides a large trapping capacity and is highly transparent for transfer of ions, neutrals, and photons for gas phase ion processing. Multiple layers of quadrupole ion traps, with 121 trapping units in each layer, can operate as a single device for MS or MS/MS analysis, or as a series of mass-selective trapping devices with interlayer ion transfers facilitated by AC and DC voltages. Automatic sorting of ions to different trapping layers based on their mass-to-charge (m/z) ratios was achieved with traps of different sizes. Tandem-in-space MS/MS has also been demonstrated with precursor ions and fragment ions trapped in separate locations. PMID:24758328

  8. Monitoring Trace Contaminants in Air Via Ion Trap Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Palmer, Peter T.; Karr, Dane; Pearson, Richard; Valero, Gustavo; Wong, Carla

    1995-01-01

    Recent passage of the Clean Air Act with its stricter regulation of toxic gas emissions, and the ever-growing number of applications which require faster turnaround times between sampling and analysis are two major factors which are helping to drive the development of new instrument technologies for in-situ, on-line, real-time monitoring. The ion trap, with its small size, excellent sensitivity, and tandem mass spectrometry capability is a rapidly evolving technology which is well-suited for these applications. In this paper, we describe the use of a commercial ion trap instrument for monitoring trace levels of chlorofluorocarbons (CFCs) and volatile organic compounds (VOCs) in air. A number of sample introduction devices including a direct transfer line interface, short column GC, and a cryotrapping interface are employed to achieve increasing levels of sensitivity. MS, MS/MS, and MS/MS/MS methods are compared to illustrate trade-offs between sensitivity and selectivity. Filtered Noise Field (FNF) technology is found to be an excellent means for achieving lower detection limits through selective storage of the ion(s) of interest during ionization. Figures of merit including typical sample sizes, detection limits, and response times are provided. The results indicate the potential of these techniques for atmospheric assessments, the High Speed Research Program, and advanced life support monitoring applications for NASA.

  9. Fluorescence imaging for visualization of the ion cloud in a quadrupole ion trap mass spectrometer.

    PubMed

    Talbot, Francis O; Sciuto, Stephen V; Jockusch, Rebecca A

    2013-12-01

    Laser-induced fluorescence is used to visualize populations of gaseous ions stored in a quadrupole ion trap (QIT) mass spectrometer. Presented images include the first fluorescence image of molecular ions collected under conditions typically used in mass spectrometry experiments. Under these "normal" mass spectrometry conditions, the radial (r) and axial (z) full-width at half maxima (FWHM) of the detected ion cloud are 615 and 214 μm, respectively, corresponding to ~6% of r0 and ~3% of z0 for the QIT used. The effects on the shape and size of the ion cloud caused by varying the pressure of helium bath gas, the number of trapped ions, and the Mathieu parameter q z are visualized and discussed. When a "tickle voltage" is applied to the exit end-cap electrode, as is done in collisionally activated dissociation, a significant elongation in the axial, but not the radial, dimension of the ion cloud is apparent. Finally, using spectroscopically distinguishable fluorophores of two different m/z values, images are presented that illustrate stratification of the ion cloud; ions of lower m/z (higher qz) are located in the center of the trapping region, effectively excluding higher m/z (lower qz) ions, which form a surrounding layer. Fluorescence images such as those presented here provide a useful reference for better understanding the collective behavior of ions in radio frequency (rf) trapping devices and how phenomena such as collisions and space-charge affect ion distribution. PMID:24092629

  10. Fluorescence Imaging for Visualization of the Ion Cloud in a Quadrupole Ion Trap Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Talbot, Francis O.; Sciuto, Stephen V.; Jockusch, Rebecca A.

    2013-12-01

    Laser-induced fluorescence is used to visualize populations of gaseous ions stored in a quadrupole ion trap (QIT) mass spectrometer. Presented images include the first fluorescence image of molecular ions collected under conditions typically used in mass spectrometry experiments. Under these "normal" mass spectrometry conditions, the radial ( r) and axial ( z) full-width at half maxima (FWHM) of the detected ion cloud are 615 and 214 μm, respectively, corresponding to ~6 % of r 0 and ~3 % of z 0 for the QIT used. The effects on the shape and size of the ion cloud caused by varying the pressure of helium bath gas, the number of trapped ions, and the Mathieu parameter q z are visualized and discussed. When a "tickle voltage" is applied to the exit end-cap electrode, as is done in collisionally activated dissociation, a significant elongation in the axial, but not the radial, dimension of the ion cloud is apparent. Finally, using spectroscopically distinguishable fluorophores of two different m/ z values, images are presented that illustrate stratification of the ion cloud; ions of lower m/ z (higher q z ) are located in the center of the trapping region, effectively excluding higher m/ z (lower q z ) ions, which form a surrounding layer. Fluorescence images such as those presented here provide a useful reference for better understanding the collective behavior of ions in radio frequency (rf) trapping devices and how phenomena such as collisions and space-charge affect ion distribution.

  11. Multiple mass analysis using an ion trap array (ITA) mass analyzer.

    PubMed

    Yu, Xiao; Chu, Yanqiu; Ling, Xing; Ding, Zhengzhi; Xu, Chongsheng; Ding, Li; Ding, Chuan-Fan

    2013-09-01

    A novel ion trap array (ITA) mass analyzer with six ion trapping and analyzing channels was investigated. It is capable of analyzing multiple samples simultaneously. The ITA was built with several planar electrodes made of stainless steel and 12 identical parallel zirconia ceramic substrates plated with conductive metal layers. Each two of the opposing ceramic electrode plates formed a boundary of an ion trap channel and six identical ion trapping and analyzing channels were placed in parallel without physical electrode between any two adjacent channels. The electric field distribution inside each channel was studied with simulation. The new design took the advantage of high precision machining attributable to the rigidity of ceramic, and the convenience of surface patterning technique. The ITA system was tested by using a two-channel electrospray ionization source, a multichannel simultaneous quadruple ion guide, and two detectors. The simultaneous analysis of two different samples with two adjacent ITA channels was achieved and independent mass spectra were obtained. For each channel, the mass resolution was tested. Additional ion trap functions such as mass-selected ion isolation and collision-induced dissociation (CID) were also tested. The results show that one ITA is well suited for multiple simultaneous mass analyses. PMID:23797864

  12. Multiple Mass Analysis Using an Ion Trap Array (ITA) Mass Analyzer

    NASA Astrophysics Data System (ADS)

    Xiao, Yu; Chu, Yanqiu; Ling, Xing; Ding, Zhengzhi; Xu, Chongsheng; Ding, Li; Ding, Chuan-Fan

    2013-09-01

    A novel ion trap array (ITA) mass analyzer with six ion trapping and analyzing channels was investigated. It is capable of analyzing multiple samples simultaneously. The ITA was built with several planar electrodes made of stainless steel and 12 identical parallel zirconia ceramic substrates plated with conductive metal layers. Each two of the opposing ceramic electrode plates formed a boundary of an ion trap channel and six identical ion trapping and analyzing channels were placed in parallel without physical electrode between any two adjacent channels. The electric field distribution inside each channel was studied with simulation. The new design took the advantage of high precision machining attributable to the rigidity of ceramic, and the convenience of surface patterning technique. The ITA system was tested by using a two-channel electrospray ionization source, a multichannel simultaneous quadruple ion guide, and two detectors. The simultaneous analysis of two different samples with two adjacent ITA channels was achieved and independent mass spectra were obtained. For each channel, the mass resolution was tested. Additional ion trap functions such as mass-selected ion isolation and collision-induced dissociation (CID) were also tested. The results show that one ITA is well suited for multiple simultaneous mass analyses.

  13. Why is sideband mass spectrometry possible with ions in a Penning trap?

    PubMed

    Gabrielse, G

    2009-05-01

    Many masses, particularly the masses of unstable nuclei, are measured with ions in Penning traps by determining the frequency of a driving force that most efficiently couples two of the three motions of trapped ions. A missing explanation of why such sideband mass spectroscopy works, contrary to simple estimates, begins with the established Brown-Gabrielse invariance theorem. PMID:19518777

  14. Why Is Sideband Mass Spectrometry Possible with Ions in a Penning Trap?

    SciTech Connect

    Gabrielse, G.

    2009-05-01

    Many masses, particularly the masses of unstable nuclei, are measured with ions in Penning traps by determining the frequency of a driving force that most efficiently couples two of the three motions of trapped ions. A missing explanation of why such sideband mass spectroscopy works, contrary to simple estimates, begins with the established Brown-Gabrielse invariance theorem.

  15. Ion trap mass spectrometric detection of laser desorbed ions from derivatized fused silica fibers

    SciTech Connect

    Garrett, A.W.; Earl, W.L.; Cisper, M.E.; Nogar, N.S.; Hemberger, P.H.

    1994-12-31

    Solid-phase microextraction of analytes from complex matrices using fused silica fibers has many advantages over traditional chemical sample preparation technique. Microextraction requires small sample sizes little sample preparation (providing rapid sample turnaround time), and greatly reduces the amount of chemical waste generated in sample preparation. These advantages make fused silica fibers attractive for direct sampling and detection experiments using laser desorption ion trap mass spectrometry (LITMS). The drawback is the very small area ({approximately}1 mm{sup 2}) exposed to laser irradiation, which limits the amount of material desorbed into the ion trap.

  16. Development and Evaluation of a Variable-Temperature Quadrupole Ion Trap Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Derkits, David; Wiseman, Alex; Snead, Russell F.; Dows, Martina; Harge, Jasmine; Lamp, Jared A.; Gronert, Scott

    2016-02-01

    A new, variable-temperature mass spectrometer system is described. By applying polyimide heating tape to the end-cap electrodes of a Bruker (Bremen, Germany) Esquire ion trap, it is possible to vary the effective temperature of the system between 40 and 100°C. The modification does not impact the operation of the ion trap and the heater can be used for extended periods without degradation of the system. The accuracy of the ion trap temperatures was assessed by examining two gas-phase equilibrium processes with known thermochemistry. In each case, the variable-temperature ion trap provided data that were in good accord with literature data, indicating the effective temperature in the ion trap environment was being successfully modulated by the changes in the set-point temperatures on the end-cap electrodes. The new design offers a convenient and effective way to convert commercial ion trap mass spectrometers into variable-temperature instruments.

  17. Development and Evaluation of a Variable-Temperature Quadrupole Ion Trap Mass Spectrometer.

    PubMed

    Derkits, David; Wiseman, Alex; Snead, Russell F; Dows, Martina; Harge, Jasmine; Lamp, Jared A; Gronert, Scott

    2016-02-01

    A new, variable-temperature mass spectrometer system is described. By applying polyimide heating tape to the end-cap electrodes of a Bruker (Bremen, Germany) Esquire ion trap, it is possible to vary the effective temperature of the system between 40 and 100°C. The modification does not impact the operation of the ion trap and the heater can be used for extended periods without degradation of the system. The accuracy of the ion trap temperatures was assessed by examining two gas-phase equilibrium processes with known thermochemistry. In each case, the variable-temperature ion trap provided data that were in good accord with literature data, indicating the effective temperature in the ion trap environment was being successfully modulated by the changes in the set-point temperatures on the end-cap electrodes. The new design offers a convenient and effective way to convert commercial ion trap mass spectrometers into variable-temperature instruments. PMID:26483183

  18. Augmenting Ion Trap Mass Spectrometers Using a Frequency Modulated Drift Tube Ion Mobility Spectrometer.

    PubMed

    Morrison, Kelsey A; Siems, William F; Clowers, Brian H

    2016-03-15

    Historically, high pressure ion mobility drift tubes have suffered from low ion duty cycles and this problem is magnified when such instrumentation is coupled with ion trap mass spectrometers. To significantly alleviate these issues, we outline the result from coupling an atmospheric pressure, dual-gate drift tube ion mobility spectrometer (IMS) to a linear ion trap mass spectrometer (LIT-MS) via modulation of the ion beam with a linear frequency chirp. The time-domain ion current, once Fourier transformed, reveals a standard ion mobility drift spectrum that corresponds to the standard mode of mobility analysis. By multiplexing the ion beam, it is possible to successfully obtain drift time spectra for an assortment of simple peptide and protein mixtures using an LIT-MS while showing improved signal intensity versus the more common signal averaging technique. Explored here are the effects of maximum injection time, solution concentration, total experiment time, and frequency swept on signal-to-noise ratios (SNRs) and resolving power. Increased inject time, concentration, and experiment time all generally led to an improvement in SNR, while a greater frequency swept increases the resolving power at the expense of SNR. Overall, chirp multiplexing of a dual-gate IMS system coupled to an LIT-MS improves ion transmission, lowers analyte detection limits, and improves spectral quality. PMID:26854901

  19. Electron Flood Charge Compensation Device for Ion Trap Secondary Ion Mass Spectrometry

    SciTech Connect

    Appelhans, Anthony David; Ward, Michael Blair; Olson, John Eric

    2002-11-01

    During secondary ion mass spectrometry (SIMS) analyses of organophosphorous compounds adsorbed onto soils, the measured anion signals were lower than expected and it was hypothesized that the low signals could be due to sample charging. An electron flood gun was designed, constructed and used to investigate sample charging of these and other sample types. The flood gun was integrated into one end cap of an ion trap secondary ion mass spectrometer and the design maintained the geometry of the self-stabilizing extraction optics used in this instrument. The SIMION ion optics program was used to design the flood gun, and experimental results agreed with the predicted performance. Results showed the low anion signals from the soils were not due to sample charging. Other insulating and conducting samples were tested using both a ReO4- and a Cs+ primary ion beam. The proximity of the sample and electron source to the ion trap aperture resulted in generation of background ions in the ion trap via electron impact (EI) ionization during the period the electron gun was flooding the sample region. When using the electron gun with the ReO4- primary beam, the required electron current was low enough that the EI background was negligible; however, the high electron flood current required with the Cs+ beam produced background EI ions that degraded the quality of the mass spectra. The consequences of the EI produced cations will have to be evaluated on a sample-by-sample basis when using electron flood. It was shown that the electron flood gun could be intentionally operated to produce EI spectra in this instrument. This offers the opportunity to measure, nearly simultaneously, species evaporating from a sample, via EI, and species bound to the surface, via SIMS.

  20. A quadrupole ion trap with cylindrical geometry operated in the mass-selective instability mode.

    PubMed

    Wells, J M; Badman, E R; Cooks, R G

    1998-02-01

    A cylindrical geometry ion trap is used to record mass spectra in the mass-selective instability mode. The geometry of the cylindrical ion trap has been optimized to maximize the quadrupole field component relative to the higher-order field content through field calculations using the Poisson/Superfish code and through experimental variation of the electrode structure. The results correspond well with predictions of the calculations. The trap has been used to record mass spectra with better than unit mass resolution, high sensitivity, and a mass/charge range of ∼600 Th. Multistage (MS(3)) experiments have been performed, and the Mathieu stability region has been experimentally mapped. The performance of this device compares satisfactorily with that of the hyperbolic ion trap. PMID:21644742

  1. Microfabricated ion trap array

    DOEpatents

    Blain, Matthew G.; Fleming, James G.

    2006-12-26

    A microfabricated ion trap array, comprising a plurality of ion traps having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale ion traps to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The reduced electrode voltage enables integration of the microfabricated ion trap array with on-chip circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of the microfabricated ion trap array can be realized in truly field portable, handheld microanalysis systems.

  2. Advances in ion trap mass spectrometry: Photodissociation as a tool for structural elucidation

    SciTech Connect

    Stephenson, J.L. Jr.; Booth, M.M.; Eyler, J.R.; Yost, R.A.

    1995-12-01

    Photo-induced dissociation (PID) is the next most frequently used method (after collisional activation) for activation of Polyatomic ions in tandem mass spectrometry. The range of internal energies present after the photon absorption process are much narrower than those obtained with collisional energy transfer. Therefore, the usefulness of PID for the study of ion structures is greatly enhanced. The long storage times and instrumental configuration of the ion trap mass spectrometer are ideally suited for photodissociation experiments. This presentation will focus on both the fundamental and analytical applications of CO{sub 2} lasers in conjunction with ion trap mass spectrometry. The first portion of this talk will examine the fundamental issues of wavelength dependence, chemical kinetics, photoabsorption cross section, and collisional effects on photodissociation efficiency. The second half of this presentation will look at novel instrumentation for electrospray/ion trap mass spectrometry, with the concurrent development of photodissociation as a tool for structural elucidation of organic compounds and antibiotics.

  3. EBIT in the Magnetic Trapping Mode: Mass Spectrometry, Atomic Lifetime Measurements, and Charge Transfer Reactions of Highly Charged Atomic Ions

    SciTech Connect

    Schweikhard, L; Beiersdorfer, P; Trabert, E

    2001-07-10

    Although it may sound like a contradiction in terms, the electron beam ion trap (EBIT) works as an ion trap even when the electron beam is switched off. We present various experiments that exploit the ''magnetic trapping mode'' for investigations of ion confinement, charge exchange processes, atomic lifetime and ion mass measurements.

  4. Secondary Ion Mass Spectrometry of Zeolite Materials: Observation of Abundant Aluminosilicate Oligomers Using an Ion Trap

    SciTech Connect

    Groenewold, Gary Steven; Kessinger, Glen Frank; Scott, Jill Rennee; Gianotto, Anita Kay; Appelhans, Anthony David; Delmore, James Edward

    2000-12-01

    Oligomeric oxyanions were observed in the secondary ion mass spectra (SIMS) of zeolite materials. The oxyanions have the general composition AlmSinO2(m+n)H(m-1)- (m + n = 2 to 8) and are termed dehydrates. For a given mass, multiple elemental compositions are possible because (Al + H) is an isovalent and isobaric substitute for Si. Using 18 keV Ga+ as a projectile, oligomer abundances are low relative to the monomers. Oligomer abundance can be increased by using the polyatomic projectile ReO4- (~5 keV). Oligomer abundance can be further increased using an ion trap (IT-) SIMS; in this instrument, long ion lifetimes (tens of ms) and relatively high He pressure result in significant collisional stabilization and increased high-mass abundance. The dehydrates rapidly react with adventitious H2O present in the IT-SIMS to form mono-, di-, and trihydrates. The rapidity of the reaction and comparison to aluminum oxyanion hydration suggest that H2O adds to the aluminosilicate oxyanions in a dissociative fashion, forming covalently bound product ions. In addition to these findings, it was noted that production of abundant oligomeric aluminosilicates could be significantly increased by substituting the countercation (NH4+) with the larger alkali ions Rb+ and Cs+. This constitutes a useful tactic for generating large aluminosilicate oligomers for surface characterization and ion-molecule reactivity studies.

  5. Design of a Laser Ablation Ion Source for High-Precision Penning Trap Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Hunt, Curtis; Ratnayake, Ishara; Hawks, Paul; Bryce, Richard; Redshaw, Matthew

    2014-05-01

    High-precision atomic mass measurements provide important data for a wide range of fields including atomic, nuclear and neutrino physics, determination of fundamental constants, and metrology. At Central Michigan University we are building a Penning trap system that will utilize ions produced by external ion sources to allow access to a wide range of isotopes, including long-lived radioactive isotopes and isotopes with low natural abundances. The ions will be transported to a ``capture'' trap, before being transferred to double precision-measurement trap structure. In this poster we will present the design of a laser ablation ion source and the ion extraction and transport optics. We will report on the current status of the construction and operation of the ion source and the CMU Penning trap. This work supported in part by NSF award no. 1307233.

  6. Novel sampling methods for use with thermal desorption ion trap mass spectrometry

    SciTech Connect

    Barshick, S.A.; Buchanan, M.V.

    1994-12-31

    Novel sampling approaches have been investigated to improve the analytical utility of thermal desorption Direct Sampling Ion Trap Mass Spectrometry (DSITMS). Because DSITMS involves the direct introduction of samples into an ion trap mass spectrometer, problems with detection capabilities (sensitivity and selectivity) can often occur when performing trace analysis in complex matrices. Various sampling approaches have been evaluated to improve thermal desorption detection capabilities and to extend the utilities of DSITMS methodologies without significantly increasing analysis times or the cost-effectiveness of DSITMS methods. Three sampling approaches have been investigated including solid phase microextraction (SPME), solid phase extraction columns (SPEC), and purge and trap.

  7. Experimental Characterization of Secular Frequency Scanning in Ion Trap Mass Spectrometers

    NASA Astrophysics Data System (ADS)

    Snyder, Dalton T.; Pulliam, Christopher J.; Wiley, Joshua S.; Duncan, Jason; Cooks, R. Graham

    2016-03-01

    Secular frequency scanning is implemented and characterized using both a benchtop linear ion trap and a miniature rectilinear ion trap mass spectrometer. Separation of tetraalkylammonium ions and those from a mass calibration mixture and from a pesticide mixture is demonstrated with peak widths approaching unit resolution for optimized conditions using the benchtop ion trap. The effects on the spectra of ion trap operating parameters, including waveform amplitude, scan direction, scan rate, and pressure are explored, and peaks at black holes corresponding to nonlinear (higher-order field) resonance points are investigated. Reverse frequency sweeps (increasing mass) on the Mini 12 are shown to result in significantly higher ion ejection efficiency and superior resolution than forward frequency sweeps that decrement mass. This result is accounted for by the asymmetry in ion energy absorption profiles as a function of AC frequency and the shift in ion secular frequency at higher amplitudes in the trap due to higher order fields. We also found that use of higher AC amplitudes in forward frequency sweeps biases ions toward ejection at points of higher order parametric resonance, despite using only dipolar excitation. Higher AC amplitudes also increase peak width and decrease sensitivity in both forward and reverse frequency sweeps. Higher sensitivity and resolution were obtained at higher trap pressures in the secular frequency scan, in contrast to conventional resonance ejection scans, which showed the opposite trend in resolution on the Mini 12. Mass range is shown to be naturally extended in secular frequency scanning when ejecting ions by sweeping the AC waveform through low frequencies, a method which is similar, but arguably superior, to the more usual method of mass range extension using low q resonance ejection.

  8. Experimental Characterization of Secular Frequency Scanning in Ion Trap Mass Spectrometers

    NASA Astrophysics Data System (ADS)

    Snyder, Dalton T.; Pulliam, Christopher J.; Wiley, Joshua S.; Duncan, Jason; Cooks, R. Graham

    2016-07-01

    Secular frequency scanning is implemented and characterized using both a benchtop linear ion trap and a miniature rectilinear ion trap mass spectrometer. Separation of tetraalkylammonium ions and those from a mass calibration mixture and from a pesticide mixture is demonstrated with peak widths approaching unit resolution for optimized conditions using the benchtop ion trap. The effects on the spectra of ion trap operating parameters, including waveform amplitude, scan direction, scan rate, and pressure are explored, and peaks at black holes corresponding to nonlinear (higher-order field) resonance points are investigated. Reverse frequency sweeps (increasing mass) on the Mini 12 are shown to result in significantly higher ion ejection efficiency and superior resolution than forward frequency sweeps that decrement mass. This result is accounted for by the asymmetry in ion energy absorption profiles as a function of AC frequency and the shift in ion secular frequency at higher amplitudes in the trap due to higher order fields. We also found that use of higher AC amplitudes in forward frequency sweeps biases ions toward ejection at points of higher order parametric resonance, despite using only dipolar excitation. Higher AC amplitudes also increase peak width and decrease sensitivity in both forward and reverse frequency sweeps. Higher sensitivity and resolution were obtained at higher trap pressures in the secular frequency scan, in contrast to conventional resonance ejection scans, which showed the opposite trend in resolution on the Mini 12. Mass range is shown to be naturally extended in secular frequency scanning when ejecting ions by sweeping the AC waveform through low frequencies, a method which is similar, but arguably superior, to the more usual method of mass range extension using low q resonance ejection.

  9. Experimental Characterization of Secular Frequency Scanning in Ion Trap Mass Spectrometers.

    PubMed

    Snyder, Dalton T; Pulliam, Christopher J; Wiley, Joshua S; Duncan, Jason; Cooks, R Graham

    2016-07-01

    Secular frequency scanning is implemented and characterized using both a benchtop linear ion trap and a miniature rectilinear ion trap mass spectrometer. Separation of tetraalkylammonium ions and those from a mass calibration mixture and from a pesticide mixture is demonstrated with peak widths approaching unit resolution for optimized conditions using the benchtop ion trap. The effects on the spectra of ion trap operating parameters, including waveform amplitude, scan direction, scan rate, and pressure are explored, and peaks at black holes corresponding to nonlinear (higher-order field) resonance points are investigated. Reverse frequency sweeps (increasing mass) on the Mini 12 are shown to result in significantly higher ion ejection efficiency and superior resolution than forward frequency sweeps that decrement mass. This result is accounted for by the asymmetry in ion energy absorption profiles as a function of AC frequency and the shift in ion secular frequency at higher amplitudes in the trap due to higher order fields. We also found that use of higher AC amplitudes in forward frequency sweeps biases ions toward ejection at points of higher order parametric resonance, despite using only dipolar excitation. Higher AC amplitudes also increase peak width and decrease sensitivity in both forward and reverse frequency sweeps. Higher sensitivity and resolution were obtained at higher trap pressures in the secular frequency scan, in contrast to conventional resonance ejection scans, which showed the opposite trend in resolution on the Mini 12. Mass range is shown to be naturally extended in secular frequency scanning when ejecting ions by sweeping the AC waveform through low frequencies, a method which is similar, but arguably superior, to the more usual method of mass range extension using low q resonance ejection. Graphical Abstract ᅟ. PMID:27032650

  10. Ion/molecule reactions performed in a miniature cylindrical ion trap mass spectrometer.

    PubMed

    Riter, Leah S; Meurer, Eduardo C; Handberg, Eric S; Laughlin, Brian C; Chen, Hao; Patterson, Garth E; Eberlin, Marcos N; Cooks, R Graham

    2003-09-01

    A recently constructed miniature mass spectrometer, based on a cylindrical ion trap (CIT) mass analyzer, is used to perform ion/molecule reactions in order to improve selectivity for in situ analysis of explosives and chemical warfare agent simulants. Six different reactions are explored, including several of the Eberlin reaction type (M. N. Eberlin and R. G. Cooks, Org. Mass Spectrom., 1993, 28, 679-687) as well as novel gas-phase Meerwein reactions. The reactions include (1) Eberlin transacetalization of the benzoyl, 2,2-dimethyloximinium, and 2,2-dimethylthiooximinium cations with 2,2-dimethyl-1,3-dioxolane to form 2-phenyl-1,3-dioxolanylium cations, 2,2-dimethylamine-1,3-dioxolanylium cations and the 2,2-dimethylamin-1,3-oxathiolanylium cations, respectively; (2) Eberlin reaction of the phosphonium ion CH3P(O)OCH3+, formed from the chemical warfare agent simulant dimethyl methylphosphonate (DMMP), with 1,4-dioxane to yield the 1,3,2-dioxaphospholanium ion, a new characteristic reaction for phosphate ester detection; (3) the novel Meerwein reaction of the ion CH3P(O)OCH3+ with propylene sulfide forming 1,3,2-oxathionylphospholanium ion; (4) the Meerwein reaction of the benzoyl cation with propylene oxide and propylene sulfide to form 4-methyl-2-phenyl-1,3-dioxolane and its thio analog, respectively; (5) ketalization of the benzoyl cation with ethylene glycol to form the 2-phenyl-1,3-dioxolanylium cation; (6) addition/NO2 elimination involving benzonitrile radical cation in reaction with nitrobenzene to form an arylated nitrile, a diagnostic reaction for explosives detection and (7) simple methanol addition to the C7H7+ ion, formed by NO2 loss from the molecular ion of p-nitrotoluene to form an intact adduct. Evidence is provided that these reactions occur to give the products described and their potential analytical utility is discussed. PMID:14529016

  11. Electronics of an ion trap with integrated time-of-flight mass spectrometer

    NASA Astrophysics Data System (ADS)

    Schneider, Christian; Schowalter, Steven J.; Yu, Peter; Hudson, Eric R.

    2016-01-01

    Recently, we reported an ion trap experiment with an integrated time-of-flight mass spectrometer (TOFMS) [Phys. Rev. Appl. 2, 034013 (2014)] focussing on the improvement of mass resolution and detection limit due to sample preparation at millikelvin temperatures. The system utilizes a radio-frequency (RF) ion trap with asymmetric drive for storing and manipulating laser-cooled ions and features radial extraction into a compact $275$ mm long TOF drift tube. The mass resolution exceeds $m / \\Delta m = 500$, which provides isotopic resolution over the whole mass range of interest in current experiments and constitutes an improvement of almost an order of magnitude over other implementations. In this manuscript, we discuss the experimental implementation in detail, which is comprised of newly developed drive electronics for generating the required voltages to operate RF trap and TOFMS, as well as control electronics for regulating RF outputs and synchronizing the TOFMS extraction.

  12. Ion Trap with Narrow Aperture Detection Electrodes for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Nagornov, Konstantin O.; Kozhinov, Anton N.; Tsybin, Oleg Y.; Tsybin, Yury O.

    2015-05-01

    The current paradigm in ion trap (cell) design for Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is the ion detection with wide aperture detection electrodes. Specifically, excitation and detection electrodes are typically 90° wide and positioned radially at a similar distance from the ICR cell axis. Here, we demonstrate that ion detection with narrow aperture detection electrodes (NADEL) positioned radially inward of the cell's axis is feasible and advantageous for FT-ICR MS. We describe design details and performance characteristics of a 10 T FT-ICR MS equipped with a NADEL ICR cell having a pair of narrow aperture (flat) detection electrodes and a pair of standard 90° excitation electrodes. Despite a smaller surface area of the detection electrodes, the sensitivity of the NADEL ICR cell is not reduced attributable to improved excite field distribution, reduced capacitance of the detection electrodes, and their closer positioning to the orbits of excited ions. The performance characteristics of the NADEL ICR cell are comparable with the state-of-the-art FT-ICR MS implementations for small molecule, peptide, protein, and petroleomics analyses. In addition, the NADEL ICR cell's design improves the flexibility of ICR cells and facilitates implementation of advanced capabilities (e.g., quadrupolar ion detection for improved mainstream applications). It also creates an intriguing opportunity for addressing the major bottleneck in FTMS—increasing its throughput via simultaneous acquisition of multiple transients or via generation of periodic non-sinusoidal transient signals.

  13. Systematic Comparison of a Two-dimensional Ion Trap and a Three-dimensional Ion Trap Mass Spectrometer in Proteomics*S

    PubMed Central

    Mayya, Viveka; Rezaul, Karim; Cong, Yu-Sheng; Han, David

    2006-01-01

    The utility and advantages of the recently introduced two-dimensional quadrupole ion trap mass spectrometer in proteomics over the traditional three-dimensional ion trap mass spectrometer have not been systematically characterized. Here we rigorously compared the performance of these two platforms by using over 100,000 tandem mass spectra acquired with identical complex peptide mixtures and acquisition parameters. Specifically we compared four factors that are critical for a successful proteomic study: 1) the number of proteins identified, 2) sequence coverage or the number of peptides identified for every protein, 3) the data base matching SEQUEST Xcorr and Sp score, and 4) the quality of the fragment ion series of peptides. We found a 4–6-fold increase in the number of peptides and proteins identified on the two-dimensional ion trap mass spectrometer as a direct result of improvement in all the other parameters examined. Interestingly more than 70% of the doubly and triply charged peptides, but not the singly charged peptides, showed better quality of fragmentation spectra on the two-dimensional ion trap. These results highlight specific advantages of the two-dimensional ion trap over the conventional three-dimensional ion traps for protein identification in proteomic experiments. PMID:15608339

  14. Infrared Multiphoton Dissociation of Peptide Cations in a Dual Pressure Linear Ion Trap Mass Spectrometer

    PubMed Central

    Gardner, Myles W.; Smith, Suncerae I.; Ledvina, Aaron R.; Madsen, James A.; Coon, Joshua J.; Schwartz, Jae C.; Stafford, George C.; Brodbelt, Jennifer S.

    2009-01-01

    A dual pressure linear ion trap mass spectrometer was modified to permit infrared multiphoton dissociation (IRMPD) in each of the two cells - the first a high pressure cell operated at nominally 5 × 10-3 Torr and the second a low pressure cell operated at nominally 3 × 10-4 Torr. When IRMPD was performed in the high pressure cell, most peptide ions did not undergo significant photodissociation; however, in the low pressure cell peptide cations were efficiently dissociated with less than 25 ms of IR irradiation regardless of charge state. IRMPD of peptide cations allowed the detection of low m/z product ions including the y1 fragments and immonium ions which are not typically observed by ion trap collision induced dissociation (CID). Photodissociation efficiencies of ~100% and MS/MS (tandem mass spectrometry) efficiencies of greater than 60% were observed for both multiply and singly protonated peptides. In general, higher sequence coverage of peptides was obtained using IRMPD over CID. Further, greater than 90% of the product ion current in the IRMPD mass spectra of doubly charged peptide ions was composed of singly charged product ions compared to the CID mass spectra in which the abundances of the multiply and singly charged product ions were equally divided. Highly charged primary product ions also underwent efficient photodissociation to yield singly charged secondary product ions, thus simplifying the IRMPD product ion mass spectra. PMID:19739654

  15. ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS BY ION TRAP TANDEM MASS SPECTROMETRY

    EPA Science Inventory

    An ion-trap mass spectrometer with a wave board and tandem mass spectrometry software was used to analyze gas chromatographically separated polycyclic aromatic hydrocarbons (PAHs) by using collision-induced dissociation (CID). The nonresonant (multiple collision) mode was used to...

  16. Final Report - Advanced Ion Trap Mass Spectrometry Program - Oak Ridge National Laboratory - Sandia National Laboratory

    SciTech Connect

    Whitten, W.B.

    2002-12-18

    This report covers the three main projects that collectively comprised the Advanced Ion Trap Mass Spectrometry Program. Chapter 1 describes the direct interrogation of individual particles by laser desorption within the ion trap mass spectrometer analyzer. The goals were (1) to develop an ''intelligent trigger'' capable of distinguishing particles of biological origin from those of nonbiological origin in the background and interferent particles and (2) to explore the capability for individual particle identification. Direct interrogation of particles by laser ablation and ion trap mass spectrometry was shown to have good promise for discriminating between particles of biological origin and those of nonbiological origin, although detailed protocols and operating conditions were not worked out. A library of more than 20,000 spectra of various types of biological particles has been assembled. Methods based on multivariate analysis and on neural networks were used to discriminate between particles of biological origin and those of nonbiological origin. It was possible to discriminate between at least some species of bacteria if mass spectra of several hundred similar particles were obtained. Chapter 2 addresses the development of a new ion trap mass analyzer geometry that offers the potential for a significant increase in ion storage capacity for a given set of analyzer operating conditions. This geometry may lead to the development of smaller, lower-power field-portable ion trap mass spectrometers while retaining laboratory-scale analytical performance. A novel ion trap mass spectrometer based on toroidal ion storage geometry has been developed. The analyzer geometry is based on the edge rotation of a quadrupolar ion trap cross section into the shape of a torus. Initial performance of this device was poor, however, due to the significant contribution of nonlinear fields introduced by the rotation of the symmetric ion-trapping geometry. These nonlinear resonances

  17. Computer Modeling of an Ion Trap Mass Analyzer, Part I: Low Pressure Regime.

    PubMed

    Nikolić, Dragan; Madzunkov, Stojan M; Darrach, Murray R

    2015-12-01

    We present the multi-particle simulation program suite Computational Ion Trap Analyzer (CITA) designed to calculate the ion trajectories within a Paul quadrupole ion trap developed by the Jet Propulsion Laboratory (JPL). CITA uses an analytical expression of the electrodynamic field, employing up to six terms in multipole expansion and a modified velocity-Verlet method to numerically calculate ion trajectories. The computer code is multithreaded and designed to run on shared-memory architectures. CITA yields near real-time simulations with full propagation of 26 particles per second per core. As a consequence, a realistic numbers of trapped ions (100+ million) can be used and their trajectories modeled, yielding a representative prediction of mass spectrometer analysis of trace gas species. When the model is compared with experimental results conducted at low pressures using the conventional quadrupole and dipole excitation modes, there is an excellent agreement with the observed peak shapes. Owing to the program's efficiency, CITA has been used to explore regions of trapping stability that are of interest to experimental research. These results are expected to facilitate a fast and reliable modeling of ion dynamics in miniature quadrupole ion trap and improve the interpretation of observed mass spectra. Graphical Abstract ᅟ. PMID:26286456

  18. Computer Modeling of an Ion Trap Mass Analyzer, Part I: Low Pressure Regime

    NASA Astrophysics Data System (ADS)

    Nikolić, Dragan; Madzunkov, Stojan M.; Darrach, Murray R.

    2015-12-01

    We present the multi-particle simulation program suite Computational Ion Trap Analyzer (CITA) designed to calculate the ion trajectories within a Paul quadrupole ion trap developed by the Jet Propulsion Laboratory (JPL). CITA uses an analytical expression of the electrodynamic field, employing up to six terms in multipole expansion and a modified velocity-Verlet method to numerically calculate ion trajectories. The computer code is multithreaded and designed to run on shared-memory architectures. CITA yields near real-time simulations with full propagation of 26 particles per second per core. As a consequence, a realistic numbers of trapped ions (100+ million) can be used and their trajectories modeled, yielding a representative prediction of mass spectrometer analysis of trace gas species. When the model is compared with experimental results conducted at low pressures using the conventional quadrupole and dipole excitation modes, there is an excellent agreement with the observed peak shapes. Owing to the program's efficiency, CITA has been used to explore regions of trapping stability that are of interest to experimental research. These results are expected to facilitate a fast and reliable modeling of ion dynamics in miniature quadrupole ion trap and improve the interpretation of observed mass spectra.

  19. Microfabricated ion trap mass spectrometry for characterization of organics and potential biomarkers

    NASA Astrophysics Data System (ADS)

    Austin, Daniel

    Mass spectrometry is a powerful analytical technique with a strong history in planetary exploration, and is the method of choice for detection and identification of organic and biological molecules. MS instrumentation can also be combined with techniques such as gas chromatography, liquid chromatography, or chiral separation, which are particularly important for analysis of complex mixtures or possible homochirality. Ion traps have several inherent advantages, including speed of analysis (important for GC-MS), MS/MS capabilities (important to identification of unknown compounds), excellent sensitivity, and ease of coupling with ambient ionization techniques that are under development for biomolecule detection. We report on progress in using microfabrication techniques to produce radiofrequency quadrupole ion traps that are much smaller, lighter, and lower power than existing instruments. We produce ion traps using an assembly of two ceramic plates, the facing surfaces of which are lithographically patterned with electrodes. This approach allows great flexibility in the trap geometry, and we have demonstrated working mass spectrometers with quadrupole, linear, and toroidal trapping fields. The approach also allows correction of higher-order terms in the electric field. With this system, mass resolution of up to 1300 has been demonstrated, which is adequate for identification of a wide range of potential biomarkers. Capabilities such as tandem analysis have also been demonstrated. Of particular interest is an ion trap that contains both quadrupole and toroidal trapping regions simultaneously and coaxially. Ions can be trapped as a large reservoir in the toroidal region and introduced in small batches to the quadrupole region for mass analysis. This capability is particularly valuable where the sample of interest is very small, such as microfossil with trace organics, and where the organic inventory is both complex and unknown. Development and results of this device

  20. Operational Parameters, Considerations, and Design Decisions for Resource-Constrained Ion Trap Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    Danell, Ryan M.; VanAmerom, Friso H. W.; Pinnick, Veronica; Cotter, Robert J.; Brickerhoff, William; Mahaffy, Paul

    2011-01-01

    Mass spectrometers are increasingly finding applications in new and unique areas, often in situations where key operational resources (i.e. power, weight and size) are limited. One such example is the Mars Organic Molecule Analyzer (MOMA). This instrument is a joint venture between NASA and the European Space Agency (ESA) to develop an ion trap mass spectrometer for chemical analysis on Mars. The constraints on such an instrument are significant as are the performance requirements. While the ideal operating parameters for an ion trap are generally well characterized, methods to maintain analytical performance with limited power and system weight need to be investigated and tested. Methods Experiments have been performed on two custom ion trap mass spectrometers developed as prototypes for the MOMA instrument. This hardware consists of quadrupole ion trap electrodes that are 70% the size of common commercial instrumentation. The trapping RF voltage is created with a custom tank circuit that can be tuned over a range of RF frequencies and is driven using laboratory supplies and amplifiers. The entire instrument is controlled with custom Lab VIEW software that allows a high degree of flexibility in the definition of the scan function defining the ion trap experiment. Ions are typically generated via an internal electron ionization source, however, a laser desorption source is also in development for analysis of larger intact molecules. Preliminary Data The main goals in this work have been to reduce the power required to generate the radio frequency trapping field used in an ion trap mass spectrometer. Generally minimizing the power will also reduce the volume and mass of the electronics to support the instrument. In order to achieve optimum performance, commercial instruments typically utilize RF frequencies in the 1 MHz range. Without much concern for power usage, they simply generate the voltage required to access the mass range of interest. In order to reduce the

  1. The mass multiplet in Penning trap ion cyclotron resonance mass spectroscopy

    NASA Astrophysics Data System (ADS)

    Barlow, S. E.

    2007-01-01

    A model for the behavior of closely spaced masses—the "mass multiplet"—in a Penning trap mass spectrometer is developed. The model shows how these species separate from each other (or not) following resonant excitation, and gives quantitative criteria for mass separation. More surprisingly, the model shows the species tend to drift to different mean cyclotron radii. This latter effect undoubtedly plays a role in the problem of abundance determinations in Penning trap mass spectrometers.

  2. Decomposition of cyclohexane ion induced by intense femtosecond laser fields by ion-trap time-of-flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Yamazaki, Takao; Watanabe, Yusuke; Kanya, Reika; Yamanouchi, Kaoru

    2016-01-01

    Decomposition of cyclohexane cations induced by intense femtosecond laser fields at the wavelength of 800 nm is investigated by ion-trap time-of-flight mass spectrometry in which cyclohexane cations C6H12+ stored in an ion trap are irradiated with intense femtosecond laser pulses and the generated fragment ions are recorded by time-of-flight mass spectrometry. The various fragment ion species, C5Hn+ (n = 7, 9), C4Hn+ (n = 5-8), C3Hn+ (n = 3-7), C2Hn+ (n = 2-6), and CH3+, identified in the mass spectra show that decomposition of C6H12+ proceeds efficiently by the photo-irradiation. From the laser intensity dependences of the yields of the fragment ion species, the numbers of photons required for producing the respective fragment ions are estimated.

  3. Evaluation of ion trap mass spectrometry for the determination of ambient nicotine

    SciTech Connect

    Wise, M.B.; Higgins, C.E.; Ilgner, R.H.; Guerin, M.R.

    1989-01-01

    A thermal desorption unit has been interfaced directly with a Finnigan Ion Trap mass spectrometer (ITMS) for the identification and quantification of trace organics in air. No chromatographic separation of the desorbed constituents is performed prior to introduction into the mass spectrometer. Instead, positive identification of a compound is made based on its collision induced dissociation (CID) tandem (MS/MS) mass spectrum. Using this technique, as little as 50 pg of a constituent desorbed from resin trap can be characterized and quantified with a sample turnaround time of only 2--3 minutes. 3 refs.

  4. On the structural denaturation of biological analytes in trapped ion mobility spectrometry - mass spectrometry.

    PubMed

    Liu, Fanny C; Kirk, Samuel R; Bleiholder, Christian

    2016-06-01

    Key to native ion mobility/mass spectrometry is to prevent the structural denaturation of biological molecules in the gas phase. Here, we systematically assess structural changes induced in the protein ubiquitin during a trapped ion mobility spectrometry (TIMS) experiment. Our analysis shows that the extent of structural denaturation induced in ubiquitin ions is largely proportional to the amount of translational kinetic energy an ion gains from the applied electric field between two collisions with buffer gas particles. We then minimize the efficiency of the structural denaturation of ubiquitin ions in the gas phase during a TIMS experiment. The resulting "soft" TIMS spectra of ubiquitin are found largely identical to those observed on "soft" elevated-pressure ion mobility drift tubes and the corresponding calibrated cross sections are consistent with structures reported from NMR experiments for the native and A-state of ubiquitin. Thus, our analysis reveals that TIMS is useful for native ion mobility/mass spectrometry analysis. PMID:26998732

  5. Ion trap mass spectrometry on a comet nucleus: the Ptolemy instrument and the Rosetta space mission.

    PubMed

    Todd, John F J; Barber, Simeon J; Wright, Ian P; Morgan, Geraint H; Morse, Andrew D; Sheridan, Simon; Leese, Mark R; Maynard, Jon; Evans, Suzanne T; Pillinger, Colin T; Drummond, Duncan L; Heys, Samantha C; Huq, S Ejaz; Kent, Barry J; Sawyer, Eric C; Whalley, Martin S; Waltham, Nicholas R

    2007-01-01

    In May 2014, the Rosetta spacecraft is scheduled to rendezvous with the comet Churyumov-Gerasimenko ('67P'). One of the instruments on board the 'Lander' which will descend on to the surface of the comet is a miniaturised GC/MS system that incorporates an ion trap mass spectrometer, specially developed for isotope ratio analysis. This article describes the development and optimisation of the ion trap for this unique application, and presents a summary of the range of pre-programmed experiments that will contribute to the characterisation of the solid and volatile cometary materials. PMID:17154436

  6. Microfabricated cylindrical ion trap

    DOEpatents

    Blain, Matthew G.

    2005-03-22

    A microscale cylindrical ion trap, having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale cylindrical ion trap to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The microscale CIT has a reduced ion mean free path, allowing operation at higher pressures with less expensive and less bulky vacuum pumping system, and with lower battery power than conventional- and miniature-sized ion traps. The reduced electrode voltage enables integration of the microscale cylindrical ion trap with on-chip integrated circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of microscale cylindrical ion traps can be realized in truly field portable, handheld microanalysis systems.

  7. Evaluation of Pulse Counting for the Mars Organic Mass Analyzer (MOMA) Ion Trap Detection Scheme

    NASA Technical Reports Server (NTRS)

    Van Amerom, Friso H.; Short, Tim; Brinckerhoff, William; Mahaffy, Paul; Kleyner, Igor; Cotter, Robert J.; Pinnick, Veronica; Hoffman, Lars; Danell, Ryan M.; Lyness, Eric I.

    2011-01-01

    The Mars Organic Mass Analyzer is being developed at Goddard Space Flight Center to identify organics and possible biological compounds on Mars. In the process of characterizing mass spectrometer size, weight, and power consumption, the use of pulse counting was considered for ion detection. Pulse counting has advantages over analog-mode amplification of the electron multiplier signal. Some advantages are reduced size of electronic components, low power consumption, ability to remotely characterize detector performance, and avoidance of analog circuit noise. The use of pulse counting as a detection method with ion trap instruments is relatively rare. However, with the recent development of high performance electrical components, this detection method is quite suitable and can demonstrate significant advantages over analog methods. Methods A prototype quadrupole ion trap mass spectrometer with an internal electron ionization source was used as a test setup to develop and evaluate the pulse-counting method. The anode signal from the electron multiplier was preamplified. The an1plified signal was fed into a fast comparator for pulse-level discrimination. The output of the comparator was fed directly into a Xilinx FPGA development board. Verilog HDL software was written to bin the counts at user-selectable intervals. This system was able to count pulses at rates in the GHz range. The stored ion count nun1ber per bin was transferred to custom ion trap control software. Pulse-counting mass spectra were compared with mass spectra obtained using the standard analog-mode ion detection. Prelin1inary Data Preliminary mass spectra have been obtained for both analog mode and pulse-counting mode under several sets of instrument operating conditions. Comparison of the spectra revealed better peak shapes for pulse-counting mode. Noise levels are as good as, or better than, analog-mode detection noise levels. To artificially force ion pile-up conditions, the ion trap was overfilled

  8. DIRECT TRACE ANALYSIS OF VOLATILE ORGANIC COMPOUNDS IN AIR USING ION TRAP MASS SPECTROMETERS WITH FILTERED NOISE FIELDS

    EPA Science Inventory

    Two ion trap mass spectrometers and direct air sampling interfaces are being evaluated in the laboratory for monitoring toxic air pollutants in real time. he mass spectrometers are the large, laboratory-based Finnigan MAT ion trap (ITMS) and the compact, field-deployable Teledyne...

  9. Stored waveform inverse Fourier transform (SWIFT) ion excitation in trapped-ion mass spectometry: Theory and applications

    NASA Astrophysics Data System (ADS)

    Guan, Shenheng; Marshall, Alan G.

    1996-12-01

    Stored waveform excitation produced by inverse Fourier transformation of a specified magnitude/phase excitation spectrum offers the most general and versatile means for broadband mass-selective excitation and ejection in Penning (FT-ICR) and Paul (quadrupole) ion trap mass spectrometry. Since the last comprehensive review of SWIFT excitation in 1987, the technique has been adopted, modified, and extended widely in both the ICR and quadrupole ion trap communities. Here, we review the principles, variations, algorithms, hardware implementation, and some applications of SWIFT for both ICR and quadrupole ion trap mass spectrometry. We show that the most desirable SWIFT waveform is that optimized to reduce both the time-domain SWIFT maximum amplitude and the amplitude near the start and end of the SWIFT waveform. We examine the "true" magnitude excitation spectrum, obtained by zero-filling and forward Fourier transforming the SWIFT time-domain waveform, in order to evaluate the trade-off between spectral magnitude uniformity and frequency (mass) selectivity. Apodization of the SWIFT waveform is optimally conducted by smoothing the excitation magnitude spectrum prior to generation of the SWIFT waveform by inverse FT. When (as for broadband ejection in a quadrupole ion trap) it is important that ions be excited near-simultaneously over a wide mass range, the phase spectrum (before inverse FT to generate the SWIFT waveform) may be overmodulated or randomly modulated ("filtered noise field"), with the recognition that very substantial non-uniformity in the "true" excitation magnitude spectrum will result.

  10. Broad spectrum drug screening using liquid chromatography-hybrid triple quadrupole linear ion trap mass spectrometry.

    PubMed

    Stone, Judy

    2010-01-01

    Centrifuged urine, internal standard (promazine), and ammonium formate buffer are mixed in an autosampler vial to achieve a 10-fold dilution of the specimen. Without additional pretreatment, 10 microL of the sample is injected onto a C18 reverse phase column for gradient analysis with ammonium formate/acetonitrile mobile phases. Drugs in the column eluent become charged in the ion source using positive electrospray atmospheric pressure ionization. Pseudomolecular drug ions are analyzed by a hybrid triple quadrupole linear ion trap mass spectrometer operated with a 264-drug selected ion monitoring (SRM) acquisition method that includes an information-dependant acquisition (IDA) algorithm. PMID:20077072

  11. Development and Deployment of Retrofit PolarisQ Ion Trap Mass Spectrometer for Isotope Ratio Measurements

    SciTech Connect

    Thompson, Cyril V.; Whitten, William B.

    2015-11-01

    This report describes Oak Ridge National Laboratory’s (ORNL) FY15 progress in support of National Nuclear Security Administration’s (NNSA) Portable Mass Spectrometer project. A retrofit PolarisQ ion trap mass spectrometer (RPMS) has been assembled from components of two PolarisQ ion trap mass spectrometers used in previous isotope ratio programs. The retrofit mass spectrometer includes a custom Hastelloy vacuum chamber which is about ¼ the size of the standard aluminum vacuum chamber and reduces the instrument weight from the original by nine pounds. In addition, the new vacuum chamber can be independently heated to reduce impurities such as water, which reacts with UF6 to produce HF in the vacuum chamber. The analyzer and all components requiring service are mounted on the chamber lid, facilitating quick and easy replacement of consumable components such as the filament and electron multiplier.

  12. Advanced Automation for Ion Trap Mass Spectrometry-New Opportunities for Real-Time Autonomous Analysis

    NASA Technical Reports Server (NTRS)

    Palmer, Peter T.; Wong, C. M.; Salmonson, J. D.; Yost, R. A.; Griffin, T. P.; Yates, N. A.; Lawless, James G. (Technical Monitor)

    1994-01-01

    The utility of MS/MS for both target compound analysis and the structure elucidation of unknowns has been described in a number of references. A broader acceptance of this technique has not yet been realized as it requires large, complex, and costly instrumentation which has not been competitive with more conventional techniques. Recent advancements in ion trap mass spectrometry promise to change this situation. Although the ion trap's small size, sensitivity, and ability to perform multiple stages of mass spectrometry have made it eminently suitable for on-line, real-time monitoring applications, advance automation techniques are required to make these capabilities more accessible to non-experts. Towards this end we have developed custom software for the design and implementation of MS/MS experiments. This software allows the user to take full advantage of the ion trap's versatility with respect to ionization techniques, scan proxies, and ion accumulation/ejection methods. Additionally, expert system software has been developed for autonomous target compound analysis. This software has been linked to ion trap control software and a commercial data system to bring all of the steps in the analysis cycle under control of the expert system. These software development efforts and their utilization for a number of trace analysis applications will be described.

  13. Design and performance of an instrument for electron impact tandem mass spectrometry and action spectroscopy of mass/charge selected macromolecular ions stored in RF ion trap*

    NASA Astrophysics Data System (ADS)

    Ranković, Milos Lj.; Giuliani, Alexandre; Milosavljević, Aleksandar R.

    2016-06-01

    A new apparatus was designed, coupling an electron gun with a linear quadrupole ion trap mass spectrometer, to perform m/ z (mass over charge) selected ion activation by electron impact for tandem mass spectrometry and action spectroscopy. We present in detail electron tracing simulations of a 300 eV electron beam inside the ion trap, design of the mechanical parts, electron optics and electronic circuits used in the experiment. We also report examples of electron impact activation tandem mass spectra for Ubiquitin protein, Substance P and Melittin peptides, at incident electron energies in the range from 280 eV to 300 eV.

  14. Triple quadrupole linear ion trap mass spectrometer for the analysis of small molecules and macromolecules.

    PubMed

    Hopfgartner, Gérard; Varesio, Emmanuel; Tschäppät, Viviane; Grivet, Chantal; Bourgogne, Emmanuel; Leuthold, Luc Alexis

    2004-08-01

    Recently, linear ion traps (LITs) have been combined with quadrupole (Q), time-of-flight (TOF) and Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS). LITs can be used either as ion accumulation devices or as commercially available, stand-alone mass spectrometers with MSn capabilities. The combination of triple quadrupole MS with LIT technology in the form of an instrument of configuration QqLIT, using axial ejection, is particularly interesting, because this instrument retains the classical triple quadrupole scan functions such as selected reaction monitoring (SRM), product ion (PI), neutral loss (NL) and precursor ion (PC) while also providing access to sensitive ion trap experiments. For small molecules, quantitative and qualitative analysis can be performed using the same instrument. In addition, for peptide analysis, the enhanced multiply charged (EMC) scan allows an increase in selectivity, while the time-delayed fragmentation (TDF) scan provides additional structural information. Various methods of operating the hybrid instrument are described for the case of the commercial Q TRAP (AB/MDS Sciex) and applications to drug metabolism analysis, quantitative confirmatory analysis, peptides analysis and automated nanoelectrospray (ESI-chip-MS) analysis are discussed. PMID:15329837

  15. The on-line charge breeding program at TRIUMF's Ion Trap For Atomic and Nuclear Science for precision mass measurements

    SciTech Connect

    Simon, M. C.; Eberhardt, B.; Jang, F.; Luichtl, M.; Robertson, D.; Chaudhuri, A.; Delheij, P.; Grossheim, A.; Kwiatkowski, A. A.; Mane, E.; Pearson, M. R.; Schultz, B. E.; Bale, J. C.; Chowdhury, U.; Ettenauer, S.; Gallant, A. T.; Dilling, J.; Lennarz, A.; Ma, T.; Andreoiu, C.; and others

    2012-02-15

    TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) constitutes the only high precision mass measurement setup coupled to a rare isotope facility capable of increasing the charge state of short-lived nuclides prior to the actual mass determination in a Penning trap. Recent developments around TITAN's charge breeder, the electron beam ion trap, form the basis for several successful experiments on radioactive isotopes with half-lives as low as 65 ms and in charge states as high as 22+.

  16. Hybrid quadrupole mass filter/quadrupole ion trap/time-of-flight-mass spectrometer for infrared multiple photon dissociation spectroscopy of mass-selected ions

    SciTech Connect

    Gulyuz, Kerim; Stedwell, Corey N.; Wang Da; Polfer, Nick C.

    2011-05-15

    We present a laboratory-constructed mass spectrometer optimized for recording infrared multiple photon dissociation (IRMPD) spectra of mass-selected ions using a benchtop tunable infrared optical parametric oscillator/amplifier (OPO/A). The instrument is equipped with two ionization sources, an electrospray ionization source, as well as an electron ionization source for troubleshooting. This hybrid mass spectrometer is composed of a quadrupole mass filter for mass selection, a reduced pressure ({approx}10{sup -5} Torr) quadrupole ion trap (QIT) for OPO irradiation, and a reflectron time-of-flight drift tube for detecting the remaining precursor and photofragment ions. A helium gas pulse is introduced into the QIT to temporarily increase the pressure and hence enhance the trapping efficiency of axially injected ions. After a brief pump-down delay, the compact ion cloud is subjected to the focused output from the continuous wave OPO. In a recent study, we implemented this setup in the study of protonated tryptophan, TrpH{sup +}, as well as collision-induced dissociation products of this protonated amino acid [W. K. Mino, Jr., K. Gulyuz, D. Wang, C. N. Stedwell, and N. C. Polfer, J. Phys. Chem. Lett. 2, 299 (2011)]. Here, we give a more detailed account on the figures of merit of such IRMPD experiments. The appreciable photodissociation yields in these measurements demonstrate that IRMPD spectroscopy of covalently bound ions can be routinely carried out using benchtop OPO setups.

  17. Reactions of vinyl chloride and methanol in a quadrupole ion trap mass spectrometer during VOC analysis

    SciTech Connect

    Bian, L.; Alley, E.G.; Lynn, B.C. Jr.

    1999-05-01

    A reaction between vinyl chloride and the solvent (methanol) was observed during volatile organic compound (VOC) analysis on a gas chromatograph/quadrupole ion trap mass spectrometer (GC/MS). A chromatographic peak at a retention time consistent with vinyl chloride produced a mass spectrum without the characteristic chlorine isotope ions m/z 62 and 64 but instead contained an apparent molecular ion, m/z 58. The m/z 58 ion is not found in the reference spectrum of vinyl chloride. This spectrum was observed when methanol was used as solvent in internal standard, surrogate standard, or analyte solutions. Subsequent VOC standard analysis indicated that the abundance of the m/z 58 ion was directly proportional to the amount of vinyl chloride in the water samples. The correct spectrum for vinyl chloride was observed when no methanol was added. From these experiments, the authors concluded that a reaction was occurring between the vinyl chloride and methanol in the ion trap producing a new species with a molecular ion at m/z 58. When ethanol was used as the solvent for the internal standard solution or surrogate standard, a correct spectrum of vinyl chloride was obtained.

  18. Human Biomonitoring of DNA Adducts by Ion Trap Multistage Mass Spectrometry.

    PubMed

    Guo, Jingshu; Turesky, Robert J

    2016-01-01

    Humans are continuously exposed to hazardous chemicals in the environment. These chemicals or their electrophilic metabolites can form adducts with genomic DNA, which can lead to mutations and the initiation of cancer. The identification of DNA adducts is required for understanding exposure and the etiological role of a genotoxic chemical in cancer risk. The analytical chemist is confronted with a great challenge because the levels of DNA adducts generally occur at <1 adduct per 10(7) nucleotides, and the amount of tissue available for measurement is limited. Ion trap mass spectrometry has emerged as an important technique to screen for DNA adducts because of the high level sensitivity and selectivity, particularly when employing multi-stage scanning (MS(n) ). The product ion spectra provide rich structural information and corroborate the adduct identities even at trace levels in human tissues. Ion trap technology represents a significant advance in measuring DNA adducts in humans. © 2016 by John Wiley & Sons, Inc. PMID:27584705

  19. An electrodynamic ion funnel interface for greater sensitivity and higher throughput with linear ion trap mass spectrometers

    NASA Astrophysics Data System (ADS)

    Page, Jason S.; Tang, Keqi; Smith, Richard D.

    2007-09-01

    An electrospray ionization interface incorporating an electrodynamic ion funnel has been designed and implemented on a linear ion trap mass spectrometer (Thermo Electron, LTQ). We found ion transmission to be greatly improved by replacing the standard capillary-skimmer interface with the capillary-ion funnel interface. An infusion study using a serial dilution of a reserpine solution showed that ion injection (accumulation) times to fill the ion trap at a given automatic gain control (AGC) target value were reduced by ~90% which resulted in an ~10-fold increase in peak intensities. In liquid chromatography tandem MS (LC-MS/MS) experiments performed using a global protein digest sample from the bacterium, Shewanella oneidensis, more peptides and proteins were identified when the ion funnel interface was used in place of the standard interface. This improvement was most pronounced at lower sample concentrations, where extended ion accumulation times are required, resulting in an ~2-fold increase in the number of protein identifications. Implementation of the ion funnel interface on a LTQ Fourier transform (FT) mass spectrometer showed a ~25-50% reduction in spectrum acquisition time. The duty cycle improvement in this case was due to the ion accumulation event contributing a larger portion to the total spectrum acquisition time.

  20. An electrodynamic ion funnel interface for greater sensitivity and higher throughput with linear ion trap mass spectrometers

    SciTech Connect

    Page, Jason S.; Tang, Keqi; Smith, Richard D.

    2007-09-01

    An electrospray ionization interface incorporating an electrodynamic ion funnel has been designed and implemented in conjunction with a linear ion trap mass spectrometer (Thermo Electron, LTQ). We found ion transmission to be greatly improved by replacing the standard capillary-skimmer interface with the capillary-ion funnel interface. An infusion study using a serial dilution of a reserpine solution showed that ion injection times to fill the ion trap were reduced by ~90% which resulted in an ~10-fold increase in reported peak intensities. In liquid chromatography (LC)-MS and LC tandem MS (MS/MS) experiments performed using a proteomic sample from the bacterium, Shewanella oneidensis, the ion funnel interface provided an ~7-fold reduction in ion injection (accumulation) times. In a series of LC-MS/MS experiments we found that more dilute S. oneidensis samples provided more peptide and protein identifications when the ion funnel interface was used in place of the standard interface. This improvement was most pronounced at lower sample concentrations, where extended ion accumulation times are required, resulting in an ~2-fold increase in the number of protein identifications. Implementation of the ion funnel interface with a LTQ Fourier transform (FT) MS requiring much greater ion populations resulted in spectrum acquisition times reduced by ~25 to 50%.

  1. Mass Measurement of Single Intact Nanoparticles in a Cylindrical Ion Trap.

    PubMed

    Zhang, Ning; Zhu, Kai; Xiong, Caiqiao; Jiang, Yurong; Chang, Huan-Cheng; Nie, Zongxiu

    2016-06-01

    Accurate nanoparticle mass characterization is a challenging task, especially at a single particle level. To solve this problem, a strategy for the mass measurement of single intact nanoparticle was proposed. A microscopy-based ion trap mass spectrometer was built up. To improve the detection sensitivity, a cylindrical ion trap with transparent conductive end-caps was used to increase the transmission of scattered light, and a vacuum ultraviolet lamp was used to increase the charge state of the isolated nanoparticle. By detecting the scattered light of the isolated nanoparticle, a series of secular frequencies were obtained, from which the corresponding mass-to-charge ratio of the nanoparticle was calculated. Finally, a Labview program was used to help deduce the charge state and absolute mass of the individual nanoparticle. Masses of gold nanoparticles with different sizes were accurately examined, which are (5.08 ± 0.44) × 10(7) Da for 20 nm, (3.55 ± 0.34) × 10(8) Da for 40 nm, and (1.22 ± 0.14) × 10(9) Da for 60 nm, respectively. The mass of MOFs with irregular shapes was also determined, which is (6.48 ± 1.08) × 10(9) Da. This method can provide the mass information on nanomaterials, thus opens up new possibility of characterizing nanoparticles at the single particle level. PMID:27167332

  2. Developments of multiplexed and miniature two-dimensional quadrupole ion trap mass spectrometers

    NASA Astrophysics Data System (ADS)

    Smith, Scott A.

    Quadrupole ion trap mass spectrometry (QIT MS) is a powerful and commonly-employed method for the specific analysis of mass, composition, and structure of gas-phase ionic chemical species. Useful for a wide variety of tasks, applications of ion traps include environmental monitoring, surface analysis (including depth profiling and imaging), ion thermochemical property elucidation, protein and DNA sequencing, and high-resolution chemical separations (through ion soft-landing). Though the principles of QIT MS have been known for over half a century, innovations in instrumentation and applications continue. As new needs for specific and sensitive chemical analysis arise, so also do new and more efficient analytical devices and methods of analysis. Such a trend is exemplified through the construction of a dual-source QIT mass spectrometer (described herein) capable of multi-source chemical analyses for the purposes of enhanced proteomic sequence coverage and for the strictly-controlled comparison of the structural differences in ion populations generated by different ionization techniques. Furthermore, as mass spectrometry becomes increasingly commonplace outside the bounds of the analytical laboratory, demand for capable researcher equipment is also increasing. Advances in instrument performance, such as can be had through enhanced power efficiency and the enabling of chemical analysis of high mass-to-charge ratio (m/z) species (e.g., proteins), will open new doors to in situ chemical analysis hand-portable mass spectrometers. Hence, research into new mass analyzer designs and methods of fabrication using stereolithography apparatus (SLA) for the purpose of creating enhanced-performance mass spectrometers are accordingly described in the text of this dissertation.

  3. Laser-induced fluorescence of Ba+ ions trapped and mass-selected in a Fourier transform ion cyclotron resonance mass spectrometer.

    PubMed

    Li, G Z; Vining, B A; Guan, S; Marshall, A G

    1996-01-01

    We present the design and preliminary results from a Fourier transform ion cyclotron resonance (ICR) mass spectrometer developed for the direct detection of UV/visible laser-induced fluorescence of trapped, mass-selected, gas-phase ions. A 3 T superconducting magnet and an open-ended multi-section cylindrical Penning trap capture and confine ions created by electron impact or laser desorption. Azimuthal quadrupolar excitation in the presence of ion/neutral collisions cools, axializes and mass selects ions as they fill the trap. A pulsed dye laser pumped by an Nd:YAG laser provides electronic energy excitation. A Brewster window and baffles on each side of the vacuum chamber reduce the scattered light from the excitation laser. Laser-induced fluorescence is collected from mirrors and lenses and directed through a quartz window and fiber-optic bundle to a photomultiplier. The ICR and optical events are controlled by a modular ICR data station and GPIB and RS-232 interfaces. An excitation spectrum is demonstrated for atomic Ba+ ions, and should extend to laser-induced fluorescence of virtually any stable positive or negative gas-phase ions of arbitrary molecular weight: molecular or quasimolecular ions, fragment ions, adduct ions, and ions formed from ion/molecule reactions. PMID:8953788

  4. Development of an ion trap/multi-turn time-of-flight mass spectrometer with potential- lift.

    PubMed

    Iwamoto, Kenichi; Nagao, Hirofumi; Toyoda, Michisato

    2009-01-01

    An ion trap/multi-turn time-of-flight (ToF) mass spectrometer with potential-lift has been developed. This system consists of an external ion source, a lens system, an ion trap, a potential-lift, a multi-turn ToF mass spectrometer and a detector. The ion trap consists of hyperbolic electrode cross-sections (Paul trap) and is used as an ion storage device. The potential-lift, which is part of the flight tube, was attached between the ion trap and the multi-turn ToF mass spectrometer. The potential-lift is known to be useful for increasing the kinetic energy of the ions. In order to check the ability of the potential-lift, mass distributions of [(CsI)(n) Cs]+ clusters (n = 1-9) were measured. The relative intensity ratios of the [(CsI)(n)Cs]+ clusters were consistent with the results obtained using other apparatus. To check the properties of the new apparatus, Xe+ isotopes were analyzed using either a linear or multi-turn ToF mass spectrometer. In the linear mode, the mass resolution was 500. In the multi-turn mode, the resolution depended on the number of cycles of the multi-turn ToF mass spectrometer; the mass resolution was 4400 (FWHM) after nine cycles. This new apparatus with a high resolution will be useful for measurements of ion-molecule reactions and photodissociations. PMID:19423910

  5. A comb-sampling method for enhanced mass analysis in linear electrostatic ion traps

    SciTech Connect

    Greenwood, J. B.; Kelly, O.; Calvert, C. R.; Duffy, M. J.; King, R. B.; Belshaw, L.; Graham, L.; Alexander, J. D.; Williams, I. D.; Bryan, W. A.; Turcu, I. C. E.; Cacho, C. M.; Springate, E.

    2011-04-15

    In this paper an algorithm for extracting spectral information from signals containing a series of narrow periodic impulses is presented. Such signals can typically be acquired by pickup detectors from the image-charge of ion bunches oscillating in a linear electrostatic ion trap, where frequency analysis provides a scheme for high-resolution mass spectrometry. To provide an improved technique for such frequency analysis, we introduce the CHIMERA algorithm (Comb-sampling for High-resolution IMpulse-train frequency ExtRAaction). This algorithm utilizes a comb function to generate frequency coefficients, rather than using sinusoids via a Fourier transform, since the comb provides a superior match to the data. This new technique is developed theoretically, applied to synthetic data, and then used to perform high resolution mass spectrometry on real data from an ion trap. If the ions are generated at a localized point in time and space, and the data is simultaneously acquired with multiple pickup rings, the method is shown to be a significant improvement on Fourier analysis. The mass spectra generated typically have an order of magnitude higher resolution compared with that obtained from fundamental Fourier frequencies, and are absent of large contributions from harmonic frequency components.

  6. Silica-fiber microextraction for laser desorption ion trap mass spectrometry

    SciTech Connect

    Cisper, M.E.; Earl, W.L.; Nogar, N.S.; Hemberger, P.H. )

    1994-06-01

    We have coupled sample collection by solid-phase microextraction on disposable fused silica optical fibers with analysis by laser desorption ion trap mass spectrometry for rapid screening of organic contaminants in complex matrices. Because the silica-fiber probe serves as both the sampling medium and the sample support for laser desorption, traditional methods of sample preparation are eliminated with the expected gains in speed and simplicity. Pyrene was the benchmark compound in these experiments but we show that the technique is also applicable to other polycyclic aromatic hydrocarbons (PAHs) and semivolatile compounds, laser dyes, pesticides, and peptides. Derivatizing the silica fiber improves the analyte collection efficiency, and firing the laser during a ring electrode rf ramp promotes dependable trapping of laser-desorbed ions. 32 refs., 5 figs.

  7. Direct sampling ion trap mass spectrometry vs. GC/MS for monitoring VOCs in groundwater

    SciTech Connect

    Wise, M.B.; Merriweather, R.; Guerin, M.R.

    1995-12-31

    Direct Sampling Ion Trap Mass Spectrometry (DSITMS) has been under refinement and demonstration by this laboratory for several years. The general technology is applicable to a wide range of problems which would benefit from high sample throughput, fast availability of results, and relatively low cost per sample analysis when compared with conventional analytical methods. At the present time, DSITMS can be used to determine targeted analytes in air, water, soil, and other media. This is accomplished by equipping an ion trap with a direct inlet system which consists of a splitter, capillary restrictor, and a set of sample inlet modules. The capillary restrictor provides the interface between atmosphere and the vacuum in the ion trap while the splitter enables sampling modules which require high gas flow rates to be used with the system. The sampling modules consist of a purge module for analyzing VOCs in water or soil, a direct air sampling module, and a thermal desorber. These modules are designed to be easily interchanged by means of quick connect fittings and a single electrical cable. In general, the DSITMS sample inlet system works equally well on all of the commercially available ion traps with which it has been tested including the Finnigan MAT ITMS, Finnigan MAT Magnum, Varian Saturn, and the Teledyne 3D-Q. Both the Magnum and 3D-Q instruments have been utilized for field applications as well as laboratory analysis. This particular study is a comparison of DSITMS with a purge and trap GC/MS for compliance monitoring of VOC`s in groundwater.

  8. Evaluation of the ion trap mass spectrometer for potential application in the space station

    SciTech Connect

    Glish, G.L.; McLuckey, S.A.

    1988-04-01

    This report describes preliminary experiments with an ion trap mass spectrometer, which were done to evaluate its potential for use in the environmental monitoring system of the proposed space station. The first section of the report describes various modes of operation of the instrument, discusses some of the present limitations, and discusses some of the potential solutions to these limitations. The next section discusses the experimental results obtained on sixteen compounds with particular emphasis on comparing these data to that expected from a standard mass spectrometer. The last section consists of a conclusion and comments on suggested future work. 16 figs.

  9. TITAN: An ion trap facility for on-line mass measurement experiments

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, A. A.; Andreoiu, C.; Bale, J. C.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Delheij, P.; Ettenauer, S.; Frekers, D.; Gallant, A. T.; Grossheim, A.; Gwinner, G.; Jang, F.; Lennarz, A.; Ma, T.; Mané, E.; Pearson, M. R.; Schultz, B. E.; Simon, M. C.; Simon, V. V.; Dilling, J.

    2014-01-01

    Precision determinations of ground state or even isomeric state masses reveal fingerprints of nuclear structure. In particular, at the limits of existence for very neutron-rich or -deficient isotopes, one can extract detailed information about nuclear structure from separation energies or binding energies. Mass measurements are important to uncover new phenomena, to test new theoretical predictions, or to refine model approaches. For example, the N = 28 shell has proven more stable than previously expected; however, the predicted new "magic" number at N = 34 in the K and Ca isotopes has yet to be confirmed experimentally. For these neutron-rich nuclei, the inclusion of three-body forces leads to significantly better predictions of the ground-state mass. Similarly, halo nuclei present an excellent application for ab-initio theory, where ground state properties, like masses and radii, test our understanding of nuclear structure. Precision mass determinations at TRIUMF are carried out with the TITAN (TRIUMF's Ion Traps for Atomic and Nuclear science) facility. It is an ion-trap setup coupled to the on-line facility ISAC. TITAN has measured masses of isotopes as short-lived as 9 ms (almost an order of magnitude shorter-lived than any other Penning trap system), and it is the only one with charge breeding capabilities, which allow us to boost the precision by almost 2 orders of magnitude. We recently made use of this feature by measuring short-lived, proton-rich Rb-isotopes, up to 74Rb while reaching the 12 + charge state, which together with other improvements led to an increase in precision by a factor 36.

  10. Buffer-Gas Cooling of a Single Ion in a Multipole Radio Frequency Trap Beyond the Critical Mass Ratio

    NASA Astrophysics Data System (ADS)

    Höltkemeier, Bastian; Weckesser, Pascal; López-Carrera, Henry; Weidemüller, Matthias

    2016-06-01

    We theoretically investigate the dynamics of a trapped ion immersed in a spatially localized buffer gas. For a homogeneous buffer gas, the ion's energy distribution reaches a stable equilibrium only if the mass of the buffer gas atoms is below a critical value. This limitation can be overcome by using multipole traps in combination with a spatially confined buffer gas. Using a generalized model for elastic collisions of the ion with the buffer-gas atoms, the ion's energy distribution is numerically determined for arbitrary buffer-gas distributions and trap parameters. Three regimes characterized by the respective analytic form of the ion's equilibrium energy distribution are found. Final ion temperatures down to the millikelvin regime can be achieved by adiabatically decreasing the spatial extension of the buffer gas and the effective ion trap depth (forced sympathetic cooling).

  11. MEMS Fabrication of Micro Cylindrical Ion Trap Mass Spectrometer for CubeSats Application

    NASA Astrophysics Data System (ADS)

    Zheng, Y.

    2015-10-01

    Microelectromechanical Systems (MEMS) technology is used to fabricate arrays of micro Cylindrical Ion Traps (μCIT) which are integrated into a miniaturized mass spectrometer (MS). The micro μCITs are built from silicon wafers and requires high machining precision, smooth surface, and high dimensional uniformity across the array for optimum mass spectrometer performance. In order to build these 3D miniature structures several MEMS processing techniques were explored and a process was developed and tested. By using the developed MEMS process, the required μCIT 4 x 4 arrays were fabricated. This included a chip design variation in which mechanical locking pits and posts were machined in the Ring Electrode (RE) chip and End Plate (EP) chips respectively, for self-assembly. The size of the assembled μCIT is only 12 mm x 12 mm x 1.5 mm. It is a key component for the miniature mass spectrometer. The micro cylindrical ion trap mass spectrometer has the advantages of low-power operation, simpler electronics and less-stringent vacuum system requirements. The MEMS batch production capabilities will also greatly lower the cost. It is a promising candidate for CubeSat and nanoSats applications for exploration of chemical distributions in space.

  12. Shedding light on the mercury mass discrepancy by weighing Hg 52+ ions in a Penning trap

    NASA Astrophysics Data System (ADS)

    Fritioff, T.; Bluhme, H.; Schuch, R.; Bergström, I.; Björkhage, M.

    2003-07-01

    In their nuclear tables Audi and Wapstra have pointed out a serious mass discrepancy between their extrapolated values for the mercury isotopes and those from a direct measurement by the Manitoba group. The values deviate by as much as 85 ppb from each other with claimed uncertainties of about 16 and 7 ppb, respectively. In order to decide which values are correct the masses of the 198Hg and 204Hg isotopes have been measured in the Stockholm Penning trap mass spectrometer SMILETRAP using 52+ ions. This charge state corresponds to a filled Ni electron configuration for which the electron binding energy can be accurately calculated. The mass values obtained are 197.966 768 44(43) u for 198Hg and 203.973 494 10(39) u for 204Hg. These values agree with those measured by the Manitoba group, with a 3 times lower uncertainty. This measurement was made possible through the implementation of a cooling technique of the highly charged mercury ions during charge breeding in the electron beam ion source used for producing the Hg 52+ ions.

  13. Automated Gain Control Ion Funnel Trap for Orthogonal Time-of-Flight Mass Spectrometry

    PubMed Central

    Ibrahim, Yehia M.; Belov, Mikhail E.; Liyu, Andrei V.; Smith, Richard D.

    2009-01-01

    Time-of-flight mass spectrometry (TOF MS) is increasingly used in proteomics research. Herein, we report on the development and characterization of a TOF MS instrument with improved sensitivity equipped with an electrodynamic ion funnel trap (IFT) that employs an automated gain control (AGC) capability. The IFT-TOF MS was coupled to a reversed-phase capillary liquid chromatography (RPLC) separation and evaluated in experiments with complex proteolytic digests. When applied to a global tryptic digest of Shewanella oneidensis proteins, an order-of-magnitude increase in sensitivity compared to that of the conventional continuous mode of operation was achieved due to efficient ion accumulation prior to TOF MS analysis. As a result of this sensitivity improvement and related improvement in mass measurement accuracy, the number of unique peptides identified in the AGC-IFT mode was 5-fold greater than that obtained in the continuous mode. PMID:18512944

  14. Ion trap simulation tools.

    SciTech Connect

    Hamlet, Benjamin Roger

    2009-02-01

    Ion traps present a potential architecture for future quantum computers. These computers are of interest due to their increased power over classical computers stemming from the superposition of states and the resulting capability to simultaneously perform many computations. This paper describes a software application used to prepare and visualize simulations of trapping and maneuvering ions in ion traps.

  15. Collisional and electric-field ionization of laser-prepared Rydberg states in an ion trap mass spectrometer

    SciTech Connect

    Ramsey, J.M.; Whitten, W.B.; Goeringer, D.E.; Buckley, B.T.

    1990-01-01

    Rydberg states of rubidium are selectively generated by one and two photon laser excitation in a quadrupole ion trap mass spectrometer. Collisional and electric-field ionization is investigated in trapping device. CCl{sub 4} is studied as a target for ionization of Rydberg states through electron attachment.

  16. Design and performance of an instrument for electron impact tandem mass spectrometry and action spectroscopy of mass/charge selected macromolecular ions stored in RF ion trap*

    NASA Astrophysics Data System (ADS)

    Ranković, Milos Lj.; Giuliani, Alexandre; Milosavljević, Aleksandar R.

    2016-05-01

    A new apparatus was designed, coupling an electron gun with a linear quadrupole ion trap mass spectrometer, to perform m/z (mass over charge) selected ion activation by electron impact for tandem mass spectrometry and action spectroscopy. We present in detail electron tracing simulations of a 300 eV electron beam inside the ion trap, design of the mechanical parts, electron optics and electronic circuits used in the experiment. We also report examples of electron impact activation tandem mass spectra for Ubiquitin protein, Substance P and Melittin peptides, at incident electron energies in the range from 280 eV to 300 eV. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  17. Design and Performance Evaluation of a Linear Ion Trap Mass Analyzer Featuring Half Round Rod Electrodes

    NASA Astrophysics Data System (ADS)

    Li, Xiaoxu; Zhang, Xiaohua; Yao, Rujiao; He, Yang; Zhu, Yongyong; Qian, Jie

    2015-05-01

    A novel linear ion trap mass analyzer featuring half round rod electrodes (HreLIT) has been built. It is mainly composed of two pairs of stainless steel electrodes which have a cross-section of half round rod and a pair of end electrodes. The HreLIT has a simple structure and so it could be assembled by hand with relatively high mechanical accuracy. The external dimension of HreLIT is 50 mm × 29.5 mm × 28 mm (length × width × height) and its internal volume is about 3.8 cm3. A home-made HreLIT mass spectrometer with three-stage vacuum system was built and the performance of HreLIT was characterized using reserpine solution and PPG standard solution. When the scan rate was 254 u/s, mass peak with FWHM of 0.14 u was achieved for ions with m/z 609, which corresponds to a mass resolution of 4350. The HreLIT was also operated at a low q value of 0.28 to extend its mass range. The experiment result showed a mass range of over 2800 u and the amplitude of radio frequency (rf) signal was only 1560 V (0-p). Three-stage tandem mass spectrometry was successfully performed in the HreLIT, and the collision-induced dissociation (CID) efficiencies of MS2 (CID of ions with m/z 609) and MS3 (CID of ions with m/z 448) were 78% and 59%, respectively.

  18. Design and performance of an atmospheric pressure sampling interface for ion-trap/time-of-flight mass spectrometry

    SciTech Connect

    Setz, Patrick D.; Schmitz, Thomas A.; Zenobi, Renato

    2006-02-15

    An ion-trap/time-of-flight mass spectrometer in combination with an atmospheric pressure sampling interface was developed in order to simultaneously profit from the ease of sample handling at ambient pressure, from the storage and accumulation capabilities of an ion trap, and from the acquisition speed and sensitivity of a time-of-flight mass spectrometer. The sampling interface is an intermediate-pressure vacuum manifold that serves to enrich sampled analytes by jet separation with respect to the carrier gas (air) and simultaneously maintain vacuum conditions inside the ion-trap/time-of-flight instrument. Neutral analyte molecules are sampled and later ionized either by electron impact or chemical ionization. Ion accumulation is performed with a rf-only quadrupole ion trap with ground potential on the end caps during storage. For mass analysis, the trap's electrodes serve as a pulsed ion source for the attached linear time-of-flight mass spectrometer. In addition, laser desorbed molecules can also be sampled with this kind of instrument. Successful operation is shown by analyzing volatile substances (aniline, bromobenzene, styrene, and perfluorotributylamine), as well as laser-desorbed organic solids. Figures of merit include a sensitivity of 10 ppm, resolving power of 300 and demonstration of a mass spectrum of laser-desorbed anthracene with a signal-to-noise ratio of 270.

  19. Direct sampling ion trap mass spectrometry (DSITMS). Innovative technology summary report

    SciTech Connect

    1998-12-01

    This report describes the cost, performance, and other key characteristics of an innovative technology for determining the presence or absence, and measuring the concentration, of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) in groundwater and soil, and in gaseous remediation process streams at hazardous waste sites. This new technology is Direct Sampling Ion Trap Mass Spectrometry (DSITMS). DSITMS introduces sample materials directly into an ion trap mass spectrometer by means of a very simple interface, such as a capillary restrictor or a polymer membrane. There is typically very little, if any, sample preparation and no chromatographic separation of the sample constituents. This means that the response of the instrument to the analytes or contaminants in a sample is nearly instantaneous, and that analytical methods based on DSITMS are fast. Analyses are typically completed in less than five minutes, and the analysis cost is generally 50% or less than the amount charged by commercial laboratories using Environmental Protection Agency (EPA) analysis methods.

  20. Electrospray liquid chromatography quadrupole ion trap mass spectrometry determination of phenyl urea herbicides in water.

    PubMed

    Draper, W M

    2001-06-01

    Phenyl urea herbicides were determined in water by electrospray quadrupole ion trap liquid chromatography-mass spectrometry (ES-QIT-LC-MS). Over a wide concentration range [M - H](-) and MH(+) ions were prominent in ES spectra. At high concentrations dimer and trimer ions appeared, and sodium, potassium, and ammonium adducts also were observed. In the case of isopturon, source collision-induced dissociation (CID) fragmentation with low offset voltages increased the ion current associated with MH(+) and diminished dimer and trimer ion abundance. In the mass analyzer CID involved common pathways, for example, daughter ions of [M - H](-) resulted from loss of R(2)NH in N',N'-dialkyl ureas or loss of C(3)H(5)NO(2) (87 amu) in N'-methoxy ureas. A 2 mm (i.d.) x 15 cm C(18) reversed phase column was used for LC-MS with a linear methanol/water gradient and 0.5 mL/min flow rate. Between 1 and 100 pg/microg/L the response was highly linear with instrument detection limits ranging from <10 to 50 pg injected. Whereas the positive ES signal intensity was greater for each of the compounds except fluometuron, negative ion monitoring gave the highest signal-to-noise ratio. Analysis of spiked Colorado River water, a source high in total dissolved solids and total organic carbon, demonstrated that ES-QIT-LC-MS was routinely capable of quantitative analysis at low nanogram per liter concentrations in conjunction with a published C(18) SPE method. Under these conditions experimental method detection limits were between 8.0 and 36 ng/L, and accuracy for measurements in the 20-50 parts per trillion range was from 77 to 96%. Recoveries were slightly lower in surface water (e.g., 39-76%), possibly due to suppression of ionization. PMID:11409961

  1. Rapid determination of nicotine in urine by direct thermal desorption ion trap mass spectrometry

    SciTech Connect

    Wise, M.B.; Ilgner, R.H.; Guerin, M.R.

    1990-01-01

    The measurement of nicotine and cotinine in physiological fluids (urine, blood serum, and saliva) is widely used as a means of assessing human exposure to environmental tobacco smoke (ETS). Although numerous analytical methods exist for these measurements, they generally involve extensive sample preparation which increases cost and decreases sample throughput. We report the use of thermal desorption directly into an ion trap mass spectrometer (ITMS) for the rapid determination of nicotine and cotinine in urine. A 1{mu}L aliquot of urine is injected into a specially designed inlet and flash vaporized directly into an ITMS through an open-split capillary restrictor interface. Isobutane chemical ionization is used to generate (M+H){sup +} ions of the analytes and collision induced dissociation is used to generate characteristic fragment ions which are used to confirm their identity. Quantification is achieved by integrating the ion current for the characteristic ions and comparing with an external working curve. Detection limits are approximately 50 pg per analyte and the sample turnaround time is approximately 3 minutes without the need for extensive sample preparation. 12 refs., 5 figs.

  2. Automated measurement of permethylated serum N-glycans by MALDI-linear ion trap mass spectrometry.

    PubMed

    Guillard, Maïlys; Gloerich, Jolein; Wessels, Hans J C T; Morava, Eva; Wevers, Ron A; Lefeber, Dirk J

    2009-08-17

    The use of N-glycan mass spectrometry for clinical diagnostics requires the development of robust high-throughput profiling methods. Still, structural assignment of glycans requires additional information such as MS(2) fragmentation or exoglycosidase digestions. We present a setting which combines a MALDI ionization source with a linear ion trap analyzer. This instrumentation allows automated measurement of samples thanks to the crystal positioning system, combined with MS(n) sequencing options. 2,5-Dihydroxybenzoic acid, commonly used for the analysis of glycans, failed to produce the required reproducibility due to its non-homogeneous crystallization properties. In contrast, alpha-cyano-4-hydroxycinnamic acid provided a homogeneous crystallization pattern and reproducibility of the measurements. Using serum N-glycans as a test sample, we focused on the automation of data collection by optimizing the instrument settings. Glycan structures were confirmed by MS(2) analysis. Although sample processing still needs optimization, this method provides a reproducible and high-throughput approach for measurement of N-glycans using a MALDI-linear ion trap instrument. PMID:19577739

  3. Direct Monitoring of Trace Atmospheric Species via Ion Trap Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Palmer, P. T.; Pearson, Richard; Saimonson, Jay D.; Wong, Carla M.; Lawless, James G. (Technical Monitor)

    1994-01-01

    There is an ever-increasing emphasis on the part of government agencies, academia, and industry on enhancing our understanding of atmospheric processes and assessing the impact of human activities on these processes. While issues such as the ozone hole and rising levels of greenhouse gases have received major attention. relatively little is known about the types, concentrations, sources, and sinks of hydrocarbons in the troposphere and stratosphere. Such information would be of tremendous utility in assessing the roles of various anthropogenic and biogenic processes on global carbon cycles. An ion trap mass spectrometer has been developed for monitoring trace levels of hydrocarbons in the atmosphere on NASA's DC-8 "flying laboratory". This aircraft is used to provide measurements in support of a number of "Mission to Planet Earth" activities and tropospheric chemistry experiments. In past missions, specific compounds have been monitored via highly specialized instrumentation, fast GO, or collection of whole air samples for subsequent ground-based analysis. The ion trap has several features. including small size. excellent sensitivity, and broad applicability, which make it highly atttrat:ive for atmospheric monitoring. The design of this instrument, its air sampling interface. and the various complications associated with aircraft-deployment will be described. Data showing the sensitivity of the instrument for detecting hydrocarbons at mixing ratios below one part-per-billion, and the use of MS/MS for direct, on-line, real-time monitoring will be presented.

  4. Rapid screening and characterization of drug metabolites using a new quadrupole-linear ion trap mass spectrometer.

    PubMed

    Hopfgartner, Gérard; Husser, Christophe; Zell, Manfred

    2003-02-01

    The application of a new hybrid RF/DC quadrupole-linear ion trap mass spectrometer to support drug metabolism and pharmacokinetic studies is described. The instrument is based on a quadrupole ion path and is capable of conventional tandem mass spectrometry (MS/MS) as well as several high-sensitivity ion trap MS scans using the final quadrupole as a linear ion trap. Several pharmaceutical compounds, including trocade, remikiren and tolcapone, were used to evaluate the capabilities of the system with positive and negative turbo ionspray, using either information-dependent data acquisition (IDA) or targeted analysis for the screening, identification and quantification of metabolites. Owing to the MS/MS in-space configuration, quadrupole-like CID spectra with ion trap sensitivity can be obtained without the classical low mass cutoff of 3D ion traps. The system also has MS(3) capability which allows fragmentation cascades to be followed. The combination of constant neutral loss or precursor ion scan with the enhanced product ion scan was found to be very selective for identifying metabolites at the picogram level in very complex matrices. Owing to the very high cycle time and, depending on the mass range, up to eight different MS experiments could be performed simultaneously without compromising chromatographic performance. Targeted product ion analysis was found to be complementary to IDA, in particular for very low concentrations. Comparable sensitivity was found in enhanced product ion scan and selected reaction monitoring modes. The instrument is particularly suitable for both qualitative and quantitative analysis. PMID:12577280

  5. An expert system/ion trap mass spectrometry approach for life support systems monitoring

    NASA Technical Reports Server (NTRS)

    Palmer, Peter T.; Wong, Carla M.; Yost, Richard A.; Johnson, Jodie V.; Yates, Nathan A.; Story, Michael

    1992-01-01

    Efforts to develop sensor and control system technology to monitor air quality for life support have resulted in the development and preliminary testing of a concept based on expert systems and ion trap mass spectrometry (ITMS). An ITMS instrument provides the capability to identify and quantitate a large number of suspected contaminants at trace levels through the use of a variety of multidimensional experiments. An expert system provides specialized knowledge for control, analysis, and decision making. The system is intended for real-time, on-line, autonomous monitoring of air quality. The key characteristics of the system, performance data and analytical capabilities of the ITMS instrument, the design and operation of the expert system, and results from preliminary testing of the system for trace contaminant monitoring are described.

  6. Quantitative determination of medroxyprogesterone acetate in plasma by liquid chromatography/electrospray ion trap mass spectrometry.

    PubMed

    Kim, S M; Kim, D H

    2001-01-01

    A sensitive and rapid liquid chromatography/electrospray ion trap mass spectrometry (LC/MS/MS) method has been developed for the quantitative determination of medroxyprogesterone acetate (MPA) in human plasma. Plasma samples (1.0 mL) were simply extracted with pentane and the extracts were analyzed by HPLC with the detection of the analyte in the selective reaction monitoring (SRM) mode. The determination of MPA was accurate and reproducible, with a limit of quantitation of 0.05 ng/mL in plasma. The standard calibration curve for MPA was linear (r = 0.998) over the concentration range 0.05-6.0 ng/mL in human plasma. Analysis precision over the concentration range of MPA was lower than 18.8% (relative standard deviation, RSD) and accuracy was between 96.2 and 108.7%. PMID:11675672

  7. Microfabricated linear Paul-Straubel ion trap

    DOEpatents

    Mangan, Michael A.; Blain, Matthew G.; Tigges, Chris P.; Linker, Kevin L.

    2011-04-19

    An array of microfabricated linear Paul-Straubel ion traps can be used for mass spectrometric applications. Each ion trap comprises two parallel inner RF electrodes and two parallel outer DC control electrodes symmetric about a central trap axis and suspended over an opening in a substrate. Neighboring ion traps in the array can share a common outer DC control electrode. The ions confined transversely by an RF quadrupole electric field potential well on the ion trap axis. The array can trap a wide array of ions.

  8. A new sheathless electrospray interface for coupling of capillary electrophoresis to ion-trap mass spectrometry.

    PubMed

    Bendahl, Lars; Hansen, Steen Honoré; Olsen, Jørgen

    2002-01-01

    A simple laboratory-made sheathless electrospray interface for coupling of capillary electrophoresis to ion-trap mass spectrometry (CE/MS) was developed. The interface was machined in-house and it was designed to be freely interchangeable with the commercially available ionization sources for the mass spectrometer. Sharpened fused-silica capillaries were coated with nickel by a simple electrodeless plating procedure and were used as all-in-one columns/emitters. The electrodeless plating produced a 2-5- micro m thick smooth nickel layer that lasted for more than 8 h of continuous electrospraying. The performance of the CE/MS interface was examined by using four cationic imipramine derivatives as test substances. Relative detection limits were calculated on the basis of the extracted ion electrophorograms and were in the range 6-130 nmol/L, corresponding to absolute detection limits in the range of 20-400 amol. The system was applied for analysis of impurities in an impure imipramine N-oxide preparation, and two of the impurities could be identified on the basis of online-MS(MS) spectra recorded in scan-dependent mode. PMID:12478579

  9. Ion funnel ion trap and process

    DOEpatents

    Belov, Mikhail E [Richland, WA; Ibrahim, Yehia M [Richland, WA; Clowers, Biran H [West Richland, WA; Prior, David C [Hermiston, OR; Smith, Richard D [Richland, WA

    2011-02-15

    An ion funnel trap is described that includes a inlet portion, a trapping portion, and a outlet portion that couples, in normal operation, with an ion funnel. The ion trap operates efficiently at a pressure of .about.1 Torr and provides for: 1) removal of low mass-to-charge (m/z) ion species, 2) ion accumulation efficiency of up to 80%, 3) charge capacity of .about.10,000,000 elementary charges, 4) ion ejection time of 40 to 200 .mu.s, and 5) optimized variable ion accumulation times. Ion accumulation with low concentration peptide mixtures has shown an increase in analyte signal-to-noise ratios (SNR) of a factor of 30, and a greater than 10-fold improvement in SNR for multiply charged analytes.

  10. Using metal complex ion-molecule reactions in a miniature rectilinear ion trap mass spectrometer to detect chemical warfare agents.

    PubMed

    Graichen, Adam M; Vachet, Richard W

    2013-06-01

    The gas-phase reactions of a series of coordinatively unsaturated [Ni(L)n](y+) complexes, where L is a nitrogen-containing ligand, with chemical warfare agent (CWA) simulants in a miniature rectilinear ion trap mass spectrometer were investigated as part of a new approach to detect CWAs. Results show that upon entering the vacuum system via a poly(dimethylsiloxane) (PDMS) membrane introduction, low concentrations of several CWA simulants, including dipropyl sulfide (simulant for mustard gas), acetonitrile (simulant for the nerve agent tabun), and diethyl phosphite (simulant for nerve agents sarin, soman, tabun, and VX), can react with metal complex ions generated by electrospray ionization (ESI), thereby providing a sensitive means of detecting these compounds. The [Ni(L)n](2+) complexes are found to be particularly reactive with the simulants of mustard gas and tabun, allowing their detection at low parts-per-billion (ppb) levels. These detection limits are well below reported exposure limits for these CWAs, which indicates the applicability of this new approach, and are about two orders of magnitude lower than electron ionization detection limits on the same mass spectrometer. The use of coordinatively unsaturated metal complexes as reagent ions offers the possibility of further tuning the ion-molecule chemistry so that desired compounds can be detected selectively or at even lower concentrations. PMID:23532782

  11. Using Metal Complex Ion-Molecule Reactions in a Miniature Rectilinear Ion Trap Mass Spectrometer to Detect Chemical Warfare Agents

    NASA Astrophysics Data System (ADS)

    Graichen, Adam M.; Vachet, Richard W.

    2013-06-01

    The gas-phase reactions of a series of coordinatively unsaturated [Ni(L)n]y+ complexes, where L is a nitrogen-containing ligand, with chemical warfare agent (CWA) simulants in a miniature rectilinear ion trap mass spectrometer were investigated as part of a new approach to detect CWAs. Results show that upon entering the vacuum system via a poly(dimethylsiloxane) (PDMS) membrane introduction, low concentrations of several CWA simulants, including dipropyl sulfide (simulant for mustard gas), acetonitrile (simulant for the nerve agent tabun), and diethyl phosphite (simulant for nerve agents sarin, soman, tabun, and VX), can react with metal complex ions generated by electrospray ionization (ESI), thereby providing a sensitive means of detecting these compounds. The [Ni(L)n]2+ complexes are found to be particularly reactive with the simulants of mustard gas and tabun, allowing their detection at low parts-per-billion (ppb) levels. These detection limits are well below reported exposure limits for these CWAs, which indicates the applicability of this new approach, and are about two orders of magnitude lower than electron ionization detection limits on the same mass spectrometer. The use of coordinatively unsaturated metal complexes as reagent ions offers the possibility of further tuning the ion-molecule chemistry so that desired compounds can be detected selectively or at even lower concentrations.

  12. Electrospray/Ion Trap Mass Spectrometry for the Detection and Identification of Organisms

    SciTech Connect

    McLuckey, Scott A.; Stephenson, James L., Jr.

    1997-12-31

    Current electrospray ion trap methodology for rapid mixture analysis of proteins used for the identification of microorganisms is described. Development of ion/ion reaction techniques (e.g. reactions of multiply-charged protein cations with singly-charged anions) from both a fundamental and practical approach are presented, detailing the necessary steps and considerations involved in complex mixture analysis. Data describing the reduction of the initial charge states of electrospray ions to arbitrarily low values, the utility of ion/ion reactions for mixture separation on the millisecond time scale, and effects of excess singly-charged reactants on detection and storage efficiency are illustrated.

  13. Tailored Noise Waveform/ Collision-Induced Dissociation of Ions Stored in a Linear Ion Trap Combined with Liquid Chromatography/Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    SciTech Connect

    Vilkov, Andrey N.; Bogdanov, Bogdan; Pasa-Tolic, Liljiana; Prior, David C.; Anderson, Gordon A.; Masselon, Christophe D.; Moore, Ronald J.; Smith, Richard D.

    2004-11-01

    A new collision-induced dissociation (CID) technique based on broadband tailored noise waveform (TNW) excitation of ions stored in a linear ion trap has been developed. In comparison with the conventional sustained off-resonance irradiation (SORI) CID method commonly used in Fourier transform ion cyclotron resonance mass spectrometry, this MS/MS technique increases throughput by eliminating the long pump-down delay associated with gas introduction into the high vacuum ICR cell region. In addition, the TNW-CID method speeds spectrum acquisition since it does not require Fourier transformation, calculation of resonant frequencies and generation of the excitation waveforms. We demonstrate TNW-CID coupled with on-line capillary reverse phase liquid chromatography separations for identification of peptides. The experimental results are compared with data obtained using conventional quadrupole ion trap MS/MS and SORI-CID MS/MS in an ICR cell.

  14. Miniaturized system of a gas chromatograph coupled with a Paul ion trap mass spectrometer

    NASA Technical Reports Server (NTRS)

    Shortt, B. J.; Darrach, M. R.; Holland, Paul M.; Chutjian, A.

    2005-01-01

    Miniature gas chromatography (GC) and miniature mass spectrometry (MS) instrumentation has been developed to identify and quantify the chemical compounds present in complex mixtures of gases. The design approach utilizes micro-GC components coupled with a Paul quadrupole ion trap (QIT) mass spectrometer. Inherent to the system are high sensitivity, good dynamic range, good QIT resolution, low GC flow-rates to minimize vacuum requirements and the need for consumables; and the use of a modular approach to adapt to volatile organic compounds dissolved in water or present in sediment. Measurements are reported on system response to gaseous species at concentrations varying over four orders of magnitude. The ability of the system to deal with complicated mixtures is demonstrated, and future improvements are discussed. The GC/QIT system described herein has a mass, volume and power that are, conservatively, one-twentieth of those of commercial off-the-shelf systems. Potential applications are to spacecraft cabin-air monitoring, robotic planetary exploration and trace-species detection for residual gas analysis and environmental monitoring.

  15. Development of a Linear Ion Trap Mass Spectrometer (LITMS) Investigation for Future Planetary Surface Missions

    NASA Technical Reports Server (NTRS)

    Brinckerhoff, W.; Danell, R.; Van Ameron, F.; Pinnick, V.; Li, X.; Arevalo, R.; Glavin, D.; Getty, S.; Mahaffy, P.; Chu, P.; Zacny, K.; Rogacki, S.; Grubisic, A.; Cornish, T.

    2014-01-01

    Future surface missions to Mars and other planetary bodies will benefit from continued advances in miniature sensor and sample handling technologies that enable high-performance chemical analyses of natural samples. Fine-scale (approx.1 mm and below) analyses of rock surfaces and interiors, such as exposed on a drill core, will permit (1) the detection of habitability markers including complex organics in association with their original depositional environment, and (2) the characterization of successive layers and gradients that can reveal the time-evolution of those environments. In particular, if broad-based and highly-sensitive mass spectrometry techniques could be brought to such scales, the resulting planetary science capability would be truly powerful. The Linear Ion Trap Mass Spectrometer (LITMS) investigation is designed to conduct fine-scale organic and inorganic analyses of short (approx.5-10 cm) rock cores such as could be acquired by a planetary lander or rover arm-based drill. LITMS combines both pyrolysis/gas chromatograph mass spectrometry (GCMS) of sub-sampled core fines, and laser desorption mass spectrometry (LDMS) of the intact core surface, using a common mass analyzer, enhanced from the design used in the Mars Organic Molecule Analyzer (MOMA) instrument on the 2018 ExoMars rover. LITMS additionally features developments based on the Sample Analysis at Mars (SAM) investigation on MSL and recent NASA-funded prototype efforts in laser mass spectrometry, pyrolysis, and precision subsampling. LITMS brings these combined capabilities to achieve its four measurement objectives: (1) Organics: Broad Survey Detect organic molecules over a wide range of molecular weight, volatility, electronegativity, concentration, and host mineralogy. (2) Organic: Molecular Structure Characterize internal molecular structure to identify individual compounds, and reveal functionalization and processing. (3) Inorganic Host Environment Assess the local chemical

  16. Characterization of impurities in tylosin using dual liquid chromatography combined with ion trap mass spectrometry.

    PubMed

    Chopra, Shruti; Van Schepdael, Ann; Hoogmartens, Jos; Adams, Erwin

    2013-03-15

    Investigation of unknown impurities in a tylosin sample was performed using liquid chromatography coupled to mass spectrometry (LC/MS). Separation was performed according to the recently described LC-UV method of Ashenafi et al. (2011) [14]. This method was reported to have a good selectivity as it was able to separate the four main components of tylosin from the already known and 23 unknown impurities. However, as this method uses a mobile phase with non-volatile constituents, direct characterization of these impurities using LC/MS was not possible. The impurity fractions were therefore first collected and then desalted before sending them to the MS. Identification of the impurities in the tylosin sample was performed with a quadruple ion trap (IT) MS, with an electrospray ionization (ESI) source in the positive ion mode. The structure of the impurities was deduced by comparing their fragmentation pattern with those of the main components of tylosin. As several peaks in the LC-UV method contained multiple compounds, using this method in total 41 new impurities were (partly) characterized. PMID:23598092

  17. A Tuning Method for Electrically Compensated Ion Cyclotron Resonance Mass Spectrometer Traps

    PubMed Central

    Brustkern, Adam M.; Rempel, Don L.; Gross, Michael L.

    2010-01-01

    We describe a method for tuning electrically compensated ion cyclotron resonance (ICR) traps by tracking the observed cyclotron frequency of an ion cloud at different oscillation mode amplitudes. Although we have used this method to tune the compensation voltages of a custom-built electrically compensated trap, the approach is applicable to other designs that incorporate electrical compensation. To evaluate the effectiveness of tuning, we examined the frequency shift as a function of cyclotron orbit size at different z-mode oscillation amplitudes. The cyclotron frequencies varied by ~ 12 ppm for ions with low z-mode oscillation amplitudes compared to those with high z-mode amplitudes. This frequency difference decreased to ~1 ppm by one iteration of trap tuning. PMID:20060743

  18. Real-Time Quantitative Analysis of H2, He, O2, and Ar by Quadrupole Ion Trap Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Ottens, Andrew K.; Harrison, W. W.; Griffin, Timothy P.; Helms, William R.; Voska, N. (Technical Monitor)

    2002-01-01

    The use of a quadrupole ion trap mass spectrometer for quantitative analysis of hydrogen and helium as well as other permanent gases is demonstrated. The customized instrument utilizes the mass selective instability mode of mass analysis as with commercial instruments; however, this instrument operates at a greater RF trapping frequency and without a buffer gas. With these differences, a useable mass range from 2 to over 50 Da is achieved, as required by NASA for monitoring the Space Shuttle during a launch countdown. The performance of the ion trap is evaluated using part-per-million concentrations of hydrogen, helium, oxygen and argon mixed into a nitrogen gas stream. Relative accuracy and precision when quantitating the four analytes were better than the NASA-required minimum of 10% error and 5% deviation, respectively. Limits of detection were below the NASA requirement of 25-ppm hydrogen and 100-ppm helium; those for oxygen and argon were slightly higher than the requirement. The instrument provided adequate performance at fast data recording rates, demonstrating the utility of an ion trap mass spectrometer as a real-time quantitative monitoring device for permanent gas analysis.

  19. Degradation study of enniatins by liquid chromatography-triple quadrupole linear ion trap mass spectrometry.

    PubMed

    Serrano, A B; Meca, G; Font, G; Ferrer, E

    2013-12-15

    Enniatins A, A1, B and B1 (ENs) are mycotoxins produced by Fusarium spp. and are normal contaminants of cereals and derivate products. In this study, the stability of ENs was evaluated during food processing by simulation of pasta cooking. Thermal treatments at different incubation times (5, 10 and 15 min) and different pH (4, 7 and 10) were applied in an aqueous system and pasta resembling system (PRS). The concentrations of the targeted mycotoxins were determined using liquid chromatography coupled to tandem mass spectrometry. High percentages of ENs reduction (81-100%) were evidenced in the PRS after the treatments at 5, 10 and 15 min of incubation. In contrast to the PRS, an important reduction of the ENs was obtained in the aqueous system after 15 min of incubation (82-100%). In general, no significant differences were observed between acid, neutral and basic solutions. Finally, several ENs degradation products were identified using the technique of liquid chromatography-triple quadrupole linear ion trap mass spectrometry. PMID:23993608

  20. Towards the hand-held mass spectrometer: design considerations, simulation, and fabrication of micrometer-scaled cylindrical ion traps

    NASA Astrophysics Data System (ADS)

    Blain, Matthew G.; Riter, Leah S.; Cruz, Dolores; Austin, Daniel E.; Wu, Guangxiang; Plass, Wolfgang R.; Cooks, R. Graham

    2004-08-01

    Breakthrough improvements in simplicity and reductions in the size of mass spectrometers are needed for high-consequence fieldable applications, including error-free detection of chemical/biological warfare agents, medical diagnoses, and explosives and contraband discovery. These improvements are most likely to be realized with the reconceptualization of the mass spectrometer, rather than by incremental steps towards miniaturization. Microfabricated arrays of mass analyzers represent such a conceptual advance. A massively parallel array of micrometer-scaled mass analyzers on a chip has the potential to set the performance standard for hand-held sensors due to the inherit selectivity, sensitivity, and universal applicability of mass spectrometry as an analytical method. While the effort to develop a complete micro-MS system must include innovations in ultra-small-scale sample introduction, ion sources, mass analyzers, detectors, and vacuum and power subsystems, the first step towards radical miniaturization lies in the design, fabrication, and characterization of the mass analyzer itself. In this paper we discuss design considerations and results from simulations of ion trapping behavior for a micrometer scale cylindrical ion trap (CIT) mass analyzer (internal radius r0 = 1 [mu]m). We also present a description of the design and microfabrication of a 0.25 cm2 array of 106 one-micrometer CITs, including integrated ion detectors, constructed in tungsten on a silicon substrate.

  1. Selective injection and isolation of ions in quadrupole ion trap mass spectrometry using notched waveforms created using the inverse Fourier transform

    SciTech Connect

    Soni, M.H.; Cooks, R.G. )

    1994-08-01

    Broad-band excitation of ions is accomplished in the quadrupole ion trap mass spectrometer using notched waveforms created by the SWIFT (stored waveform inverse Fourier transform) technique. A series of notched SWIFT pulses are applied during the period of ion injection from an external Cs[sup +] source to resonantly eject all ions whose resonance frequencies fall within the frequency range of the pulse while injecting only those analyte ions whose resonance frequencies fall within the limits of the notch. This allows selective injection and accumulation of the ions of interest and continuous ejection of the unwanted ions. This is shown to result in significant improvement in S/N ratio, resolution, and sensitivity for the analyte ions of interest. Selective ion injection is demonstrated by injecting the protonated molecules of peptides VSV and gramicidin S and the intact cation of l-carnitine hydrochloride, using singly notched SWIFT pulses. Multiply notched SWIFT pulses are used to simultaneously inject ions of different m/z values of l-carnitine hydrochloride into the ion trap. A new coarse/fine ion isolation procedure, which employs a doubly notched SWIFT pulse, is demonstrated for isolating ions of a single m/z value of 4-bromobiphenyl from a population of trapped ions. 36 refs., 10 figs., 2 tabs.

  2. Ion trap device

    DOEpatents

    Ibrahim, Yehia M.; Smith, Richard D.

    2016-01-26

    An ion trap device is disclosed. The device includes a series of electrodes that define an ion flow path. A radio frequency (RF) field is applied to the series of electrodes such that each electrode is phase shifted approximately 180 degrees from an adjacent electrode. A DC voltage is superimposed with the RF field to create a DC gradient to drive ions in the direction of the gradient. A second RF field or DC voltage is applied to selectively trap and release the ions from the device. Further, the device may be gridless and utilized at high pressure.

  3. Evaluation of a sheathless capillary electrophoresis/electrospray ionization interface on an ion trap mass spectrometer

    SciTech Connect

    Kriger, M.S.; Cook, K.D.; Ramsey, R.S.

    1994-12-31

    The use of small diameter fused silica capillaries has proven advantageous in several electrospray (ES) mass spectrometric (MS) applications. Enhanced sensitivity and reduced background provide very low limits of detection. Prompted by these findings, the authors have developed an improved capillary electrophoresis (CE)/ES interface and evaluated its performance on a quadrupole ion trap MS using specially prepared fused silica capillary columns. The capillary tip is tapered, then gold-coated using a proprietary process that provides physical and chemical stability. (This process will be described in a subsequent publication, following determination of its patent status by the University of Tennessee Research Corporation). Tapering focuses the electric field, enabling electrospray of highly conductive aqueous solutions prior to the onset of a corona discharge. These capillaries have been used for CE/ES without a sheath solvent, thus avoiding dilution and increased background. The gold coating is not removed from the capillary by application and removal of cellophane adhesive tape, demonstrating excellent physical adhesion. Microscopic inspection has revealed that the coating remains uncompromised when sonicated in water, methanol, ethanol, propanol, acetic acid buffer (10 mM; pH 3.5), concentrated HCl (12.1 M), or potassium hydroxide (1 M). The coating did not survive sonication in aqua regia or piranha solution (30% H{sub 2}O{sub 2}/H{sub 2}SO{sub 4} 1:4).

  4. A Dual Source Ion Trap Mass Spectrometer for the Mars Organic Molecule Analyzer of ExoMars 2018

    NASA Technical Reports Server (NTRS)

    Brickerhoff, William B.; vanAmerom, F. H. W.; Danell, R. M.; Arevalo, R.; Atanassova, M.; Hovmand, L.; Mahaffy, P. R.; Cotter, R. J.

    2011-01-01

    We present details on the objectives, requirements, design and operational approach of the core mass spectrometer of the Mars Organic Molecule Analyzer (MOMA) investigation on the 2018 ExoMars mission. The MOMA mass spectrometer enables the investigation to fulfill its objective of analyzing the chemical composition of organic compounds in solid samples obtained from the near surface of Mars. Two methods of ionization are realized, associated with different modes of MOMA operation, in a single compact ion trap mass spectrometer. The stringent mass and power constraints of the mission have led to features such as low voltage and low frequency RF operation [1] and pulse counting detection.

  5. Characterization of the chemical composition of white chrysanthemum flowers of Hangzhou by using high-performance ion trap mass spectrometry.

    PubMed

    Zhou, Xiahui; Chen, Xiaocheng; Wu, Xin; Cao, Gang; Zhang, Junjie

    2016-04-01

    In this study, high-performance liquid chromatography coupled with amaZon SL high-performance ion trap mass spectrometry was used to analyze the target components in white chrysanthemum flowers of Hangzhou. Twenty-one components were detected and identified in both white chrysanthemum flowers of Hangzhou samples by using target compound analysis. Furthermore, seven new compounds in white chrysanthemum flowers of Hangzhou were found and identified by analyzing the fragment ion behavior in the mass spectra. The established method can be expedient for the global quality investigation of complex components in herbal medicines and food. PMID:26843262

  6. Improved Linear-Ion-Trap Frequency Standard

    NASA Technical Reports Server (NTRS)

    Prestage, John D.

    1995-01-01

    Improved design concept for linear-ion-trap (LIT) frequency-standard apparatus proposed. Apparatus contains lengthened linear ion trap, and ions processed alternately in two regions: ions prepared in upper region of trap, then transported to lower region for exposure to microwave radiation, then returned to upper region for optical interrogation. Improved design intended to increase long-term frequency stability of apparatus while reducing size, mass, and cost.

  7. Linear ion-trap mass spectrometric characterization of human pituitary nitrotyrosine-containing proteins

    NASA Astrophysics Data System (ADS)

    Zhan, Xianquan; Desiderio, Dominic M.

    2007-01-01

    The nitric oxide-mediated Tyr-nitration of endogenous proteins is associated with several pathological and physiological processes. In order to investigate the presence - and potential roles - of Tyr-nitration in the human pituitary, a large-format two-dimensional gel separation plus a Western blot against a specific anti-3-nitrotyrosine antibody were used to separate and detect nitroproteins from a human pituitary proteome. The nitroproteins were subjected to in-gel trypsin digestion, and high-sensitivity vacuum matrix-assisted laser desorption/ionization (vMALDI) linear ion-trap tandem mass spectrometry was used to analyze the tryptic peptides. Those MS/MS data were used to determine the amino acid sequence and the specific nitration site of each tryptic nitropeptide, and were matched to corresponding proteins with Bioworks TuboSEQUEST software. Compared to our previous study, 16 new nitrotyrosine-immunoreactive positive Western blot spots were found within the area pI 3.0-10 and Mr 10-100 kDa. Four new nitroproteins were discovered: the stanniocalcin 1 precursor--involved in calcium and phosphate metabolism; mitochondrial co-chaperone protein HscB, which might act as a co-chaperone in iron-sulfur cluster assembly in mitochrondria; progestin and adipoQ receptor family member III--a seven-transmembrane receptor; proteasome subunit alpha type 2--involved in an ATP/ubiquitin-dependent non-lysosomal proteolytic pathway. Those data demonstrate that nitric oxide-mediated Tyr-nitration might participate in various biochemical, metabolic, and pathological processes in the human pituitary.

  8. Nonlinear integrable ion traps

    SciTech Connect

    Nagaitsev, S.; Danilov, V.; /SNS Project, Oak Ridge

    2011-10-01

    Quadrupole ion traps can be transformed into nonlinear traps with integrable motion by adding special electrostatic potentials. This can be done with both stationary potentials (electrostatic plus a uniform magnetic field) and with time-dependent electric potentials. These potentials are chosen such that the single particle Hamilton-Jacobi equations of motion are separable in some coordinate systems. The electrostatic potentials have several free adjustable parameters allowing for a quadrupole trap to be transformed into, for example, a double-well or a toroidal-well system. The particle motion remains regular, non-chaotic, integrable in quadratures, and stable for a wide range of parameters. We present two examples of how to realize such a system in case of a time-independent (the Penning trap) as well as a time-dependent (the Paul trap) configuration.

  9. Detection of Chemical/Biological Agents and Stimulants using Quadrupole Ion Trap Mass Spectrometry

    SciTech Connect

    Harmon, S.H.; Hart, K.J.; Vass, A.A.; Wise, M.B.; Wolf, D.A.

    1999-06-14

    expanded with additional bacteria and fungi. These spectra were acquired on a Finnigan Magnum ion trap using helium buffer gas. A new database of Cl spectra of microorganisms is planned using the CBMS Block II instrument and air as the buffer gas. Using the current database, the fatty acid composition of the organisms was compared using the percentage of the ion current attributable to fatty acids. The data presented suggest promising rules for discrimination of these organisms. Strain, growth media and vegetative state do contribute to some of the distributions observed in the data. However, the data distributions observed in the current study only reflect our experience to date and do not fully represent the variability that might be expected in practice: Acquisition of MS/ MS spectra has begun (using He and air buffer gas) of the protonated molecular ion of a variety of fatty acids and for a number of ions nominally assigned as fatty acids from microorganisms. These spectra will be used to help verify fatty acid .

  10. A differentially pumped dual linear quadrupole ion trap (DLQIT) mass spectrometer: a mass spectrometer capable of MS(n) experiments free from interfering reactions.

    PubMed

    Owen, Benjamin C; Jarrell, Tiffany M; Schwartz, Jae C; Oglesbee, Rob; Carlsen, Mark; Archibold, Enada F; Kenttämaa, Hilkka I

    2013-12-01

    A novel differentially pumped dual linear quadrupole ion trap (DLQIT) mass spectrometer was designed and built to facilitate tandem MS experiments free from interfering reactions. The instrument consists of two differentially pumped Thermo Scientific linear quadrupole ion trap (LQIT) systems that have been connected via an ion transfer octupole encased in a machined manifold. Tandem MS experiments can be performed in the front trap and then the resulting product ions can be transferred via axial ejection into the back trap for further, independent tandem MS experiments in a differentially pumped area. This approach allows the examination of consecutive collision-activated dissociation (CAD) and ion-molecule reactions without unwanted side reactions that often occur when CAD and ion-molecule reactions are examined in the same space. Hence, it greatly facilitates investigations of ion structures. In addition, the overall lower pressure of the DLQIT, as compared to commercial LQIT instruments, results in a reduction of unwanted side reactions with atmospheric contaminants, such as water and oxygen, in CAD and ion-molecule experiments. PMID:24171553

  11. Characterizing the gas phase ion chemistry of an ion trap mobility spectrometry based explosive trace detector using a tandem mass spectrometer.

    PubMed

    Kozole, Joseph; Tomlinson-Phillips, Jill; Stairs, Jason R; Harper, Jason D; Lukow, Stefan R; Lareau, Richard T; Boudries, Hacene; Lai, Hanh; Brauer, Carolyn S

    2012-09-15

    A commercial-off-the-shelf (COTS) ion trap mobility spectrometry (ITMS) based explosive trace detector (ETD) has been interfaced to a triple quadrupole mass spectrometer (MS/MS) for the purpose of characterizing the gas phase ion chemistry intrinsic to the ITMS instrument. The overall objective of the research is to develop a fundamental understanding of the gas phase ionization processes in the ITMS based ETD to facilitate the advancement of its operational effectiveness as well as guide the development of next generation ETDs. Product ion masses, daughter ion masses, and reduced mobility values measured by the ITMS/MS/MS configuration for a suite of nitro, nitrate, and peroxide containing explosives are reported. Molecular formulas, molecular structures, and ionization pathways for the various product ions are inferred using the mass and mobility data in conjunction with density functional theory. The predominant product ions are identified as follows: [TNT-H](-) for trinitrotoluene (TNT), [RDX+Cl](-) for cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), [NO(3)](-) for ethylene glycol dinitrate (EGDN), [NG+NO(3)](-) for nitroglycerine (NG), [PETN+NO(3)](-) for pentaerythritol tetranitrate (PETN), [HNO(3)+NO(3)](-) for ammonium nitrate (NH(4)NO(3)), [HMTD-NC(3)H(6)O(3)+H+Cl](-) for hexamethylene triperoxide diamine (HMTD), and [(CH(3))(2)CNH(2)](+) for triacetone triperoxide (TATP). The predominant ionization pathways for the formation of the various product ions are determined to include proton abstraction, ion-molecule attachment, autoionization, first-order and multi-order thermolysis, and nucleophilic substitution. The ion trapping scheme in the reaction region of the ITMS instrument is shown to increase predominant ion intensities relative to the secondary ion intensities when compared to non-ion trap operation. PMID:22967626

  12. Tandem-in-space and tandem-in-time mass spectrometry: Triple quadrupoles and quadrupole ion traps

    SciTech Connect

    Johnson, J.V.; Yost, R.A. ); Kelley, P.E.; Bradford, D.C. )

    1990-10-15

    Tandem-in-time and tandem-in-space MS/MS on quadrupole ion trap (ITMS) and triple quadrupole (TQMS) tandem mass spectrometers, respectively, were compared by evaluating the MS/MS daughter spectra, efficiencies of collision-induced dissociation (CID), limits of detection, and dynamic ranges obtained for the methane positive chemical ionization (PCI)-CID of two alkylphosphonates. Although the yield of daughter ions is dependent upon a number of instrumental parameters on both instruments, with judicious selection of parameters the ITMS and TQMS both yielded daughter ions of similar relative abundances. The ITMS had greater efficiencies of fragmentation, collection, and mass selection and transmission of the daughter ions to the detector. With PCI-MS/MS analysis of diisopropyl methylphosphonate standards introduced via capillary gas chromatography, full daughter spectra could be obtained for as little as 15 pg and 1.5 ng injected for the ITMS and the TQMS, respectively.

  13. Determination of vanillin, ethyl vanillin, and coumarin in infant formula by liquid chromatography-quadrupole linear ion trap mass spectrometry.

    PubMed

    Shen, Yan; Han, Chao; Liu, Bin; Lin, Zhengfeng; Zhou, Xiujin; Wang, Chengjun; Zhu, Zhenou

    2014-02-01

    A simple, precise, accurate, and validated liquid chromatography-quadrupole linear ion trap mass spectrometry method was developed for the determination of vanillin, ethyl vanillin, and coumarin in infant formula samples. Following ultrasonic extraction with methanol/water (1:1, vol/vol), and clean-up on an HLB solid-phase extraction cartridge (Waters Corp., Milford, MA), samples were separated on a Waters XSelect HSS T3 column (150 × 2.1-mm i.d., 5-μm film thickness; Waters Corp.), with 0.1% formic acid solution-acetonitrile as mobile phase at a flow rate of 0.25 mL/min. Quantification of the target was performed by the internal standard approach, using isotopically labeled compounds for each chemical group, to correct matrix effects. Data acquisition was carried out in multiple reaction monitoring transitions mode, monitoring 2 multiple reaction monitoring transitions to ensure an accurate identification of target compounds in the samples. Additional identification and confirmation of target compounds were performed using the enhanced product ion modus of the linear ion trap. The novel liquid chromatography-quadrupole linear ion trap mass spectrometry platform offers the best sensitivity and specificity for characterization and quantitative determination of vanillin, ethyl vanillin, and coumarin in infant formula and fulfills the quality criteria for routine laboratory application. PMID:24359823

  14. Collision induced dissociation of protonated N-nitrosodimethylamine by ion trap mass spectrometry: Ultimate carcinogens in gas phase

    NASA Astrophysics Data System (ADS)

    Kulikova, Natalia; Baker, Michael; Gabryelski, Wojciech

    2009-12-01

    Collision induced dissociation of protonated N-nitrosodimethylamine (NDMA) and isotopically labeled N-nitrosodimethyl-d6-amine (NDMA-d6) was investigated by sequential ion trap mass spectrometry to establish mechanisms of gas phase reactions leading to intriguing products of this potent carcinogen. The fragmentation of (NDMA + H+) occurs via two dissociation pathways. In the alkylation pathway, homolytic cleavage of the N-O bond of N-dimethyl, N'-hydroxydiazenium ion generates N-dimethyldiazenium distonic ion which reacts further by a CH3 radical loss to form methanediazonium ion. Both methanediazonium ion and its precursor are involved in ion/molecule reactions. Methanediazonium ion showed to be capable of methylating water and methanol molecules in the gas phase of the ion trap and N-dimethyldiazenium distonic ion showed to abstract a hydrogen atom from a solvent molecule. In the denitrosation pathway, a tautomerization of N-dimethyl, N'-hydroxydiazenium ion to N-nitrosodimethylammonium intermediate ion results in radical cleavage of the N-N bond of the intermediate ion to form N-dimethylaminium radical cation which reacts further through [alpha]-cleavage to generate N-methylmethylenimmonium ion. Although the reactions of NDMA in the gas phase are different to those for enzymatic conversion of NDMA in biological systems, each activation method generates the same products. We will show that collision induced dissociation of N-nitrosodiethylamine (NDEA) and N-nitrosodipropylamine (NDPA) is also a feasible approach to gain information on formation, stability, and reactivity of alkylating agents originating from NDEA and NDPA. Investigating such biologically relevant, but highly reactive intermediates in the condensed phase is hampered by the short life-times of these transient species.

  15. Sympathetic cooling of a mass-mismatched two-ion chain in a double-well trap potential

    SciTech Connect

    Hasegawa, Taro

    2011-05-15

    Sympathetic cooling of two-ion system, in which one is laser-cooled and the other is sympathetically cooled and their masses are mismatched, in a linear rf trap with a double-well potential is proposed. The double-well potential consists of two wells, and there is one ion in each well. The axial frequencies of the two wells and the spatial interval between them are experimentally controllable. By theoretical analysis, the normal modes of the small oscillations around the equilibrium are derived, and a measure of the sympathetic cooling rate is obtained. As a result, it is found that the sympathetic cooling rate is fast when the frequency of the axial motion of the sympathetically cooled ion is close to that of the laser-cooled ion. In the double-well potential, the sympathetic cooling rate of the ion species whose mass is much heavier or lighter than that of the laser-cooled ion can be fast. The sympathetic cooling rate of C{sub 60}{sup +} by the laser-cooled Ba{sup +} in the double-well potential is estimated to be about 80 times faster than in the conventional setup. The double-well potential may be made by the microfabricated electrode configuration or by the optical dipole force trap.

  16. Asymmetric ion trap

    DOEpatents

    Barlow, Stephan E.; Alexander, Michael L.; Follansbee, James C.

    1997-01-01

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity.

  17. A Novel Dual-Pressure Linear Ion Trap Mass Spectrometer Improves the Analysis of Complex Protein Mixtures

    PubMed Central

    Pekar, Tonya; Blethrow, Justin D.; Schwartz, Jae C.; Merrihew, Gennifer E.; MacCoss, Michael J.; Swaney, Danielle L.; Russell, Jason D.; Coon, Joshua J.; Zabrouskov, Vlad

    2009-01-01

    The considerable progress in high throughput proteomics analysis via liquid chromatography-electrospray ionization-tandem mass spectrometry over the last decade has been fueled to a large degree by continuous improvements in instrumentation. High throughput identification experiments are based on peptide sequencing and are largely accomplished through the use of tandem mass spectrometry, with ion trap and trap-based instruments having become broadly adopted analytical platforms. To satisfy increasingly demanding requirements for depth of characterization and throughput, we present a newly developed dual-pressure linear ion trap mass spectrometer (LTQ Velos) that features increased sensitivity, afforded by a new source design, and demonstrates practical cycle times two times shorter than that of an LTQ XL, while improving or maintaining spectral quality for MS/MS fragmentation spectra. These improvements resulted in a substantial increase in the detection and identification of both proteins and unique peptides from the complex proteome of Caenorhabditis elegans, as compared to existing platforms. The greatly increased ion flux into the mass spectrometer in combination with improved isolation of low-abundance precursor ions resulted in increased detection of low-abundance peptides. These improvements cumulatively resulted in a substantially greater penetration into the baker’s yeast (Saccharomyces cerevisiae) proteome compared to LTQ XL. Alternatively, faster cycle times on the new instrument allowed for higher throughput for a given depth of proteome analysis, with more peptides and proteins identified in 60 min using an LTQ Velos than in 180 min using an LTQ XL. When mass analysis was carried out with resolution in excess of 25,000 FWHM, it became possible to isotopically resolve a small intact protein and its fragments, opening possibilities for top down experiments. PMID:19689114

  18. Mars Organic Molecule Analyzer (MOMA) Mass Spectrometer Flight Model and Future Ion Trap-Based Planetary Instruments

    NASA Astrophysics Data System (ADS)

    Brinckerhoff, W. B.; van Amerom, F. H. W.; Danell, R.; Pinnick, V. T.; Arevalo, R. D., Jr.; Li, X.; Grubisic, A.; Getty, S.; Hovmand, L.; Mahaffy, P. R.

    2015-12-01

    The Mars Organic Molecule Analyzer (MOMA) investigation on the 2018 ExoMars rover will examine the chemical composition of samples acquired from depths of up to two meters below the martian surface, where organics may be protected from radiative and oxidative degradation. MOMA combines pyrolysis gas chromatography mass spectrometry (GCMS) of bulk powder samples and Mars ambient laser desorption mass spectrometry (LDMS) surface analysis, using a single ion trap MS. This dual source design enables MOMA to detect compounds over a wide range of molecular weights and volatilities. The structure of any detected organics may be further examined using MOMA's tandem mass spectrometry (MS/MS) mode. The flight model (FM) ion trap sensor and electronics have been assembled under the extremely clean and sterile conditions required by ExoMars, and have met or exceeded all performance specifications during initial functional tests. After Mars ambient thermal cycling and calibration, the FM will be delivered as a subsystem of MOMA to rover integration in mid-2016. There MOMA will join complementary rover instruments such as the Raman and MicrOmega spectrometers designed to analyze common drill samples. Following the MOMA design, linear ion trap mass spectrometer (LITMS)-based instruments are under development for future missions. LITMS adds enhanced capabilities such as precision (point-by-point) analysis of drill cores, negative ion detection, a wider mass range, and higher temperature pyrolysis with precision evolved gas analysis, while remaining highly compact and robust. Each of the capabilities of LITMS has been demonstrated on breadboard hardware. The next phase will realize an end-to-end brassboard at flight scale that will meet stringent technology readiness level (TRL) 6 criteria, indicating readiness for development toward missions to Mars, comets, asteroids, outer solar system moons, and beyond.

  19. An improved thin-layer chromatography/mass spectrometry coupling using a surface sampling probe electrospray ion trap system

    SciTech Connect

    Ford, Michael J; Van Berkel, Gary J

    2004-01-01

    A combined surface sampling probe/electrospray emitter coupled with an ion trap mass spectrometer was used for the direct read out of unmodified reversed-phase C18 thin-layer chromatography (TLC) plates. The operation of the surface sampling electrospray ionization interface in positive and negative ionization modes was demonstrated through the direct analysis of TLC plates on which a commercial test mix comprised of four dye compounds viz., rhodamine B, fluorescein, naphthol blue black, and fast green FCF, and an extract of the caffeine-containing plant Ilex vomitoria, were spotted and developed. Acquisition of full-scan mass spectra and automated collection of MS/MS product ion spectra while scanning a development lane along the surface of a TLC plate demonstrated the advantages of using an ion trap in this combination. Details of the sampling system, benefits of analyzing a developed lane in both positive ion and negative ion modes, levels of detection while surface scanning, surface scan speed effects, and the utility of three-dimensional data display, are also discussed.

  20. Broad-Spectrum Drug Screening Using Liquid Chromatography-Hybrid Triple-Quadrupole Linear Ion Trap Mass Spectrometry.

    PubMed

    Stone, Judy

    2016-01-01

    Urine is processed with a simple C18 solid-phase extraction (SPE) and reconstituted in mobile phase. The liquid chromatography system (LC) injects 10 μL of extracted sample onto a reverse-phase LC column for gradient analysis with ammonium formate/acetonitrile mobile phases. Drugs in the column eluent become charged in the ion source using positive electrospray ionization (ESI). Pseudomolecular ions (M + H) are analyzed by a hybrid triple-quadrupole linear ion trap (QqQ and QqLIT) mass spectrometer using an SRM-IDA-EPI acquisition. An initial 125 compound selected ion monitoring (SRM) survey scan (triple quadrupole or QqQ mode) is processed by the information-dependent acquisition (IDA) algorithm. The IDA algorithm selects SRM signals from the survey scan with a peak height above the threshold (the three most abundant SRM signals above 1000 cps) to define precursor ions for subsequent dependent scanning. In the dependent QqLIT scan(s), selected precursor ion(s) are passed through the first quadrupole (Q1), fragmented with three different collision energies in the collision cell (Q2 or q), and product ions are collected in the third quadrupole (Q3), now operating as a linear ion trap (LIT). The ions are scanned out of the LIT in a mass dependent manner to produce a full-scan product ion spectrum (m/z 50-700) defined as an Enhanced (meaning acquired in LIT mode) Product Ion (EPI) spectrum (Mueller et al., Rapid Commun Mass Spectrom 19:1332-1338, 2005). Each EPI spectrum is linked to its precursor ion and to the associated SRM peak from the survey scan. EPI spectra are automatically searched against a 125 drug library of reference EPI spectra for identification. When the duty cycle is complete (one survey scan of 125 SRMs plus 0-3 dependent IDA-EPI scans) the mass spectrometer begins another survey scan of the 125 SRMs. PMID:26660183

  1. ANALYSIS FOR B-LACTAM ANTIBIOTICS IN KIDNEY TISSUE BY LIQUID CHROMATOGRAPHY WITH ELECTROSPRAY IONIZATION AND SELECTIVE REACTION MONITORING/TANDEM ION TRAP MASS SPECTROMETRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eleven B-lactams antibiotics were analyzed in fortified and incurred beef kidney tissue using high-performance liquid chromatography/selective reaction monitoring/tandem ion trap mass spectrometry. The analytes included: deacetylcephapirin, amoxicillin, cephapirin, desfuroylceftiofur cysteine disul...

  2. Finnigan ion trap mass spectrometer detection limits and thermal energy analyzer interface status report and present capabilities

    SciTech Connect

    Alcaraz, A.; Andresen, B.; Martin, W.

    1990-10-18

    A new Finnigan ion trap mass spectrometer was purchased and installed at LLNL. Over a period of several months the instrument was tested under a variety of conditions utilizing a capillary gas chromatography interface which allowed separated organic compounds to be carried directly into the ion source of the mass spectrometer. This direct interface allowed maximum analytical sensitivity. A variety of critical tests were performed in order to optimize the sensitivity of the system under a variety of analysis conditions. These tests altered the critical time cycles of the ionization, ion trapping, and detection. Various carrier gas pressures were also employed in order to ascertain the overall sensitivity of the instrument. In addition we have also interfaced a thermal energy analyzer (TEA) to the gas chromatograph in order to simultaneously detect volatile nitrogen containing compounds while mass spectral data is being acquired. This is the first application at this laboratory of simultaneous ultra-trace detections while utilizing two orthogonal analytical techniques. In particular, explosive-related compound and/or residues are of interest to the general community in water, soil and gas sampler. In this paper are highlighted a few examples of the analytical power of this new GC-TEA-ITMS technology.

  3. Identification of epoxide functionalities in protonated monofunctional analytes by using ion/molecule reactions and collision-activated dissociation in different ion trap tandem mass spectrometers.

    PubMed

    Eismin, Ryan J; Fu, Mingkun; Yem, Sonoeun; Widjaja, Fanny; Kenttämaa, Hilkka I

    2012-01-01

    A mass spectrometric method has been delineated for the identification of the epoxide functionalities in unknown monofunctional analytes. This method utilizes gas-phase ion/molecule reactions of protonated analytes with neutral trimethyl borate (TMB) followed by collision-activated dissociation (CAD) in an ion trapping mass spectrometer (tested for a Fourier-transform ion cyclotron resonance and a linear quadrupole ion trap). The ion/molecule reaction involves proton transfer from the protonated analyte to TMB, followed by addition of the analyte to TMB and elimination of methanol. Based on literature, this reaction allows the general identification of oxygen-containing analytes. Vinyl and phenyl epoxides can be differentiated from other oxygen-containing analytes, including other epoxides, based on the loss of a second methanol molecule upon CAD of the addition/methanol elimination product. The only other analytes found to undergo this elimination are some amides but they also lose O = B-R (R = group bound to carbonyl), which allows their identification. On the other hand, other epoxides can be differentiated from vinyl and phenyl epoxides and from other monofunctional analytes based on the loss of (CH(3)O)(2)BOH or formation of protonated (CH(3)O)(2)BOH upon CAD of the addition/methanol elimination product. For propylene oxide and 2,3-dimethyloxirane, the (CH(3)O)(2)BOH fragment is more basic than the hydrocarbon fragment, and the diagnostic ion (CH(3)O)(2)BOH (2) (+) is formed. These reactions involve opening of the epoxide ring. The only other analytes found to undergo (CH(3)O)(2)BOH elimination are carboxylic acids, but they can be differentiated from the rest based on several published ion/molecule reaction methods. Similar results were obtained in the Fourier-transform ion cyclotron resonance and linear quadrupole ion trap mass spectrometer. PMID:22002227

  4. Identification of Epoxide Functionalities in Protonated Monofunctional Analytes by Using Ion/Molecule Reactions and Collision-Activated Dissociation in Different Ion Trap Tandem Mass Spectrometers

    NASA Astrophysics Data System (ADS)

    Eismin, Ryan J.; Fu, Mingkun; Yem, Sonoeun; Widjaja, Fanny; Kenttämaa, Hilkka I.

    2012-01-01

    A mass spectrometric method has been delineated for the identification of the epoxide functionalities in unknown monofunctional analytes. This method utilizes gas-phase ion/molecule reactions of protonated analytes with neutral trimethyl borate (TMB) followed by collision-activated dissociation (CAD) in an ion trapping mass spectrometer (tested for a Fourier-transform ion cyclotron resonance and a linear quadrupole ion trap). The ion/molecule reaction involves proton transfer from the protonated analyte to TMB, followed by addition of the analyte to TMB and elimination of methanol. Based on literature, this reaction allows the general identification of oxygen-containing analytes. Vinyl and phenyl epoxides can be differentiated from other oxygen-containing analytes, including other epoxides, based on the loss of a second methanol molecule upon CAD of the addition/methanol elimination product. The only other analytes found to undergo this elimination are some amides but they also lose O = B-R (R = group bound to carbonyl), which allows their identification. On the other hand, other epoxides can be differentiated from vinyl and phenyl epoxides and from other monofunctional analytes based on the loss of (CH3O)2BOH or formation of protonated (CH3O)2BOH upon CAD of the addition/methanol elimination product. For propylene oxide and 2,3-dimethyloxirane, the (CH3O)2BOH fragment is more basic than the hydrocarbon fragment, and the diagnostic ion (CH3O)2BOH{2/+} is formed. These reactions involve opening of the epoxide ring. The only other analytes found to undergo (CH3O)2BOH elimination are carboxylic acids, but they can be differentiated from the rest based on several published ion/molecule reaction methods. Similar results were obtained in the Fourier-transform ion cyclotron resonance and linear quadrupole ion trap mass spectrometer.

  5. Direct atmospheric pressure chemical ionisation ion trap mass spectrometry for aroma analysis: Speed, sensitivity and resolution of isobaric compounds

    NASA Astrophysics Data System (ADS)

    Jublot, Lionel; Linforth, Robert S. T.; Taylor, Andrew J.

    2005-06-01

    Atmospheric pressure chemical ionisation (APCI) sources were developed for real time analysis of volatile release from foods using an ion trap (IT) mass spectrometer (MS). Key objectives were spectral simplicity (minimal fragmentation), response time and signal to noise ratio. The benefits of APCI-IT-MS were assessed by comparing the performance for in vivo and headspace analyses with that obtained using APCI coupled to a quadrupole mass analyser. Using MS-MS, direct APCI-IT-MS was able to differentiate mixtures of some C6 and terpene isobaric aroma compounds. Resolution could be achieved for some compounds by monitoring specific secondary ions. Direct resolution was also achieved with two of the three isobaric compounds released from chocolate with time as the sample was eaten.

  6. A single trapped ion in a finite range trap

    SciTech Connect

    Bagheri Harouni, M.; Davoudi Darareh, M.

    2011-04-15

    Research Highlights: > We present a method to describe dynamics of an ion confined in a finite size trap. > The trap is modeled with a potential in the context of an f-deformed oscillator. > The ion exhibits nonclassical properties such as squeezing and quantum interference. > . > Also this system can be used to generate highly excited motional Fock state. > The Hilbert space size effects and nano traps can be investigated by this model. - Abstract: This paper presents a method to describe dynamics of an ion confined in a realistic finite range trap. We model this realistic potential with a solvable one and we obtain dynamical variables (raising and lowering operators) of this potential. We consider coherent interaction of this confined ion in a finite range trap and we show that its center-of-mass motion steady state is a special kind of nonlinear coherent states. Physical properties of this state and their dependence on the finite range of potential are studied.

  7. Mass Spectrometry Parameters Optimization for the 46 Multiclass Pesticides Determination in Strawberries with Gas Chromatography Ion-Trap Tandem Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Fernandes, Virgínia C.; Vera, Jose L.; Domingues, Valentina F.; Silva, Luís M. S.; Mateus, Nuno; Delerue-Matos, Cristina

    2012-12-01

    Multiclass analysis method was optimized in order to analyze pesticides traces by gas chromatography with ion-trap and tandem mass spectrometry (GC-MS/MS). The influence of some analytical parameters on pesticide signal response was explored. Five ion trap mass spectrometry (IT-MS) operating parameters, including isolation time (IT), excitation voltage (EV), excitation time (ET), maximum excitation energy or " q" value (q), and isolation mass window (IMW) were numerically tested in order to maximize the instrument analytical signal response. For this, multiple linear regression was used in data analysis to evaluate the influence of the five parameters on the analytical response in the ion trap mass spectrometer and to predict its response. The assessment of the five parameters based on the regression equations substantially increased the sensitivity of IT-MS/MS in the MS/MS mode. The results obtained show that for most of the pesticides, these parameters have a strong influence on both signal response and detection limit. Using the optimized method, a multiclass pesticide analysis was performed for 46 pesticides in a strawberry matrix. Levels higher than the limit established for strawberries by the European Union were found in some samples.

  8. Collection method for chemical particulates on surfaces with detection using thermal desorption-ion trap mass spectrometry.

    PubMed

    Ewing, K J; Gibson, D; Sanghera, J; Miklos, F

    2013-05-01

    Successful analysis of particulate/low vapor pressure analytes such as explosives and toxic chemicals, and commercial pesticides require new sampling tools that enable detection of these analytes using current vapor phase detection instruments. We describe a sampling approach that uses stainless steel screens coated with a sticky polydimethyl siloxane (PDMS) coating to capture particulates from surfaces. Preliminary results for the collection of dimethyl methylphosphonate (DMMP) sorbed onto silica gel (SG) particulates (DMMP/SG) from a surface with subsequent analysis by thermal desorption-cylindrical ion trap mass spectrometry (TD-CITMS) are reported. PMID:23601282

  9. Characterization of dihydrostreptomycin-related substances by liquid chromatography coupled to ion trap mass spectrometry.

    PubMed

    Pendela, Murali; Hoogmartens, Jos; Van Schepdael, Ann; Adams, Erwin

    2009-06-01

    Dihydrostreptomycin sulphate (DHS) is a water-soluble, broad-spectrum aminoglycoside antibiotic. For quantitative analysis, the European Pharmacopoeia (Ph. Eur.) prescribes an ion-pairing liquid chromatography/ultraviolet (LC/UV) method using a C18 stationary phase. Several unknown compounds were detected in commercial samples. Hence, for characterization of these unknown peaks in a commercial DHS sample, the Ph. Eur. method was coupled to mass spectrometry (MS). However, since the Ph. Eur. method uses a non-volatile mobile phase, each peak eluted was collected and desalted before introduction into the mass spectrometer. The desalting procedure was applied to remove the non volatile salt, buffer and ion-pairing reagent in the collected fraction. In total, 20 impurities were studied and 14 of them were newly characterized. Five impurities which are already reported in the literature were also traced in this LC/UV method. PMID:19449319

  10. Active stabilization of ion trap radiofrequency potentials

    NASA Astrophysics Data System (ADS)

    Johnson, K. G.; Wong-Campos, J. D.; Restelli, A.; Landsman, K. A.; Neyenhuis, B.; Mizrahi, J.; Monroe, C.

    2016-05-01

    We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a radiofrequency (rf) Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic oscillation frequency to be better than 10 Hz or 10 ppm. This represents a suppression of ambient noise on the rf circuit by 34 dB. This technique could impact the sensitivity of ion trap mass spectrometry and the fidelity of quantum operations in ion trap quantum information applications.

  11. Some Rare Earth Elements Analysis by Microwave Plasma Torch Coupled with the Linear Ion Trap Mass Spectrometry

    PubMed Central

    Xiong, Xiaohong; Jiang, Tao; Qi, Wenhao; Zuo, Jun; Yang, Meiling; Fei, Qiang; Xiao, Saijin; Yu, Aimin; Zhu, Zhiqiang; Chen, Huanwen

    2015-01-01

    A sensitive mass spectrometric analysis method based on the microwave plasma technique is developed for the fast detection of trace rare earth elements (REEs) in aqueous solution. The plasma was produced from a microwave plasma torch (MPT) under atmospheric pressure and was used as ambient ion source of a linear ion trap mass spectrometer (LTQ). Water samples were directly pneumatically nebulized to flow into the plasma through the central tube of MPT. For some REEs, the generated composite ions were detected in both positive and negative ion modes and further characterized in tandem mass spectrometry. Under the optimized conditions, the limit of detection (LOD) was at the level 0.1 ng/mL using MS2 procedure in negative mode. A single REE analysis can be completed within 2~3 minutes with the relative standard deviation ranging between 2.4% and 21.2% (six repeated measurements) for the 5 experimental runs. Moreover, the recovery rates of these REEs are between the range of 97.6%–122.1%. Two real samples have also been analyzed, including well and orange juice. These experimental data demonstrated that this method is a useful tool for the field analysis of REEs in water and can be used as an alternative supplement of ICP-MS. PMID:26421013

  12. Determination of triacylglycerol regioisomers using electrospray ionization-quadrupole ion trap mass spectrometry with a kinetic method.

    PubMed

    Leveque, Nathalie L; Acheampong, Akwasi; Heron, Sylvie; Tchapla, Alain

    2012-04-13

    The kinetic method was applied to differentiate and quantify mixtures of regioisomeric triacylglycerols (TAGs) by generating and mass selecting alkali ion bound metal dimeric clusters with a TAG chosen as reference (ref) and examining their competitive dissociations in a quadrupole ion trap mass spectrometer. This methodology readily distinguished pairs of regioisomers (AAB/ABA) such as LLO/LOL, OOP/OPO and SSP/SPS and consequently distinguished sn-1/sn-3, sn-2 substituents on the glycerol backbone. The dimeric complex ions [ref, Li, TAG((AAB and/or ABA))](+) generated by electrospray ionization mass spectrometry were subjected to collision induced dissociation causing competitive loss of either the neutral TAG reference (ref) leading to [Li(AAB and/or ABA)](+) or the neutral TAG molecule (TAG((AAB and/or ABA))) leading to [ref, Li](+). The ratio of the two competitive dissociation rates, defined by the product ion branching ratio (R(iso)), was related via the kinetic method to the regioisomeric composition of the investigated TAG mixture. In this work, a linear correlation was established between composition of the mixture of each TAG regioisomer and the logarithm of the branching ratio for competitive fragmentation. Depending on the availability of at least one TAG regioisomer as standard, the kinetic method and the standard additions method led to the quantitative analysis of natural TAG mixtures. PMID:22444537

  13. Some Rare Earth Elements Analysis by Microwave Plasma Torch Coupled with the Linear Ion Trap Mass Spectrometry.

    PubMed

    Xiong, Xiaohong; Jiang, Tao; Qi, Wenhao; Zuo, Jun; Yang, Meiling; Fei, Qiang; Xiao, Saijin; Yu, Aimin; Zhu, Zhiqiang; Chen, Huanwen

    2015-01-01

    A sensitive mass spectrometric analysis method based on the microwave plasma technique is developed for the fast detection of trace rare earth elements (REEs) in aqueous solution. The plasma was produced from a microwave plasma torch (MPT) under atmospheric pressure and was used as ambient ion source of a linear ion trap mass spectrometer (LTQ). Water samples were directly pneumatically nebulized to flow into the plasma through the central tube of MPT. For some REEs, the generated composite ions were detected in both positive and negative ion modes and further characterized in tandem mass spectrometry. Under the optimized conditions, the limit of detection (LOD) was at the level 0.1 ng/mL using MS(2) procedure in negative mode. A single REE analysis can be completed within 2~3 minutes with the relative standard deviation ranging between 2.4% and 21.2% (six repeated measurements) for the 5 experimental runs. Moreover, the recovery rates of these REEs are between the range of 97.6%-122.1%. Two real samples have also been analyzed, including well and orange juice. These experimental data demonstrated that this method is a useful tool for the field analysis of REEs in water and can be used as an alternative supplement of ICP-MS. PMID:26421013

  14. Structural Distinction of Diacyl-, Alkylacyl, and Alk-1-Enylacyl Glycerophosphocholines as [M - 15]- Ions by Multiple-Stage Linear Ion-Trap Mass Spectrometry with Electrospray Ionization

    NASA Astrophysics Data System (ADS)

    Hsu, Fong-Fu; Lodhi, Irfan J.; Turk, John; Semenkovich, Clay F.

    2014-08-01

    We describe a linear ion-trap (LIT) multiple-stage (MSn) mass spectrometric approach towards differentiation of alkylacyl, alk-1-enylacyl- and diacyl-glycerophoscholines (PCs) as the [M - 15]- ions desorbed by electrospray ionization (ESI) in the negative-ion mode. The MS4 mass spectra of the [M - 15 - R2'CH = CO]- ions originated from the three PC subfamilies are readily distinguishable, resulting in unambiguous distinction of the lipid classes. This method is applied to two alkyl ether rich PC mixtures isolated from murine bone marrow neutrophils and kidney, respectively, to explore its utility in the characterization of complex PC mixture of biological origin, resulting in the realization of the detailed structures of the PC species, including various classes and many minor isobaric isomers.

  15. Structural elucidation of monoterpene oxidation products by ion trap fragmentation using on-line atmospheric pressure chemical ionisation mass spectrometry in the negative ion mode.

    PubMed

    Warscheid, B; Hoffmann, T

    2001-01-01

    Based on ion trap mass spectrometry, an on-line method is described which provides valuable information on the molecular composition of structurally complex organic aerosols. The investigated aerosols were generated from the gas-phase ozonolysis of various C(10)H(16)-terpenes (alpha-pinene, beta-pinene, 3-carene, sabinene, limonene), and directly introduced into the ion source of the mass spectrometer. Negative ion chemical ionisation at atmospheric pressure (APCI(-)) enabled the detection of multifunctional carboxylic acid products by combining inherent sensitivity and molecular weight information. Sequential low-energy collision-induced product ion fragmentation experiments (MS(n)) were performed in order to elucidate characteristic decomposition pathways of the compounds. Dicarboxylic acids, oxocarboxylic acids and hydroxyketocarboxylic acid products could be clearly distinguished by multistage on-line MS. Furthermore, sabinonic acid and two C(9)-ether compounds were tentatively identified for the first time by applying on-line APCI(-)-MS(n). PMID:11746892

  16. Imaging MS Methodology for More Chemical Information in Less Data Acquisition Time Utilizing a Hybrid Linear Ion Trap-Orbitrap Mass Spectrometer

    SciTech Connect

    Perdian, D. C.; Lee, Young Jin

    2010-11-15

    A novel mass spectrometric imaging method is developed to reduce the data acquisition time and provide rich chemical information using a hybrid linear ion trap-orbitrap mass spectrometer. In this method, the linear ion trap and orbitrap are used in tandem to reduce the acquisition time by incorporating multiple linear ion trap scans during an orbitrap scan utilizing a spiral raster step plate movement. The data acquisition time was decreased by 43-49% in the current experiment compared to that of orbitrap-only scans; however, 75% or more time could be saved for higher mass resolution and with a higher repetition rate laser. Using this approach, a high spatial resolution of 10 {micro}m was maintained at ion trap imaging, while orbitrap spectra were acquired at a lower spatial resolution, 20-40 {micro}m, all with far less data acquisition time. Furthermore, various MS imaging methods were developed by interspersing MS/MS and MSn ion trap scans during orbitrap scans to provide more analytical information on the sample. This method was applied to differentiate and localize structural isomers of several flavonol glycosides from an Arabidopsis flower petal in which MS/MS, MSn, ion trap, and orbitrap images were all acquired in a single data acquisition.

  17. Comparison of liquid chromatography using triple quadrupole and quadrupole ion trap mass analyzers to determine pesticide residues in oranges.

    PubMed

    Soler, Carla; Mañes, Jordi; Picó, Yolanda

    2005-03-01

    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 72-92% by LC-QIT/MS with the R.S.D. from five replicate analysis 4-14% and 8-18%, respectively. Matrix effects were tested for both techniques by standard addition to blank extracts. Although the matrix effects are not originated in mass analyzer but in the LC/MS interface, they were, generally, more marked by LC-QIT-MS than by LC-TQ/MS. The limits of quantification (LOQs) were 0.005-0.2 mg kg(-1) by both equipments--appropriate values for determining these pesticides in orange from the regulatory point of view. The results indicate that the TQ provides higher precision, better linearity, it is more robust, and when the purpose of the analysis is quantitative determination, preferable over the QIT. However, the application of both mass spectrometers to analyze orange samples conventionally treated showed that any can be used for qualitative and quantitative purposes. PMID:15844516

  18. Thermally Accelerated Oxidative Degradation of Quercetin Using Continuous Flow Kinetic Electrospray-Ion Trap-Time of Flight Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Barnes, Jeremy S.; Foss, Frank W.; Schug, Kevin A.

    2013-10-01

    Thermally accelerated oxidative degradation of aqueous quercetin at pH 5.9 and 7.4 was kinetically measured using an in-house built online continuous flow device made of concentric capillary tubes, modified to fit to the inlet of an electrospray ionization-ion trap-time-of-flight-mass spectrometer (ESI-IT-TOF-MS). Time-resolved mass spectral measurements ranging from 2 to 21 min were performed in the negative mode to track intermediate degradation products and to evaluate the degradation rate of the deprotonated quercetin ion, [Q-H]-. Upon heating solutions in the presence of dissolved oxygen, degradation of [Q-H]- was observed and was accelerated by an increase in pH and temperature. Regardless of the condition, the same degradation pathways were observed. Degradation mechanisms and structures were determined using higher order tandem mass spectrometry (up to MS3) and high mass accuracy. The observed degradation mechanisms included oxidation, hydroxylation, and ring-cleavage by nucleophilic attack. A chalcan-trione structure formed by C-ring opening after hydroxylation at C2 was believed to be a precursor for other degradation products, formed by hydroxylation at the C2, C3, and C4 carbons from attack by nucleophilic species. This resulted in A-type and B-type ions after cross-ring cleavage of the C-ring. Based on time of appearance and signal intensity, nucleophilic attack at C3 was the preferred degradation pathway, which generated 2,4,6-trihydroxymandelate and 2,4,6-trihydroxyphenylglyoxylate ions. Overall, 23 quercetin-related ions were observed.

  19. Ion trap in a semiconductor chip

    NASA Astrophysics Data System (ADS)

    Stick, D.; Hensinger, W. K.; Olmschenk, S.; Madsen, M. J.; Schwab, K.; Monroe, C.

    2006-01-01

    The electromagnetic manipulation of isolated atoms has led to many advances in physics, from laser cooling and Bose-Einstein condensation of cold gases to the precise quantum control of individual atomic ions. Work on miniaturizing electromagnetic traps to the micrometre scale promises even higher levels of control and reliability. Compared with `chip traps' for confining neutral atoms, ion traps with similar dimensions and power dissipation offer much higher confinement forces and allow unparalleled control at the single-atom level. Moreover, ion microtraps are of great interest in the development of miniature mass-spectrometer arrays, compact atomic clocks and, most notably, large-scale quantum information processors. Here we report the operation of a micrometre-scale ion trap, fabricated on a monolithic chip using semiconductor micro-electromechanical systems (MEMS) technology. We confine, laser cool and measure heating of a single 111Cd+ ion in an integrated radiofrequency trap etched from a doped gallium-arsenide heterostructure.

  20. Single CdSe/ZnS nanocrystals in an ion trap: charge and mass determination and photophysics evolution with changing mass, charge, and temperature.

    PubMed

    Bell, David M; Howder, Collin R; Johnson, Ryan C; Anderson, Scott L

    2014-03-25

    We report measurements of fluorescence intermittency (blinking) and spectral behavior for single semiconductor nanocrystal quantum dots (QDs) isolated in the gas phase and discuss the effects on fluorescence of the QD charge state and heating to the point of sublimation. Core-shell CdSe/ZnS QDs were trapped in a quadrupole ion trap and detected by laser-induced fluorescence. The mass (M) and charge (Q) were determined nondestructively, and both were followed continuously over the course of hours or days. Emission spectra of the trapped QDs are significantly red-shifted relative to the solution-phase emission from the same particles. The temperature of the trapped QDs is determined by the balance between laser heating and collisional cooling and thermal emission, and it is possible to heat the particles to remove ligands or to the point of sublimation. QDs are observed to be emissive during sublimation, for up to 85% mass loss, with emission intensity roughly proportional to the surface area. Eventually, the fluorescence quantum yield drops suddenly, and the QDs begin to blink. The method used is versatile and will allow studies of quantum dot optical properties as a function of size, ligand removal, heating, surface oxidation, and other manipulations, where these properties are continuously correlated with the mass and charge. PMID:24410129

  1. Differentiation of regioisomeric aromatic ketocarboxylic acids by atmospheric pressure chemical ionization CAD tandem mass spectrometry in a linear quadrupole ion trap mass spectrometer

    SciTech Connect

    Amundson, Lucas M.; Owen, Ben C.; Gallardo, Vanessa A.; Habicht, S. C.; Fu, M.; Shea, R. C.; Mossman, A. B.; Kenttämaa, Hilkka I.

    2011-01-01

    Positive-mode atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS n ) was tested for the differentiation of regioisomeric aromatic ketocarboxylic acids. Each analyte forms exclusively an abundant protonated molecule upon ionization via positive-mode APCI in a commercial linear quadrupole ion trap (LQIT) mass spectrometer. Energy-resolved collision-activated dissociation (CAD) experiments carried out on the protonated analytes revealed fragmentation patterns that varied based on the location of the functional groups. Unambiguous differentiation between the regioisomers was achieved in each case by observing different fragmentation patterns, different relative abundances of ion-molecule reaction products, or different relative abundances of fragment ions formed at different collision energies. The mechanisms of some of the reactions were examined by H/D exchange reactions and molecular orbital calculations.

  2. Differentiation of Regioisomeric Aromatic Ketocarboxylic Acids by Positive Mode Atmospheric Pressure Chemical Ionization Collision-Activated Dissociation Tandem Mass Spectrometry in a Linear Quadrupole Ion Trap Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Amundson, Lucas M.; Owen, Benjamin C.; Gallardo, Vanessa A.; Habicht, Steven C.; Fu, Mingkun; Shea, Ryan C.; Mossman, Allen B.; Kenttämaa, Hilkka I.

    2011-04-01

    Positive-mode atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS n ) was tested for the differentiation of regioisomeric aromatic ketocarboxylic acids. Each analyte forms exclusively an abundant protonated molecule upon ionization via positive-mode APCI in a commercial linear quadrupole ion trap (LQIT) mass spectrometer. Energy-resolved collision-activated dissociation (CAD) experiments carried out on the protonated analytes revealed fragmentation patterns that varied based on the location of the functional groups. Unambiguous differentiation between the regioisomers was achieved in each case by observing different fragmentation patterns, different relative abundances of ion-molecule reaction products, or different relative abundances of fragment ions formed at different collision energies. The mechanisms of some of the reactions were examined by H/D exchange reactions and molecular orbital calculations.

  3. Analysis of environmental contaminates in hair using an ion trap mass spectrometer with a filtered noise field waveboard

    SciTech Connect

    Alcaraz, A.; Hulsey, S.S.; Frantz, C.E.; Andresen, B.D.

    1994-12-31

    A variety of methods have been established using mass spectrometry (MS) for the analysis of chemicals in hair. Much of this past work has been focused on the detection of drugs of abuse. Human hair has been analyzed either directly by probe distillation (DIP) with some preliminary clean-up using HPLC or solid phase extraction (SPE). However, established drug analysis methods do not apply for the detection of some environmental contaminates. In this study, the authors selected 2,4,6-trinitrotoluene (TNT) and malathion as the target compounds. In addition two types of hair samples were analyzed: (1) human hair fortified with either TNT or malathion and (2) hair from mice who ingested the same analytes. The analytical method was DIP-EI-MS/MS with an ion trap mass spectrometer equipped with a filtered noise field wave board.

  4. Rapid analysis of animal drug residues by microcolumn solid-phase extraction and thermal desorption-ion trap mass spectrometry

    SciTech Connect

    Barshick, S.A.; Buchanan, M.V.

    1994-11-01

    A new approach was developed for the rapid and quantitative determination of an anthelmintic drug, phenothiazine, in milk. The technique involves a simple extraction procedure using a C{sub 18} microcolumn disc, followed by thermal desorption of the analyte from the disc directly into an ion trap mass spectrometer. The compounds are selectively ionized by isobutane chemical ionization and detected by tandem mass spectrometry. With this approach, 10 ppb detection limits were achieved with as little as 100 {mu}L mild and only 10 min of analysis time. This approach was used to analyze samples of milk taken from a cow administered a one-time therapeutic dose of phenothiazine. The target compound could be detected at 56 post-dosage, corresponding to a concentration of 30 ppb. 13 refs., 3 figs., 2 tabs.

  5. Identification and quantification of active alkaloids in Catharanthus roseus by liquid chromatography-ion trap mass spectrometry.

    PubMed

    Chen, Qinhua; Zhang, Wenpeng; Zhang, Yulin; Chen, Jing; Chen, Zilin

    2013-08-15

    Catharanthus roseus is an important dicotyledonous medicinal plant that produces anticancer compounds. The active alkaloids vinblastine, vindoline, ajmalicine, catharanthine, and vinleurosine were identified by direct-injection ion trap-mass spectrometry (IT-MS) for collecting MS(1-2) spectra. The determinations of five alkaloids were accomplished by liquid chromatography (LC) with UV and MS detections. The analytes provided good signals corresponding to the protonated molecular ions [M+H](+) and product ions. The precursor ions and product ions for quantification of vinblastine, vindoline, ajmalicine, catharanthine, and vinleurosine were m/z 825→807, 457→397, 353→144, 337→144 and 809→748 by LC-IT-MS, respectively. Two methods were used to evaluate a number of validation characteristics (repeatability, LOD, calibration range, and recovery). MS provided a high selectivity and sensitivity for determination of five alkaloids in positive mode. After optimisation of the methods, separation, identification and quantification of the five components in C. roseus were comprehensively accomplished by HPLC with UV and MS detection. PMID:23561180

  6. A Quadrupole Ion Trap Mass Spectrometer for Quantitative Analysis of Nitrogen-Purged Compartments within the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Ottens, Andrew K.; Griffin, Timothy P.; Helms, William R.; Yost, Richard A.; Steinrock, T. (Technical Monitor)

    2001-01-01

    To enter orbit, the Space Shuttle burns 1.8 million liters of liquid hydrogen combined with 0.8 million liters of liquid oxygen through three rocket engines mounted in the aft. NASA monitors the nitrogen-purged aft compartment for increased levels of hydrogen or oxygen in order to detect and determine the severity of a cryogenic fuel leak. Current monitoring is accomplished with a group of mass spectrometer systems located as much as 400 feet away from the Shuttle. It can take up to 45 seconds for gas to reach the mass spectrometer, which precludes monitoring for leaks in the final moments before liftoff (the orbiter engines are started at T-00:06 seconds). To remedy the situation, NASA is developing a small rugged mass spectrometer to be used as point-sensors around the Space Shuttle. As part of this project, numerous mass analyzer technologies are being investigated. Presented here are the preliminary results for one such technology, quadrupole ion trap mass spectrometry (QITMS). A compact QITMS system has been developed in-house at the University of Florida for monitoring trace levels of four primary gases, hydrogen, helium, oxygen, and argon, all in a nitrogen background. Since commercially available QITMS systems are incapable of mass analysis at m/z(exp 2), the home-built system is preferred for the evaluation of QITMS technology.

  7. On-line capillary electrophoresis/microelectrospray ionization-tandem mass spectrometry using an ion trap storage/time-of-flight mass spectrometer with SWIFT technology.

    PubMed

    Jin, X; Kim, J; Parus, S; Lubman, D M; Zand, R

    1999-08-15

    The development of a system capable of the speed required for on-line capillary electrophoresis-tandem mass spectrometry (CE-MS/MS) of tryptic digests is described. The ion trap storage/reflectron time-of-flight (IT/reTOF) mass spectrometer is used as a nonscanning detector for rapid CE separation, where the peptides are ionized on-line using electrospray ionization (ESI). The ESI produced ions are stored in the ion trap and dc pulse injected into the reTOF-MS at a rate sufficient to maintain the separation achieved by CE. Using methodology generated by software and hardware developed in our lab, we can produce SWIFT (Stored Waveform Inverse Fourier Transform) ion isolation and TICKLE activation/fragmentation voltage waveforms to generate MS/MS at a rate as high as 10 Hz so that the MS/MS spectra can be optimized on even a 1-2 s eluting peak. In CE separations performed on tryptic digests of dogfish myelin basic protein (MBP) where eluting peaks 4-8 s wide are observed, it is demonstrated that an acquisition rate of 4 Hz provides > 20 spectra/peak and is more than sufficient to provide optimized MS/MS spectra of each of the eluting peaks in the electropherogram. The detailed structural analysis of dogfish MBP including several posttranslational modifications using CE-MS and CE-MS/MS is demonstrated using this method with < 10 fmol of material consumed. PMID:10464485

  8. Identification of 2-aminothiazolobenzazepine metabolites in human, rat, dog, and monkey microsomes by ion-molecule reactions in linear quadrupole ion trap mass spectrometry.

    PubMed

    Zhang, Minli; Eismin, Ryan; Kenttämaa, Hilkka; Xiong, Hui; Wu, Ye; Burdette, Doug; Urbanek, Rebecca

    2015-03-01

    2-Aminothiazolobenzazepine (2-ATBA), 7-[(1-methyl-1H-pyrazol-4-yl)methyl]-6,7,8,9-tetrahydro-5H-[1,3]thiazolo[4,5-h][3]benzazepin-2-amine, is a D2 partial agonist that has demonstrated antipsychotic effects in a rodent in vivo efficacy model. The metabolite profile showed that 2-ATBA is mainly metabolized by oxidation. However, identification of the oxidation site(s) in the 2-aminothiazole group presents a challenge for the traditional metabolite identification methods such as liquid chromatography/mass spectrometry and NMR due to the lack of unique tandem mass spectrometry fragmentation patterns for ions with the 2-aminothiazole group oxidized at different sites and the lack of stability for purification or reference standard synthesis. We describe the characterization of the oxidized heteroatoms of the 2-aminothiazole group via gas-phase ion-molecule reactions (GPIMR) in a modified linear quadrupole ion trap mass spectrometer. The GPIMR reagents used were dimethyl disulfide, tert-butyl peroxide, and tri(dimethylamino)borane. Each reagent was introduced into the ion trap through the helium line and was allowed to react with the protonated metabolites. The ionic ion-molecule reaction products and their fragmentation profiles were compared with the profiles of the ionic ion-molecule reaction products of protonated reference compounds that had specific heteroatom functionalities. The oxidized 2-aminothiazole metabolite of 2-ATBA showed a similar GPIMR profile to that of the reference compounds with a tertiary N-oxide functionality and distinct from the profiles of the reference compounds with N-aryl hydroxylamine, nitroso, or pyridine N-oxide functionalities. This study demonstrates the feasibility of fingerprinting the chemical nature of oxidized nitrogen functional groups via GPIMR profiling for metabolite structure elucidation. PMID:25547868

  9. Identification of cephapirin metabolites and degradants in bovine milk by electrospray ionization--ion trap tandem mass spectrometry.

    PubMed

    Heller, D N; Kaplan, D A; Rummel, N G; von Bredow, J

    2000-12-01

    Liquid chromatography-ion trap tandem mass spectrometry (LC-MS/MS) with electrospray ionization was used to identify cephapirin metabolites and degradants in milk from cows dosed with cephapirin. The milk was extracted according to a previously published procedure. Structures for various components were tentatively identified by their molecular weight, product ion mass spectra, and/or correspondence to standard mass spectra. These components may have occurred as metabolites or as degradants that occurred on storage or during extraction. Compounds identified in the milk included cephapirin, desacetylcephapirin, cephapirin lactone, hydrolyzed cephapirin, and a reduced cephapirin lactone that has not previously been reported. Methylcephapirin was also identified, possibly as a trace contaminant in the formulation. Analysis of incurred milk extracts showed that cephapirin and desacetylcephapirin are the major residues in milk. Desacetylcephapirin residues persisted about as long as the parent drug. The detection limit for both residues by LC-MS/MS was approximately 1 ng/mL in milk. These results have implications for microbiological methods or rapid test kits, if such methods or kits respond to cephapirin metabolites and degradants present in the milk. PMID:11141270

  10. Experiments in Planar Multipole Ion Traps

    NASA Astrophysics Data System (ADS)

    Clark, Rob; Burke, Timothy; Green, Dylan

    2016-05-01

    We present the design and demonstration of multipole ion traps based on concentric rings. We have developed both surface-electrode and layered planar trap designs which enable one to null the quadratic term in the electric potential to a high degree. Experiments demonstrating frequency upconversion of an applied signal demonstrate the nonlinear dynamics present in the trap. Applications include quantum chaos, ultracold chemistry, and, potentially, mass spectrometry. We acknowledge support from the Research Corporation for Science Advancement and from The Citadel Foundation.

  11. Characterization of column packing materials in high-performance liquid chromatography by charge-detection quadrupole ion trap mass spectrometry.

    PubMed

    Xiong, Caiqiao; Zhou, Xiaoyu; Chen, Rui; Zhang, Yiming; Peng, Wen-Ping; Nie, Zongxiu; Chang, Huan-Cheng; Liu, Huwei; Chen, Yi

    2011-07-01

    This article reports an application of charge-detection quadrupole ion trap mass spectrometry (CD-ITMS) to characterize the column packing materials in high-performance liquid chromatography (HPLC). Both the mean mass and the mass distribution of the packing materials are obtained and used to calculate the specific surface area of unbonded silica, the carbon load of the bonded silica, and their particle size distributions. The obtained specific surface areas and carbon loads are consistent with those measured independently by nitrogen sorption and elemental analysis respectively, whereas the derived size distributions show better resolution than that measured by a laser particle size analyzer. Furthermore, we evaluate the uniformity of particle size, which is the key parameter for column efficiency of the liquid chromatography by analyzing the mass distribution of the packing materials at the top and bottom of the column. A broader mass distribution, which yields decreased column efficiency, is observed for the column top because of the excessive use of the column. Our results suggest that CD-ITMS can serve as an alternative means for the characterization of the packing materials in HPLC and is potentially useful for column quality control. PMID:21612293

  12. Identification of the sulfoxide functionality in protonated analytes via ion/molecule reactions in linear quadrupole ion trap mass spectrometry.

    PubMed

    Sheng, Huaming; Williams, Peggy E; Tang, Weijuan; Zhang, Minli; Kenttämaa, Hilkka I

    2014-09-01

    A mass spectrometric method utilizing gas-phase ion/molecule reactions of 2-methoxypropene (MOP) has been developed for the identification of the sulfoxide functionality in protonated analytes in a LQIT mass spectrometer. Protonated sulfoxide analytes react with MOP to yield an abundant addition product (corresponding to 37-99% of the product ions), which is accompanied by a much slower proton transfer. The total efficiency (percent of gas-phase collisions leading to products) of the reaction is moderate (3-14%). A variety of compounds with different functional groups, including sulfone, hydroxylamino, N-oxide, aniline, phenol, keto, ester, amino and hydroxy, were examined to probe the selectivity of this reaction. Most of the protonated compounds with proton affinities lower than that of MOP react mainly via proton transfer to MOP. The formation of adduct-MeOH ions was found to be characteristic for secondary N-hydroxylamines. N-Oxides formed abundant MOP adducts just like sulfoxides, but sulfoxides can be differentiated from N-oxides based on their high reaction efficiencies. The reaction was tested by using the anti-inflammatory drug sulindac (a sulfoxide) and its metabolite sulindac sulfone. The presence of a sulfoxide functionality in the drug but a sulfone functionality in the metabolite was readily demonstrated. The presence of other functionalities in addition to sulfoxide in the analytes was found not to influence the diagnostic reactivity. PMID:24968187

  13. Quantum computing with trapped ions

    SciTech Connect

    Hughes, R.J.

    1998-01-01

    The significance of quantum computation for cryptography is discussed. Following a brief survey of the requirements for quantum computational hardware, an overview of the ion trap quantum computation project at Los Alamos is presented. The physical limitations to quantum computation with trapped ions are analyzed and an assessment of the computational potential of the technology is made.

  14. Ion Behavior in an Electrically Compensated Ion Cyclotron Resonance Trap

    PubMed Central

    Brustkern, Adam M.; Rempel, Don L.; Gross, Michael L.

    2010-01-01

    We recently described a new electrically compensated trap in FT ion cyclotron resonance mass spectrometry and developed a means of tuning traps of this general design. Here, we describe a continuation of that research by comparing the ion transient lifetimes and the resulting mass resolving powers and signal-to-noise (S/N) ratios that are achievable in the compensated vs. uncompensated modes of this trap. Transient lifetimes are ten times longer under the same conditions of pressure, providing improved mass resolving power and S/N ratios. The mass resolving power as a function of m/z is linear (log-log plot) and nearly equal to the theoretical maximum. Importantly, the ion cyclotron frequency as a function of ion number decreases linearly in accord with theory, unlike its behavior in the uncompensated mode. This linearity should lead to better control in mass calibration and increased mass accuracy than achievable in the uncompensated mode. PMID:21499521

  15. Action spectroscopy of SrCl{sup +} using an integrated ion trap time-of-flight mass spectrometer

    SciTech Connect

    Puri, Prateek Schowalter, Steven J.; Hudson, Eric R.; Kotochigova, Svetlana; Petrov, Alexander

    2014-07-07

    The photodissociation cross-section of SrCl{sup +} is measured in the spectral range of 36 000–46 000 cm{sup −1} using a modular time-of-flight mass spectrometer (TOF-MS). By irradiating a sample of trapped SrCl{sup +} molecular ions with a pulsed dye laser, X{sup 1}Σ{sup +} state molecular ions are electronically excited to the repulsive wall of the A{sup 1}Π state, resulting in dissociation. Using the TOF-MS, the product fragments are detected and the photodissociation cross-section is determined for a broad range of photon energies. Detailed ab initio calculations of the SrCl{sup +} molecular potentials and spectroscopic constants are also performed and are found to be in good agreement with experiment. The spectroscopic constants for SrCl{sup +} are also compared to those of another alkaline earth halogen, BaCl{sup +}, in order to highlight structural differences between the two molecular ions. This work represents the first spectroscopy and ab initio calculations of SrCl{sup +}.

  16. Structurally diagnostic ion-molecule reactions and collisionally activated dissociation of 1,4-benzodiazepines in a quadrupole ion trap mass spectrometer.

    PubMed

    McCarley, T D; Brodbelt, J

    1993-09-01

    The ion-molecule reactions of various 1,4-benzodiazepines and dimethyl ether ions were studied with a quadrupole ion trap mass spectrometer. The methoxymethylene ions of dimethyl ether selectively react with 3-hydroxy-1,4-benzodiazepines (temazepam, oxazepam) to form (M+13)+ adducts by methylene substitution, and they react with 1,4-benzodiazepines that do not have hydroxyl substituents (diazepam, nordiazepam, nitrazepam) to form (M+15)+ adduct by a simple methyl cation transfer. These adducts are formed by elimination of methanol or formaldehyde, respectively, from (M+CH2OCH3)+ precursor ions. Ion-molecule reactions of model compounds with dimethyl ether ions suggest that the reactive site in the formation of (M+15)+ adducts is the imine functional group of the 1,4-benzodiazepines, while the reactive site for formation of (M+13)+ adducts involves a functional group interaction between the hydroxyl and carbonyl functional groups. Fragmentation induced by chemical ionization and collisionally activated dissociation provides further structural information for the differentiation of 1,4-benzodiazepines. Also, the gas-phase basicities of diazepam and temazepam have been estimated by bracketing techniques to be between 220.7 and 222.2 kcal/mol. PMID:8238931

  17. Appropriate choice of collision-induced dissociation energy for qualitative analysis of notoginsenosides based on liquid chromatography hybrid ion trap time-of-flight mass spectrometry.

    PubMed

    Wang, Guang-Ji; Fu, Han-Xu; Xiao, Jing-Cheng; Ye, Wei; Rao, Tai; Shao, Yu-Hao; Kang, Dian; Xie, Lin; Liang, Yan

    2016-04-01

    Liquid chromatography hybrid ion trap/time-of-flight mass spectrometry possessesd both the MS(n) ability of ion trap and the excellent resolution of a time-of-flight, and has been widely used to identify drug metabolites and determine trace multi-components for in natural products. Collision energy, one of the most important factors in acquiring MS(n) information, could be set freely in the range of 10%-400%. Herein, notoginsenosides were chosen as model compounds to build a novel methodology for the collision energy optimization. Firstly, the fragmental patterns of the representatives for the authentic standards of protopanaxadiol-type and protopanaxatriol-type notoginsenosides authentic standards were obtained based on accurate MS(2) and MS(3) measurements via liquid chromatography hybrid ion trap/time-of-flight mass spectrometry. Then the extracted ion chromatograms of characteristic product ions of notoginsenosides in Panax Notoginseng Extract, which were produced under a series of collision energies and, were compared to screen out the optimum collision energies values for MS(2) and MS(3). The results demonstrated that the qualitative capability of liquid chromatography hybrid ion trap/time-of-flight mass spectrometry was greatly influenced by collision energies, and 50% of MS(2) collision energy was found to produce the highest collision-induced dissociation efficiency for notoginsenosides. BesidesAddtionally, the highest collision-induced dissociation efficiency appeared when the collision energy was set at 75% in the MS(3) stage. PMID:27114315

  18. Generic detection of basic taxoids in wood of European Yew (Taxus baccata) by liquid chromatography-ion trap mass spectrometry.

    PubMed

    Kite, Geoffrey C; Rowe, Emily R; Veitch, Nigel C; Turner, Jill E; Dauncey, Elizabeth A

    2013-02-01

    The occurrence of the cardiotoxin taxine (comprising taxine B and several other basic taxoids) in leaves of Taxus baccata L. (European yew) is well known and has led to public concerns about the safety of eating or drinking from utensils crafted from the wood of this poisonous species. The occurrence of basic taxoids in the heartwood of T. baccata had not been examined in detail, although the bark is known to contain 2'β-deacetoxyaustrospicatine. Initial examination of heartwood extracts for 2'β-deacetoxyaustrospicatine by liquid chromatography-mass spectrometry (LC-MS) revealed the presence of this basic taxoid at about 0.0007% dry weight, using a standard isolated from bark. Analyses for taxine B, however, proved negative at the extract concentration analysed. Observing other basic taxoids within the heartwood extracts was facilitated by developing generic LC-MS methods that utilised a fragment arising from the N-containing acyl group of basic taxoids as a reporter ion. Of the various MS strategies available on a hybrid ion trap-orbitrap instrument that allowed observation of this reporter ion, combining all-ion collisions with high resolution ion filtering by the orbitrap was most effective, both in terms of the number of basic taxoids detected and sensitivity. Numerous basic taxoids, in addition to 2'β-deacetoxyaustrospicatine, were revealed by this method in heartwood extracts of T. baccata. Red wine readily extracted the basic taxoids from heartwood while coffee extracted them less efficiently. Contamination with basic taxoids could also be detected in soft cheese that had been spread onto wood. The generic LC-MS method for detecting basic taxoids complements specific methods for detecting taxine B when investigating yew poisoning cases in which the analysis of complex extracts may be required or taxine B has not been detected. PMID:23314400

  19. High Pressure Mass Spectrometry: The Generation of Mass Spectra at Operating Pressures Exceeding 1 Torr in a Microscale Cylindrical Ion Trap.

    PubMed

    Blakeman, Kenion H; Wolfe, Derek W; Cavanaugh, Craig A; Ramsey, J Michael

    2016-05-17

    We present the first demonstration of high pressure mass spectrometry (HPMS), which we define as mass spectrometry performed at pressures greater than 100 mTorr. Mass analysis is shown at operational pressures exceeding 1 Torr of helium buffer gas. A differentially pumped MS system was constructed for HPMS development consisting of two chambers. The first chamber (mass analysis chamber) was operated at pressures up to 1.2 Torr and contained the ionization source and a microscale cylindrical ion trap (CIT) mass analyzer. The CIT had critical dimensions of r0 = 500 μm and z0 = 650 μm. The second chamber was held at a lower pressure (≤10 mTorr) and contained an electron multiplier for detection. Mass spectra for xenon, 2-chloroethyl ethyl sulfide (CEES), and octane were acquired with helium buffer gas pressures ranging from 0.04 to 1.2 Torr in the mass analysis chamber. Full-width at half-maximum of mass spectral peaks was found to increase 143% for xenon, 40% for CEES, and 77% for octane over this pressure range, with maximum peak widths of 1.19, 1.26, and 0.82 Da, respectively. Data were fitted with an algebraic model that factors in ion-neutral collision peak broadening effects at high pressures. Experimental and theoretical peak broadening slopes showed good agreement at buffer gas pressures greater than 0.2 Torr. Experiments presented here demonstrate mass spectrometry at pressures orders of magnitude higher than conventionally practiced with any type of mass analyzer. The use of HPMS provides a way to eliminate turbo pumping requirements, leading to significant reduction in MS system size, weight, and power and facilitating a path toward compact/hand-held mass spectrometers with numerous potential applications. PMID:27109864

  20. A quadrupole ion trap mass spectrometer for in-situ UHV analyses on Earth and other planetary environments

    NASA Astrophysics Data System (ADS)

    Cox, S. E.; Madzunkov, S. M.; Simcic, J.; Farley, K. A.

    2014-12-01

    The JPL quadrupole ion trap mass spectrometer presents an exceptional opportunity for combining cutting edge terrestrial geochemical research with the next generation of extraterrestrial science. The QIT is a small mass spectrometer that filters particles of different mass by electron ionization and subsequent separation with a quadrupole RF field. The latest version is capable of achieving very high resolution (R > 1000) without an increase in power consumption through the addition of a dipole RF to augment the primary quadrupole field. Crucially, we demonstrate the ability to achieve this resolution with high sensitivity (> 1014 cps/Torr), and at UHV without the addition of a cooling gas. In this mode, the high sensitivity and extremely low background allow the measurement of a large number of species in very small samples. Most laboratory instruments are too heavy, large, and energy-intensive to fly on spacecraft in their optimal forms. As a result, instruments for spaceflight have traditionally been heavily-modified versions of terrestrial instruments, designed to be lighter, smaller, and more efficient than their terrestrial counterparts, at the expense of analytical capabilities. The JPL QIT, in contrast, weighs less than 1 kg, is only a few cm in size, and consumes less than 30W. Only the accompanying UHV system and supporting electronics must be extensively redesigned for spaceflight, and NASA already possesses pumps capable of fulfilling this need. The opportunity for parallel development for terrestrial and extraterrestrial labs and the capability of direct comparison between planetary science and terrestrial geochemistry will benefit both fields.

  1. Comprehensive Lipidome Analysis by Shotgun Lipidomics on a Hybrid Quadrupole-Orbitrap-Linear Ion Trap Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Almeida, Reinaldo; Pauling, Josch Konstantin; Sokol, Elena; Hannibal-Bach, Hans Kristian; Ejsing, Christer S.

    2015-01-01

    Here we report on the application of a novel shotgun lipidomics platform featuring an Orbitrap Fusion mass spectrometer equipped with an automated nanoelectrospray ion source. To assess the performance of the platform for in-depth lipidome analysis, we evaluated various instrument parameters, including its high resolution power unsurpassed by any other contemporary Orbitrap instrumentation, its dynamic quantification range and its efficacy for in-depth structural characterization of molecular lipid species by quadrupole-based higher-energy collisional dissociation (HCD), and ion trap-based resonant-excitation collision-induced dissociation (CID). This evaluation demonstrated that FTMS analysis with a resolution setting of 450,000 allows distinguishing isotopes from different lipid species and features a linear dynamic quantification range of at least four orders of magnitude. Evaluation of fragmentation analysis demonstrated that combined use of HCD and CID yields complementary fragment ions of molecular lipid species. To support global lipidome analysis, we designed a method, termed MSALL, featuring high resolution FTMS analysis for lipid quantification, and FTMS2 analysis using both HCD and CID and ITMS3 analysis utilizing dual CID for in-depth structural characterization of molecular glycerophospholipid species. The performance of the MSALL method was benchmarked in a comparative analysis of mouse cerebellum and hippocampus. This analysis demonstrated extensive lipidome quantification covering 311 lipid species encompassing 20 lipid classes, and identification of 202 distinct molecular glycerophospholipid species when applying a novel high confidence filtering strategy. The work presented here validates the performance of the Orbitrap Fusion mass spectrometer for in-depth lipidome analysis.

  2. Evaluating Multiplexed Quantitative Phosphopeptide Analysis on a Hybrid Quadrupole Mass Filter/Linear Ion Trap/Orbitrap Mass Spectrometer

    PubMed Central

    2015-01-01

    As a driver for many biological processes, phosphorylation remains an area of intense research interest. Advances in multiplexed quantitation utilizing isobaric tags (e.g., TMT and iTRAQ) have the potential to create a new paradigm in quantitative proteomics. New instrumentation and software are propelling these multiplexed workflows forward, which results in more accurate, sensitive, and reproducible quantitation across tens of thousands of phosphopeptides. This study assesses the performance of multiplexed quantitative phosphoproteomics on the Orbitrap Fusion mass spectrometer. Utilizing a two-phosphoproteome model of precursor ion interference, we assessed the accuracy of phosphopeptide quantitation across a variety of experimental approaches. These methods included the use of synchronous precursor selection (SPS) to enhance TMT reporter ion intensity and accuracy. We found that (i) ratio distortion remained a problem for phosphopeptide analysis in multiplexed quantitative workflows, (ii) ratio distortion can be overcome by the use of an SPS-MS3 scan, (iii) interfering ions generally possessed a different charge state than the target precursor, and (iv) selecting only the phosphate neutral loss peak (single notch) for the MS3 scan still provided accurate ratio measurements. Remarkably, these data suggest that the underlying cause of interference may not be due to coeluting and cofragmented peptides but instead from consistent, low level background fragmentation. Finally, as a proof-of-concept 10-plex experiment, we compared phosphopeptide levels from five murine brains to five livers. In total, the SPS-MS3 method quantified 38 247 phosphopeptides, corresponding to 11 000 phosphorylation sites. With 10 measurements recorded for each phosphopeptide, this equates to more than 628 000 binary comparisons collected in less than 48 h. PMID:25521595

  3. A Generic Multiple Reaction Monitoring Based Approach for Plant Flavonoids Profiling Using a Triple Quadrupole Linear Ion Trap Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Yan, Zhixiang; Lin, Ge; Ye, Yang; Wang, Yitao; Yan, Ru

    2014-06-01

    Flavonoids are one of the largest classes of plant secondary metabolites serving a variety of functions in plants and associating with a number of health benefits for humans. Typically, they are co-identified with many other secondary metabolites using untargeted metabolomics. The limited data quality of untargeted workflow calls for a shift from the breadth-first to the depth-first screening strategy when a specific biosynthetic pathway is focused on. Here we introduce a generic multiple reaction monitoring (MRM)-based approach for flavonoids profiling in plants using a hybrid triple quadrupole linear ion trap (QTrap) mass spectrometer. The approach includes four steps: (1) preliminary profiling of major aglycones by multiple ion monitoring triggered enhanced product ion scan (MIM-EPI); (2) glycones profiling by precursor ion triggered EPI scan (PI-EPI) of major aglycones; (3) comprehensive aglycones profiling by combining MIM-EPI and neutral loss triggered EPI scan (NL-EPI) of major glycone; (4) in-depth flavonoids profiling by MRM-EPI with elaborated MRM transitions. Particularly, incorporation of the NH3 loss and sugar elimination proved to be very informative and confirmative for flavonoids screening. This approach was applied for profiling flavonoids in Astragali radix ( Huangqi), a famous herb widely used for medicinal and nutritional purposes in China. In total, 421 flavonoids were tentatively characterized, among which less than 40 have been previously reported in this medicinal plant. This MRM-based approach provides versatility and sensitivity that required for flavonoids profiling in plants and serves as a useful tool for plant metabolomics.

  4. Hydrolysis of VX on concrete: rate of degradation by direct surface interrogation using an ion trap secondary ion mass spectrometer.

    PubMed

    Groenewold, Gary S; Williams, John M; Appelhans, Anthony D; Gresham, Garold L; Olson, John E; Jeffery, Mark T; Rowland, Brad

    2002-11-15

    The nerve agent VX (O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate) is lethal at very low levels of exposure, which can occur by dermal contact with contaminated surfaces. Hence, behavior of VX in contact with common urban or industrial surfaces is a subject of acute interest. In the present study, VX was found to undergo complete degradation when in contact with concrete surfaces. The degradation was directly interrogated at submonolayer concentrations by periodically performing secondary ion mass spectrometry (SIMS) analyses after exposure of the concrete to VX. The abundance of the [VX + H]+ ion in the SIMS spectra was observed to decrease in an exponential fashion, consistent with first-order or pseudo-first-order behavior. This phenomenon enabled the rate constant to be determined at 0.005 min(-1) at 25 degrees C, which corresponds to a half-life of about 3 h on the concrete surface. The decrease in [VX + H]+ was accompanied by an increase in the abundance of the principal degradation product diisopropylaminoethanethiol (DESH), which arises by cleavage of the P-S bond. Degradation to form DESH is accompanied by the formation of ethyl methylphosphonic acid, which is observable only in the negative ion spectrum. A second degradation product was also implicated, which corresponded to a diisopropylvinylamine isomer (perhaps N,N-diisopropyl aziridinium) that arose via cleavage of the S-C bond. No evidence was observed for the formation of the toxic S-2-diisopropylaminoethyl methylphosphonothioic acid. The degradation rate constants were measured at four different temperatures (24-50 degrees C), which resulted in a linear Arrhenius relationship and an activation energy of 52 kJ mol(-1). This value agrees with previous values observed for VX hydrolysis in alkaline solutions, which suggests that the degradation of submonolayer VX is dominated by alkaline hydrolysis within the adventitious water film on the concrete surface. PMID:12487301

  5. Hydrolysis of VX on Concrete: Rate of Degradation by Direct Surface Interrogation using an Ion Trap Secondary Ion Mass Spectrometer

    SciTech Connect

    Groenewold, Gary Steven; Appelhans, Anthony David; Gresham, Garold Linn; Olson, John Eric; Rowland, B.; Williams, j.; Jeffery, M. T.

    2002-09-01

    The nerve agent VX (O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate) is lethal at very low levels of exposure, which can occur by dermal contact with contaminated surfaces. Hence, behavior of VX in contact with common urban or industrial surfaces is a subject of acute interest. In the present study, VX was found to undergo complete degradation when in contact with concrete surfaces. The degradation was directly interrogated at submonolayer concentrations by periodically performing secondary ion mass spectrometry (SIMS) analyses after exposure of the concrete to VX. The abundance of the [VX + H]+ ion in the SIMS spectra was observed to decrease in an exponential fashion, consistent with first-order or pseudo-first-order behavior. This phenomenon enabled the rate constant to be determined at 0.005 min-1 at 25 C, which corresponds to a half-life of about 3 h on the concrete surface. The decrease in [VX + H]+ was accompanied by an increase in the abundance of the principal degradation product diisopropylaminoethanethiol (DESH), which arises by cleavage of the P-S bond. Degradation to form DESH is accompanied by the formation of ethyl methylphosphonic acid, which is observable only in the negative ion spectrum. A second degradation product was also implicated, which corresponded to a diisopropylvinylamine isomer (perhaps N,N-diisopropyl aziridinium) that arose via cleavage of the S-C bond. No evidence was observed for the formation of the toxic S-2-diisopropylaminoethyl methylphosphonothioic acid. The degradation rate constants were measured at four different temperatures (24-50 C), which resulted in a linear Arrhenius relationship and an activation energy of 52 kJ mol-1. This value agrees with previous values observed for VX hydrolysis in alkaline solutions, which suggests that the degradation of submonolayer VX is dominated by alkaline hydrolysis within the adventitious water film on the concrete surface.

  6. Electrospray Ionization/Ion Mobility Spectrometer/Cylindrical Ion Trap Mass Spectrometer System for In-Situ Detection of Organic Compounds

    NASA Technical Reports Server (NTRS)

    Kanik, I.; Johnson, P. V.; Beegle, L. W.; Cooks, R. G.; Laughlin, B. C.; Hill, H. H.

    2003-01-01

    The potential of an Electrospray Ionization/Ion Mobility Spectrometer/Cylindrical Ion Trap Mass Spectrometer (ESI/IMS/CIT-MS) as an analytical instrument for analyzing material extracted from rock and soil samples as part of a suite of instruments on the proposed 2009 Mars Science Lander (MSL) will be demonstrated. This instrument will be able to identify volatile compounds as well as resident organic molecules on the parts-per-billion (ppb) level. Also, it will be able to obtain an inventory of chemical species on the surface of Mars which will result in a better understanding of ongoing surface chemistry. Finally, questions relevant to biological processes will be answered with the complete inventory of surface and near surface organic molecules that the ESI/IMS/CIT is capable of performing.

  7. POLAR ORGANIC CHEMICAL INTEGRATIVE SAMPLING AND LIQUID CHROMATOGRAPHY-ELECTROSPRAY/ION-TRAP MASS SPECTROMETRY FOR ASSESSING SELECTED PRESCRIPTION AND ILLICIT DRUGS IN TREATED SEWAGE EFFLUENTS

    EPA Science Inventory

    The purpose of the research presented in this paper is two-fold: (1) to demonstrate the 4 coupling of two state-of-the-art techniques: a time-weighted polar organic integrative sampler (POCIS) and micro-liquid chromatography-electrospray/ion trap mass spectrometry (u-LC-6 ES/ITMS...

  8. Detection of cw-related species in complex aerosol particles deposited on surfaces with an ion trap-based aerosol mass spectrometer

    SciTech Connect

    Harris, William A; Reilly, Pete; Whitten, William B

    2007-01-01

    A new type of aerosol mass spectrometer was developed by minimal modification of an existing commercial ion trap to analyze the semivolatile components of aerosols in real time. An aerodynamic lens-based inlet system created a well-collimated particle beam that impacted into the heated ionization volume of the commercial ion trap mass spectrometer. The semivolatile components of the aerosols were thermally vaporized and ionized by electron impact or chemical ionization in the source. The nascent ions were extracted and injected into the ion trap for mass analysis. The utility of this instrument was demonstrated by identifying semivolatile analytes in complex aerosols. This study is part of an ongoing effort to develop methods for identifying chemical species related to CW agent exposure. Our efforts focused on detection of CW-related species doped on omnipresent aerosols such as house dust particles vacuumed from various surfaces found in any office building. The doped aerosols were sampled directly into the inlet of our mass spectrometer from the vacuumed particle stream. The semivolatile analytes were deposited on house dust and identified by positive ion chemical ionization mass spectrometry up to 2.5 h after deposition. Our results suggest that the observed semivolatile species may have been chemisorbed on some of the particle surfaces in submonolayer concentrations and may remain hours after deposition. This research suggests that identification of trace CW agent-related species should be feasible by this technique.

  9. Gas chromatography-ion trap tandem mass spectrometry method for the analysis of methoxylated polybrominated diphenyl ethers in fish.

    PubMed

    Losada, S; Santos, F J; Covaci, A; Galceran, M T

    2010-08-01

    Gas chromatography coupled to ion trap tandem mass spectrometry (GC-ITMS-MS) is proposed for the analysis of methoxylated polybrominated diphenyl ethers (MeO-PBDEs) in fish and shellfish. MS-MS operating parameters related to the isolation and fragmentation of the precursor ions were optimized to achieve maximum sensitivity and selectivity. This new method allows the determination of both MeO-PBDEs and PBDEs in a single run. Low limits of detection (0.4-2.5 pg injected) and high precision (RSD<13%) were achieved. A sample treatment based on a selective pressurized liquid extraction (PLE) using Florisil as fat retainer was applied for the analysis of these compounds in fish samples. Method limits of quantification ranged from 0.11 to 0.95 ng g(-1) lipid weight for MeO-PBDEs and between 0.18 and 0.50 ng g(-1) lipid weight for PBDEs. In addition, good repeatability of the whole method was achieved (RSD<15%). The suitability of the method was evaluated by analyzing a certified reference material (SRM 1945, whale blubber) with satisfactory results. The developed method was applied to the simultaneous analysis of MeO-PBDEs and PBDEs in fish and shellfish samples from the Mediterranean Sea. PMID:20615508

  10. Progress at the Penning Trap Mass Spectrometer ``THe-Trap''

    NASA Astrophysics Data System (ADS)

    Hoecker, Martin; Eronen, Tommi; Ketter, Jochen; Streubel, Sebastian; Blaum, Klaus; van Dyck, Robert S.

    2012-03-01

    In 2008, the ``University of Washington Penning-Trap Mass Spectrometer'' (UW-PTMS), originally designed and built by the Van Dyck group, was moved to the Max-Planck-Insitute for Nuclear Physics in Heidelberg, Germany. It was set up in a dedicated laboratory that meets both the radiation-safety requirements, and the environment-stabilization demands for a high-precision measurement of the tritium/helium-3 mass ratio. Our goal is to measure this mass ratio with a relative uncertainty of 10-11, which would be more than an order of magnitude better than the previous best measurement. It would decrease the uncertainty in the tritium beta decay Q-value (an important parameter in the ongoing search for the neutrino mass by experiments such as KATRIN) by the same factor. In order to emphasize the specialization of our experiment with regard to Tritium and ^3Helium, it was renamed to ``THe-Trap''. THe-Trap features a double Penning-trap for rapid ion exchange, an external ion source to minimize trap contamination, a novel Zener-based voltage source, and active as well as passive stabilization of temperature, pressure and the magnetic field of the superconducting magnet. An overview of the project and a report on the recent progress will be given.

  11. Mass trapping for Anastrepha suspensa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mass trapping has been found to be highly effective for control of pest fruit flies when populations are low and a highly effective lure is available for the target species. Successful population control through mass trapping is an indicator that attract-and-kill bait stations may be equally succes...

  12. A high-resolution scanning microprobe matrix-assisted laser desorption/ionization ion source for imaging analysis on an ion trap/Fourier transform ion cyclotron resonance mass spectrometer.

    PubMed

    Koestler, Martin; Kirsch, Dieter; Hester, Alfons; Leisner, Arne; Guenther, Sabine; Spengler, Bernhard

    2008-10-01

    A new scanning microprobe matrix-assisted laser desorption/ionization (SMALDI) ion source for high spatial resolution has been developed for linear ion trap and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). The source is fully compatible with commercial ion trap flanges (such as the LTQ series, Thermo Fisher Scientific). The source is designed for atmospheric pressure (AP) operation but is also suitable for mid-pressure operation. The AP mode is especially useful for investigating volatile compounds. The source can be interchanged with other ion sources within a minute when operated in the AP mode. Combining high-lateral resolution MALDI imaging with high mass resolution and high mass accuracy mass spectrometry, available in the FT-ICR mode, provides a new quality of analytical information, e.g. from biological samples. First results obtained with the new ion source demonstrate a maximum lateral resolution of 0.6 by 0.5 microm. Depending on the limit of detection of the chosen mass analyzer, however, the size of the focus had to be enlarged to a diameter of up to 8 microm in the FT-ICR mode, in order to create enough ions for detection. Mass spectra acquired for analytical imaging were obtained from single laser pulses per pixel in all the experiments. This mode allows us to investigate biological thin sections with desorption focus diameters in the micrometer range, known to cause complete evaporation of material under the laser focus with a very limited number of laser pulses. As a first example, peptide samples deposited in microstructures were investigated with the new setup. A high quality and validity of the acquired images were obtained in the ion trap mode due to the low limit of detection. High mass resolution and accuracy but poorer image quality were obtained in the ICR mode due to the lower detection sensitivity of the ICR detector. PMID:18819119

  13. Direct analysis of highly oxidised organic aerosol constituents by on-line ion trap mass spectrometry in the negative-ion mode.

    PubMed

    Warscheid, Bettina; Hoffmann, Thorsten

    2002-01-01

    On-line ion trap mass spectrometry (ITMS) enables the characterisation of constituents of biogenic secondary organic aerosols in complex organic reaction mixtures. This real-time analysis is achieved by directly introducing the airborne particles into the ion source of the mass spectrometer. Negative-ion chemical ionisation at atmospheric pressure (APCI(-)) was used as the ionisation method of choice. The aerosols were generated from the gas-phase ozonolysis of two C10H16-terpenes (alpha-pinene and limonene), and investigated by performing on-line APCI(-)-ITMS(n). Highly oxidised compounds were tentatively identified as important particle-phase products. Based on recent investigations of low-energy collision-induced dissociation pathways of a wide range of deprotonated multifunctional carboxylic acid species derived from monoterpene precursors (Warscheid B, Hoffmann T. Rapid Commun. Mass Spectrom. 2001; 15: 2259), the formation of structurally different C10H16O5 and C10H16O6 species, such as acidic esters from alpha-pinene and aldo-hydroxycarboxylic acids from limonene, is proposed. PMID:11870886

  14. Quantitative analysis of sphingolipids for lipidomics using triple quadrupole and quadrupole linear ion trap mass spectrometers[S

    PubMed Central

    Shaner, Rebecca L.; Allegood, Jeremy C.; Park, Hyejung; Wang, Elaine; Kelly, Samuel; Haynes, Christopher A.; Sullards, M. Cameron; Merrill, Alfred H.

    2009-01-01

    Sphingolipids are a highly diverse category of bioactive compounds. This article describes methods that have been validated for the extraction, liquid chromatographic (LC) separation, identification and quantitation of sphingolipids by electrospray ionization, tandem mass spectrometry (ESI-MS/MS) using triple quadrupole (QQQ, API 3000) and quadrupole-linear-ion trap (API 4000 QTrap, operating in QQQ mode) mass spectrometers. Advantages of the QTrap included: greater sensitivity, similar ionization efficiencies for sphingolipids with ceramide versus dihydroceramide backbones, and the ability to identify the ceramide backbone of sphingomyelins using a pseudo-MS3 protocol. Compounds that can be readily quantified using an internal standard cocktail developed by the LIPID MAPS Consortium are: sphingoid bases and sphingoid base 1-phosphates, more complex species such as ceramides, ceramide 1-phosphates, sphingomyelins, mono- and di-hexosylceramides, and these complex sphingolipids with dihydroceramide backbones. With minor modifications, glucosylceramides and galactosylceramides can be distinguished, and more complex species such as sulfatides can also be quantified, when the internal standards are available. JLR LC ESI-MS/MS can be utilized to quantify a large number of structural and signaling sphingolipids using commercially available internal standards. The application of these methods is illustrated with RAW264.7 cells, a mouse macrophage cell line. These methods should be useful for a wide range of focused (sphingo)lipidomic investigations. PMID:19036716

  15. New perspectives in laser analytics: Resonance-enhanced multiphoton ionization in a Paul ion trap combined with a time-of-flight mass spectrometer

    NASA Astrophysics Data System (ADS)

    Bisling, Peter; Heger, Hans Jörg; Michaelis, Walfried; Weitkamp, Claus; Zobel, Harald

    1995-04-01

    A new laser analytical device has been developed that is based on resonance-enhanced multiphoton ionization in the very center of a radio-frequency quadrupole ion trap. Applications in speciation anlaysis of biological and enviromental samples and in materials science will all benefit from laser-optical selectivity in the resonance excitation process, combined with mass-spectropic sensivity which is further enhanced by the ion accumulation and storage capability.

  16. Penning trap mass measurements utilizing highly charged ions as a path to benchmark isospin-symmetry breaking corrections in 74Rb

    NASA Astrophysics Data System (ADS)

    Malbrunot-Ettenauer, S.; Brunner, T.; Chowdhury, U.; Gallant, A. T.; Simon, V. V.; Brodeur, M.; Chaudhuri, A.; Mané, E.; Simon, M. C.; Andreoiu, C.; Audi, G.; Crespo López-Urrutia, J. R.; Delheij, P.; Gwinner, G.; Lapierre, A.; Lunney, D.; Pearson, M. R.; Ringle, R.; Ullrich, J.; Dilling, J.

    2015-04-01

    Penning trap mass measurements of neutron-deficient Rb isotopes have been performed at TRIUMF's Ion Trap for Atomic and Nuclear Science (TITAN) facility by utilizing highly charged ions (HCIs). As imperative for a new approach with significant gain in measurement precision, experimental procedures, and systematic uncertainties are discussed in detail. Among the investigated nuclides, the superallowed nuclear β emitter 74Rb will especially benefit from the advantage offered by HCI because the limited attainable precision owing to its short half-life (T1 /2=65 ms) represents a challenge for conventional Penning trap mass spectrometry. Motivated by an updated QEC value for 74Rb of 10 416.8(3.9) keV and its large isospin-symmetry breaking corrections, we present a new test to benchmark the consistency between theoretical models of isospin-symmetry breaking corrections in superallowed decays, the conserved vector current hypothesis, and experimental data.

  17. Liquid chromatography quadrupole linear ion trap mass spectrometry for multiclass screening and identification of lipophilic marine biotoxins in bivalve mollusks.

    PubMed

    Wu, Haiyan; Guo, Mengmeng; Tan, Zhijun; Cheng, Haiyan; Li, Zhaoxin; Zhai, Yuxiu

    2014-09-01

    A liquid chromatography quadrupole linear ion trap mass spectrometry method with fast polarity switching and a scheduled multiple reaction monitoring algorithm mode was developed for multiclass screening and identification of lipophilic marine biotoxins in bivalve molluscs. A major advantage of the method is that it can detect members of all six groups of lipophilic marine biotoxins [okadaic acid (OA), yessotoxins (YTX), azaspiracids (AZA), pectenotoxins (PTX), cyclic imines (CI), and brevetoxins (PbTx)], thereby allowing quantification and high confidence identification from a single liquid chromatography tandem mass spectrometry (LC-MS/MS) injection. An enhanced product ion (EPI) library was constructed after triggered collection of data via information-dependent acquisition (IDA) of EPI spectra from standard samples. A separation method for identifying 17 target toxins in a single analysis within 12min was developed and tested. Different solid phase extraction sorbents, the matrix effect (for oyster, scallop, and mussel samples), and stability of the standards also were evaluated. Matrix-matched calibration was used for quantification of the toxins. The limits of detection were 0.12-13.6μg/kg, and the limits of quantification were 0.39-45.4μg/kg. The method was used to analyze 120 shellfish samples collected from farming areas along the coast of China, and 7% of the samples were found to be contaminated with toxins. The library search identified PbTx-3, YTX, OA, PTX2, AZA1, AZA2, and desmethylspirolide C (SPX1). Overall, the method exhibited excellent sensitivity and reproducibility, and it will have broad applications in the monitoring of lipophilic marine biotoxins. PMID:25086754

  18. Sensitive and comprehensive detection of chemical warfare agents in air by atmospheric pressure chemical ionization ion trap tandem mass spectrometry with counterflow introduction.

    PubMed

    Seto, Yasuo; Sekiguchi, Hiroshi; Maruko, Hisashi; Yamashiro, Shigeharu; Sano, Yasuhiro; Takayama, Yasuo; Sekioka, Ryoji; Yamaguchi, Shintaro; Kishi, Shintaro; Satoh, Takafumi; Sekiguchi, Hiroyuki; Iura, Kazumitsu; Nagashima, Hisayuki; Nagoya, Tomoki; Tsuge, Kouichiro; Ohsawa, Isaac; Okumura, Akihiko; Takada, Yasuaki; Ezawa, Naoya; Watanabe, Susumu; Hashimoto, Hiroaki

    2014-05-01

    A highly sensitive and specific real-time field-deployable detection technology, based on counterflow air introduction atmospheric pressure chemical ionization, has been developed for a wide range of chemical warfare agents (CWAs) comprising gaseous (two blood agents, three choking agents), volatile (six nerve gases and one precursor agent, five blister agents), and nonvolatile (three lachrymators, three vomiting agents) agents in air. The approach can afford effective chemical ionization, in both positive and negative ion modes, for ion trap multiple-stage mass spectrometry (MS(n)). The volatile and nonvolatile CWAs tested provided characteristic ions, which were fragmented into MS(3) product ions in positive and negative ion modes. Portions of the fragment ions were assigned by laboratory hybrid mass spectrometry (MS) composed of linear ion trap and high-resolution mass spectrometers. Gaseous agents were detected by MS or MS(2) in negative ion mode. The limits of detection for a 1 s measurement were typically at or below the microgram per cubic meter level except for chloropicrin (submilligram per cubic meter). Matrix effects by gasoline vapor resulted in minimal false-positive signals for all the CWAs and some signal suppression in the case of mustard gas. The moisture level did influence the measurement of the CWAs. PMID:24678766

  19. Iterative mass spectrometry and X-ray crystallography to study ion-trapping and rearrangements by a flexible cluster.

    PubMed

    Zhang, Kun; Kurmoo, Mohamedally; Wei, Lian-Qiang; Zeng, Ming-Hua

    2013-01-01

    An important aspect of chemical reactions involves understanding the intermediate steps from reactants to products. The iterative use of mass spectrometry and X-Ray crystallography is demonstrated to be a powerful combination in this respect. We have applied them in identifying molecular clusters in solution followed by their solid-state structural characterizations. We used a key ligand, 2-[(2-hydroxy-3-methoxy-benzylidene)-amino]-ethanesulfonate (L), which serves as chelating/bridging units to stabilize the precursor [Li₄Ni₆(OH)₂(L)₆(CH₃CN)₆](ClO₄)₂·4CH₃CN. The results of subsequent reactions witness a cascade of processes involving fragmentation, inner bridging ligand substitution (OH⁻ to OCH₃⁻), changing modes of binding (chelate to monodentate) of the key ligand, ion-trapping and exchange (Li⁺, Na⁺ and Ca²⁺) and their site preferences, coordinating and non-coordinating solvents (CH₃CN to CH₃OH, H₂O and EtOH) replacement. The flexibility of the Ni₃OL₃ species in solution permits the formation of six derivatives. The complimentary techniques open a broader prospect for cluster design and applications. PMID:24343303

  20. Simultaneous screening and confirmation of multiple classes of drug residues in fish by liquid chromatography-ion trap mass spectrometry.

    PubMed

    Smith, Shani; Gieseker, Charles; Reimschuessel, Renate; Decker, Christie-Sue; Carson, Mary C

    2009-11-13

    LC-ion trap mass spectrometry was used to screen and confirm 38 compounds from a variety of drug classes in four species of fish: trout, salmon, catfish, and tilapia. Samples were extracted with acetonitrile and hexane. The acetonitrile phase was evaporated, redissolved in water and acetonitrile, and analyzed by gradient chromatography on a phenyl column. MS(2) or MS(3) spectra were monitored for each compound. Qualitative method performance was evaluated by the analysis over several days of replicate samples of control fish, fish fortified with a drug mixture at 1 ppm, 0.1 ppm and 0.01 ppm, and fish dosed with a representative from each drug class. Half of the 38 drugs were confirmed at 0.01 ppm, the lowest fortification level. This included all of the quinolones and fluoroquinolones, the macrolides, malachite green, and most of the imidazoles. Florfenicol amine, metronidazole, sulfonamides, tetracyclines, and most of the betalactams were confirmed at 0.1 ppm. Ivermectin and penicillin G were only detectable in the 1 ppm fortified samples. With the exception of amoxicillin, emamectin, metronidazole, and tylosin, residue presence was confirmed in all the dosed fish. PMID:19616215

  1. Analysis of 40 weight loss compounds adulterated in health supplements by liquid chromatography quadrupole linear ion trap mass spectrometry.

    PubMed

    Zeng, Yun; Xu, Yimin; Kee, Chee-Leong; Low, Min-Yong; Ge, Xiaowei

    2016-03-01

    In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) with scheduled multiple reaction monitoring (MRM) enhanced product ion (EPI) method was developed for simultaneous determination of 40 compounds with weight loss effect, including bisacodyl, phenolphthalein, and sibutramine and its metabolites, etc. They might be adulterated in health supplements to get prominent weight loss effect. The samples were analyzed using a Q-Trap 5500 coupled with high performance liquid chromatography (HPLC) and a CORTECS ultra performance liquid chromatography (UPLC) C18 column (100 mm x 2.1 mm x1.6 µm). Scheduled MRM was used as survey scan, MS2 spectra acquired in the EPI mode were used to perform library searching to increase the confidence of detection. Limits of detection were less than 10 ng/g for the majority of the analytes. A total of 447 weight loss products were tested in our laboratory in the past three years. Among these samples, 119 samples were found to be adulterated with one or more weight loss compounds, including sibutramine, its metabolites benzyl sibutramine and desmethyl sibutramine; phenolphthalein; bisacodyl; furosemide; liothyronine (T3); and thyroxine (T4). Copyright © 2015 John Wiley & Sons, Ltd. PMID:26305055

  2. Trace analysis of explosives in seawater using solid-phase microextraction and gas chromatography/ion trap mass spectrometry

    SciTech Connect

    Barshick, S.A.; Griest, W.H.

    1998-07-15

    Complex matrices typically cannot be analyzed directly to obtain the selectivity and sensitivity required for most trace analysis applications. To circumvent this problem, solid-phase microextraction (SPME) techniques were used to preconcentrate analytes selectively prior to gas chromatographic/ion trap mass spectrometric analysis. This approach was applied to the trace analysis of explosives and their metabolites in seawater. The choice of SPME sorbent phase was shown to be important especially for the amino metabolites of trinitrotoluene (TNT) and RDX, which were extracted better on polar phases. Although equilibration times were quite lengthy, on the order of 30 min or greater, a sampling time of only 10 min was shown to be sufficient for achieving low part-per-billion (ppb) to part-per-trillion (ppt) detection limits for TNT and the amino metabolites in real seawater samples. While SPME was ideal for rapid screening of explosives in seawater samples, methods for improving the reproducibility and accuracy of quantification are still being investigated.

  3. Iterative Mass Spectrometry and X-Ray Crystallography to Study Ion-Trapping and Rearrangements by a Flexible Cluster

    PubMed Central

    Zhang, Kun; Kurmoo, Mohamedally; Wei, Lian-Qiang; Zeng, Ming-Hua

    2013-01-01

    An important aspect of chemical reactions involves understanding the intermediate steps from reactants to products. The iterative use of mass spectrometry and X-Ray crystallography is demonstrated to be a powerful combination in this respect. We have applied them in identifying molecular clusters in solution followed by their solid-state structural characterizations. We used a key ligand, 2-[(2-hydroxy-3-methoxy-benzylidene)-amino]-ethanesulfonate (L), which serves as chelating/bridging units to stabilize the precursor [Li4Ni6(OH)2(L)6(CH3CN)6](ClO4)2·4CH3CN. The results of subsequent reactions witness a cascade of processes involving fragmentation, inner bridging ligand substitution (OH− to OCH3−), changing modes of binding (chelate to monodentate) of the key ligand, ion-trapping and exchange (Li+, Na+ and Ca2+) and their site preferences, coordinating and non-coordinating solvents (CH3CN to CH3OH, H2O and EtOH) replacement. The flexibility of the Ni3OL3 species in solution permits the formation of six derivatives. The complimentary techniques open a broader prospect for cluster design and applications. PMID:24343303

  4. Improved 6-Plex Tandem Mass Tags Quantification Throughput Using a Linear Ion Trap-High-Energy Collision Induced Dissociation MS(3) Scan.

    PubMed

    Liu, Jane M; Sweredoski, Michael J; Hess, Sonja

    2016-08-01

    The use of tandem mass tags (TMT) as an isobaric labeling strategy is a powerful method for quantitative proteomics, yet its accuracy has traditionally suffered from interference. This interference can be largely overcome by selecting MS(2) fragment precursor ions for high-energy collision induced dissociation (HCD) MS(3) analysis in an Orbitrap scan. While this approach minimizes the interference effect, sensitivity suffers due to the high AGC targets and long acquisition times associated with MS(3) Orbitrap detection. We investigated whether acquiring the MS(3) scan in a linear ion trap with its lower AGC target would increase overall quantification levels with a minimal effect on precision and accuracy. Trypsin-digested proteins from Saccharomyces cerevisiae were tagged with 6-plex TMT reagents. The sample was subjected to replicate analyses using either the Orbitrap or the linear ion trap for the HCD MS(3) scan. HCD MS(3) detection in the linear ion trap vs Orbitrap increased protein identification by 66% with minor loss in precision and accuracy. Thus, the use of a linear ion trap-HCD MS(3) scan during a 6-plex TMT experiment can improve overall identification levels while maintaining the power of multiplexed quantitative analysis. PMID:27377715

  5. Accurate mass screening and identification of emerging contaminants in environmental samples by liquid chromatography-hybrid linear ion trap Orbitrap mass spectrometry.

    PubMed

    Hogenboom, A C; van Leerdam, J A; de Voogt, P

    2009-01-16

    The European Reach legislation will possibly drive producers to develop newly designed chemicals that will be less persistent, bioaccumulative or toxic. If this innovation leads to an increased use of more hydrophilic chemicals it may result in higher mobilities of chemicals in the aqueous environment. As a result, the drinking water companies may face stronger demands on removal processes as the hydrophilic compounds inherently are more difficult to remove. Monitoring efforts will also experience a shift in focus to more water-soluble compounds. Screening source waters on the presence of (emerging) contaminants is an essential step in the control of the water cycle from source to tap water. In this article, some of our experiences are presented with the hybrid linear ion trap (LTQ) FT Orbitrap mass spectrometer, in the area of chemical water analysis. A two-pronged strategy in mass spectrometric research was employed: (i) exploring effluent, surface, ground- and drinking-water samples searching for accurate masses corresponding to target compounds (and their product ions) known from, e.g. priority lists or the scientific literature and (ii) full-scan screening of water samples in search of 'unknown' or unexpected masses, followed by MS(n) experiments to elucidate the structure of the unknowns. Applications of both approaches to emerging water contaminants are presented and discussed. Results are presented for target analysis search for pharmaceuticals, benzotriazoles, illicit drugs and for the identification of unknown compounds in a groundwater sample and in a polar extract of a landfill soil sample (a toxicity identification evaluation bioassay sample). The applications of accurate mass screening and identification described in this article demonstrate that the LC-LTQ FT Orbitrap MS is well equipped to meet the challenges posed by newly emerging polar contaminants. PMID:18771771

  6. Identification of new oxycodone metabolites in human urine by capillary electrophoresis-multiple-stage ion-trap mass spectrometry.

    PubMed

    Baldacci, A; Caslavska, J; Wey, A B; Thormann, W

    2004-10-01

    Capillary electrophoresis-electrospray ionization multiple-stage ion-trap mass spectrometry (CE-MSn) and computer simulation of fragmentation are demonstrated to be effective tools to detect and identify phase I and phase II metabolites of oxycodone (OCOD) in human urine. OCOD is a strong analgesic used for the management of moderate to severe mainly postoperative or cancer-related pain whose metabolism in man is largely unknown. Using an aqueous pH 9 ammonium acetate buffer and CE-MSn (n < or = 5), OCOD and its phase I metabolites produced by O-demethylation, N-demethylation, 6-ketoreduction and N-oxidation (such as oxymorphone, noroxycodone, noroxymorphone, 6-oxycodol, nor-6-oxycodol, oxycodone-N-oxide and 6-oxycodol-N-oxide) and phase II conjugates with glucuronic acid of several of these compounds could be detected in alkaline solid-phase extracts of a patient urine that was collected during a pharmacotherapy episode with daily ingestion of 240-320 mg of OCOD chloride. The data for three known OCOD metabolites for which the standards had to be synthesized in-house, 6-oxycodol, nor-6-oxycodol and oxycodone-N-oxide, were employed to identify two new metabolites, the N-oxidized derivative of 6-oxycodol and an O-glucuronide of this compound. CE-MSn and computer simulation of fragmentation also led to the identification of the N-glucuronide of noroxymorphone, another novel OCOD metabolite for which no standard compound or mass spectra library data were available. PMID:15532584

  7. Characterization of the synthesis of N,N-dimethyltryptamine by reductive amination using gas chromatography ion trap mass spectrometry.

    PubMed

    Brandt, Simon D; Moore, Sharon A; Freeman, Sally; Kanu, Abu B

    2010-07-01

    The present study established an impurity profile of a synthetic route to the hallucinogenic N,N-dimethyltryptamine (DMT). The synthesis was carried out under reductive amination conditions between tryptamine and aqueous formaldehyde in the presence of acetic acid followed by reduction with sodium cyanoborohydride. Analytical characterization of this synthetic route was carried out by gas chromatography ion trap mass spectrometry using electron- and chemical-ionization modes. Methanol was employed as a liquid CI reagent and the impact of stoichiometric modifications on side-products formation was also investigated. Tryptamine 1, DMT 2, 2-methyltetrahydro-β-carboline (2-Me-THBC, 3), N-methyl-N-cyanomethyltryptamine (MCMT, 4), N-methyltryptamine (NMT, 5), 2-cyanomethyl-tetrahydro-β-carboline (2-CM-THBC, 6) and tetrahydro-β-carboline (THBC, 7) have been detected under a variety of conditions. Replacement of formaldehyde solution with paraformaldehyde resulted in incomplete conversion of the starting material whereas a similar replacement of sodium cyanoborohydride with sodium borohydride almost exclusively produced THBC instead of the expected DMT. Compounds 1 to 7 were quantified and the limits of detection were 28.4, 87.7, 21.5, 23.4, 41.1, 36.6, and 34.9 ng mL(-1), respectively. The limits of quantification for compounds 1 to 7 were 32.4, 88.3, 25.4, 24.6, 41.4, 39.9, and 37.0 µg mL(-1), respectively. Linearity was observed in the range of 20.8-980 µg mL(-1) with correlation coefficients > 0.99. The application holds great promise in the area of forensic chemistry where development of reliable analytical methods for the detection, identification, and quantification of DMT are crucial and also in pharmaceutical analysis where DMT might be prepared for use in human clinical studies. PMID:20648523

  8. Experimental investigation of planar ion traps

    SciTech Connect

    Pearson, C. E.; Leibrandt, D. R.; Bakr, W. S.; Mallard, W. J.; Brown, K. R.; Chuang, I. L.

    2006-03-15

    Chiaverini et al. [Quantum Inf. Comput. 5, 419 (2005)] recently suggested a linear Paul trap geometry for ion-trap quantum computation that places all of the electrodes in a plane. Such planar ion traps are compatible with modern semiconductor fabrication techniques and can be scaled to make compact, many-zone traps. In this paper we present an experimental realization of planar ion traps using electrodes on a printed circuit board to trap linear chains of tens of charged particles of 0.44 {mu}m diameter in a vacuum of 15 Pa (10{sup -1} torr). With these traps we address concerns about the low trap depth of planar ion traps and develop control electrode layouts for moving ions between trap zones without facing some of the technical difficulties involved in an atomic ion-trap experiment. Specifically, we use a trap with 36 zones (77 electrodes) arranged in a cross to demonstrate loading from a traditional four-rod linear Paul trap, linear ion movement, splitting and joining of ion chains, and movement of ions through intersections. We further propose an additional dc-biased electrode above the trap which increases the trap depth dramatically, and a planar ion-trap geometry that generates a two-dimensional lattice of point Paul traps.

  9. Liquid chromatography tandem mass spectrometric quantitation of sulfamethazine and its metabolites: direct analysis of swine urine by triple quadrupole and by ion trap mass spectrometry.

    PubMed

    Bartolucci, G; Pieraccini, G; Villanelli, F; Moneti, G; Triolo, A

    2000-01-01

    This work describes a new method for the quantitation of trace amounts of sulfamethazine (SMZ) and its main metabolite, N4-acetylsulfamethazine (Ac-SMZ), in swine urine, using high-performance liquid chromatography (HPLC) tandem mass spectrometric analysis of crude urine after addition of internal standard and simple dilution with water. The aim was to determine whether residues of this sulfamidic drug, normally administered to swine in order to prevent infectious diseases, were present in urine at levels lower than those permitted by regulatory authorities before human consumption (EU Project SMT, contract number CT 96-2092). A 10 microL volume of diluted urine was injected into a very short, narrow-bore chromatographic column (Zorbax SB-C18 2.1 i. d. x30 mm length, 3.5 microm pore size). Elution of the analytes of interest was achieved in less than seven minutes using a rapid gradient (from 20 to 80% methanol in 3 minutes). Either a PE Sciex API 365 triple quadrupole (QqQ), operated in the selected reaction monitoring (SRM) mode, or a Finnigan LCQ ion trap (IT) mass spectrometer, operated in narrow-range product ion scan, was used as the final detector. Electrospray (ESI) was used as the ionization technique. A comparison of the two tandem mass spectrometers was performed by analyzing the same set of test samples, at three concentration levels, on three different days. Linearity of responses of the calibration standards, intra- and inter-assay precision of the samples, specificity and limits of detection were evaluated for both systems. Both the QqQ and the IT instrument was suitable for rapid, sensitive and specific determination of the analytes, although the overall performance of the QqQ was slightly superior in terms of linearity, precision and sensitivity. PMID:10844733

  10. Direct analysis of volatile organic compounds in human breath using a miniaturized cylindrical ion trap mass spectrometer with a membrane inlet.

    PubMed

    Riter, Leah S; Laughlin, Brian C; Nikolaev, Eugene; Cooks, R Graham

    2002-01-01

    Membrane introduction mass spectrometry (MIMS) coupled to a miniature mass spectrometer equipped with a cylindrical ion trap (CIT) analyzer was used to monitor the flavor components, 3-phenyl-2-propenal and methyl salicylate, found in cinnamon and wintergreen candies, respectively, directly from human breath. The poly(dimethylsiloxane) (PDMS) membrane was operated in a trap-and-release mode, where the temperature of the membrane was cycled during the experiments, which permitted temporal resolution of the two compounds of interest, facilitating their observation in the complex sample. Under these thermally driven conditions, the 10-90% rise times for both compounds are similar (15 s for methyl salicylate, 17 s for 3-phenyl-2-propenal), but the difference in diffusivity means that the signal for 3-phenyl-2-propenal is delayed and the 10% point occurs 6 s later than that for wintergreen. Additional specificity needed for complex samples was gained by using tandem mass spectrometry. PMID:12478583

  11. EDITORIAL: Modern applications of trapped ions Modern applications of trapped ions

    NASA Astrophysics Data System (ADS)

    Knoop, Martina; Hilico, Laurent; Eschner, Jürgen

    2009-08-01

    Ion traps are fantastic tools to explore the world of electrons, atomic and molecular ions, or charged clusters, in the classical as well as in the quantum regime. Extremely long storage times allow probing even of single particles with very high precision. The mass selectivity of the trapping devices is exploited in many experiments, in particular for mass metrology. An overwhelming part of the experiments and ideas rely on the very high level of parameter control which is offered by the ion trap. Manipulation of individual ions and engineering of well defined quantum states are the fundamental techniques to take the experiments beyond existing frontiers and to unprecedented precision. This special issue presents state-of-the-art theory and experiments in a variety of tutorials, reviews and research papers. More than half of these contributions form a follow-up to the first workshop on Modern Applications of Trapped Ions held in Les Houches, France, in May 2008. A great number of topics is covered in atomic and molecular physics, with ion traps as a common tool. The variety of approaches is meant to make this digest a helpful resource to the whole ion trapping community. Among the contributions, four major - while still overlapping - domains can be identified. Novel ion trap design is the motor of future developments and applications. Spectacular progress has been made in the domain of quantum information processing, such as the realization of planar traps, which opens the way to large-scale quantum computation. In this issue, this enthralling subject is introduced by a tutorial and two review articles, completed by contributions on different experimental realizations. Precision measurements belong to a more traditional domain which nevertheless evolves at the forefront of research: metrology of frequencies and fundamental constants, measurements of g-factors or high-precision mass measurements are the foundations of atomic and molecular physics. The creation and

  12. Penning trap mass measurement of 72Br

    NASA Astrophysics Data System (ADS)

    Valverde, A. A.; Bollen, G.; Cooper, K.; Eibach, M.; Gulyuz, K.; Izzo, C.; Morrissey, D. J.; Ringle, R.; Sandler, R.; Schwarz, S.; Sumithrarachchi, C. S.; Villari, A. C. C.

    2015-03-01

    The Low Energy Beam and Ion Trap (LEBIT) Penning trap mass spectrometer was used to perform an improved-precision mass measurement of 72Br and the low-lying isomeric state, Brm72, giving mass excesses of -59 062.2 (1.0 )keV and -58 960.9 (1.2 )keV , respectively. These values are consistent with the values from the 2012 atomic mass evaluation [Chin. Phys. C 36, 1603 (2012), 10.1088/1674-1137/36/12/003] and the Nubase2012 evaluation of nuclear properties [Chin. Phys. C 36, 1157 (2012), 10.1088/1674-1137/36/12/001]. The uncertainties on the mass of the ground state and isomeric state have been reduced by a factor of seven.

  13. Screening for DNA adducts by data-dependent constant neutral loss-triple stage mass spectrometry with a linear quadrupole ion trap mass spectrometer.

    PubMed

    Bessette, Erin E; Goodenough, Angela K; Langouët, Sophie; Yasa, Isil; Kozekov, Ivan D; Spivack, Simon D; Turesky, Robert J

    2009-01-15

    A two-dimensional linear quadrupole ion trap mass spectrometer (LIT/MS) was employed to simultaneously screen for DNA adducts of environmental, dietary, and endogenous genotoxicants, by data-dependent constant neutral loss scanning followed by triple-stage mass spectrometry (CNL-MS3). The loss of the deoxyribose (dR) from the protonated DNA adducts ([M + H - 116]+) in the MS/MS scan mode triggered the acquisition of MS3 product ion spectra of the aglycone adducts [BH2]+. Five DNA adducts of the tobacco carcinogen 4-aminobiphenyl (4-ABP) were detected in human hepatocytes treated with 4-ABP, and three DNA adducts of the cooked-meat carcinogen 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) were identified in the livers of rats exposed to MeIQx, by the CNL-MS3 scan mode. Buccal cell DNA from tobacco smokers was screened for DNA adducts of various classes of carcinogens in tobacco smoke including 4-ABP, 2-amino-9H-pyrido[2,3-b]indole (AalphaC), and benzo[a]pyrene (BaP); the cooked-meat carcinogens MeIQx, AalphaC, and 2-amino-1-methyl-6-phenylmidazo[4,5-b]pyridine (PhIP); and the lipid peroxidation products acrolein (AC) and trans-4-hydroxynonenal (HNE). The CNL-MS3 scanning technique can be used to simultaneously screen for multiple DNA adducts derived from different classes of carcinogens, at levels of adduct modification approaching 1 adduct per 108 unmodified DNA bases, when 10 microg of DNA is employed for the assay. PMID:19086795

  14. Development of a Kingdon ion trap system for trapping externally injected highly charged ions.

    PubMed

    Numadate, Naoki; Okada, Kunihiro; Nakamura, Nobuyuki; Tanuma, Hajime

    2014-10-01

    We have developed a Kingdon ion trap system for the purpose of the laboratory observation of the x-ray forbidden transitions of highly charged ions (HCIs). Externally injected Ar(q+) (q = 5-7) with kinetic energies of 6q keV were successfully trapped in the ion trap. The energy distribution of trapped ions is discussed in detail on the basis of numerical simulations. The combination of the Kingdon ion trap and the time-of-flight mass spectrometer enabled us to measure precise trapping lifetimes of HCIs. As a performance test of the instrument, we measured trapping lifetimes of Ar(q+) (q = 5-7) under a constant number density of H2 and determined the charge-transfer cross sections of Ar(q+)(q = 5, 6)-H2 collision systems at binary collision energies of a few eV. It was confirmed that the present cross section data are consistent with previous data and the values estimated by some scaling formula. PMID:25362383

  15. Development of a Kingdon ion trap system for trapping externally injected highly charged ions

    SciTech Connect

    Numadate, Naoki; Okada, Kunihiro; Nakamura, Nobuyuki; Tanuma, Hajime

    2014-10-01

    We have developed a Kingdon ion trap system for the purpose of the laboratory observation of the x-ray forbidden transitions of highly charged ions (HCIs). Externally injected Ar{sup q+} (q = 5–7) with kinetic energies of 6q keV were successfully trapped in the ion trap. The energy distribution of trapped ions is discussed in detail on the basis of numerical simulations. The combination of the Kingdon ion trap and the time-of-flight mass spectrometer enabled us to measure precise trapping lifetimes of HCIs. As a performance test of the instrument, we measured trapping lifetimes of Ar{sup q+} (q = 5–7) under a constant number density of H₂ and determined the charge-transfer cross sections of Ar{sup q+}(q = 5, 6)-H₂ collision systems at binary collision energies of a few eV. It was confirmed that the present cross section data are consistent with previous data and the values estimated by some scaling formula.

  16. A cooler Penning trap for the TITAN mass measurement facility

    SciTech Connect

    Chowdhury, U.; Kootte, B.; Good, M.; Lascar, D.; Schultz, B. E.; Dilling, J.; Gwinner, G.

    2015-01-09

    The TITAN facility at TRIUMF makes use of highly charged ions, charge-bred in an electron beam ion trap, to carry out accurate mass measurements on radioactive isotopes. We report on our progress to develop a cooler Penning trap, CPET, which aims at reducing the energy spread of the ions to ≈ 1 eV/charge prior to injection into the mass measurement trap. In off-line mode, we can now trap electron plasmas for minutes, and we observe the damping of the m = 1 diocotron plasma mode within ≈ 2 s.

  17. Highly charged ion secondary ion mass spectroscopy

    DOEpatents

    Hamza, Alex V.; Schenkel, Thomas; Barnes, Alan V.; Schneider, Dieter H.

    2001-01-01

    A secondary ion mass spectrometer using slow, highly charged ions produced in an electron beam ion trap permits ultra-sensitive surface analysis and high spatial resolution simultaneously. The spectrometer comprises an ion source producing a primary ion beam of highly charged ions that are directed at a target surface, a mass analyzer, and a microchannel plate detector of secondary ions that are sputtered from the target surface after interaction with the primary beam. The unusually high secondary ion yield permits the use of coincidence counting, in which the secondary ion stops are detected in coincidence with a particular secondary ion. The association of specific molecular species can be correlated. The unique multiple secondary nature of the highly charged ion interaction enables this new analytical technique.

  18. Miniaturized GC/MS instrumentation for in situ measurements: micro gas chromatography coupled with miniature quadrupole array and paul ion trap mass spectrometers

    NASA Technical Reports Server (NTRS)

    Holland, P.; Chutjian, A.; Darrach, M.; Orient, O.

    2002-01-01

    Miniaturized chemical instrumentation is needed for in situ measurements in planetary exploration and other spaceflight applications where factors such as reduction in payload requirements and enhanced robustness are important. In response to this need, we are 'continuing to develop miniaturized GC/MS instrumentation which combines chemical separations by gas chromatography (GC) with mass spectrometry (MS) to provide positive identification of chemical compounds in complex mixtures of gases, such as those found in the International Space Station's cabin atmosphere. Our design approach utilizes micro gas chromatography components coupled with either a miniature quadrupole mass spectrometer array (QMSA) or compact, high-resolution Paul ion trap.

  19. Structure elucidation of degradation products of the antibiotic amoxicillin with ion trap MS(n) and accurate mass determination by ESI TOF.

    PubMed

    Nägele, Edgar; Moritz, Ralf

    2005-10-01

    Today, it is necessary to identify relevant compounds appearing in discovery and development of new drug substances in the pharmaceutical industry. For that purpose, the measurement of accurate molecular mass and empirical formula calculation is very important for structure elucidation in addition to other available analytical methods. In this work, the identification and confirmation of degradation products in a finished dosage form of the antibiotic drug amoxicillin obtained under stress conditions will be demonstrated. Structure elucidation is performed utilizing liquid chromatography (LC) ion trap MS/MS and MS3 together with accurate mass measurement of the molecular ions and of the collision induced dissociation (CID) fragments by liquid chromatography electro spray ionization time-of-flight mass spectrometry (LC/ESI-TOF). PMID:16099170

  20. Solid-phase microextraction gas chromatography/ion trap mass spectrometry and multistage mass spectrometry experiments in the characterization of germacrene D.

    PubMed

    Gioacchini, A M; Menotta, M; Polidori, E; Giomaro, G; Stocchi, V

    2002-12-01

    Germacrene D is a vegetable pheromone utilized in interactions among organisms belonging to different species. For the first time, using solid-phase microextraction/gas chromatography/ion trap mass spectrometry, the presence of this compound was detected in an in vitro mycorrhizal synthesis system where the mycelium of the ectomycorrhizal fungus Tuber borchii Vittad. interacts with the plant Tilia Americana L. From this symbiosis, a new structure, called ectomycorrhiza, is formed where the two symbionts exchange nutrients and metabolites. It seems that only after this interaction can the mycelium develop the fruitbody, commonly known as truffle. The results obtained allowed us to ascertain that germacrene D was synthesized by the plant exclusively in the presence of T. borchii. The originality of these data prompted us to hypothesize that this compound could be involved in the first step of ectomycorrhiza formation, as it is able to stimulate specific fungi receptors. In fact, plants release hundreds of secondary metabolites that are important in their interactions with other organisms. PMID:12489082

  1. Characterization and quantification of 10-hydroxycamptothecine in Camptotheca acuminate and its medicinal preparation by liquid chromatography-ion trap mass spectrometry.

    PubMed

    Chen, Qinhua; Pan, Guangmin; Xiong, Lin; He, Hongsheng; Yang, Hangdong

    2013-12-01

    A rapid and sensitive method for the identification and quantification of 10-hydroxycamptothecine (HCPT) in Camptotheca acuminata Decne is described. The HCPT standard solution was directly infused into the ion trap mass spectrometers (IT/MS) for collecting the MS(n) spectra. The electrospray ionization (ESI) mass spectral fragmentation pathway of HCPT was proposed and the ESI-MS(n) fragmentation behavior of HCPT was deduced in detail. The major fragment ions of HCPT were confirmed by MS(n) in both negative ion and positive ion mode. The possible main cleavage pathway of fragment ions was studied. Quantification of HCPT was assigned in negative-ion mode at a product ion at m/z 363 → 319 by LC-MS. The LC-MS method was validated for linearity, sensitivity, accuracy and precision, and then used to determine the content of the HCPT. Lastly, the LC-MS method was successfully applied to determine HCPT in real samples of Camptotheca acuminate Decne and its medicinal preparation in the first time. PMID:23813501

  2. Reducing Space Charge Effects in a Linear Ion Trap by Rhombic Ion Excitation and Ejection.

    PubMed

    Zhang, Xiaohua; Wang, Yuzhuo; Hu, Lili; Guo, Dan; Fang, Xiang; Zhou, Mingfei; Xu, Wei

    2016-07-01

    Space charge effects play important roles in ion trap operations, which typically limit the ion trapping capacity, dynamic range, mass accuracy, and resolving power of a quadrupole ion trap. In this study, a rhombic ion excitation and ejection method was proposed to minimize space charge effects in a linear ion trap. Instead of applying a single dipolar AC excitation signal, two dipolar AC excitation signals with the same frequency and amplitude but 90° phase difference were applied in the x- and y-directions of the linear ion trap, respectively. As a result, mass selective excited ions would circle around the ion cloud located at the center of the ion trap, rather than go through the ion cloud. In this work, excited ions were then axially ejected and detected, but this rhombic ion excitation method could also be applied to linear ion traps with ion radial ejection capabilities. Experiments show that space charge induced mass resolution degradation and mass shift could be alleviated with this method. For the experimental conditions in this work, space charge induced mass shift could be decreased by ~50%, and the mass resolving power could be improved by ~2 times at the same time. Graphical Abstract ᅟ. PMID:27080008

  3. Reducing Space Charge Effects in a Linear Ion Trap by Rhombic Ion Excitation and Ejection

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaohua; Wang, Yuzhuo; Hu, Lili; Guo, Dan; Fang, Xiang; Zhou, Mingfei; Xu, Wei

    2016-07-01

    Space charge effects play important roles in ion trap operations, which typically limit the ion trapping capacity, dynamic range, mass accuracy, and resolving power of a quadrupole ion trap. In this study, a rhombic ion excitation and ejection method was proposed to minimize space charge effects in a linear ion trap. Instead of applying a single dipolar AC excitation signal, two dipolar AC excitation signals with the same frequency and amplitude but 90° phase difference were applied in the x- and y-directions of the linear ion trap, respectively. As a result, mass selective excited ions would circle around the ion cloud located at the center of the ion trap, rather than go through the ion cloud. In this work, excited ions were then axially ejected and detected, but this rhombic ion excitation method could also be applied to linear ion traps with ion radial ejection capabilities. Experiments show that space charge induced mass resolution degradation and mass shift could be alleviated with this method. For the experimental conditions in this work, space charge induced mass shift could be decreased by ~50%, and the mass resolving power could be improved by ~2 times at the same time.

  4. Cryogenic ion trapping systems with surface-electrode traps

    NASA Astrophysics Data System (ADS)

    Antohi, P. B.; Schuster, D.; Akselrod, G. M.; Labaziewicz, J.; Ge, Y.; Lin, Z.; Bakr, W. S.; Chuang, I. L.

    2009-01-01

    We present two simple cryogenic rf ion trap systems in which cryogenic temperatures and ultra high vacuum pressures can be reached in as little as 12 h. The ion traps are operated either in a liquid helium bath cryostat or in a low vibration closed cycle cryostat. The fast turn around time and availability of buffer gas cooling made the systems ideal for testing surface-electrode ion traps. The vibration amplitude of the closed cycled cryostat was found to be below 106 nm. We evaluated the systems by loading surface-electrode ion traps with S88r+ ions using laser ablation, which is compatible with the cryogenic environment. Using Doppler cooling we observed small ion crystals in which optically resolved ions have a trapped lifetime over 2500 min.

  5. The trapped mercury ion frequency standard

    NASA Technical Reports Server (NTRS)

    Mcguire, M. D.

    1977-01-01

    Singly ionized mercury atoms have a structure similar to neutral alkali atoms. They can be maintained as ions for very long times in an RF quadrupole ion trap. Thus, their ground state hyperfine structure can be used to make a frequency standard using optical pumping techniques similar to the well-known rubidium standard. The mass 199 isotope of mercury has an ionic hyperfine structure of 40.5 GHz. In a trap system a linewidth of 10 Hz has been measured. An expression is presented for the short-term stability of a proposed mercury standard as set by the achieved signal to noise ratio. There is prospect of further improvement. Long-term stability is affected by second order doppler effect, and by pressure, light, and Stark shifts. However, these appear either sufficiently small or sufficiently controlable that the proposed mercury ion standard would be competitive with existing standards.

  6. Precise measurements of the atomic masses of silicon-28, phosphorus-31, sulfur-32, krypton-84,86, xenon-129,132,136, and the dipole moment of PH+ using single-ion and two-ion Penning trap techniques

    NASA Astrophysics Data System (ADS)

    Redshaw, Matthew

    This dissertation describes high precision measurements of atomic masses by measuring the cyclotron frequency of ions trapped singly, or in pairs, in a precision, cryogenic Penning trap. By building on techniques developed at MIT for measuring the cyclotron frequency of single trapped ions, the atomic masses of 84,86Kr, and 129,132,136Xe have been measured to less than a part in 1010 fractional precision. By developing a new technique for measuring the cyclotron frequency ratio of a pair of simultaneously trapped ions, the atomic masses of 28Si, 31P and 32S have been measured to 2 or 3 parts in 10 11. This new technique has also been used to measure the dipole moment of PH+. During the course of these measurements, two significant, but previously unsuspected sources of systematic error were discovered, characterized and eliminated. Extensive tests for other sources of systematic error were performed and are described in detail. The mass measurements presented here provide a significant increase in precision over previous values for these masses, by factors of 3 to 700. The results have a broad range of physics applications: The mass of 136 Xe is important for searches for neutrinoless double-beta-decay; the mass of 28Si is relevant to the re-definition of the artifact kilogram in terms of an atomic mass standard; the masses of 84,86Kr, and 129,132,136Xe provide convenient reference masses for less precise mass spectrometers in diverse fields such as nuclear physics and chemistry; and the dipole moment of PH+ provides a test of molecular structure calculations.

  7. Rapid screening and characterization of drug metabolites using multiple ion monitoring dependent product ion scan and postacquisition data mining on a hybrid triple quadrupole-linear ion trap mass spectrometer.

    PubMed

    Yao, Ming; Ma, Li; Duchoslav, Eva; Zhu, Mingshe

    2009-06-01

    Multiple ion monitoring (MIM)-dependent acquisition with a triple quadrupole-linear ion trap mass spectrometer (Q-trap) was previously developed for drug metabolite profiling. In the analysis, multiple predicted metabolite ions are monitored in both Q1 and Q3 regardless of their fragmentations. The collision energy in Q2 is set to a low value to minimize fragmentation. Once an expected metabolite is detected by MIM, enhanced product ion (EPI) spectral acquisition of the metabolite is triggered. To analyze in vitro metabolites, MIM-EPI retains the sensitivity and selectivity similar to that of multiple reaction monitoring (MRM)-EPI in the analysis of in vitro metabolites. Here we present an improved approach utilizing MIM-EPI for data acquisition and multiple data mining techniques for detection of metabolite ions and recovery of their MS/MS spectra. The postacquisition data processing tools included extracted ion chromatographic analysis, product ion filtering and neutral loss filtering. The effectiveness of this approach was evaluated by analyzing oxidative metabolites of indinavir and glutathione (GSH) conjugates of clozapine and 4-ethylphenol in liver microsome incubations. Results showed that the MIM-EPI-based data mining approach allowed for comprehensive detection of metabolites based on predicted protonated molecules, product ions or neutral losses without predetermination of the parent drug MS/MS spectra. Additionally, it enabled metabolite detection and MS/MS acquisition in a single injection. This approach is potentially useful in high-throughout screening of metabolic soft spots and reactive metabolites at the drug discovery stage. PMID:19418486

  8. Determination of amphetamine-type stimulants, cocaine and ketamine in human hair by liquid chromatography/linear ion trap-Orbitrap hybrid mass spectrometry.

    PubMed

    Miyaguchi, Hajime; Inoue, Hiroyuki

    2011-09-01

    An LTQ Orbitrap XL hybrid mass spectrometry method was developed for the determination of illicit drugs and their metabolites, including amphetamine (AP), methamphetamine (MA), dimethylamphetamine (DMA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), ketamine (KET), norketamine (NK), cocaine (COC) and benzoylecgonine (BE), in hair. Micropulverized extraction was employed for sample preparation using a small hair sample (2 cm piece or 0.2 mg). Recoveries of the analytes during sample preparation were estimated using fortified hair samples and ranged from 35.5% for COC to 71.7% for AP. High resolution full-scan mass spectra and unit resolution product-ion spectra were obtained with the Orbitrap analyzer and the linear ion-trap analyzer, respectively. High-resolution extracted ion chromatograms at a tolerance of 3 ppm were utilized for quantification. The analytes were identified using the product-ion spectra in combination with the accurate masses of the corresponding protonated molecules observed in the high-resolution mass spectra. Lower limits of quantification obtained from a 0.2 mg hair sample were 0.050 ng mg(-1) (MDMA, KET and BE), 0.10 ng mg(-1) (AP, MA, DMA, NK and COC) and 0.50 ng mg(-1) (MDA). Two reference materials were analyzed for verification, and segmental analysis of single strands of hair specimens from actual cases was performed. PMID:21331390

  9. Determination of carnitine and acylcarnitines in urine by high-performance liquid chromatography-electrospray ionization ion trap tandem mass spectrometry.

    PubMed

    Vernez, Laurence; Hopfgartner, Gérard; Wenk, Markus; Krähenbühl, Stephan

    2003-01-17

    A high-performance liquid chromatography-mass spectrometry method has been developed for the simultaneous determination of native carnitine and eight acylcarnitines in urine. The procedure uses a solid-phase extraction on a cation-exchange column and the separation is performed without derivatization within 17 min on a reversed-phase C8 column in the presence of a volatile ion-pairing reagent. The detector was an ion trap mass spectrometer and quantification was carried out in the MS-MS mode. Validation was done for aqueous standards at ranges between 0.75 and 200 micromol/l, depending on the compound. Carnitine was quantified in urine and comparison with a radioenzymatic assay gave a satisfactory correlation (R2 = 0.981). The assay could be successfully applied to the diagnostic of pathological acylcarnitines profile of metabolic disorders in urines of patients suffering from different organic acidurias. PMID:12564691

  10. Separation and Identification of Isomeric Glycans by Selected Accumulation-Trapped Ion Mobility Spectrometry-Electron Activated Dissociation Tandem Mass Spectrometry.

    PubMed

    Pu, Yi; Ridgeway, Mark E; Glaskin, Rebecca S; Park, Melvin A; Costello, Catherine E; Lin, Cheng

    2016-04-01

    One of the major challenges in structural characterization of oligosaccharides is the presence of many structural isomers in most naturally occurring glycan mixtures. Although ion mobility spectrometry (IMS) has shown great promise in glycan isomer separation, conventional IMS separation occurs on the millisecond time scale, largely restricting its implementation to fast time-of-flight (TOF) analyzers which often lack the capability to perform electron activated dissociation (ExD) tandem MS analysis and the resolving power needed to resolve isobaric fragments. The recent development of trapped ion mobility spectrometry (TIMS) provides a promising new tool that offers high mobility resolution and compatibility with high-performance Fourier transform ion cyclotron resonance (FTICR) mass spectrometers when operated under the selected accumulation-TIMS (SA-TIMS) mode. Here, we present our initial results on the application of SA-TIMS-ExD-FTICR MS to the separation and identification of glycan linkage isomers. PMID:26959868

  11. Metabonomic Study of Biochemical Changes in Human Hair of Heroin Abusers by Liquid Chromatography Coupled with Ion Trap-Time of Flight Mass Spectrometry.

    PubMed

    Xie, Pu; Wang, Tie-jie; Yin, Guo; Yan, Yan; Xiao, Li-he; Li, Qing; Bi, Kai-shun

    2016-01-01

    Hair analysis is with the advantage of non-invasive collection and long surveillance window. The present study employed a sensitive and reliable liquid chromatography coupled with ion trap-time of flight mass spectrometry method to study the metabonomic characters in the hair of 58 heroin abusers and 72 non-heroin abusers. Results indicated that certain endogenous metabolites, such as sorbitol and cortisol, were accelerated, and the level of arachidonic acid, glutathione, linoleic acid, and myristic acid was decreased in hair of heroin abusers. The metabonomic study is helpful for further understanding of heroin addiction and clinical diagnosis. PMID:26445826

  12. An improved linear ion trap physics package

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.

    1993-01-01

    This article describes an improvement in the architecture of the physics package used in the Linear Ion Trap (LIT)-based frequency standard recently developed at JPL. This new design is based on the observation that ions can be moved along the axis of an LIT by applied dc voltages. The state selection and interrogation region can be separated from the more critical microwave resonance region where the multiplied local oscillator signal is compared with the stable atomic transition. This separation relaxes many of the design constraints of the present units. Improvements include increased frequency stability and a substantial reduction in size, mass, and cost of the final frequency standard.

  13. [Rapid screening and confirming carcinogenic banned azo colorants in textiles by high performance liquid chromatography-linear ion trap/orbitrap high-resolution mass spectrometry].

    PubMed

    Yun, Huan; Liu, Xin; Wang, Jing; Yan, Hua; Cui, Fengyun; Zhang, Zhaohui

    2013-09-01

    A method of high performance liquid chromatography-linear ion trap/orbitrap highresolution mass spectrometry (HPLC-LTP/Orbitrap MS) was ued to screen and confirm-banned azo colorants in textiles rapidly. The analytes were reduced to carcinogenic aromatic amines with sodium dithionite in citrate buffer solution. The reduced solution was extracted bydiatomite, and loadd onto an Acquity UPLC BEH C18 column (50 mm x 2.1 MM. 1.7 microm) with a gradient elution of methanol and 0.1% (v/v) methane acid aqueous solution, and finally detected by linear ion trap/orbitrap high-resolution mass spectrometry in positive ESI mode. In mass spectrometry method, the MS spectrum of high-resolution and the collision induced dissociation (CID) spectrum of data-dependent scan mode were used for screening analysis and conformation, respectively. The calibration curves showed a good linearity in the range of 0.05 -2.00 mg/b, and the correlation coefficients (r) were higher than 0.99. By detecting spiked samples, the limits of quantification were 0.08 mg/kg for all the residues and the recoveries were in the range of 65.5% - 111.5% with the relative standard deviations (RSDs) between 0.87% and 2.49%. The results indicate that the method is simple, rapid, sensitive and suitable for the qualitative and quantitative analysis of carcinogenic aromatic amines in textiles. PMID:24392621

  14. How far can ion trap miniaturization go? Parameter scaling and space-charge limits for very small cylindrical ion traps.

    PubMed

    Tian, Yuan; Higgs, Jessica; Li, Ailin; Barney, Brandon; Austin, Daniel E

    2014-03-01

    A broad effort is underway to make radiofrequency (RF) ion trap mass spectrometers small enough for portable chemical analysis. A variety of trap geometries and fabrication approaches are under development from several research groups. A common issue is the reduced trapping capacity in smaller traps, with the associated reduction in sensitivity. This article explores the key variables that scale with trap size including RF voltage, frequency, electrical capacitance, power and pseudopotential well depth. High-field electric breakdown constrains the maximum RF voltages used in smaller ion traps. Simulations show the effects of space charge and the limits of trapping capacity as a function of trap dimensions for cylindrical ion traps down to the micrometer level. RF amplitudes that scale as the 1/3, 1/2 and 2/3 power of trap radius, r0, were studied. At a fixed level of performance, the number of analyzable ions scales as r0(n), with n ranging from 1.55 to 1.75 depending on the choice of voltage scaling. The implications for miniaturized ion trap mass spectrometry are discussed. PMID:24619549

  15. Single-trapped-ion vibronic Raman laser

    NASA Astrophysics Data System (ADS)

    di Fidio, C.; Vogel, W.; de Matos Filho, R. L.; Davidovich, L.

    2002-01-01

    We propose a model for a single-trapped-ion vibronic Raman laser and study its dynamics by using quantum-trajectory methods. In our treatment, it is essential that both the cavity field of the high-finesse optical cavity and the center-of-mass vibrational motion of the trapped ion be quantized. A transition from a super-Poissonian light source to a Poissonian lasing regime is obtained by increasing the Raman coupling constant. Furthermore, we demonstrate that a nonclassical regime can be realized, where the photon statistics becomes sub-Poissonian and the photons leak out of the cavity in an antibunched manner. This is achieved by exploiting nonlinear Stark shifts inherent in the model, which depend on both the number of cavity photons and the number of vibrational quanta.

  16. Characterization of diacylglycerol isomers in edible oils using gas chromatography-ion trap electron ionization mass spectrometry.

    PubMed

    Zhu, Hanjiang; Clegg, Michael S; Shoemaker, Charles F; Wang, Selina C

    2013-08-23

    Verifying the authenticity of edible oils is of international concern. A new quality control standard for olive oil has been proposed that relates the ratio of 1,2-diacylglycerol (DAG) to 1,3-DAG to sensory aspects of olive oil. DAGs and their isomers are difficult to quantitate and characterize by Flame Ionization Gas Chromatography (GC-FID) due to the lack of suitable standards. Mass detectors offer the advantage of providing structural detail to the eluding DAG(s), thus removing ambiguity to the identification of both resolved and unresolved DAGs in GC chromatograms. In this study, a GC Electron Ionization Mass Spectrometry (GC-EI-MS) method was developed to determine the fatty acid composition and molecular structure of trimethylsilyl (TMS) derivatized DAGs present in edible oils. Twenty-two species of DAG isomers were identified in refined coconut oil and unrefined olive oil utilizing signature fragment ions, [M-15](+), [M-89](+), [M-RCO2](+), [RCO2+58](+) and [M-RCO2CH2](+). The [M-RCO2CH2](+) ion is considered the key diagnostic ion to distinguish between DAG positional isomers. MS/MS spectra of [M-RCO2](+) and [M-15](+) ions obtained from commercial standards containing both 1,2- and 1,3-DAG isomers were used as a model system to confirm the identification of DAG isomers in natural products. Furthermore, a number of reaction mechanisms are proposed to explain the formation of the most abundant mass fragments of DAGs and their isomers. PMID:23880469

  17. [Screening and confirmation of 24 hormones in cosmetics by ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry].

    PubMed

    Li, Zhaoyong; Wang, Fengmei; Niu, Zengyuan; Luo, Xin; Zhang, Gang; Chen, Junhui

    2014-05-01

    A method of ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UPLC-LTQ/Orbitrap MS) was established to screen and confirm 24 hormones in cosmetics. Various cosmetic samples were extracted with methanol. The extract was loaded onto a Waters ACQUITY UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 microm) using a gradient elution of acetonitrile/water containing 0.1% (v/v) formic acid for the separation. The accurate mass of quasi-molecular ion was acquired by full scanning of electrostatic field orbitrap. The rapid screening was carried out by the accurate mass of quasi-molecular ion. The confirmation analysis for targeted compounds was performed with the retention time and qualitative fragments obtained by data dependent scan mode. Under the optimal conditions, the 24 hormones were routinely detected with mass accuracy error below 3 x 10(-6) (3 ppm), and good linearities were obtained in their respective linear ranges with correlation coefficients higher than 0.99. The LODs (S/N = 3) of the 24 compounds were < or = 10 microg/kg, which can meet the requirements for the actual screening of cosmetic samples. The developed method was applied to screen the hormones in 50 cosmetic samples. The results demonstrate that the method is a useful tool for the rapid screening and identification of the hormones in cosmetics. PMID:25185307

  18. Fundamentals of Trapped Ion Mobility Spectrometry

    NASA Astrophysics Data System (ADS)

    Michelmann, Karsten; Silveira, Joshua A.; Ridgeway, Mark E.; Park, Melvin A.

    2015-01-01

    Trapped ion mobility spectrometry (TIMS) is a relatively new gas-phase separation method that has been coupled to quadrupole orthogonal acceleration time-of-flight mass spectrometry. The TIMS analyzer is a segmented rf ion guide wherein ions are mobility-analyzed using an electric field that holds ions stationary against a moving gas, unlike conventional drift tube ion mobility spectrometry where the gas is stationary. Ions are initially trapped, and subsequently eluted from the TIMS analyzer over time according to their mobility ( K). Though TIMS has achieved a high level of performance ( R > 250) in a small device (<5 cm) using modest operating potentials (<300 V), a proper theory has yet to be produced. Here, we develop a quantitative theory for TIMS via mathematical derivation and simulations. A one-dimensional analytical model, used to predict the transit time and theoretical resolving power, is described. Theoretical trends are in agreement with experimental measurements performed as a function of K, pressure, and the axial electric field scan rate. The linear dependence of the transit time with 1/ K provides a fundamental basis for determination of reduced mobility or collision cross section values by calibration. The quantitative description of TIMS provides an operational understanding of the analyzer, outlines the current performance capabilities, and provides insight into future avenues for improvement.

  19. Atomic Clock Based On Linear Ion Trap

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Dick, G. John

    1992-01-01

    Highly stable atomic clock based on excitation and measurement of hyperfine transition in 199Hg+ ions confined in linear quadrupole trap by radio-frequency and static electric fields. Configuration increases stability of clock by enabling use of enough ions to obtain adequate signal while reducing non-thermal component of motion of ions in trapping field, reducing second-order Doppler shift of hyperfine transition. Features described in NPO-17758 "Linear Ion Trap for Atomic Clock." Frequency standard based on hyperfine transition described in NPO-17456, "Trapped-Mercury-Ion Frequency Standard."

  20. Determination of non-ionic polyethoxylated surfactants in wastewater and river water by mixed hemimicelle extraction and liquid chromatography-ion trap mass spectrometry.

    PubMed

    Cantero, Manuel; Rubio, Soledad; Pérez-Bendito, Dolores

    2005-03-01

    The capability of hemimicelles-based solid phase extraction (SPE)/liquid chromatography/atmospheric pressure chemical ionisation in positive mode, ion trap mass spectrometry (LC/(APCl+-IT)-MS) for the concentration, separation and quantitation of non-ionic surfactants has been investigated. Concentration was based on the formation of mixed aggregates of analytes [alkylphenol ethoxylates (APE, octyl and nonyl) and alkyl ethoxylates (AE, C12-C16)] with the anionic surfactant sodium dodecyl sulphate (SDS) that is adsorbed on alumina. Parameters affecting SPE were investigated on the basis that hemimicelles are dynamic entities in equilibrium with the aqueous phase. The performance of ion trap mass spectrometry for MS and MS/MS quantitation of non-ionic homologues was assessed. Recoveries of analytes from wastewater influent and effluent and river water samples ranged between 91 and 98% and were found independent on the length of the alkyl chain under the optimised conditions. Anionic surfactants did not interfere to the levels found in environmental samples. The detection limits ranged between 14 and 111 ng/l for wastewater influent, 10 and 40 for wastewater effluent and 4 and 35 for river water, after concentration of 250, 500 and 750 ml of sample, respectively. The approach was applied to the determination of AE and APE in influent and effluent samples from four wastewater treatment plants and four river samples. The concentrations of individual non-ionic surfactants found ranged between 0.3 and 373 microg/l. PMID:15844521

  1. An integrated approach for profiling oxidative metabolites and glutathione adducts using liquid chromatography coupled with ultraviolet detection and triple quadrupole-linear ion trap mass spectrometry.

    PubMed

    Chen, Guiying; Cheng, Zhongzhe; Zhang, Kerong; Jiang, Hongliang; Zhu, Mingshe

    2016-09-10

    The use of liquid chromatography (LC) coupled with triple quadrupole linear ion trap (Qtrap) mass spectrometry (MS) for both quantitative and qualitative analysis in drug metabolism and pharmacokinetic studies is of great interest. Here, a new Qtrap-based analytical methodology for simultaneous detection, structural characterization and semi-quantitation of in vitro oxidative metabolites and glutathione trapped reactive metabolites was reported. In the current study, combined multiple ion monitoring and multiple reaction monitoring were served as surveying scans to trigger product ion spectral acquisition of oxidative metabolites and glutathione adduct, respectively. Then, detection of metabolites and recovery of their MS/MS spectra were accomplished using multiple data mining approaches. Additionally, on-line ultraviolet (UV) detection was employed to determine relative concentrations of major metabolites. Analyses of metabolites of clozapine and nomifensine in rat liver microsomes not only revealed multiple oxidative metabolites and glutathione adducts, but also identified their major oxidative metabolism and bioactivation pathways. The results demonstrated that the LC/UV/MS method enabled Qtrap to perform the comprehensive profiling of oxidative metabolites and glutathione adducts in vitro. PMID:27497649

  2. Direct quantitative analysis of organic compounds in the gas and particle phase using a modified atmospheric pressure chemical ionization source in combination with ion trap mass spectrometry.

    PubMed

    Warscheid, Bettina; Kückelmann, Ulrich; Hoffmann, Thorsten

    2003-03-15

    A slightly modified atmospheric pressure chemical ionization source is employed for direct quantitative analysis of volatile or semivolatile organic compounds in air. The method described here is based on the direct introduction of an analyte in the gas or particle phase, or both, into the ion source of a commercial ion trap mass spectrometer. For quantitation, a standard solution is directly transferred into the vaporizer unit of the ion source via a deactivated fused-silica capillary by using the sheath liquid syringe pump, which is part of the mass spectrometer. The standard addition procedure is conducted by varying the pump rate of a diluted solution of the standard compound in methanol/water. A N2 sheath gas flow is applied for optimal vaporization and mixing with the analyte gas stream. By performing detailed reagent ion monitoring experiments, it is shown that the relative signal intensity of [M + H]+ ions is dependent on the relative humidity of the analyte gas stream as well as the composition and concentration of CI reagent ions. The method is validated by a comparison of the standard addition results with a calibration test gas of known concentration. To demonstrate the potential of atmospheric pressure chemical ionization mass spectrometry as a quantitative analytical technique for on-line investigations, a tropospherically relevant reaction is carried out in a 493-L reaction chamber at atmospheric pressure and 296 K in synthetic air at 50% relative humidity. Finally, the applicability of the technique to rapidly differentiate between analytes in the gas and particle phase is demonstrated. PMID:12659203

  3. METHOD AND APPARATUS FOR TRAPPING IONS IN A MAGNETIC FIELD

    DOEpatents

    Luce, J.S.

    1962-04-17

    A method and apparatus are described for trapping ions within an evacuated container and within a magnetic field utilizing dissociation and/or ionization of molecular ions to form atomic ions and energetic neutral particles. The atomic ions are magnetically trapped as a result of a change of charge-to- mass ratio. The molecular ions are injected into the container and into the path of an energetic carbon arc discharge which dissociates and/or ionizes a portion of the molecular ions into atomic ions and energetic neutrals. The resulting atomic ions are trapped by the magnetic field to form a circulating beam of atomic ions, and the energetic neutrals pass out of the system and may be utilized in a particle accelerator. (AEC)

  4. Characterization of polar lipids of listeria monocytogenes by HCD and low energy CAD linear ion-trap mass spectrometry with electrospray ionization

    PubMed Central

    Tatituri, Raju V. V.; Wolf, Benjamin J.; Brenner, Michael B.; Turk, John; Hsu, Fong-Fu

    2015-01-01

    Listeria monocytogenes (L. monocytogenes) is a facultative, Gram-positive, food-borne bacterium, which causes serious infections. Although it is known that lipid play important roles in the survival of listeria, the detailed structures of these lipids have not been established. In this contribution, we described linear ion-trap multiple-stage mass spectrometric approaches with high resolution mass spectrometry toward complete structural analysis including the identities of the fatty acid substituents and their position on the glycerol backbone of the polar lipids, mainly phosphatidylglycerol, cardiolipin (CL), and lysyl-CL from L. monocytogenes., The location of the methyl side group along the fatty acid chain in each lipid family was characterized by a charge-switch strategy. This is achieved by first alkaline hydrolysis to release the fatty acid substituents, followed by tandem mass spectrometry on their N-(4-aminomethylphenyl) pyridinium (AMPP) derivatives as the M+ ions. Several findings in this study are unique (1) we confirm the presence of a plasmalogen PG family that has not been previous reported; (2) an ion arising from a rare internal loss of lysyl-glycerol residue was observed in the MS2 spectrum of lysyl-CL, permitting its distinction from other CL subfamilies. PMID:25656850

  5. Trapped-Mercury-Ion Frequency Standard

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Dick, G. John; Maleki, Lutfollah

    1991-01-01

    Report describes principle of operation, design, and results of initial measurements on trapped-mercury-ion frequency-standard apparatus at NASA's Jet Propulsion Laboratory. New frequency standard being developed. Based on linear ion trap described in (NPO-17758). Expected to show much better short-term frequency stability because of increased ion-storage capacity.

  6. New ion trap for frequency standard applications

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.; Dick, G. J.; Maleki, L.

    1989-01-01

    A novel linear ion trap was designed, which permits storage of a large number of ions with reduced susceptibility to the second-order Doppler effect caused by the RF confining fields. This new trap should store about 20 times the number of ions as a conventional RF trap with no corresponding increase in second-order Doppler shift from the confining field. In addition, the sensitivity of this shift to trapping parameters, i.e., RF voltage, RF frequency, and trap size, is greatly reduced.

  7. Ultrafast entanglement of trapped ions

    NASA Astrophysics Data System (ADS)

    Neyenhuis, Brian; Johnson, Kale; Mizrahi, Jonathan; Wong-Campos, David; Monroe, Christopher

    2014-05-01

    We have demonstrated ultrafast spin-motion entanglement of a single atomic ion using a short train of intense laser pulses. This pulse train gives the ion a spin-dependent kick where each spin state receives a discrete momentum kick in opposite directions. Using a series of these spin-dependent kicks we can realize a two qubit gate. In contrast to gates using spectroscopically resolved motional sidebands, these gates may be performed faster than the trap oscillation period, making them potentially less sensitive to noise. Additionally this gate is temperature insensitive and does not require the ions to be cooled to the Lamb-Dicke limit. We show that multiple kicks can be strung together to create a ``Schrodinger cat'' like state, where the large separation between the two parts of the wavepacket allow us to accumulate the phase shift necessary for a gate in a shorter amount of time. We will present a realistic pulse scheme for a two ion gate, and our progress towards its realization. This work is supported by grants from the U.S. Army Research Office with funding from the DARPA OLE program, IARPA, and the MURI program; and the NSF Physics Frontier Center at JQI.

  8. Identification of the nitrogen-based blister agents bis(2-chloroethyl)methylamine (HN-2) and tris(2-chloroethyl)amine (HN-3) and their hydrolysis products on soil using ion trap secondary ion mass spectrometry.

    PubMed

    Gresham, G L; Groenewold, G S; Olson, J E

    2000-12-01

    The nitrogen blister agents HN-2 (bis(2-chloroethyl)methylamine) and HN-3 (tris(2-chloroethyl)amine) were directly analyzed on the surface of soil samples using ion trap secondary ion mass spectrometry (SIMS). In the presence of water, HN-1 (bis(2-choroethyl)ethylamine), HN-2 and HN-3 undergo hydrolysis to form N-ethyldiethanolamine, N-methyldiethanolamine and triethanolamine (TEA), respectively; these compounds can be readily detected as adsorbed species on soil particles. When soil samples spiked with HN-3 in alcohol were analyzed, 2-alkoxyethylamine derivatives were observed on the sample surfaces. This result shows that nitrogen blister agents will undergo condensation reactions with nucleophilic compounds and emphasizes the need for an analytical methodology capable of detecting a range of degradation and condensation products on environmental surfaces. The ability of ion trap SIMS to isolate and accumulate ions, and then perform tandem mass spectrometric analysis improves the detection of low-abundance surface contaminants and the selectivity of the technique. Utilizing these techniques, the limits of detection for HN-3 were studied as a function of surface coverage. It was found that HN-3 could be detected at a surface coverage of 0.01 monolayer, which corresponds to 20 ppm (mass/mass) for a soil having a surface area of 2.2 m(2) g(-1). TEA, the exhaustive hydrolysis product of HN-3, was detected at a surface coverage of 0.001 monolayer, which corresponds to 0.86 ppm. PMID:11180637

  9. Cryogenic resonator design for trapped ion experiments in Paul traps

    NASA Astrophysics Data System (ADS)

    Brandl, M. F.; Schindler, P.; Monz, T.; Blatt, R.

    2016-06-01

    Trapping ions in Paul traps require high radio frequency voltages, which are generated using resonators. When operating traps in a cryogenic environment, an in-vacuum resonator showing low loss is crucial to limit the thermal load to the cryostat. In this study, we present a guide for the design and production of compact, shielded cryogenic resonators. We produced and characterized three different types of resonators and furthermore demonstrate efficient impedance matching of these resonators at cryogenic temperatures.

  10. Compact toroidal ion-trap design and optimization

    SciTech Connect

    Madsen, M. J.; Gorman, C. H.

    2010-10-15

    We present the design of a type of compact toroidal, or 'halo', ion trap. Such traps may be useful for mass spectrometry, studying small Coulomb cluster rings, quantum-information applications, or other quantum simulations where a ring topology is of interest. We present results from a Monte Carlo optimization of the trap design parameters using finite-element analysis simulations that minimize higher-order anharmonic terms in the trapping pseudopotential, while maintaining complete control over ion placement at the pseudopotential node in three dimensions using static bias fields. These simulations are based on a practical electrode design using readily available parts, yet can be easily scaled to any size trap with similar electrode spacings. We also derive the conditions for a crystal structure transition for two ions in the compact halo trap, the first nontrivial transition for Coulomb crystals in this geometry.