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Sample records for ion mobility separations

  1. Hybrid ion mobility and mass spectrometry as a separation tool.

    Science.gov (United States)

    Ewing, Michael A; Glover, Matthew S; Clemmer, David E

    2016-03-25

    Ion mobility spectrometry (IMS) coupled to mass spectrometry (MS) has seen spectacular growth over the last two decades. Increasing IMS sensitivity and capacity with improvements in MS instrumentation have driven this growth. As a result, a diverse new set of techniques for separating ions by their mobility have arisen, each with characteristics that make them favorable for some experiments and some mass spectrometers. Ion mobility techniques can be broken down into dispersive and selective techniques based upon whether they pass through all mobilities for later analysis by mass spectrometry or select ions by mobility or a related characteristic. How ion mobility techniques fit within a more complicated separation including mass spectrometry and other techniques such as liquid chromatography is of fundamental interest to separations scientists. In this review we explore the multitude of ion mobility techniques hybridized to different mass spectrometers, detailing current challenges and opportunities for each ion mobility technique and for what experiments one technique might be chosen over another. The underlying principles of ion mobility separations, including: considerations regarding separation capabilities, ion transmission, signal intensity and sensitivity, and the impact that the separation has upon the ion structure (i.e., the possibility of configurational changes due to ion heating) are discussed.

  2. Method and device for ion mobility separations

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Yehia M.; Garimella, Sandilya V. B.; Smith, Richard D.

    2017-07-11

    Methods and devices for ion separations or manipulations in gas phase are disclosed. The device includes a single non-planar surface. Arrays of electrodes are coupled to the surface. A combination of RF and DC voltages are applied to the arrays of electrodes to create confining and driving fields that move ions through the device. The DC voltages are static DC voltages or time-dependent DC potentials or waveforms.

  3. Method for enhancing the resolving power of ion mobility separations over a limited mobility range

    Science.gov (United States)

    Shvartsburg, Alexandre A; Tang, Keqi; Smith, Richard D

    2014-09-23

    A method for raising the resolving power, specificity, and peak capacity of conventional ion mobility spectrometry is disclosed. Ions are separated in a dynamic electric field comprising an oscillatory field wave and opposing static field, or at least two counter propagating waves with different parameters (amplitude, profile, frequency, or speed). As the functional dependencies of mean drift velocity on the ion mobility in a wave and static field or in unequal waves differ, only single species is equilibrated while others drift in either direction and are mobility-separated. An ion mobility spectrum over a limited range is then acquired by measuring ion drift times through a fixed distance inside the gas-filled enclosure. The resolving power in the vicinity of equilibrium mobility substantially exceeds that for known traveling-wave or drift-tube IMS separations, with spectra over wider ranges obtainable by stitching multiple segments. The approach also enables low-cutoff, high-cutoff, and bandpass ion mobility filters.

  4. Variables Affecting the Internal Energy of Peptide Ions During Separation by Differential Ion Mobility Spectrometry

    Science.gov (United States)

    Santiago, Brandon G.; Campbell, Matthew T.; Glish, Gary L.

    2017-10-01

    Differential ion mobility spectrometry (DIMS) devices separate ions on the basis of differences in ion mobility in low and high electric fields, and can be used as a stand-alone analytical method or as a separation step before further analysis. As with other ion mobility separation techniques, the ability of DIMS separations to retain the structural characteristics of analytes has been of concern. For DIMS separations, this potential loss of ion structure originates from the fact that the separations occur at atmospheric pressure and the ions, during their transit through the device, undergo repeated collisions with the DIMS carrier gas while being accelerated by the electric field. These collisions have the ability to increase the internal energy distribution of the ions, which can cause isomerization or fragmentation. The increase in internal energy of the ions is based on a number of variables, including the dispersion field and characteristics of the carrier gas such as temperature and composition. The effects of these parameters on the intra-DIMS fragmentation of multiply charged ions of the peptides bradykinin (RPPGFSPFR) and GLISH are discussed herein. Furthermore, similarities and differences in the internal energy deposition that occur during collisional activation in tandem mass spectrometry experiments are discussed, as the fragmentation pathways accessed by both are similar. [Figure not available: see fulltext.

  5. Separation of peptides from detergents using ion mobility spectrometry.

    Science.gov (United States)

    Bagag, Aïcha; Giuliani, Alexandre; Canon, Francis; Réfrégiers, Matthieu; Le Naour, François

    2011-11-30

    Mass spectrometry (MS) has dramatically evolved in the last two decades and has been the driving force of the spectacular expansion of proteomics during this period. However, the very poor compatibility of MS with detergents is still a technical obstacle in some studies, in particular on membrane proteins. Indeed, the high hydrophobicity of membrane proteins necessitates the use of detergents for their extraction and solubilization. Here, we address the analytical potential of high-field asymmetric waveform ion mobility spectrometry (FAIMS) for separating peptides from detergents. The study was focused on peptides from the human integral membrane protein CD9. A tryptic peptide was mixed with the non-ionic detergents Triton X-100 or beta-D-dodecyl maltoside (DDM) as well as with the ionic detergents sodium dodecyl sulfate (SDS) or sodium deoxycholate (SDC). Although electrospray ionization (ESI) alone led to a total suppression of the peptide ion signal on mass spectra with only detection of the detergents, use of FAIMS allowed separation and clear identification of the peptide with any of the detergents studied. The detection and identification of the target compound in the presence of an excess of detergents are then feasible. FAIMS should prove especially useful in the structural and proteomic analysis of membrane proteins.

  6. Characterization of Traveling Wave Ion Mobility Separations in Structures for Lossless Ion Manipulations.

    Science.gov (United States)

    Hamid, Ahmed M; Ibrahim, Yehia M; Garimella, Sandilya V B; Webb, Ian K; Deng, Liulin; Chen, Tsung-Chi; Anderson, Gordon A; Prost, Spencer A; Norheim, Randolph V; Tolmachev, Aleksey V; Smith, Richard D

    2015-11-17

    We report on the development and characterization of a traveling wave (TW)-based Structures for Lossless Ion Manipulations (TW-SLIM) module for ion mobility separations (IMS). The TW-SLIM module uses parallel arrays of rf electrodes on two closely spaced surfaces for ion confinement, where the rf electrodes are separated by arrays of short electrodes, and using these TWs can be created to drive ion motion. In this initial work, TWs are created by the dynamic application of dc potentials. The capabilities of the TW-SLIM module for efficient ion confinement, lossless ion transport, and ion mobility separations at different rf and TW parameters are reported. The TW-SLIM module is shown to transmit a wide mass range of ions (m/z 200-2500) utilizing a confining rf waveform (∼1 MHz and ∼300 Vp-p) and low TW amplitudes (<20 V). Additionally, the short TW-SLIM module achieved resolutions comparable to existing commercially available low pressure IMS platforms and an ion mobility peak capacity of ∼32 for TW speeds of <210 m/s. TW-SLIM performance was characterized over a wide range of rf and TW parameters and demonstrated robust performance. The combined attributes of the flexible design and low voltage requirements for the TW-SLIM module provide a basis for devices capable of much higher resolution and more complex ion manipulations.

  7. Multidimensional Separation of Natural Products Using Liquid Chromatography Coupled to Hadamard Transform Ion Mobility Mass Spectrometry

    Science.gov (United States)

    Liu, Wenjie; Zhang, Xing; Knochenmuss, Richard; Siems, William F.; Hill, Herbert H.

    2016-05-01

    A high performance liquid chromatograph (HPLC)was interfaced to an atmospheric drift tube ion mobility time of flight mass spectrometry. The power of multidimensional separation was demonstrated using chili pepper extracts. The ambient pressure drift tube ion mobility provided high resolving powers up to 166 for the HPLC eluent. With implementation of Hadamard transform (HT), the duty cycle for the ion mobility drift tube was increased from less than 1% to 50%, and the ion transmission efficiency was improved by over 200 times compared with pulsed mode, improving signal to noise ratio 10 times. HT ion mobility and TOF mass spectrometry provide an additional dimension of separation for complex samples without increasing the analysis time compared with conventional HPLC.

  8. Squeezing of Ion Populations and Peaks in Traveling Wave Ion Mobility Separations and Structures for Lossless Ion Manipulations using Compression Ratio Ion Mobility Programming

    Energy Technology Data Exchange (ETDEWEB)

    Garimella, Venkata BS; Hamid, Ahmed M.; Deng, Liulin; Ibrahim, Yehia M.; Webb, Ian K.; Baker, Erin M.; Prost, Spencer A.; Norheim, Randolph V.; Anderson, Gordon A.; Smith, Richard D.

    2016-11-02

    In this work, we report an approach for spatial and temporal gas phase ion population manipulation, and demonstrate its application for the collapse of the ion distributions in ion mobility (IM) separations into tighter packets providing higher sensitivity measurements in conjunction with mass spectrometry (MS). We do this for ions moving from a conventionally traveling wave (TW)-driven region to a region where the TW is intermittently halted or ‘stuttered’. This approach causes the ion packets spanning a number of TW-created traveling traps (TT) to be redistributed into fewer TT, resulting in spatial compression. The degree of spatial compression is controllable and determined by the ratio of stationary time of the TW in the second region to its moving time. This compression ratio ion mobility programming (CRIMP) approach has been implemented using Structures for Lossless Ion Manipulations (SLIM) in conjunction with MS. CRIMP with the SLIM-MS platform is shown to provide increased peak intensities, reduced peak widths, and improved S/N ratios with MS detection. CRIMP also provides a foundation for extremely long path length and multi-pass IM separations in SLIM providing greatly enhanced IM resolution by reducing the detrimental effects of diffusional peak broadening due to increasing peak widths.

  9. Squeezing of Ion Populations and Peaks in Traveling Wave Ion Mobility Separations and Structures for Lossless Ion Manipulations Using Compression Ratio Ion Mobility Programming.

    Science.gov (United States)

    Garimella, Sandilya V B; Hamid, Ahmed M; Deng, Liulin; Ibrahim, Yehia M; Webb, Ian K; Baker, Erin S; Prost, Spencer A; Norheim, Randolph V; Anderson, Gordon A; Smith, Richard D

    2016-12-06

    In this work we report an approach for spatial and temporal gas-phase ion population manipulation, wherein we collapse ion distributions in ion mobility (IM) separations into tighter packets providing higher sensitivity measurements in conjunction with mass spectrometry (MS). We do this for ions moving from a conventional traveling wave (TW)-driven region to a region where the TW is intermittently halted or "stuttered". This approach causes the ion packets spanning a number of TW-created traveling traps (TT) to be redistributed into fewer TT, resulting in spatial compression. The degree of spatial compression is controllable and determined by the ratio of stationary time of the TW in the second region to its moving time. This compression ratio ion mobility programming (CRIMP) approach has been implemented using "structures for lossless ion manipulations" (SLIM) in conjunction with MS. CRIMP with the SLIM-MS platform is shown to provide increased peak intensities, reduced peak widths, and improved signal-to-noise (S/N) ratios with MS detection. CRIMP also provides a foundation for extremely long path length and multipass IM separations in SLIM providing greatly enhanced IM resolution by reducing the detrimental effects of diffusional peak broadening and increasing peak widths.

  10. Isotope separation using high-field asymmetric waveform ion mobility spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, David A.; Purves, Randy W.; Guevremont, Roger E-mail: roger.guevremont@nrc.ca

    2000-08-01

    A new apparatus for gas-phase separation of stable elemental isotopes at atmospheric pressure is described. A gaseous mixture of chloride isotopes was generated using electrospray ionization and introduced into the analyzer region of a high-field asymmetric waveform ion mobility spectrometer (FAIMS). The ion current exiting the FAIMS was sampled into a quadrupole mass spectrometer for isotope identification.

  11. Achieving High Resolution Ion Mobility Separations Using Traveling Waves in Compact Multiturn Structures for Lossless Ion Manipulations

    Energy Technology Data Exchange (ETDEWEB)

    Hamid, Ahmed M.; Garimella, Sandilya V. B.; Ibrahim, Yehia M.; Deng, Liulin; Zheng, Xueyun; Webb, Ian K.; Anderson, Gordon A.; Prost, Spencer A.; Norheim, Randolph V.; Tolmachev, Aleksey V.; Baker, Erin S.; Smith, Richard D.

    2016-09-20

    We report on ion mobility separations (IMS) achievable using traveling waves in a Structures for Lossless Ion Manipulations (TW-SLIM) module having a 44-cm path length and sixteen 90º turns. The performance of the TW-SLIM module was evaluated for ion transmission, and ion mobility separations with different RF, TW parameters and SLIM surface gaps in conjunction with mass spectrometry. In this work TWs were created by the transient and dynamic application of DC potentials. The TW-SLIM module demonstrated highly robust performance and the ion mobility resolution achieved even with sixteen close spaced turns was comparable to a similar straight path TW-SLIM module. We found an ion mobility peak capacity of ~ 31 and peak generation rate of 780 s-1 for TW speeds of <210 m/s using the current multi-turn TW-SLIM module. The separations achieved for isomers of peptides and tetrasaccharides were found to be comparable to those from a ~ 0.9-m drift tube-based IMS-MS platform operated at the same pressure (4 torr). The combined attributes of flexible design, low voltage requirements and lossless ion transmission through multiple turns for the present TW-SLIM module provides a basis for SLIM devices capable of achieving much greater ion mobility resolutions via greatly extended ion path lengths and compact serpentine designs that do not significantly impact the instrumentation profile, a direction described in a companion manuscript.

  12. Greatly Increasing Trapped Ion Populations for Mobility Separations Using Traveling Waves in Structures for Lossless Ion Manipulations

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Liulin; Ibrahim, Yehia M.; Garimella, Sandilya V. B.; Webb, Ian K.; Hamid, Ahmed M.; Norheim, Randolph V.; Prost, Spencer A.; Sandoval, Jeremy A.; Baker, Erin S.; Smith, Richard D.

    2016-10-18

    The initial use of traveling waves (TW) for ion mobility (IM) separations using a structures for lossless ion manipulations (SLIM) employed an ion funnel trap (IFT) to accumulate ions from a continuous electrospray ionization source, and limited to injected ion populations of ~106 charges due to the onset of space charge effects in the trapping region. Additional limitations arise due to the loss of resolution for the injection of ions over longer periods (e.g. in extended pulses). In this work a new SLIM ‘flat funnel’ (FF) module has been developed and demonstrated to enable the accumulation of much larger ion populations and their injection for IM separations. Ion current measurements indicate a capacity of ~3.2×108 charges for the extended trapping volume, over an order of magnitude greater than the IFT. The orthogonal ion injection into a funnel shaped separation region can greatly reduce space charge effects during the initial IM separation stage, and the gradually reduced width of the path allows the ion packet to be increasingly compressed in the lateral dimension as the separation progresses, allowing e.g. efficient transmission through conductance limits or compatibility with subsequent ion manipulations. This work examined the TW, RF, and DC confining field SLIM parameters involved in ion accumulation, injection, transmission and separation in the FF IM module using both direct ion current and MS measurements. Wide m/z range ion transmission is demonstrated, along with significant increases in signal to noise (S/N) ratios due to the larger ion populations injected. Additionally, we observed a reduction in the chemical background, which was attributed to more efficient desolvation of solvent related clusters over the extended ion accumulation periods. The TW SLIM FF IM module is anticipated to be especially effective as a front end for long path SLIM IM separation modules.

  13. Greatly Increasing Trapped Ion Populations for Mobility Separations Using Traveling Waves in Structures for Lossless Ion Manipulations.

    Science.gov (United States)

    Deng, Liulin; Ibrahim, Yehia M; Garimella, Sandilya V B; Webb, Ian K; Hamid, Ahmed M; Norheim, Randolph V; Prost, Spencer A; Sandoval, Jeremy A; Baker, Erin S; Smith, Richard D

    2016-10-07

    The initial use of traveling waves (TW) for ion mobility (IM) separations using structures for lossless ion manipulations (SLIM) employed an ion funnel trap (IFT) to accumulate ions from a continuous electrospray ionization source and was limited to injected ion populations of ∼10(6) charges due to the onset of space charge effects in the trapping region. Additional limitations arise due to the loss of resolution for the injection of ions over longer periods, such as in extended pulses. In this work a new SLIM "flat funnel" (FF) module has been developed and demonstrated to enable the accumulation of much larger ion populations and their injection for IM separations. Ion current measurements indicate a capacity of ∼3.2 × 10(8) charges for the extended trapping volume, over an order of magnitude greater than that of the IFT. The orthogonal ion injection into a funnel shaped separation region can greatly reduce space charge effects during the initial IM separation stage, and the gradually reduced width of the path allows the ion packet to be increasingly compressed in the lateral dimension as the separation progresses, allowing efficient transmission through conductance limits or compatibility with subsequent ion manipulations. This work examined the TW, rf, and dc confining field SLIM parameters involved in ion accumulation, injection, transmission, and IM separation in the FF module using both direct ion current and MS measurements. Wide m/z range ion transmission is demonstrated, along with significant increases in the signal-to-noise ratios (S/N) due to the larger ion populations injected. Additionally, we observed a reduction in the chemical background, which was attributed to more efficient desolvation of solvent related clusters over the extended ion accumulation periods. The TW SLIM FF IM module is anticipated to be especially effective as a front end for long path SLIM IM separation modules.

  14. Enhanced Mixture Separations of Metal Adducted Tetrasaccharides Using Frequency Encoded Ion Mobility Separations and Tandem Mass Spectrometry

    Science.gov (United States)

    Morrison, Kelsey A.; Bendiak, Brad K.; Clowers, Brian H.

    2016-10-01

    Using five isomeric tetrasaccharides in combination with seven multivalent metals, the impact on mobility separations and resulting CID spectra were examined using a hybrid ion mobility atmospheric pressure drift tube system coupled with a linear ion trap. By enhancing the duty cycle of the drift tube system using a linearly chirped frequency, the collision-induced dissociation spectra were encoded in the mobility domain according to the drift times of each glycan isomer precursor. Differential fragmentation patterns correlated with precursor drift times ensured direct assignment of fragments with precursor structure whether as individual standards or in a mixture of isomers. In addition to certain metal ions providing higher degrees of separation than others, in select cases more than one arrival time distribution was observed for a single pure carbohydrate isomer. These observations suggest the existence of alternative coordination sites within a single monomeric species, but more interesting was the observation of different fragmentation ion yields for carbohydrate dimers formed through metal adduction. Positive-ion data were also compared with negative-ion species, where dimer formation did not occur and single peaks were observed for each isomeric tetrasaccharide-alditol. This enhanced analytical power has implications not only for carbohydrate molecules but also for a wide variety of complex mixtures of molecules where dissociation spectra may potentially be derived from combinations of monomeric, homodimeric, and heterodimeric species having identical nominal m/z values.

  15. Ion Mobility Separations of Isomers based upon Long Path Length Structures for Lossless Ion Manipulations Combined with Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Liulin [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Ibrahim, Yehia M. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Baker, Erin S. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Aly, Noor A. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Hamid, Ahmed M. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Zhang, Xing [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Zheng, Xueyun [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Garimella, Sandilya V. B. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Webb, Ian K. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Prost, Spencer A. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Sandoval, Jeremy A. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Norheim, Randolph V. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Anderson, Gordon A. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Tolmachev, Aleksey V. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA; Smith, Richard D. [Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 902 Battelle Blvd Richland, WA 99352 USA

    2016-07-01

    Mass spectrometry (MS)-based multi-omic measurements, including proteomics, metabolomics, lipidomics, and glycomics, are increasingly transforming our ability to characterize and understand biological systems, but, presently have limitations due to the chemical diversity and range of abundances of biomolecules in complex samples. Advances addressing these challenges increasingly are based upon the ability to quickly separate, react and otherwise manipulate sample components for analysis by MS. Here we report on a new approach using Structures for Lossless Ion Manipulations (SLIM) to enable long serpentine path ion mobility spectrometry (IMS) separations followed by MS analyses. This approach provides previously unachieved mobility biomolecule isomer separations for biomolecular species, in conjunction with more effective ion utilization, and producing a basis for the improved characterization of very small samples.

  16. Enhancing bottom-up and top-down proteomic measurements with ion mobility separations.

    Science.gov (United States)

    Baker, Erin Shammel; Burnum-Johnson, Kristin E; Ibrahim, Yehia M; Orton, Daniel J; Monroe, Matthew E; Kelly, Ryan T; Moore, Ronald J; Zhang, Xing; Théberge, Roger; Costello, Catherine E; Smith, Richard D

    2015-08-01

    Proteomic measurements with greater throughput, sensitivity, and structural information are essential for improving both in-depth characterization of complex mixtures and targeted studies. While LC separation coupled with MS (LC-MS) measurements have provided information on thousands of proteins in different sample types, the introduction of a separation stage that provides further component resolution and rapid structural information has many benefits in proteomic analyses. Technical advances in ion transmission and data acquisition have made ion mobility separations an opportune technology to be easily and effectively incorporated into LC-MS proteomic measurements for enhancing their information content. Herein, we report on applications illustrating increased sensitivity, throughput, and structural information by utilizing IMS-MS and LC-IMS-MS measurements for both bottom-up and top-down proteomics measurements.

  17. Separation and identification of isomeric glycopeptides by high field asymmetric waveform ion mobility spectrometry.

    Science.gov (United States)

    Creese, Andrew J; Cooper, Helen J

    2012-03-01

    The analysis of intact glycopeptides by mass spectrometry is challenging due to the numerous possibilities for isomerization, both within the attached glycan and the location of the modification on the peptide backbone. Here, we demonstrate that high field asymmetric wave ion mobility spectrometry (FAIMS), also known as differential ion mobility, is able to separate isomeric O-linked glycopeptides that have identical sequences but differing sites of glycosylation. Two glycopeptides from the glycoprotein mucin 5AC, GT(GalNAc)TPSPVPTTSTTSAP and GTTPSPVPTTST(GalNAc)TSAP (where GalNAc is O-linked N-acetylgalactosamine), were shown to coelute following reversed-phase liquid chromatography. However, FAIMS analysis of the glycopeptides revealed that the compensation voltage ranges in which the peptides were transmitted differed. Thus, it is possible at certain compensation voltages to completely separate the glycopeptides. Separation of the glycopeptides was confirmed by unique reporter ions produced by supplemental activation electron transfer dissociation mass spectrometry. These fragments also enable localization of the site of glycosylation. The results suggest that glycan position plays a key role in determining gas-phase glycopeptide structure and have implications for the application of FAIMS in glycoproteomics.

  18. Ion Mobility Separations of Isomers based upon Long Path Length Structures for Lossless Ion Manipulations Combined with Mass Spectrometry.

    Science.gov (United States)

    Deng, Liulin; Ibrahim, Yehia M; Baker, Erin S; Aly, Noor A; Hamid, Ahmed M; Zhang, Xing; Zheng, Xueyun; Garimella, Sandilya V B; Webb, Ian K; Prost, Spencer A; Sandoval, Jeremy A; Norheim, Randolph V; Anderson, Gordon A; Tolmachev, Aleksey V; Smith, Richard D

    2016-07-01

    Mass spectrometry (MS)-based multi-omic measurements, including proteomics, metabolomics, lipidomics, and glycomics, are increasingly transforming our ability to characterize and understand biological systems. Multi-omic analyses and the desire for comprehensive measurement coverage presently have limitations due to the chemical diversity and range of abundances of biomolecules in complex samples. Advances addressing these challenges increasingly are based upon the ability to quickly separate, react and otherwise manipulate sample components for analysis by MS. Here we report on a new approach using Structures for Lossless Ion Manipulations (SLIM) to enable long serpentine path ion mobility spectrometry (IMS) separations followed by MS analyses. This approach provides previously unachieved resolution for biomolecular species, in conjunction with more effective ion utilization, and a basis for greatly improved characterization of very small sample sizes.

  19. Isomer separation and gas-phase configurations of organoruthenium anticancer complexes: ion mobility mass spectrometry and modeling.

    Science.gov (United States)

    Williams, Jonathan P; Bugarcic, Tijana; Habtemariam, Abraha; Giles, Kevin; Campuzano, Iain; Rodger, P Mark; Sadler, Peter J

    2009-06-01

    We have used ion mobility-mass spectrometry combined with molecular modeling for the separation and configurational analysis of three low-molecular-weight isomeric organoruthenium anticancer complexes containing ortho-, meta-, or para-terphenyl arene ligands. The isomers were separated using ion mobility based on traveling-wave technology and the experimentally determined collision cross sections were compared to theoretical calculations. Excellent agreement was observed between the experimentally and theoretically derived measurements.

  20. Achieving High Resolution Ion Mobility Separations Using Traveling Waves in Compact Multiturn Structures for Lossless Ion Manipulations.

    Science.gov (United States)

    Hamid, Ahmed M; Garimella, Sandilya V B; Ibrahim, Yehia M; Deng, Liulin; Zheng, Xueyun; Webb, Ian K; Anderson, Gordon A; Prost, Spencer A; Norheim, Randolph V; Tolmachev, Aleksey V; Baker, Erin S; Smith, Richard D

    2016-09-20

    We report on ion mobility (IM) separations achievable using traveling waves (TW) in a Structures for Lossless Ion Manipulations (SLIM) module having a 44 cm path length and 16 90° turns. The performance of the TW-SLIM module was evaluated for ion transmission and IM separations with different RF, TW parameters, and SLIM surface gaps in conjunction with mass spectrometry. In this work, TWs were created by the transient and dynamic application of DC potentials. The module demonstrated highly robust performance and, even with 16 closely spaced turns, achieving IM resolution performance and ion transmission comparable to a similar straight path module. We found an IM peak capacity of ∼31 and peak generation rate of 780 s(-1) for TW speeds of ∼80 m/s using the current multi-turn TW-SLIM module. The separations achieved for isomers of peptides and tetrasaccharides were found to be comparable to those from a ∼0.9-m drift tube-based IM-MS platform operated at the same pressure (4 Torr). The combined attributes of flexible design, low voltage requirements and lossless ion transmission through multiple turns for the present TW-SLIM module provides a basis for SLIM devices capable of achieving much greater IM resolution via greatly extended ion path lengths and using compact serpentine designs.

  1. Differential Ion Mobility Separations in up to 100% Helium Using Microchips

    Energy Technology Data Exchange (ETDEWEB)

    Shvartsburg, Alexandre A.; Ibrahim, Yehia M.; Smith, Richard D.

    2014-01-09

    The performance of differential IMS (FAIMS) analyzers is much enhanced by gases comprising He, especially He/N2 buffers. However, electrical breakdown has limited the He fraction in those mixtures to ~50 - 75%, depending on the field strength. By Paschen law, the threshold field for breakdown increases at shorter distances. This allows FAIMS using chips with microscopic channels to utilize much stronger field intensities (E) than “full-size” analyzers with wider gaps. Here we show that those chips can employ higher He fractions up to 100%. Use of He-rich gases improves the resolution and resolution/sensitivity balance substantially, although less than for full-size analyzers. The optimum He fraction is ~80%, in line with first-principles theory. Hence one can now measure the dependences of ion mobility on E in pure He, where ion-molecule cross section calculations are much more tractable than in other gases that form deeper and more complex interaction potentials. This capability may facilitate quantitative modeling of high-field ion mobility behavior and thus FAIMS separation properties, which would enable a priori extraction of structural information about the ions from FAIMS data.

  2. Differential ion mobility separations in up to 100% helium using microchips.

    Science.gov (United States)

    Shvartsburg, Alexandre A; Ibrahim, Yehia M; Smith, Richard D

    2014-03-01

    The performance of differential IMS (FAIMS) analyzers is much enhanced by gases comprising He, especially He/N2 mixtures. However, electrical breakdown has limited the He fraction to ~50%-75%, depending on the field strength. By the Paschen law, the threshold field for breakdown increases at shorter distances. This allows FAIMS using chips with microscopic channels to utilize much stronger field intensities (E) than "full-size" analyzers with wider gaps. Here we show that those chips can employ higher He fractions up to 100%. Use of He-rich gases improves the resolution and resolution/sensitivity balance substantially, although less than for full-size analyzers. The optimum He fraction is ~80%, in line with first-principles theory. Hence, one can now measure the dependences of ion mobility on E in pure He, where ion-molecule cross section calculations are much more tractable than in other gases that form deeper and more complex interaction potentials. This capability may facilitate quantitative modeling of high-field ion mobility behavior and, thus, FAIMS separation properties, which would enable a priori extraction of structural information about the ions.

  3. Lipid and Glycolipid Isomer Analyses Using Ultra-High Resolution Ion Mobility Spectrometry Separations

    Energy Technology Data Exchange (ETDEWEB)

    Wojcik, Roza; Webb, Ian; Deng, Liulin; Garimella, Sandilya; Prost, Spencer; Ibrahim, Yehia; Baker, Erin; Smith, Richard

    2017-01-01

    Understanding the biological mechanisms related to lipids and glycolipids is challenging due to the vast number of possible isomers. Mass spectrometry (MS) measurements are currently the dominant approach for studying and providing detailed information on lipid and glycolipid structures. However, difficulties in distinguishing many structural isomers (e.g. distinct acyl chain positions, double bond locations, as well as glycan isomers) inhibit the understanding of their biological roles. Here we utilized ultra-high resolution ion mobility spectrometry (IMS) separations based upon the use of traveling waves in a serpentine long path length multi-pass Structures for Lossless Manipulations (SLIM) to enhance isomer resolution. The multi-pass arrangement allowed separations ranging from ~16 m (1 pass) to ~470 m (32 passes) to be investigated for the distinction of lipids and glycolipids with extremely small structural differences. These ultra-high resolution SLIM IMS-MS analyses provide a foundation for exploring and better understanding isomer specific biological and disease processes.

  4. Lipid and Glycolipid Isomer Analyses Using Ultra-High Resolution Ion Mobility Spectrometry Separations

    Directory of Open Access Journals (Sweden)

    Roza Wojcik

    2017-01-01

    Full Text Available Understanding the biological roles and mechanisms of lipids and glycolipids is challenging due to the vast number of possible isomers that may exist. Mass spectrometry (MS measurements are currently the dominant approach for studying and providing detailed information on lipid and glycolipid presence and changes. However, difficulties in distinguishing the many structural isomers, due to the distinct lipid acyl chain positions, double bond locations or specific glycan types, inhibit the delineation and assignment of their biological roles. Here we utilized ultra-high resolution ion mobility spectrometry (IMS separations by applying traveling waves in a serpentine multi-pass Structures for Lossless Ion Manipulations (SLIM platform to enhance the separation of selected lipid and glycolipid isomers. The multi-pass arrangement allowed the investigation of paths ranging from ~16 m (one pass to ~60 m (four passes for the distinction of lipids and glycolipids with extremely small structural differences. These ultra-high resolution SLIM IMS-MS analyses provide a foundation for exploring and better understanding isomer-specific biological activities and disease processes.

  5. Real-time 2D separation by LC × differential ion mobility hyphenated to mass spectrometry.

    Science.gov (United States)

    Varesio, Emmanuel; Le Blanc, J C Yves; Hopfgartner, Gérard

    2012-03-01

    The liquid chromatography-mass spectrometry (LC-MS) analysis of complex samples such as biological fluid extracts is widespread when searching for new biomarkers as in metabolomics. The success of this hyphenation resides in the orthogonality of both separation techniques. However, there are frequent cases where compounds are co-eluting and the resolving power of mass spectrometry (MS) is not sufficient (e.g., isobaric compounds and interfering isotopic clusters). Different strategies are discussed to solve these cases and a mixture of eight compounds (i.e., bromazepam, chlorprothixene, clonapzepam, fendiline, flusilazol, oxfendazole, oxycodone, and pamaquine) with identical nominal mass (i.e., m/z 316) is taken to illustrate them. Among the different approaches, high-resolution mass spectrometry or liquid chromatography (i.e., UHPLC) can easily separate these compounds. Another technique, mostly used with low resolving power MS analyzers, is differential ion mobility spectrometry (DMS), where analytes are gas-phase separated according to their size-to-charge ratio. Detailed investigations of the addition of different polar modifiers (i.e., methanol, ethanol, and isopropanol) into the transport gas (nitrogen) to enhance the peak capacity of the technique were carried out. Finally, a complex urine sample fortified with 36 compounds of various chemical properties was analyzed by real-time 2D separation LC×DMS-MS(/MS). The addition of this orthogonal gas-phase separation technique in the LC-MS(/MS) hyphenation greatly improved data quality by resolving composite MS/MS spectra, which is mandatory in metabolomics when performing database generation and search.

  6. Enhancing glycan isomer separations with metal ions and positive and negative polarity ion mobility spectrometry-mass spectrometry analyses

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xueyun; Zhang, Xing; Schocker, Nathaniel S.; Renslow, Ryan S.; Orton, Daniel J.; Khamsi, Jamal; Ashmus, Roger A.; Almeida, Igor C.; Tang, Keqi; Costello, Catherine E.; Smith, Richard D.; Michael, Katja; Baker, Erin S.

    2016-09-07

    Glycomics has become an increasingly important field of research since glycans play critical roles in biology processes ranging from molecular recognition and signaling to cellular communication. Glycans often conjugate with other biomolecules such as proteins and lipids, and alter their properties and functions, so understanding the effect glycans have on cellular systems is essential. However the analysis of glycans is extremely difficult due to their complexity and structural diversity (i.e., the number and identity of monomer units, and configuration of their glycosidic linkages and connectivities). In this work, we coupled ion mobility spectrometry with mass spectrometry (IMS-MS) to characterize glycan standards and biologically important isomers of synthetic αGal-containing O-glycans including glycotopes of the protozoan parasite Trypanosoma cruzi, which is the causative agent of Chagas disease. IMS-MS results showed significant differences for the glycan structural isomers when analyzed in positive and negative polarity and complexed with different metal cations. These results suggest specific metal ions or ion polarities could be used to target and baseline separate glycan isomers of interest with IMS-MS.

  7. Separation of Opiate Isomers Using Electrospray Ionization and Paper Spray Coupled to High-Field Asymmetric Waveform Ion Mobility Spectrometry

    Science.gov (United States)

    Manicke, Nicholas E.; Belford, Michael

    2015-05-01

    One limitation in the growing field of ambient or direct analysis methods is reduced selectivity caused by the elimination of chromatographic separations prior to mass spectrometric analysis. We explored the use of high-field asymmetric waveform ion mobility spectrometry (FAIMS), an ambient pressure ion mobility technique, to separate the closely related opiate isomers of morphine, hydromorphone, and norcodeine. These isomers cannot be distinguished by tandem mass spectrometry. Separation prior to MS analysis is, therefore, required to distinguish these compounds, which are important in clinical chemistry and toxicology. FAIMS was coupled to a triple quadrupole mass spectrometer, and ionization was performed using either a pneumatically assisted heated electrospray ionization source (H-ESI) or paper spray, a direct analysis method that has been applied to the direct analysis of dried blood spots and other complex samples. We found that FAIMS was capable of separating the three opiate structural isomers using both H-ESI and paper spray as the ionization source.

  8. Coupling Front-End Separations, Ion Mobility Spectrometry, and Mass Spectrometry For Enhanced Multidimensional Biological and Environmental Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xueyun [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352,; Wojcik, Roza [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352,; Zhang, Xing [Skaggs School of Pharmacy and Pharmaceutical Sciences, Anschutz Medical Campus, University of Colorado, Denver, Colorado 80045; Ibrahim, Yehia M. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352,; Burnum-Johnson, Kristin E. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352,; Orton, Daniel J. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352,; Monroe, Matthew E. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352,; Moore, Ronald J. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352,; Smith, Richard D. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352,; Baker, Erin S. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352,

    2017-06-12

    Ion mobility spectrometry (IMS) is a widely used analytical technique for rapid molecular separations in the gas phase. IMS alone is useful, but its coupling with mass spectrometry (MS) and front-end separations has been extremely beneficial for increasing measurement sensitivity, peak capacity of complex mixtures, and the scope of molecular information in biological and environmental sample analyses. Multiple studies in disease screening and environmental evaluations have even shown these IMS-based multidimensional separations extract information not possible with each technique individually. This review highlights 3-dimensional separations using IMS-MS in conjunction with a range of front-end techniques, such as gas chromatography (GC), supercritical fluid chromatography (SFC), liquid chromatography (LC), solid phase extractions (SPE), capillary electrophoresis (CE), field asymmetric ion mobility spectrometry (FAIMS), and microfluidic devices. The origination, current state, various applications, and future capabilities for these multidimensional approaches are described to provide insight into the utility and potential of each technique.

  9. Characterization of polysorbate 85, a nonionic surfactant, by liquid chromatography vs. ion mobility separation coupled with tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Solak Erdem, Nilüfer; Alawani, Nadrah; Wesdemiotis, Chrys, E-mail: wesdemiotis@uakron.edu

    2014-01-15

    Graphical abstract: -- Highlights: •Liquid chromatography (LC) separates amphiphilic blends according to hydrophobicity. •Ion mobility (IM) spectrometry separates these blends based on molecular size/shape. •LC–MS provides the separation resolution needed for quantifying fatty acid content. •IM–MS enables rapid, solvent-free separation and the detection of trace components. •With either method, tandem MS allows to count the hydrophobic substituents. -- Abstract: Liquid chromatography (LC) and ion mobility (IM) separation have been coupled with mass spectrometry (MS) and tandem mass spectrometry (MS{sup 2}) to characterize a commercially important nonionic surfactant, polysorbate 85. The constituents of this amphiphilic blend contained a sorbitan or isosorbide core that was chain extended with poly(ethylene oxide) (PEO) and partially esterified at the PEO termini with oleic acid or, to a lesser extent, other fatty acids. Using interactive LC in reverse-phase mode, the oligomers of the surfactant were separated according to their hydrophobicity/hydrophilicity balance. On the other hand, IM spectrometry dispersed the surfactant oligomers by their charge and collision cross section (i.e. size/shape). With either separation method, an increased number of fatty ester groups and/or lack of the polar sorbitan (or isosorbide) core led to higher retention/drift times, enabling the separation of isobaric species or species with superimposed isotope patterns, so that their ester content could be conclusively identified by MS{sup 2}. LC–MS and IM–MS permitted the detection of several byproducts besides the major PEO-sorbitan oleate oligomers. LC–MS provides the separation resolution needed for quantitative determination of the degree of esterification. IM–MS, which minimizes analysis time and solvent use, is ideally suitable for a fast, qualitative survey of samples differing in their minor constituents or impurities.

  10. Energy-Resolved Ion Mobility-Mass Spectrometry—A Concept to Improve the Separation of Isomeric Carbohydrates

    Science.gov (United States)

    Hoffmann, Waldemar; Hofmann, Johanna; Pagel, Kevin

    2014-03-01

    Recent works using ion mobility-mass spectrometry (IM-MS) have highlighted the power of this instrumental configuration to tackle one of the greatest challenges in glycomics and glycoproteomics: the existence of isobaric isomers. For a successful separation of species with identical mass but different structure via IM-MS, it is crucial to have sufficient IM resolution. In commercially available IM-MS instruments, however, this resolution is limited by the design of the instrument and usually cannot be increased at-will without extensive modifications. Here, we present a systematic approach to improve the resolving capability of IM-MS instruments using so-called energy-resolved ion mobility-mass spectrometry. The technique utilizes the fact that individual components in an isobaric mixture fragment at considerably different energies when activated in the gas phase via collision-induced dissociation (CID). As a result, certain components can be suppressed selectively at increased CID activation energy. Using a mixture of four isobaric carbohydrates, we show that each of the individual sugars can be resolved and unambiguously identified even when their drift times differ by as little as 3 %. However, the presented results also indicate that a certain difference in the gas-phase stability of the individual components is crucial for a successful separation via energy-resolved IM-MS.

  11. Energy-resolved ion mobility-mass spectrometry--a concept to improve the separation of isomeric carbohydrates.

    Science.gov (United States)

    Hoffmann, Waldemar; Hofmann, Johanna; Pagel, Kevin

    2014-03-01

    Recent works using ion mobility-mass spectrometry (IM-MS) have highlighted the power of this instrumental configuration to tackle one of the greatest challenges in glycomics and glycoproteomics: the existence of isobaric isomers. For a successful separation of species with identical mass but different structure via IM-MS, it is crucial to have sufficient IM resolution. In commercially available IM-MS instruments, however, this resolution is limited by the design of the instrument and usually cannot be increased at-will without extensive modifications. Here, we present a systematic approach to improve the resolving capability of IM-MS instruments using so-called energy-resolved ion mobility-mass spectrometry. The technique utilizes the fact that individual components in an isobaric mixture fragment at considerably different energies when activated in the gas phase via collision-induced dissociation (CID). As a result, certain components can be suppressed selectively at increased CID activation energy. Using a mixture of four isobaric carbohydrates, we show that each of the individual sugars can be resolved and unambiguously identified even when their drift times differ by as little as 3%. However, the presented results also indicate that a certain difference in the gas-phase stability of the individual components is crucial for a successful separation via energy-resolved IM-MS.

  12. Ion mobility spectrometry

    CERN Document Server

    Eiceman, GA

    2005-01-01

    Key Developments for Faster, More Precise Detection Capabilities Driven by the demand for the rapid and advanced detection of explosives, chemical and biological warfare agents, and narcotics, ion mobility spectrometry (IMS) undergone significant refinements in technology, computational capabilities, and understanding of the principles of gas phase ion chemistry and mobility. Beginning with a thorough discussion of the fundamental theories and physics of ion mobility, Ion Mobility Spectrometry, Second Edition describes the recent advances in instrumentation and newly

  13. Ultra-High Resolution Ion Mobility Separations Utilizing Traveling Waves in a 13 m Serpentine Path Length Structures for Lossless Ion Manipulations Module

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Liulin; Ibrahim, Yehia M.; Hamid, Ahmed M.; Garimella, Sandilya V. B.; Webb, Ian K.; Zheng, Xueyun; Prost, Spencer A.; Sandoval, Jeremy A.; Norheim, Randolph V.; Anderson, Gordon A.; Tolmachev, Aleksey V.; Baker, Erin S.; Smith, Richard D.

    2016-09-20

    We report the development and initial evaluation of a 13-m path length Structures for Lossless Manipulations (SLIM) module for achieving high resolution separations using traveling waves (TW) with ion mobility (IM) spectrometry. The TW SLIM module was fabricated using two mirror-image printed circuit boards with appropriately configured RF, DC and TW electrodes and positioned with a 2.75-mm inter-surface gap. Ions were effective confined between the surfaces by RF-generated pseudopotential fields and moved losslessly through a serpentine path including 44 “U” turns using TWs. The ion mobility resolution was characterized at different pressures, gaps between the SLIM surfaces, TW and RF parameters. After initial optimization the SLIM IM-MS module provided about 5-fold higher resolution separations than present commercially available drift tube or traveling wave IM-MS platforms. Peak capacity and peak generation rates achieved were 246 and 370 s-1, respectively, at a TW speed of 148 m/s. The high resolution achieved in the TW SLIM IM-MS enabled e.g., isomeric sugars (Lacto-N-fucopentaose I and Lacto-N-fucopentaose II) to be baseline resolved, and peptides from a albumin tryptic digest much better resolved than with existing commercial IM-MS platforms. The present work also provides a foundation for the development of much higher resolution SLIM devices based upon both considerably longer path lengths and multi-pass designs.

  14. Ultra-High Resolution Ion Mobility Separations Utilizing Traveling Waves in a 13 m Serpentine Path Length Structures for Lossless Ion Manipulations Module.

    Science.gov (United States)

    Deng, Liulin; Ibrahim, Yehia M; Hamid, Ahmed M; Garimella, Sandilya V B; Webb, Ian K; Zheng, Xueyun; Prost, Spencer A; Sandoval, Jeremy A; Norheim, Randolph V; Anderson, Gordon A; Tolmachev, Aleksey V; Baker, Erin S; Smith, Richard D

    2016-09-20

    We report the development and initial evaluation of a 13 m path length Structures for Lossless Manipulations (SLIM) module for achieving high resolution separations using traveling waves (TW) with ion mobility (IM) spectrometry. The TW SLIM module was fabricated using two mirror-image printed circuit boards with appropriately configured RF, DC, and TW electrodes and positioned with a 2.75 mm intersurface gap. Ions were effectively confined in field-generated conduits between the surfaces by RF-generated pseudopotential fields and moved losslessly through a serpentine path including 44 "U" turns using TWs. The ion mobility resolution was characterized at different pressures, gaps between the SLIM surfaces, and TW and RF parameters. After initial optimization, the SLIM IM-MS module provided about 5-fold higher resolution separations than present commercially available drift tube or traveling wave IM-MS platforms. Peak capacity and peak generation rates achieved were 246 and 370 s(-1), respectively, at a TW speed of 148 m/s. The high resolution achieved in the TW SLIM IM-MS enabled, e.g., isomeric sugars (lacto-N-fucopentaose I and lacto-N-fucopentaose II) to be baseline resolved, and peptides from an albumin tryptic digest were much better resolved than with existing commercial IM-MS platforms. The present work also provides a foundation for the development of much higher resolution SLIM devices based upon both considerably longer path lengths and multipass designs.

  15. Enhancement of biological mass spectrometry by using separations based on changes in ion mobility (FAIMS and DMS).

    Science.gov (United States)

    Purves, Randy W

    2013-01-01

    Analysis of complex biological samples for low-level analytes by liquid chromatography-tandem mass spectrometry (LC-MS/MS) often requires additional selectivity. Differential mobility techniques (FAIMS and DMS) have been shown to enhance LC-MS/MS analyses by separating ions in the gas-phase on a millisecond timescale by use of a mechanism that is complementary to both liquid chromatography and mass spectrometry. In this overview, a simplified description of the operation of these devices is given and an example presented that illustrates the utility of FAIMS (DMS) for solving a challenging analytical assay. Important recent advances in the field, including work with gas modifiers, are presented, along with an outlook for the technology.

  16. Broad Separation of Isomeric Lipids by High-Resolution Differential Ion Mobility Spectrometry with Tandem Mass Spectrometry

    Science.gov (United States)

    Bowman, Andrew P.; Abzalimov, Rinat R.; Shvartsburg, Alexandre A.

    2017-08-01

    Maturation of metabolomics has brought a deeper appreciation for the importance of isomeric identity of lipids to their biological role, mirroring that for proteoforms in proteomics. However, full characterization of the lipid isomerism has been thwarted by paucity of rapid and effective analytical tools. A novel approach is ion mobility spectrometry (IMS) and particularly differential or field asymmetric waveform IMS (FAIMS) at high electric fields, which is more orthogonal to mass spectrometry. Here we broadly explore the power of FAIMS to separate lipid isomers, and find a 75% success rate across the four major types of glycero- and phospho- lipids ( sn, chain length, double bond position, and cis/ trans). The resolved isomers were identified using standards, and (for the first two types) tandem mass spectrometry. These results demonstrate the general merit of incorporating high-resolution FAIMS into lipidomic analyses.

  17. Ion mobility sensor system

    Science.gov (United States)

    Xu, Jun; Watson, David B.; Whitten, William B.

    2013-01-22

    An ion mobility sensor system including an ion mobility spectrometer and a differential mobility spectrometer coupled to the ion mobility spectrometer. The ion mobility spectrometer has a first chamber having first end and a second end extending along a first direction, and a first electrode system that generates a constant electric field parallel to the first direction. The differential mobility spectrometer includes a second chamber having a third end and a fourth end configured such that a fluid may flow in a second direction from the third end to the fourth end, and a second electrode system that generates an asymmetric electric field within an interior of the second chamber. Additionally, the ion mobility spectrometer and the differential mobility spectrometer form an interface region. Also, the first end and the third end are positioned facing one another so that the constant electric field enters the third end and overlaps the fluid flowing in the second direction.

  18. Enhancing bottom-up and top-down proteomic measurements with ion mobility separations

    OpenAIRE

    Baker, Erin Shammel; Kristin E. Burnum-Johnson; Ibrahim, Yehia M.; Orton, Daniel J.; Monroe, Matthew E.; Kelly, Ryan T.; Moore, Ronald J.; Zhang, Xing; Théberge, Roger; Costello, Catherine E.; Smith, Richard D.

    2015-01-01

    Proteomic measurements with greater throughput, sensitivity, and structural information are essential for improving both in-depth characterization of complex mixtures and targeted studies. While LC separation coupled with MS (LC–MS) measurements have provided information on thousands of proteins in different sample types, the introduction of a separation stage that provides further component resolution and rapid structural information has many benefits in proteomic analyses. Technical advance...

  19. Correlation ion mobility spectroscopy

    Science.gov (United States)

    Pfeifer, Kent B.; Rohde, Steven B.

    2008-08-26

    Correlation ion mobility spectrometry (CIMS) uses gating modulation and correlation signal processing to improve IMS instrument performance. Closely spaced ion peaks can be resolved by adding discriminating codes to the gate and matched filtering for the received ion current signal, thereby improving sensitivity and resolution of an ion mobility spectrometer. CIMS can be used to improve the signal-to-noise ratio even for transient chemical samples. CIMS is especially advantageous for small geometry IMS drift tubes that can otherwise have poor resolution due to their small size.

  20. Miniaturized Ion Mobility Spectrometer

    Science.gov (United States)

    Kaye, William J. (Inventor); Stimac, Robert M. (Inventor)

    2015-01-01

    By utilizing the combination of a unique electronic ion injection control circuit in conjunction with a particularly designed drift cell construction, the instantly disclosed ion mobility spectrometer achieves increased levels of sensitivity, while achieving significant reductions in size and weight. The instant IMS is of a much simpler and easy to manufacture design, rugged and hermetically sealed, capable of operation at high temperatures to at least 250.degree. C., and is uniquely sensitive, particularly to explosive chemicals.

  1. Localization of Post-Translational Modifications in Peptide Mixtures via High-Resolution Differential Ion Mobility Separations Followed by Electron Transfer Dissociation

    Science.gov (United States)

    Baird, Matthew A.; Shvartsburg, Alexandre A.

    2016-12-01

    Precise localization of post-translational modifications (PTMs) on proteins and peptides is an outstanding challenge in proteomics. While electron transfer dissociation (ETD) has dramatically advanced PTM analyses, mixtures of localization variants that commonly coexist in cells often require prior separation. Although differential or field asymmetric waveform ion mobility spectrometry (FAIMS) achieves broad variant resolution, the need for standards to identify the features has limited the utility of approach. Here we demonstrate full a priori characterization of variant mixtures by high-resolution FAIMS coupled to ETD and the procedures to systematically extract the FAIMS spectra for all variants from such data.

  2. Localization of Post-Translational Modifications in Peptide Mixtures via High-Resolution Differential Ion Mobility Separations Followed by Electron Transfer Dissociation

    Science.gov (United States)

    Baird, Matthew A.; Shvartsburg, Alexandre A.

    2016-09-01

    Precise localization of post-translational modifications (PTMs) on proteins and peptides is an outstanding challenge in proteomics. While electron transfer dissociation (ETD) has dramatically advanced PTM analyses, mixtures of localization variants that commonly coexist in cells often require prior separation. Although differential or field asymmetric waveform ion mobility spectrometry (FAIMS) achieves broad variant resolution, the need for standards to identify the features has limited the utility of approach. Here we demonstrate full a priori characterization of variant mixtures by high-resolution FAIMS coupled to ETD and the procedures to systematically extract the FAIMS spectra for all variants from such data.

  3. Enhanced capabilities for imaging gangliosides in murine brain with matrix-assisted laser desorption/ionization and desorption electrospray ionization mass spectrometry coupled to ion mobility separation.

    Science.gov (United States)

    Škrášková, Karolina; Claude, Emmanuelle; Jones, Emrys A; Towers, Mark; Ellis, Shane R; Heeren, Ron M A

    2016-07-15

    The increased interest in lipidomics calls for improved yet simplified methods of lipid analysis. Over the past two decades, mass spectrometry imaging (MSI) has been established as a powerful technique for the analysis of molecular distribution of a variety of compounds across tissue surfaces. Matrix-assisted laser desorption/ionization (MALDI) MSI is widely used to study the spatial distribution of common lipids. However, a thorough sample preparation and necessity of vacuum for efficient ionization might hamper its use for high-throughput lipid analysis. Desorption electrospray ionization (DESI) is a relatively young MS technique. In DESI, ionization of molecules occurs under ambient conditions, which alleviates sample preparation. Moreover, DESI does not require the application of an external matrix, making the detection of low mass species more feasible due to the lack of chemical matrix background. However, irrespective of the ionization method, the final information obtained during an MSI experiment is very complex and its analysis becomes challenging. It was shown that coupling MSI to ion mobility separation (IMS) simplifies imaging data interpretation. Here we employed DESI and MALDI MSI for a lipidomic analysis of the murine brain using the same IMS-enabled instrument. We report for the first time on the DESI IMS-MSI of multiply sialylated ganglioside species, as well as their acetylated versions, which we detected directly from the murine brain tissue. We show that poly-sialylated gangliosides can be imaged as multiply charged ions using DESI, while they are clearly separated from the rest of the lipid classes based on their charge state using ion mobility. This represents a major improvement in MSI of intact fragile lipid species. We additionally show that complementary lipid information is reached under particular conditions when DESI is compared to MALDI MSI.

  4. Differential mobility separation of leukotrienes and protectins.

    Science.gov (United States)

    Jónasdóttir, Hulda S; Papan, Cyrus; Fabritz, Sebastian; Balas, Laurence; Durand, Thierry; Hardardottir, Ingibjorg; Freysdottir, Jona; Giera, Martin

    2015-01-01

    Differential mobility spectrometry (DMS) is capable of separating stereoisomeric molecular ions based on their mobility in an oscillating electrical field with an asymmetric waveform. Thus, it is an "orthogonal" technique to chromatography and (tandem) mass spectrometry. Bioactive lipids, particularly of the eicosanoid and docosanoid class feature numerous stereoisomers, which exhibit a highly specific structure-activity relationship. Moreover, the geometry of these compounds also reflects their biochemical origin. Therefore, the unambiguous characterization of related isomers of the eicosanoid and docosanoid classes is of fundamental importance to the understanding of their origin and function in many biological processes. Here we show, that SelexION DMS technology coupled to μLC-MS/MS is capable of differentiating at least five closely related leukotrienes partially coeluting and (almost) unresolvable using LC-MS/MS only. We applied the developed method to the separation of LTB4 and its coeluting isomer 5S,12S-diHETE in murine peritoneal exudate cells, showing that LTB4 is present only after zymosan A injection while its isomer 5S,12S-diHETE is produced after saline (PBS) administration. Additionally, we show that the SelexION technology can also be applied to the separation of PD1 and PDX (10S,17S-diHDHA), two isomeric protectins.

  5. Enantiomeric Separation of Amino Alcohols by Ion-pair Chromatography

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions, enantiomeric propranolol, norephedrine, metropolol and salbutamol were separated using dichloromethane -1-pentanol (97:3, v/v) as mobile phase on Lichrospher-100-DIOL column.

  6. Separators for Lithium Ion Batteries

    Institute of Scientific and Technical Information of China (English)

    G.C.Li; H.P.Zhang; Y.P.Wu

    2007-01-01

    1 Results A separator for rechargeable batteries is a microporous membrane placed between electrodes of opposite polarity, keeping them apart to prevent electrical short circuits and at the same time allowing rapid transport of lithium ions that are needed to complete the circuit during the passage of current in an electrochemical cell, and thus plays a key role in determining the performance of the lithium ion battery. Here provides a comprehensive overview of various types of separators for lithium io...

  7. Field Asymmetric Waveform Ion Mobility Spectrometry Studies of Proteins: Dipole Alignment in Ion Mobility Spectrometry?

    Energy Technology Data Exchange (ETDEWEB)

    Shvartsburg, Alexandre A.; Bryskiewicz, Tadeusz; Purves, Randy; Tang, Keqi; Guevremont, Roger; Smith, Richard D.

    2006-11-02

    Approaches to characterization and separation of ions involving their mobilities in gases were developed since 1960-s. Conventional ion mobility spectrometry (IMS) measures the absolute mobility and the field asymmetric waveform IMS (FAIMS) exploits the difference between mobilities at high and low electric fields. However, all previous work was based on the orientationally averaged cross-sections Ωavg between ions and buffer gas molecules. Virtually all large ions are electric dipoles that will be oriented by a sufficiently strong electric field. At typical FAIMS conditions, that must happen for dipole moments > ~400 Debye, found for many macroions including most proteins above ~30 kDa. Mobilities of aligned dipoles depend on directional cross-sections Ωdir (rather than Ωavg), which should have a major effect on FAIMS separation parameters. Here we study the FAIMS behavior of ESI-generated ions for ten proteins up to ~70 kDa. Those above 29 kDa exhibit a strong increase of mobility at high field, which is consistent with predicted ion dipole alignment. This effect expands the FAIMS peak capacity by an order of magnitude, allowing separation of up to ~102 distinct protein conformers and revealing information about Ωdir and ion dipole moment that is of potential utility for structural characterization. Possible means to extend the dipole alignment to smaller ions are discussed.

  8. Fundamentals of traveling wave ion mobility spectrometry.

    Science.gov (United States)

    Shvartsburg, Alexandre A; Smith, Richard D

    2008-12-15

    Traveling wave ion mobility spectrometry (TW IMS) is a new IMS method implemented in the Synapt IMS/mass spectrometry system (Waters). Despite its wide adoption, the foundations of TW IMS were only qualitatively understood and factors governing the ion transit time (the separation parameter) and resolution remained murky. Here we develop the theory of TW IMS using derivations and ion dynamics simulations. The key parameter is the ratio (c) of ion drift velocity at the steepest wave slope to wave speed. At low c, the ion transit velocity is proportional to the squares of mobility (K) and electric field intensity (E), as opposed to linear scaling in drift tube (DT) IMS and differential mobility analyzers. At higher c, the scaling deviates from quadratic in a way controlled by the waveform profile, becoming more gradual with the ideal triangular profile but first steeper and then more gradual for realistic profiles with variable E. At highest c, the transit velocity asymptotically approaches the wave speed. Unlike with DT IMS, the resolving power of TW IMS depends on mobility, scaling as K(1/2) in the low-c limit and less at higher c. A nonlinear dependence of the transit time on mobility means that the true resolving power of TW IMS differs from that indicated by the spectrum. A near-optimum resolution is achievable over an approximately 300-400% range of mobilities. The major predicted trends are in agreement with TW IMS measurements for peptide ions as a function of mobility, wave amplitude, and gas pressure. The issues of proper TW IMS calibration and ion distortion by field heating are also discussed. The new quantitative understanding of TW IMS separations allows rational optimization of instrument design and operation and improved spectral calibration.

  9. Differential Mobility Spectrometer with Spatial Ion Detector and Methods Related Thereto

    Science.gov (United States)

    Duong, Tuan A. (Inventor); Kanik, Isik (Inventor); Duong, Vu A. (Inventor)

    2013-01-01

    Differential mobility spectrometer with spatial ion detector and methods related thereto are disclosed. The use of one or more spatial detector within differential mobility spectrometry can provide for the identification and separation of ions with similar mobility and mass.

  10. Material review of Li ion battery separators

    Science.gov (United States)

    Weber, Christoph J.; Geiger, Sigrid; Falusi, Sandra; Roth, Michael

    2014-06-01

    Separators for Li Ion batteries have a strong impact on cell production, cell performance, life, as well as reliability and safety. The separator market volume is about 500 million m2 mainly based on consumer applications. It is expected to grow strongly over the next decade for mobile and stationary applications using large cells. At present, the market is essentially served by polyolefine membranes. Such membranes have some technological limitations, such as wettability, porosity, penetration resistance, shrinkage and meltdown. The development of a cell failure due to internal short circuit is potentially closely related to separator material properties. Consequently, advanced separators became an intense area of worldwide research and development activity in academia and industry. New separator technologies are being developed especially to address safety and reliability related property improvements.

  11. Treatise on the measurement of molecular masses with ion mobility spectrometry.

    Science.gov (United States)

    Valentine, Stephen J; Clemmer, David E

    2009-07-15

    The ability to separate isotopes by high-resolution ion mobility spectrometry techniques is considered as a direct means for determining mass at ambient pressures. Calculations of peak shapes from the transport equation show that it should be possible to separate isotopes for low-mass ions (ion mobility analyzers. The mass accuracy associated with this isotopic separation approach based on ion mobility separation is considered. Finally, we predict several isotopes that should be separable.

  12. Laser-ablation electrospray ionization mass spectrometry with ion mobility separation reveals metabolites in the symbiotic interactions of soybean roots and rhizobia

    Energy Technology Data Exchange (ETDEWEB)

    Stopka, Sylwia A. [Department of Chemistry, W. M. Keck Institute for Proteomics Technology and Applications, The George Washington University, Washington DC 20052 USA; Agtuca, Beverly J. [Divisions of Plant Sciences and Biochemistry, C. S. Bond Life Sciences Center, University of Missouri, Columbia MO 65211 USA; Koppenaal, David W. [Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Paša-Tolić, Ljiljana [Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Stacey, Gary [Divisions of Plant Sciences and Biochemistry, C. S. Bond Life Sciences Center, University of Missouri, Columbia MO 65211 USA; Vertes, Akos [Department of Chemistry, W. M. Keck Institute for Proteomics Technology and Applications, The George Washington University, Washington DC 20052 USA; Anderton, Christopher R. [Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA

    2017-05-23

    Technologies enabling in situ metabolic profiling of living plant systems are invaluable for understanding physiological processes and could be used for rapid phenotypic screening (e.g., to produce plants with superior biological nitrogen fixing ability). The symbiotic interaction between legumes and nitrogen-fixing soil bacteria results in a specialized plant organ (i.e., root nodule), where the exchange of nutrients between host and endosymbiont occurs. Laser ablation electrospray ionization mass spectrometry (LAESI-MS) is a method that can be performed under ambient conditions requiring minimal sample preparation. Here, we employed LAESI-MS to explore the well-characterized symbiosis between soybean (Glycine max L. Merr.) and its compatible symbiont, Bradyrhizobium japonicum. The utilization of ion mobility separation (IMS) improved the molecular coverage, selectivity, and identification of the detected biomolecules. Specifically, incorporation of IMS resulted in an increase of 153 detected metabolites in the nodule samples. The data presented demonstrates the advantages of using LAESI-IMS-MS for the rapid analysis of intact root nodules, uninfected root segments, and free-living rhizobia. Untargeted pathway analysis revealed several metabolic processes within the nodule (e.g., zeatin, riboflavin, and purine synthesis). Compounds specific to the uninfected root and bacteria were also detected. Lastly, we performed depth-profiling of intact nodules to reveal the location of metabolites to the cortex and inside the infected region, and lateral profiling of sectioned nodules confirmed these molecular distributions. Our results established the feasibility of LAESI-IMS-MS for the analysis and spatial mapping of plant tissues, with its specific demonstration to improve our understanding of the soybean-rhizobial symbiosis.

  13. Mothers' Mobility after Separation : Do Grandmothers Matter?

    NARCIS (Netherlands)

    Das, Marjolijn; de Valk, Helga; Merz, Eva-Maria

    2017-01-01

    Starting from a life course perspective, this study aims to gain more insight into mobility patterns of recently separated mothers, focusing especially on moves to the location of their own mother: the maternal grandmother. Separated mothers, having linked lives with their own mothers, may benefit

  14. Chromatographic separation of inorganic ions on thin layers of titanium phosphate ion-exchanger.

    Science.gov (United States)

    Ghoulipour, Vanik; Safari, Moharram

    2014-12-01

    The chromatographic behavior of 30 inorganic cations has been studied on thin layers of titanium phosphate ion-exchanger using several aqueous, organic and mixed mobile phases. The separation of one ion from several other ions and also ternary and binary separations have been developed. Some important analytical separations are reported. The effect of pH of the mobile phase on retention factor (Rf) values of the cations in the presence of complex-forming anion along with the separation power of the ion-exchanger were studied. This ion-exchanger exhibits high sorption capacity and varying selectivity towards metal ions and makes it a suitable stationaiy phase in thin layer chromatography.

  15. Chromatographic separation of inorganic ions on thin layers of titanium phosphate ion-exchanger

    Institute of Scientific and Technical Information of China (English)

    Vanik GHOULIPOUR; Moharram SAFARI

    2014-01-01

    The chromatographic behavior of 30 inorganic cations has been studied on thin layers of titanium phosphate ion-exchanger using several aqueous,organic and mixed mobile phases. The separation of one ion from several other ions and also ternary and binary separations have been developed. Some important analytical separations are reported. The effect of pH of the mobile phase on retention factor(Rf)values of the cations in the presence of complex-forming anion along with the separation power of the ion-exchanger were studied. This ion-exchanger exhibits high sorption capacity and varying selectivity towards metal ions and makes it a suitable stationary phase in thin layer chromatography.

  16. Direct determination of 2,4,6-tricholoroanisole in wines by single-drop ionic liquid microextraction coupled with multicapillary column separation and ion mobility spectrometry detection.

    Science.gov (United States)

    Márquez-Sillero, Isabel; Cárdenas, Soledad; Valcárcel, Miguel

    2011-10-21

    This article evaluates the capability of single drop ionic liquid microextraction coupled with multicapillary column (MCC) and ion mobility spectrometry (IMS) for the determination of 2,4,6-trichloroanisole (2,4,6-TCA) in wines. The proposed methodology permits the direct analysis of the samples without any additional treatment other than dilution. This is achieved thanks to the selectivity provided by the ionic liquid selected as extractant, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide, as well as the response of the analyte in the IMS working in negative ionization mode. Moreover, the multicapillary column avoids the interference of ethanol in the ion mobility spectra. The analysis of the sample takes ca. 35 min to be completed. The limit of detection was low as 0.01 ng L(-1) using 2 mL of wine sample. Different calibration curves were constructed using aqueous standards, red and white wines, being the signals comparable, with an RSD similar to the method variability. Finally, a set of samples of different nature and packed in different containers were analysed. It was found than those with cork stoppers presented the highest concentration of 2,4,6-TCA.

  17. Residential mobility and migration of the separated

    Directory of Open Access Journals (Sweden)

    Maarten van Ham

    2007-12-01

    Full Text Available Separation is known to have a disruptive effect on the housing careers of those involved, mainly because a decrease in resources causes (temporary downward moves on the housing ladder. Little is known about the geographies of the residential mobility behaviour of the separated. Applying a hazard analysis to retrospective life-course data for the Netherlands, we investigate three hypotheses: individuals who experienced separation move more often than do steady singles and people in intact couple relationships, they are less likely to move over long distances, and they move more often to cities than people in intact couple relationships. The results show that separation leads to an increase in mobility, to moves over short distance for men with children, and to a prevalence of the city as a destination of moves.

  18. Using Ion Exchange Chromatography to Separate and Quantify Complex Ions

    Science.gov (United States)

    Johnson, Brian J.

    2014-01-01

    Ion exchange chromatography is an important technique in the separation of charged species, particularly in biological, inorganic, and environmental samples. In this experiment, students are supplied with a mixture of two substitution-inert complex ions. They separate the complexes by ion exchange chromatography using a "flash"…

  19. Using Ion Exchange Chromatography to Separate and Quantify Complex Ions

    Science.gov (United States)

    Johnson, Brian J.

    2014-01-01

    Ion exchange chromatography is an important technique in the separation of charged species, particularly in biological, inorganic, and environmental samples. In this experiment, students are supplied with a mixture of two substitution-inert complex ions. They separate the complexes by ion exchange chromatography using a "flash"…

  20. A new ion mobility-linear ion trap instrument for complex mixture analysis.

    Science.gov (United States)

    Donohoe, Gregory C; Maleki, Hossein; Arndt, James R; Khakinejad, Mahdiar; Yi, Jinghai; McBride, Carroll; Nurkiewicz, Timothy R; Valentine, Stephen J

    2014-08-19

    A new instrument that couples a low-pressure drift tube with a linear ion trap mass spectrometer is demonstrated for complex mixture analysis. The combination of the low-pressure separation with the ion trapping capabilities provides several benefits for complex mixture analysis. These include high sensitivity, unique ion fragmentation capabilities, and high reproducibility. Even though the gas-phase separation and the mass measurement steps are each conducted in an ion filtering mode, detection limits for mobility-selected peptide ions are in the tens of attomole range. In addition to ion separation, the low-pressure drift tube can be used as an ion fragmentation cell yielding mobility-resolved fragment ions that can be subsequently analyzed by multistage tandem mass spectrometry (MS(n)) methods in the ion trap. Because of the ion trap configuration, these methods can be comprised of any number (limited by ion signal) of collision-induced dissociation (CID) and electron transfer dissociation (ETD) processes. The high reproducibility of the gas-phase separation allows for comparison of two-dimensional ion mobility spectrometry (IMS)-MS data sets in a pixel-by-pixel fashion without the need for data set alignment. These advantages are presented in model analyses representing mixtures encountered in proteomics and metabolomics experiments.

  1. Device for separating non-ions from ions

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Yehia M.; Smith, Richard D.

    2017-01-31

    A device for separating non-ions from ions is disclosed. The device includes a plurality of electrodes positioned around a center axis of the device and having apertures therein through which the ions are transmitted. An inner diameter of the apertures varies in length. At least a portion of the center axis between the electrodes is non-linear.

  2. Mobility-resolved ion selection in uniform drift field ion mobility spectrometry/mass spectrometry: dynamic switching in structures for lossless ion manipulations.

    Science.gov (United States)

    Webb, Ian K; Garimella, Sandilya V B; Tolmachev, Aleksey V; Chen, Tsung-Chi; Zhang, Xinyu; Cox, Jonathan T; Norheim, Randolph V; Prost, Spencer A; LaMarche, Brian; Anderson, Gordon A; Ibrahim, Yehia M; Smith, Richard D

    2014-10-07

    A Structures for Lossless Ion Manipulations (SLIM) module that allows ion mobility separations and the switching of ions between alternative drift paths is described. The SLIM switch component has a "Tee" configuration and allows the efficient switching of ions between a linear path and a 90-degree bend. By controlling switching times, ions can be efficiently directed to an alternative channel as a function of their mobilities. In the initial evaluation the switch is used in a static mode and shown compatible with high performance ion mobility separations at 4 Torr. In the dynamic mode, we show that mobility-selected ions can be switched into the alternative channel, and that various ion species can be independently selected based on their mobilities for time-of-flight mass spectrometer (TOF MS) IMS detection and mass analysis. This development also provides the basis of, for example, the selection of specific mobilities for storage and accumulation, and the key component of modules for the assembly of SLIM devices enabling much more complex sequences of ion manipulations.

  3. [Ion mobility spectrometry for the isomeric volatile organic compounds].

    Science.gov (United States)

    Han, Hai-yan; Jia, Xian-de; Huang, Guo-dong; Wang, Hong-mei; Li, Jian-quan; Jin, Shun-ping; Jiang, Hai-he; Chu, Yan-nan; Zhou, Shi-kang

    2007-10-01

    Ion mobility spectrometry (IMS) is based on determining the drift velocities, which the ionized sample molecules attain in the weak electric field of a drift tube at atmospheric pressure. The drift behavior can be affected by structural differences of the analytes, so that ion mobility spectrometry has the ability to separated isomeric compounds. In the present article, an introduction to IMS is given, followed by a description of the instrument used for the experiments to differentiate isomeric compounds. Positive ion mobility spectras of three kinds of isomeric volatile organic compounds were studied in a homemade high-resolution IMS apparatus with a discharge ionization source. The study includes the differences in the structure of carbon chain, the style of function group, and the position of function group. The reduced mobility values were determined, which are in very good agreement with the previously reported theoretical values using neural network theory. The influence of the structural features of the substances and including the size and shape of the molecule has been investigated. The reduced mobility values increases in the order: alcohols ion mobility spectra of the constitutional isomers studied reflect the influence of structural features. In order to calibrate or determine the detection limits and the sensitivity of the ion mobility spectrometry, the exponential dilution flask (EDF) was used. Using this method, the detection limit of the analytes can reach the order of magnitude of ng x L(-1).

  4. Ion mobility spectrometer with virtual aperture grid

    Science.gov (United States)

    Pfeifer, Kent B.; Rumpf, Arthur N.

    2010-11-23

    An ion mobility spectrometer does not require a physical aperture grid to prevent premature ion detector response. The last electrodes adjacent to the ion collector (typically the last four or five) have an electrode pitch that is less than the width of the ion swarm and each of the adjacent electrodes is connected to a source of free charge, thereby providing a virtual aperture grid at the end of the drift region that shields the ion collector from the mirror current of the approaching ion swarm. The virtual aperture grid is less complex in assembly and function and is less sensitive to vibrations than the physical aperture grid.

  5. Spatial Ion Peak Compression and its Utility in Ion Mobility Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Garimella, Sandilya V. B.; Ibrahim, Yehia M.; Tang, Keqi; Webb, Ian K.; Baker, Erin S.; Tolmachev, Aleksey V.; Chen, Tsung-Chi; Anderson, Gordon A.; Smith, Richard D.

    2016-04-06

    A novel concept for ion spatial peak compression is described, and discussed primarily in the context of ion mobility spectrometry (IMS). Using theoretical and numerical methods, the effects of using non-constant (e.g., linearly varying) electric fields on ion distributions (e.g., an ion mobility peak) is evaluated both in the physical and temporal domains. The application of linearly decreasing electric field in conjunction with conventional drift field arrangements is shown to lead to a reduction in IMS physical peak width. When multiple ion packets in a selected mobility window are simultaneously subjected to such fields, there is ion packet compression, i.e., a reduction in peak widths of all species. This peak compression occurs with a modest reduction of resolution, but which can be quickly recovered as ions drift in a constant field after the compression event. Compression also yields a significant increase in peak intensities. In addition, approaches for peak compression in traveling wave IMS are also discussed. Ion mobility peak compression can be particularly useful for mitigating diffusion driven peak spreading over very long path length separations (e.g., in cyclic multi-pass arrangements), and for achieving higher S/N and IMS resolution over a selected mobility range.

  6. Mobility-Selected Ion Trapping and Enrichment Using Structures for Lossless Ion Manipulations.

    Science.gov (United States)

    Chen, Tsung-Chi; Ibrahim, Yehia M; Webb, Ian K; Garimella, Sandilya V B; Zhang, Xing; Hamid, Ahmed M; Deng, Liulin; Karnesky, William E; Prost, Spencer A; Sandoval, Jeremy A; Norheim, Randolph V; Anderson, Gordon A; Tolmachev, Aleksey V; Baker, Erin S; Smith, Richard D

    2016-02-02

    The integration of ion mobility spectrometry (IMS) with mass spectrometry (MS) and the ability to trap ions in IMS-MS measurements is of great importance for performing reactions, accumulating ions, and increasing analytical measurement sensitivity. The development of Structures for Lossless Ion Manipulations (SLIM) offers the potential for ion manipulations in an extended and more effective manner, while opening opportunities for many more complex sequences of manipulations. Here, we demonstrate an ion separation and trapping module and a method based upon SLIM that consists of a linear mobility ion drift region, a switch/tee and a trapping region that allows the isolation and accumulation of mobility-separated species. The operation and optimization of the SLIM switch/tee and trap are described and demonstrated for the enrichment of the low abundance ions. A linear improvement in ion intensity was observed with the number of trapping/accumulation events using the SLIM trap, illustrating its potential for enhancing the sensitivity of low abundance or targeted species.

  7. Fast ion extraction in laser isotope separation

    Energy Technology Data Exchange (ETDEWEB)

    Hazak, G.; Gell, Y.; Boneh, Y.; Goshen, S.

    1980-10-01

    An analysis of the E x B scheme for fast ion extraction in laser isotope separation is presented. Using an analytically solvable model and a numerical simulation we have found that the scheme can meet the rather severe time and space restrictions imposed by the large cross section for charge exchange.

  8. Dual mode ion mobility spectrometer and method for ion mobility spectrometry

    Science.gov (United States)

    Scott, Jill R [Idaho Falls, ID; Dahl, David A [Idaho Falls, ID; Miller, Carla J [Idaho Falls, ID; Tremblay, Paul L [Idaho Falls, ID; McJunkin, Timothy R [Idaho Falls, ID

    2007-08-21

    Ion mobility spectrometer apparatus may include an ion interface that is operable to hold positive and negative ions and to simultaneously release positive and negative ions through respective positive and negative ion ports. A first drift chamber is operatively associated with the positive ion port of the ion interface and encloses an electric field therein. A first ion detector operatively associated with the first drift chamber detects positive ions from the first drift chamber. A second drift chamber is operatively associated with the negative ion port of the ion interface and encloses an electric field therein. A second ion detector operatively associated with the second drift chamber detects negative ions from said second drift chamber.

  9. Device for two-dimensional gas-phase separation and characterization of ion mixtures

    Science.gov (United States)

    Tang, Keqi; Shvartsburg, Alexandre A.; Smith, Richard D.

    2006-12-12

    The present invention relates to a device for separation and characterization of gas-phase ions. The device incorporates an ion source, a field asymmetric waveform ion mobility spectrometry (FAIMS) analyzer, an ion mobility spectrometry (IMS) drift tube, and an ion detector. In one aspect of the invention, FAIMS operating voltages are electrically floated on top of the IMS drift voltage. In the other aspect, the FAIMS/IMS interface is implemented employing an electrodynamic ion funnel, including in particular an hourglass ion funnel. The present invention improves the efficiency (peak capacity) and sensitivity of gas-phase separations; the online FAIMS/IMS coupling creates a fundamentally novel two-dimensional gas-phase separation technology with high peak capacity, specificity, and exceptional throughput.

  10. Ion mobility spectrometry for detection of skin volatiles

    OpenAIRE

    Ruzsanyi, Veronika; Mochalski, Pawel; Schmid, Alex; Wiesenhofer, Helmut; Klieber, Martin; Hinterhuber, Hartmann; Amann, Anton

    2012-01-01

    Volatile organic compounds (VOCs) released by humans through their skin were investigated in near real time using ion mobility spectrometry after gas chromatographic separation with a short multi-capillary column. VOCs typically found in a small nitrogen flow covering the skin are 3-methyl-2-butenal, 6-methylhept-5-en-2-one, sec-butyl acetate, benzaldehyde, octanal, 2-ethylhexanol, nonanal and decanal at volume fractions in the low part per billion-(ppb) range. The technique presented here ma...

  11. The development of ion mobility technology

    Science.gov (United States)

    Beliakov, V. V.; Golovin, A. V.; Vasilev, V. K.; Malkin, E. K.; Gromov, E. A.; Ivanov, I. A.; Matusko, M. A.; Lipatov, D. Y.

    2016-10-01

    Increased terrorist threat in recent years makes it especially important to improve the custom equipment including the development of ion mobility spectrometers for reliable, realtime and sensitive identification of illicit substances. The paper summarizes different approaches used in recent developments in the last years: statistical analysis, sampling automation and construction materials study.

  12. Ion mobility analysis of lipoproteins

    Science.gov (United States)

    Benner, W. Henry; Krauss, Ronald M.; Blanche, Patricia J.

    2007-08-21

    A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

  13. Interpretative optimization of the isocratic ion chromatographic separation of anions

    Directory of Open Access Journals (Sweden)

    Todorović Žaklina N.

    2016-01-01

    Full Text Available Interpretive retention modeling was utilized to optimize the isocratic ion chromatographic (IC separation of the nine anions (formate, fluoride, chloride, nitrite, bromide, nitrate, phosphate, sulfate, oxalate. The carbonate-bicarbonate eluent was used and separation was done on a Dionex AS14 ion-exchange column. The influence of combined effects of two mobile phase factors, the total eluent concentration (2 - 6 mM and the carbonate/bicaronate ratio from 1:9 to 9:1 (which corespondent to pH range 9.35 - 11.27, on the IC separation was studied. The multiple species analyte/eluent model that takes into account ion-exchange equilibria of the eluent and sample anions was used. In order to estimate the parameters in the model, a non-linear fitting of the retention data, obtained at two-factor three-level experimental design, was applied. To find the optimal conditions in the experimental design, the normalized resolution product as a chromatographic objective function was employed. This criterion includes both the individual peak resolution and the total analysis time. A good agreement between experimental and simulated chromatograms was obtained. [Projekat Ministarstva nauke Republike Srbije, br. III43009

  14. Pendular Proteins in Gases and New Avenues for Characterization of Macromolecules by Ion Mobility Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shvartsburg, Alexandre A.; Noskov, Sergei; Purves, Randy; Smith, Richard D.

    2009-04-21

    Polar molecules align in electric fields when the dipole energy (proportional to field intensity E × dipole moment p) exceeds the thermal rotational energy. Small molecules have low p and align only at inordinately high E or upon extreme cooling. Many biomacromolecules and ions are strong permanent dipoles and may align at E achievable in gases and room temperature. The collision cross sections of aligned ions with gas molecules generally differ from orientationally averaged quantities, affecting ion mobilities measured in ion mobility spectrometry (IMS). Field asymmetric waveform IMS (FAIMS) separates ions by the difference between mobilities at high and low E and hence can resolve and identify macroion conformers based on the mobility difference between pendular and free rotor states. An exceptional sensitivity of that difference to the ion geometry and charge distribution holds the potential for a powerful new method for separation and characterization of macromolecular species. Theory predicts that the pendular alignment of ions in gases at any E requires a minimum p depending on the ion mobility, gas pressure, and temperature. At ambient conditions used in current FAIMS systems, the p for realistic ions must exceed ~300 - 400 Debye. The dipole moments of proteins statistically increase with increasing mass, and such values are typical above ~30 kDa. FAIMS analyses of protein ions and complexes of ~30 - 130 kDa show an order-of-magnitude expansion of separation space compared to smaller proteins and other ions, consistent with expectations for the dipole-aligned regime.

  15. Mixed oxygen ion/electron-conducting ceramics for oxygen separation

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, J.W.; Armstrong, T.R.; Armstrong, B.L. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-08-01

    Mixed oxygen ion and electron-conducting ceramics are unique materials that can passively separate high purity oxygen from air. Oxygen ions move through a fully dense ceramic in response to an oxygen concentration gradient, charge-compensated by an electron flux in the opposite direction. Compositions in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, perovskites where M=Sr, Ca, and Ba, and N=Mn, Ni, Cu, Ti, and Al, have been prepared and their electrical, oxygen permeation, oxygen vacancy equilibria, and catalytic properties evaluated. Tubular forms, disks, and asymmetric membrane structures, a thin dense layer on a porous support of the same composition, have been fabricated for testing purposes. In an oxygen partial gradient, the passive oxygen flux through fully dense structures was highly dependent on composition. An increase in oxygen permeation with increased temperature is attributed to both enhanced oxygen vacancy mobility and higher vacancy populations. Highly acceptor-doped compositions resulted in oxygen ion mobilities more than an order of magnitude higher than yttria-stabilized zirconia. The mixed conducting ceramics have been utilized in a membrane reactor configuration to upgrade methane to ethane and ethylene. Conditions were established to balance selectivity and throughput in a catalytic membrane reactor constructed from mixed conducting ceramics.

  16. High sensitivity field asymmetric ion mobility spectrometer

    Science.gov (United States)

    Chavarria, Mario A.; Matheoud, Alessandro V.; Marmillod, Philippe; Liu, Youjiang; Kong, Deyi; Brugger, Jürgen; Boero, Giovanni

    2017-03-01

    A high sensitivity field asymmetric ion mobility spectrometer (FAIMS) was designed, fabricated, and tested. The main components of the system are a 10.6 eV UV photoionization source, an ion filter driven by a high voltage/high frequency n-MOS inverter circuit, and a low noise ion detector. The ion filter electronics are capable to generate square waveforms with peak-to-peak voltages up to 1000 V at frequencies up to 1 MHz with adjustable duty cycles. The ion detector current amplifier has a gain up to 1012 V/A with an effective equivalent input noise level down to about 1 fA/Hz1/2 during operation with the ion filter at the maximum voltage and frequency. The FAIMS system was characterized by detecting different standard chemical compounds. Additionally, we investigated the use of a synchronous modulation/demodulation technique to improve the signal-to-noise ratio in FAIMS measurements. In particular, we implemented the modulation of the compensation voltage with the synchronous demodulation of the ion current. The analysis of the measurements at low concentration levels led to an extrapolated limit of detection for acetone of 10 ppt with an averaging time of 1 s.

  17. Separation of metal ions in nitrate solution by ultrasonic atomization

    Science.gov (United States)

    Sato, Masanori; Ikeno, Masayuki; Fujii, Toshitaka

    2004-11-01

    In the ultrasonic atomization of metal nitrate solutions, the molar ratio of metal ions is changed between solution and mist. Small molar metal ions tend to be transferred to mist by ultrasonic wave acceleration, while large molar ions tend to remain in solution. As a result, metal ions can be separated by ultrasonic atomization. We show experimental data and propose a conceptual mechanism for the ultrasonic separation of metal ions.

  18. Proton-bound cluster ions in ion mobility spectrometry.

    Science.gov (United States)

    Ewing, R G; Eiceman, G A; Stone, J A

    1999-10-28

    Gaseous oxygen and nitrogen bases, both singly and as binary mixtures, have been introduced into ion mobility spectrometers to study the appearance of protonated molecules, and proton-bound dimers and trimers. At ambient temperature it was possible to simultaneously observe, following the introduction of molecule A, comparable intensities of peaks ascribable to the reactant ion (H2O)nH+, the protonated molecule AH+ and AH+ H2O, and the symmetrical proton bound dimer A2H+. Mass spectral identification confirmed the identifications and also showed that the majority of the protonated molecules were hydrated and that the proton-bound dimers were hydrated to a much lesser extent. No significant peaks ascribable to proton-bound trimers were obtained no matter how high the sample concentration. Binary mixtures containing molecules A and B, in some cases gave not only the peaks unique to the individual compounds but also peaks due to asymmetrical proton bound dimers AHB+. Such ions were always present in the spectra of mixtures of oxygen bases but were not observed for several mixtures of oxygen and nitrogen bases. The dimers, which were not observable, notable for their low hydrogen bond strengths, must have decomposed in their passage from the ion source to the detector, i.e. in a time less than approximately 5 ms. When the temperature was lowered to -20 degrees C, trimers, both homogeneous and mixed, were observed with mixtures of alcohols. The importance of hydrogen bond energy, and hence operating temperature, in determining the degree of solvation of the ions that will be observed in an ion mobility spectrometer is stressed. The possibility is discussed that a displacement reaction involving ambient water plays a role in the dissociation.

  19. Electrically Driven Ion Separations in Permeable Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Bruening, Merlin [Michigan State Univ., East Lansing, MI (United States)

    2017-04-21

    Membranes are attractive for a wide range of separations due to their low energy costs and continuous operation. To achieve practical fluxes, most membranes consist of a thin, selective skin on a highly permeable substrate that provides mechanical strength. Thus, this project focused on creating new methods for forming highly selective ultrathin skins as well as modeling transport through these coatings to better understand their unprecedented selectivities. The research explored both gas and ion separations, and the latter included transport due to concentration, pressure and electrical potential gradients. This report describes a series of highlights of the research and then provides a complete list of publications supported by the grant. These publications have been cited more than 4000 times. Perhaps the most stunning finding is the recent discovery of monovalent/divalent cation and anion selectivities around 1000 when modifying cation- and anion-exchange membranes with polyelectrolyte multilayers (PEMs). This discovery builds on many years of exciting research. (Citation numbers refer to the journal articles in the bibliography.)

  20. Ion mobility spectrometry for detection of skin volatiles.

    Science.gov (United States)

    Ruzsanyi, Veronika; Mochalski, Pawel; Schmid, Alex; Wiesenhofer, Helmut; Klieber, Martin; Hinterhuber, Hartmann; Amann, Anton

    2012-12-12

    Volatile organic compounds (VOCs) released by humans through their skin were investigated in near real time using ion mobility spectrometry after gas chromatographic separation with a short multi-capillary column. VOCs typically found in a small nitrogen flow covering the skin are 3-methyl-2-butenal, 6-methylhept-5-en-2-one, sec-butyl acetate, benzaldehyde, octanal, 2-ethylhexanol, nonanal and decanal at volume fractions in the low part per billion-(ppb) range. The technique presented here may contribute to elucidating some physiological processes occurring in the human skin.

  1. Aspirated capacitor measurements of air conductivity and ion mobility spectra

    CERN Document Server

    Aplin, K L

    2005-01-01

    Measurements of ions in atmospheric air are used to investigate atmospheric electricity and particulate pollution. Commonly studied ion parameters are (1) air conductivity, related to the total ion number concentration, and (2) the ion mobility spectrum, which varies with atmospheric composition. The physical principles of air ion instrumentation are long-established. A recent development is the computerised aspirated capacitor, which measures ions from (a) the current of charged particles at a sensing electrode, and (b) the rate of charge exchange with an electrode at a known initial potential, relaxing to a lower potential. As the voltage decays, only ions of higher and higher mobility are collected by the central electrode and contribute to the further decay of the voltage. This enables extension of the classical theory to calculate ion mobility spectra by inverting voltage decay time series. In indoor air, ion mobility spectra determined from both the novel voltage decay inversion, and an established volt...

  2. Ion mobilities in Xe/Ne and other rare-gas mixtures.

    Science.gov (United States)

    Piscitelli, D; Phelps, A V; de Urquijo, J; Basurto, E; Pitchford, L C

    2003-10-01

    The ion mobility or drift velocity data important for modeling glow discharges in rare gas mixtures are not generally available, nor are the ion-neutral scattering cross sections needed to calculate these data. In this paper we propose a set of cross sections for Xe+ and Ne+ collisions with Xe and Ne atoms. Ion mobilities at 300 K calculated using this cross section set in a Monte Carlo simulation are reported for reduced field strengths, E/N, up to 1500 x 10(-21) V m(2), in pure gases and in Xe/Ne mixtures containing 5% and 20% Xe/Ne, which are mixtures of interest for plasma display panels (PDPs). The calculated Xe+ mobilities depend strongly on the mixture composition, but the Ne+ mobility varies only slightly with increasing Xe in the mixture over the range studied here. The mobilities in pure gases compare well with available experimental values, and mobilities in gas mixtures at low E/N compare well with our recent measurements which will be published separately. Results from these calculations of ion mobilities are used to evaluate the predictions of Blanc's law and of the mixture rule proposed by Mason and Hahn [Phys. Rev. A 5, 438 (1972)] for determining the ion mobilities in mixtures from a knowledge of the mobilities in each of the pure gases. The mixture rule of Mason and Hahn is accurate to better than 10% at high field strengths over a wide range of conditions of interest for modeling PDPs. We conclude that a good estimate of ion mobilities at high E/N in Xe/Ne and other binary rare gas mixtures can be obtained using this mixture rule combined with known values of mobilities in parent gases and with the Langevin form for mobility of rare gas ions ion in other gases. This conclusion is supported by results in Ar/Ne mixtures which are also presented here.

  3. QconCAT standard for calibration of ion mobility-mass spectrometry systems.

    Science.gov (United States)

    Chawner, Ross; McCullough, Bryan; Giles, Kevin; Barran, Perdita E; Gaskell, Simon J; Eyers, Claire E

    2012-11-01

    Ion mobility-mass spectrometry (IM-MS) is a useful technique for determining information about analyte ion conformation in addition to mass/charge ratio. The physical principles that govern the mobility of an ion through a gas in the presence of a uniform electric field are well understood, enabling rotationally averaged collision cross sections (Ω) to be directly calculated from measured drift times under well-defined experimental conditions. However, such "first principle" calculations are not straightforward for Traveling Wave (T-Wave) mobility separations due to the range of factors that influence ion motion through the mobility cell. If collision cross section information is required from T-Wave mobility separations, then calibration of the instruments using known standards is essential for each set of experimental conditions. To facilitate such calibration, we have designed and generated an artificial protein based on the QconCAT technology, QCAL-IM, which upon proteolysis can be used as a universal ion mobility calibration standard. This single unique standard enables empirical calculation of peptide ion collision cross sections from the drift time on a T-Wave mobility instrument.

  4. Energy landscapes for mobile ions in ion conducting solids

    Indian Academy of Sciences (India)

    S Adams

    2006-11-01

    Structure property function relationships provide valuable guidelines in the systematic development of advanced functional materials with tailored properties. It is demonstrated that an augmented bond valence approach can be effectively used to establish such relationships for solid electrolytes. A bond valence analysis of local structure models for disordered systems or interfaces based on reverse Monte Carlo (RMC) fits or molecular dynamics (MD) simulations yields quantitative predictions of the ion transport characteristics. As demonstrated here for a range of metaphosphate and diborate glasses, the complete description of the energy landscape for mobile ions also provides an effective tool for achieving a more detailed understanding of ion transport in glasses. The investigation of time evolutions can be included, if the bond valence analysis is based on MD trajectories. In principle, this allows quantifying the time and temperature dependence of pathway characteristics, provided that a suitable empirical force-field is available. For the example of LiPO3, the remaining differences between simulated and experimental structures are investigated and a compensation method is discussed.

  5. Compression Ratio Ion Mobility Programming (CRIMP) Accumulation and Compression of Billions of Ions for Ion Mobility-Mass Spectrometry Using Traveling Waves in Structures for Lossless Ion Manipulations (SLIM).

    Science.gov (United States)

    Deng, Liulin; Garimella, Sandilya V B; Hamid, Ahmed M; Webb, Ian K; Attah, Isaac K; Norheim, Randolph V; Prost, Spencer A; Zheng, Xueyun; Sandoval, Jeremy A; Baker, Erin S; Ibrahim, Yehia M; Smith, Richard D

    2017-06-20

    We report on the implementation of a traveling wave (TW) based compression ratio ion mobility programming (CRIMP) approach within structures for lossless ion manipulations (SLIM) that enables both greatly enlarged trapped ion charge capacities and also efficient ion population compression for use in ion mobility (IM) separations. Ion accumulation is conducted in a SLIM serpentine ultralong path with extended routing (SUPER) region after which CRIMP compression allows the large ion populations to be "squeezed". The SLIM SUPER IM module has two regions, one operating with conventional traveling waves (i.e., traveling trap; TT region) and the second having an intermittently pausing or "stuttering" TW (i.e., stuttering trap; ST region). When a stationary voltage profile was used in the ST region, ions are blocked at the TT-ST interface and accumulated in the TT region and then can be released by resuming a conventional TW in the ST region. The population can also be compressed using CRIMP by the repetitive merging of ions distributed over multiple TW bins in the TT region into a single TW bin in the ST region. Ion accumulation followed by CRIMP compression provides the basis for the use of larger ion populations for IM separations. We show that over 10(9) ions can be accumulated with high efficiency in the present device and that the extent of subsequent compression is only limited by the space charge capacity of the trapping region. Approximately 5 × 10(9) charges introduced from an electrospray ionization source were trapped for a 40 s accumulation period, more than 2 orders of magnitude greater than the previously reported charge capacity of an ion funnel trap. Importantly, we show that extended ion accumulation in conjunction with CRIMP compression and multiple passes through the serpentine path provides the basis for a highly desirable combination of ultrahigh sensitivity and SLIM SUPER high-resolution IM separations.

  6. Determining the isomeric heterogeneity of neutral oligosaccharide-alditols of bovine submaxillary mucin using negative ion traveling wave ion mobility mass spectrometry.

    Science.gov (United States)

    Li, Hongli; Bendiak, Brad; Siems, William F; Gang, David R; Hill, Herbert H

    2015-02-17

    Negative ions produced by electrospray ionization were used to evaluate the isomeric heterogeneity of neutral oligosaccharide-alditols isolated from bovine submaxillary mucin (BSM). The oligosaccharide-alditol mixture was preseparated on an off-line high-performance liquid chromatography (HPLC) column, and the structural homogeneity of individual LC fractions was investigated using a Synapt G2 traveling wave ion mobility spectrometer coupled between quadupole and time-of-flight mass spectrometers. Mixtures of isomers separated by both chromatography and ion mobility spectrometry were studied. Tandem mass spectrometry (MS/MS) of multiple mobility peaks having the same mass-to-charge ratio (m/z) demonstrated the presence of different structural isomers and not differences in ion conformations due to charge site location. Although the oligosaccharide-alditol mixture was originally separated by HPLC, multiple ion mobility peaks due to structural isomers were observed for a number of oligosaccharide-alditols from single LC fractions. The collision-induced dissociation cells located in front of and after the ion mobility separation device enabled oligosaccharide precursor or product ions to be separated by ion mobility and independent fragmentation spectra to be acquired for isomeric carbohydrate precursor or product ions. MS/MS spectra so obtained for independent mobility peaks at a single m/z demonstrated the presence of structural variants or stereochemical isomers having the same molecular formula. This was observed both for oligosaccharide precursor and product ions. In addition, mobilities of both [M - H](-) and [M + Cl](-) ions, formed by adding NH4OH or NH4Cl to the electrospray solvent, were examined and compared for selected oligosaccharide-alditols. Better separation among structural isomers appeared to be achieved for some [M + Cl](-) anions.

  7. Improving Ionic Conductivity and Lithium-Ion Transference Number in Lithium-Ion Battery Separators.

    Science.gov (United States)

    Zahn, Raphael; Lagadec, Marie Francine; Hess, Michael; Wood, Vanessa

    2016-12-07

    The microstructure of lithium-ion battery separators plays an important role in separator performance; however, here we show that a geometrical analysis falls short in predicting the lithium-ion transport in the electrolyte-filled pore space. By systematically modifying the surface chemistry of a commercial polyethylene separator while keeping its microstructure unchanged, we demonstrate that surface chemistry, which alters separator-electrolyte interactions, influences ionic conductivity and lithium-ion transference number. Changes in separator surface chemistry, particularly those that increase lithium-ion transference numbers can reduce voltage drops across the separator and improve C-rate capability.

  8. Comparison of the mobilities of negative and positive ions in nonpolar solutions.

    Science.gov (United States)

    Ivanishko, Irina S; Borovkov, Vsevolod I

    2010-08-01

    The mobilities of organic radical ions of different molecular volumes have been determined in squalane and hexane solutions to study the influence of the ion charge sign on the ionic mobility in a weakly polar liquid. The relative mobility of geminate radical ions was measured using the method of time-resolved electric field effect in the recombination fluorescence. To determine the mobility of cations and anions separately, a trend in the value of the relative mobility was analyzed by varying the mobility of one of the geminate partners. The ratios between the mobilities of the anion and the cation of the same molecules were found to be about 1.1. It was shown that in liquid alkanes, the solvent electrostriction was the main factor determining a decrease in the mobility of an ion as compared to the parent neutral molecule. The strong dependence of the electrostrictive effect on the radius of the ionic solvation shell allows the observed difference between negative and positive charge carriers by a small but systematic difference in the effective radii of the ions to be explained.

  9. A novel technique to determine atmospheric ion mobility spectra

    CERN Document Server

    Aplin, K L

    2003-01-01

    Detailed tropospheric ion measurements are needed to improve understanding of the electrical microphysics affecting clouds. Additionally, atmospheric ion mobility spectra can be used to identify ion growth processes leading to condensation nucleus formation. However these measurements are rare, particularly in the troposphere where the majority of clouds form. Developments in the operating theory of the classical instrument for ion measurement, the aspirated cylindrical capacitor, are described, which enable ion mobility spectrum information to be extracted from the rate of voltage decay of the aspirated capacitor in air. In this paper, data from historical balloon-borne ion counter ascents will be reanalysed to extract new ion mobility spectra from simple voltage time series. Such data recovery will increase the amount of atmospheric ion spectra available for analysis.

  10. Ion mobility spectrometry for food quality and safety.

    Science.gov (United States)

    Vautz, W; Zimmermann, D; Hartmann, M; Baumbach, J I; Nolte, J; Jung, J

    2006-11-01

    Ion mobility spectrometry is known to be a fast and sensitive technique for the detection of trace substances, and it is increasingly in demand not only for protection against explosives and chemical warfare agents, but also for new applications in medical diagnosis or process control. Generally, a gas phase sample is ionized by help of ultraviolet light, ss-radiation or partial discharges. The ions move in a weak electrical field towards a detector. During their drift they collide with a drift gas flowing in the opposite direction and, therefore, are slowed down depending on their size, shape and charge. As a result, different ions reach the detector at different drift times, which are characteristic for the ions considered. The number of ions reaching the detector are a measure of the concentration of the analyte. The method enables the identification and quantification of analytes with high sensitivity (ng l(-1) range). The selectivity can even be increased - as necessary for the analyses of complex mixtures - using pre-separation techniques such as gas chromatography or multi-capillary columns. No pre-concentration of the sample is necessary. Those characteristics of the method are preserved even in air with up to a 100% relative humidity rate. The suitability of the method for application in the field of food quality and safety - including storage, process and quality control as well as the characterization of food stuffs - was investigated in recent years for a number of representative examples, which are summarized in the following, including new studies as well: (1) the detection of metabolites from bacteria for the identification and control of their growth; (2) process control in food production - beer fermentation being an example; (3) the detection of the metabolites of mould for process control during cheese production, for quality control of raw materials or for the control of storage conditions; (4) the quality control of packaging materials during

  11. Shutterless ion mobility spectrometer with fast pulsed electron source

    Science.gov (United States)

    Bunert, E.; Heptner, A.; Reinecke, T.; Kirk, A. T.; Zimmermann, S.

    2017-02-01

    Ion mobility spectrometers (IMS) are devices for fast and very sensitive trace gas analysis. The measuring principle is based on an initial ionization process of the target analyte. Most IMS employ radioactive electron sources, such as 63Ni or 3H. These radioactive materials have the disadvantage of legal restrictions and the electron emission has a predetermined intensity and cannot be controlled or disabled. In this work, we replaced the 3H source of our IMS with 100 mm drift tube length with our nonradioactive electron source, which generates comparable spectra to the 3H source. An advantage of our emission current controlled nonradioactive electron source is that it can operate in a fast pulsed mode with high electron intensities. By optimizing the geometric parameters and developing fast control electronics, we can achieve very short electron emission pulses for ionization with high intensities and an adjustable pulse width of down to a few nanoseconds. This results in small ion packets at simultaneously high ion densities, which are subsequently separated in the drift tube. Normally, the required small ion packet is generated by a complex ion shutter mechanism. By omitting the additional reaction chamber, the ion packet can be generated directly at the beginning of the drift tube by our pulsed nonradioactive electron source with only slight reduction in resolving power. Thus, the complex and costly shutter mechanism and its electronics can also be omitted, which leads to a simple low-cost IMS-system with a pulsed nonradioactive electron source and a resolving power of 90.

  12. Secondary electrospray ionization ion mobility spectrometry/mass spectrometry of illicit drugs.

    Science.gov (United States)

    Wu, C; Siems, W F; Hill, H H

    2000-01-15

    A secondary electrospray ionization (SESI) method was developed as a nonradioactive ionization source for ion mobility spectrometry (IMS). This SESI method relied on the gas-phase interaction between charged particles created by electrospray ionization (ESI) and neutral gaseous sample molecules. Mass spectrometry (MS) was used as the detection method after ion mobility separation for ion identification. Preliminary investigations focussed on understanding the ionization process of SESI. The performance of ESI-IMS and SESI-IMS for illicit drug detection was evaluated by determining the analytical figures of merit. In general, SESI had a higher ionization efficiency for small volatile molecules compared with the electrospray method. The potential of developing a universal interface for both GC- and LC-MS with an addition stage of mobility separation was demonstrated.

  13. Compression Ratio Ion Mobility Programming (CRIMP) Accumulation and Compression of Billions of Ions for Ion Mobility-Mass Spectrometry Using Traveling Waves in Structures for Lossless Ion Manipulations (SLIM)

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Liulin; Garimella, Sandilya V. B.; Hamid, Ahmed M.; Webb, Ian K.; Attah, Isaac K.; Norheim, Randolph V.; Prost, Spencer A.; Zheng, Xueyun; Sandoval, Jeremy A.; Baker, Erin S.; Ibrahim, Yehia M.; Smith, Richard D.

    2017-05-25

    We report on the implementation of a traveling wave (TW) based compression ratio ion mobility programming (CRIMP) approach within Structures for Lossless Ion Manipulations (SLIM) that enables both greatly enlarged trapped ion charge capacities and also their subsequent efficient compression for use in ion mobility (IM) separations. Ion accumulation is conducted in a long serpentine path TW SLIM region after which CRIMP allows the large ion populations to be ‘squeezed’. The compression process occurs at an interface between two SLIM regions, one operating conventionally and the second having an intermittently pausing or ‘stuttering’ TW, allowing the contents of multiple bins of ions from the first region to be merged into a single bin in the second region. In this initial work stationary voltages in the second region were used to block ions from exiting the first (trapping) region, and the resumption of TWs in the second region allows ions to exit, and the population to also be compressed if CRIMP is applied. In our initial evaluation we show that the number of charges trapped for a 40 s accumulation period was ~5×109, more than two orders of magnitude greater than the previously reported charge capacity using an ion funnel trap. We also show that over 1×109 ions can be accumulated with high efficiency in the present device, and that the extent of subsequent compression is only limited by the space charge capacity of the trapping region. Lower compression ratios allow increased IM peak heights without significant loss of signal, while excessively large compression ratios can lead to ion losses and other artifacts. Importantly, we show that extended ion accumulation in conjunction with CRIMP and multiple passes provides the basis for a highly desirable combination of ultra-high sensitivity and ultra-high resolution IM separations using SLIM.

  14. Ion reactions for isobar separation in accelerator mass spectrometry

    CERN Document Server

    Litherland, A E; Doupe, J P

    2003-01-01

    The use of resonant and near resonant keV ion reactions for isobar separation in AMS is discussed. It is shown that these and other ionic reactions can be useful provided that the multiple scattering is taken into account.

  15. Field applications of ion-mobility spectrometry

    Science.gov (United States)

    Brown, Patricia A.

    1997-02-01

    Ion mobility spectrometry (IMS) is an excellent tool for detection of controlled substances under field conditions. Plasmagrams and tables showing the results of field applications will be discussed. Residues of drugs, such as cocaine and heroin, can be left anywhere including vehicles, boats, and houses. In houses, the carpets, walls, and floors are good locations for residues to adhere. Individual clothing can also be contaminated with drug residue. Vehicles that are suspected of having previously smuggled illegal substances can be vacuumed and screened. Tablets that look similar and respond the same when screened with the Marquis reagent can be differentiated by IMS. With Southern California being the 'methamphetamine capital of the world' and the resurgence of phencyclidine, IMS has proven extremely valuable in the screening of abandoned clandestine laboratory sites and vehicles in which the clandestine laboratories; chemicals and glassware were transported. IMS is very responsive to ephedrine/pseudophedrine, a precursor of methamphetamine and 1-piperidinocyclohexanecarbonitrile, an intermediate of phencyclidine. Once residues are detected, vacuum samples, and/or methanol wipes are collected and analyzed at the DEA Laboratory for confirmation of the suspected substance using GC-IRD or Mass Spectrometry.

  16. Ion mobility studies of carbohydrates as group I adducts: isomer specific collisional cross section dependence on metal ion radius.

    Science.gov (United States)

    Huang, Yuting; Dodds, Eric D

    2013-10-15

    Carbohydrates play numerous critical roles in biological systems. Characterization of oligosaccharide structures is essential to a complete understanding of their functions in biological processes; nevertheless, their structural determination remains challenging in part due to isomerism. Ion mobility spectrometry provides the means to resolve gas phase ions on the basis of their shape-to-charge ratios, thus providing significant potential for separation and differentiation of carbohydrate isomers. Here, we report on the determination of collisional cross sections for four groups of isomeric carbohydrates (including five isomeric disaccharides, four isomeric trisaccharides, two isomeric pentasaccharides, and two isomeric hexasaccharides) as their group I metal ion adducts (i.e., [M + Li](+), [M + Na](+), [M + K](+), [M + Rb](+), and [M + Cs](+)). In all, 65 collisional cross sections were measured, the great majority of which have not been previously reported. As anticipated, the collisional cross sections of the carbohydrate metal ion adducts generally increase with increasing metal ion radius; however, the collisional cross sections were found to scale with the group I cation size in isomer specific manners. Such measurements are of substantial analytical value, as they illustrate how the selection of charge carrier influences carbohydrate ion mobility determinations. For example, certain pairs of isomeric carbohydrates assume unique collisional cross sections upon binding one metal ion, but not another. On the whole, these data suggest a role for the charge carrier as a probe of carbohydrate structure and thus have significant implications for the continued development and application of ion mobility spectrometry for the distinction and resolution of isomeric carbohydrates.

  17. Mineral Separation in a CELSS by Ion-exchange Chromatography

    Science.gov (United States)

    Ballou, E. V.; Spitze, L. A.; Wong, F. W.; Wydeven, T.; Johnson, C. C.

    1982-01-01

    Operational parameters pertinent to ion exchange chromatography separation were identified. The experiments were performed with 9 mm diameter ion exchange columns and conventional column accessories. The cation separation beds were packed with AG 50W-X2 strong acid cation exchange resin in H(+) form and 200-400 dry mesh particle size. The stripper beds used in some experiments were packed with AG 1-XB strong base cation exchange resin in OH(-) form and 200-400 dry mesh particle size.

  18. Examining the Influence of Phosphorylation on Peptide Ion Structure by Ion Mobility Spectrometry-Mass Spectrometry

    Science.gov (United States)

    Glover, Matthew S.; Dilger, Jonathan M.; Acton, Matthew D.; Arnold, Randy J.; Radivojac, Predrag; Clemmer, David E.

    2016-05-01

    Ion mobility spectrometry-mass spectrometry (IMS-MS) techniques are used to study the general effects of phosphorylation on peptide structure. Cross sections for a library of 66 singly phosphorylated peptide ions from 33 pairs of positional isomers, and unmodified analogues were measured. Intrinsic size parameters (ISPs) derived from these measurements yield calculated collision cross sections for 85% of these phosphopeptide sequences that are within ±2.5% of experimental values. The average ISP for the phosphoryl group (0.64 ± 0.05) suggests that in general this moiety forms intramolecular interactions with the neighboring residues and peptide backbone, resulting in relatively compact structures. We assess the capability of ion mobility to separate positional isomers (i.e., peptide sequences that differ only in the location of the modification) and find that more than half of the isomeric pairs have >1% difference in collision cross section. Phosphorylation is also found to influence populations of structures that differ in the cis/ trans orientation of Xaa-Pro peptide bonds. Several sequences with phosphorylated Ser or Thr residues located N-terminally adjacent to Pro residues show fewer conformations compared to the unmodified sequences.

  19. Helicity separation in Heavy-Ion Collisions

    CERN Document Server

    Baznat, Mircea; Sorin, Alexander; Teryaev, Oleg

    2013-01-01

    We study the P-odd effects related to the vorticity of the medium formed in noncentral heavy ion collisions. Using the kinetic Quark-Gluon Strings Model we perform the numerical simulations of the vorticity and hydrodynamical helicity for the various atomic numbers, energies and centralities. We observed the vortical structures typically occupying the relatively small fraction of the fireball volume. In the course of numerical simulations the noticeable hydrodanamical helicity was observed manifesting the specific mirror behaviour with respect to the reaction plane. The effect is maximal at the NICA and FAIR energy range.

  20. Artificial neural networks for the prediction of peptide drift time in ion mobility mass spectrometry

    Directory of Open Access Journals (Sweden)

    Plasencia Manolo

    2010-04-01

    Full Text Available Abstract Background There is an increasing usage of ion mobility-mass spectrometry (IMMS in proteomics. IMMS combines the features of ion mobility spectrometry (IMS and mass spectrometry (MS. It separates and detects peptide ions on a millisecond time-scale. IMS separates peptide ions based on drift time that is determined by the collision cross-section of each peptide ion in a given experiment condition. A peptide ion's collision cross-section is related to the ion size and shape resulted from the peptide amino acid sequence and their modifications. This inherent relation between the drift time of peptide ion and peptide sequence indicates that the drift time of peptide ions can be used to infer peptide sequence and therefore, for peptide identification. Results This paper describes an artificial neural networks (ANNs regression model for the prediction of peptide ion drift time in IMMS. Each peptide in this work was represented using three descriptors (i.e., molecular weight, sequence length and a two-dimensional sequence index. An ANN predictor consisting of four input nodes, three hidden nodes and one output node was constructed for peptide ion drift time prediction. For the model training and testing, a 10-fold cross-validation strategy was employed for three datasets each containing different charge states. Dataset one contains 212 singly-charged peptide ions, dataset two has 306 doubly-charged peptide ions, and dataset three has 77 triply-charged peptide ions. Our proposed method achieved 94.4%, 93.6% and 74.2% prediction accuracy for singly-, doubly- and triply-charged peptide ions, respectively. Conclusions An ANN-based method has been developed for predicting the drift time of peptide ions in IMMS. The results achieved here demonstrate the effectiveness and efficiency of the prediction model. This work can enhance the confidence of protein identification by combining with current database search approaches for protein identification.

  1. Application of PVDF composite for lithium-ion battery separator

    Science.gov (United States)

    Sabrina, Q.; Majid, N.; Prihandoko, B.

    2016-11-01

    In this study a composite observed in PVDF composite as lithium ion battery separator. Observation of performance cell battery with cyclic voltametry and charge discharge capacity. Surface morphology PVDF separator and commercial separator observed with Scanning electron microscopy (SEM). Cyclic Voltamerty test (CV) and Charge Discharge (CD) showed a capacity value on the coin cell. Coin cell is composed of material LiFePO4 cathode, anode material of lithium metal and varies as graphite, liquid electrolyte varied use LiBOB and LiPF6. While the PVDF as compared to the commercial separator. Coin cell commercial separator has a better high capacity value when compared with Coin cell with the PVDF separator. Life cycle coin cell with the commercial separator material is still longer than coin cell separator with PVDF Copolymer. Development of PVDF as separator remains to be done in order to improve the performance of the battery exceeds the usage of commercial material.

  2. Extending the dynamic range of the ion trap by differential mobility filtration.

    Science.gov (United States)

    Hall, Adam B; Coy, Stephen L; Kafle, Amol; Glick, James; Nazarov, Erkinjon; Vouros, Paul

    2013-09-01

    A miniature, planar, differential ion mobility spectrometer (DMS) was interfaced to an LCQ classic ion trap to conduct selective ion filtration prior to mass analysis in order to extend the dynamic range of the trap. Space charge effects are known to limit the functional ion storage capacity of ion trap mass analyzers and this, in turn, can affect the quality of the mass spectral data generated. This problem is further exacerbated in the analysis of mixtures where the indiscriminate introduction of matrix ions results in premature trap saturation with non-targeted species, thereby reducing the number of parent ions that may be used to conduct MS/MS experiments for quantitation or other diagnostic studies. We show that conducting differential mobility-based separations prior to mass analysis allows the isolation of targeted analytes from electrosprayed mixtures preventing the indiscriminate introduction of matrix ions and premature trap saturation with analytically unrelated species. Coupling these two analytical techniques is shown to enhance the detection of a targeted drug metabolite from a biological matrix. In its capacity as a selective ion filter, the DMS can improve the analytical performance of analyzers such as quadrupole (3D or linear) and ion cyclotron resonance (FT-ICR) ion traps that depend on ion accumulation.

  3. Extending the Dynamic Range of the Ion Trap by Differential Mobility Filtration

    Science.gov (United States)

    Hall, Adam B.; Coy, Stephen L.; Kafle, Amol; Glick, James; Nazarov, Erkinjon

    2013-01-01

    A miniature, planar, differential ion mobility spectrometer (DMS) was interfaced to an LCQ classic ion trap to conduct selective ion filtration prior to mass analysis in order to extend the dynamic range of the trap. Space charge effects are known to limit the functional ion storage capacity of ion trap mass analyzers and this, in turn, can affect the quality of the mass spectral data generated. This problem is further exacerbated in the analysis of mixtures where the indiscriminate introduction of matrix ions results in premature trap saturation with non-targeted species, thereby reducing the number of parent ions that may be used to conduct MS/MS experiments for quantitation or other diagnostic studies. We show that conducting differential mobility-based separations prior to mass analysis allows the isolation of targeted analytes from electrosprayed mixtures preventing the indiscriminate introduction of matrix ions and premature trap saturation with analytically unrelated species. Coupling these two analytical techniques is shown to enhance the detection of a targeted drug metabolite from a biological matrix. In its capacity as a selective ion filter, the DMS can improve the analytical performance of analyzers such as quadrupole (3-D or linear) and ion cyclotron resonance (FT-ICR) ion traps that depend on ion accumulation. PMID:23797861

  4. Determination of alcohol compounds using corona discharge ion mobility spectrometry

    Institute of Scientific and Technical Information of China (English)

    HAN Hai-yan; HUANG Guo-dong; JIN Shun-ping; ZHENG Pei-chao; XU Guo-hua; LI Jian-quan; WANG Hong-mei; CHU Yan-nan

    2007-01-01

    Ion mobility spectrometry (IMS) is a very fast, highly sensitive, and inexpensive technique, it permits efficient monitoring of volatile organic compounds like alcohols. In this article, positive ion mobility spectra for six alcohol organic compounds have been systematically studied for the first time using a high-resolution IMS apparatus equipped with a discharge ionization source. Utilizing protonated water cluster ions (H2O)nH+ as the reactant ions and clean air as the drift gas, alcohol organic compounds, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol and 2-octanol, all exhibit product ion characteristic peaks in their respective ion mobility spectrometry, that is a result of proton transfer reactions between the alcohols and reaction ions (H2O)nH+. The mixture of these alcohols, including two isomers, has been detected, and the result shows that they can also be distinguished effectively in the ion mobility spectrum. The reduced mobility values have been determined, which are in very well agreement with the traditional 63Ni-IMS experimental values. The exponential dilution method was used to calibrate the alcohol concentrations, and a detection limit available for the alcohols is in order of magnitude of a few ng/L.

  5. Separation of organic ion exchange resins from sludge -- engineering study

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, J.B.

    1998-08-25

    This engineering study evaluates the use of physical separation technologies to separate organic ion exchange resin from KE Basin sludge prior to nitric acid dissolution. This separation is necessitate to prevent nitration of the organics in the acid dissolver. The technologies under consideration are: screening, sedimentation, elutriation. The recommended approach is to first screen the Sludge and resin 300 microns then subject the 300 microns plus material to elutriation.

  6. Phase Separation Dynamics in Isotropic Ion-Intercalation Particles

    CERN Document Server

    Zeng, Yi

    2013-01-01

    Lithium-ion batteries exhibit complex nonlinear dynamics, resulting from diffusion and phase transformations coupled to ion intercalation reactions. Using the recently developed Cahn-Hilliard reaction (CHR) theory, we investigate a simple mathematical model of ion intercalation in a spherical solid nanoparticle, which predicts transitions from solid-solution radial diffusion to two-phase shrinking-core dynamics. This general approach extends previous Li-ion battery models, which either neglect phase separation or postulate a spherical shrinking-core phase boundary, by predicting phase separation only under appropriate circumstances. The effect of the applied current is captured by generalized Butler-Volmer kinetics, formulated in terms of diffusional chemical potentials, and the model consistently links the evolving concentration profile to the battery voltage. We examine sources of charge/discharge asymmetry, such as asymmetric charge transfer and surface "wetting" by ions within the solid, which can lead to...

  7. Laser photodissociation and spectroscopy of mass-separated biomolecular ions

    CERN Document Server

    Polfer, Nicolas C

    2014-01-01

    This lecture notes book presents how enhanced structural information of biomolecular ions can be obtained from interaction with photons of specific frequency - laser light. The methods described in the book ""Laser photodissociation and spectroscopy of mass-separated biomolecular ions"" make use of the fact that the discrete energy and fast time scale of photoexcitation can provide more control in ion activation. This activation is the crucial process producing structure-informative product ions that cannot be generated with more conventional heating methods, such as collisional activation. Th

  8. Separation of ions in acidic solution by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, M.

    1997-10-08

    Capillary electrophoresis (CE) is an effective method for separating ionic species according to differences in their electrophoretic mobilities. CE separations of amino acids by direct detection are difficult due to their similar electrophoretic mobilities and low absorbances. However, native amino acids can be separated by CE as cations at a low pH by adding an alkanesulfonic acid to the electrolyte carrier which imparts selectivity to the system. Derivatization is unnecessary when direct UV detection is used at 185 nm. Simultaneous speciation of metal cations such as vanadium (IV) and vanadium (V) can easily be performed without complexation prior to analysis. An indirect UV detection scheme for acidic conditions was also developed using guanidine as the background carrier electrolyte (BCE) for the indirect detection of metal cations. Three chapters have been removed for separate processing. This report contains introductory material, references, and general conclusions. 80 refs.

  9. Lifetimes and stabilities of familiar explosives molecular adduct complexes during ion mobility measurements

    Science.gov (United States)

    McKenzie, Alan; DeBord, John Daniel; Ridgeway, Mark; Park, Melvin; Eiceman, Gary; Fernandez-Lima, Francisco

    2015-01-01

    Trapped ion mobility spectrometry coupled to mass spectrometry (TIMS-MS) was utilized for the separation and identification of familiar explosives in complex mixtures. For the first time, molecular adduct complex lifetimes, relative stability, binding energies and candidate structures are reported for familiar explosives. Experimental and theoretical results showed that the adduct size and reactivity, complex binding energy and the explosive structure tailors the stability of the molecular adduct complex. TIMS flexibility to adapt the mobility separation as a function of the molecular adduct complex stability (i.e., short or long IMS experiments / low or high IMS resolution) permits targeted measurements of explosives in complex mixtures with higher confidence levels. PMID:26153567

  10. Traveling-wave ion mobility mass spectrometry of protein complexes

    DEFF Research Database (Denmark)

    Salbo, Rune; Bush, Matthew F; Naver, Helle

    2012-01-01

    The collision cross-section (Ω) of a protein or protein complex ion can be measured using traveling-wave (T-wave) ion mobility (IM) mass spectrometry (MS) via calibration with compounds of known Ω. The T-wave Ω-values depend strongly on instrument parameters and calibrant selection. Optimization...

  11. Monte Carlo Simulation of Ion Trajectories of Reacting Chemical Systems: Mobility of Small Water Clusters in Ion Mobility Spectrometry

    Science.gov (United States)

    Wissdorf, Walter; Seifert, Luzia; Derpmann, Valerie; Klee, Sonja; Vautz, Wolfgang; Benter, Thorsten

    2013-04-01

    For the comprehensive simulation of ion trajectories including reactive collisions at elevated pressure conditions, a chemical reaction simulation (RS) extension to the popular SIMION software package was developed, which is based on the Monte Carlo statistical approach. The RS extension is of particular interest to SIMION users who wish to simulate ion trajectories in collision dominated environments such as atmospheric pressure ion sources, ion guides (e.g., funnels, transfer multi poles), chemical reaction chambers (e.g., proton transfer tubes), and/or ion mobility analyzers. It is well known that ion molecule reaction rate constants frequently reach or exceed the collision limit obtained from kinetic gas theory. Thus with a typical dwell time of ions within the above mentioned devices in the ms range, chemical transformation reactions are likely to occur. In other words, individual ions change critical parameters such as mass, mobility, and chemical reactivity en passage to the analyzer, which naturally strongly affects their trajectories. The RS method simulates elementary reaction events of individual ions reflecting the behavior of a large ensemble by a representative set of simulated reacting particles. The simulation of the proton bound water cluster reactant ion peak (RIP) in ion mobility spectrometry (IMS) was chosen as a benchmark problem. For this purpose, the RIP was experimentally determined as a function of the background water concentration present in the IMS drift tube. It is shown that simulation and experimental data are in very good agreement, demonstrating the validity of the method.

  12. Method of multiplexed analysis using ion mobility spectrometer

    Science.gov (United States)

    Belov, Mikhail E.; Smith, Richard D.

    2009-06-02

    A method for analyzing analytes from a sample introduced into a Spectrometer by generating a pseudo random sequence of a modulation bins, organizing each modulation bin as a series of submodulation bins, thereby forming an extended pseudo random sequence of submodulation bins, releasing the analytes in a series of analyte packets into a Spectrometer, thereby generating an unknown original ion signal vector, detecting the analytes at a detector, and characterizing the sample using the plurality of analyte signal subvectors. The method is advantageously applied to an Ion Mobility Spectrometer, and an Ion Mobility Spectrometer interfaced with a Time of Flight Mass Spectrometer.

  13. Atmospheric pressure ionization and gas phase ion mobility studies of isomeric dihalogenated benzenes using different ionization techniques

    Science.gov (United States)

    Borsdorf, H.; Nazarov, E. G.; Eiceman, G. A.

    2004-03-01

    Ion mobility spectrometry (IMS) featuring different ionization techniques was used to analyze isomeric ortho-, meta- and para-dihalogenated benzenes in order to assess how structural features affect ion formation and drift behavior. The structure of the product ions formed was investigated by atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) and IMS-MS coupling. Photoionization provided [M]+ ions for chlorinated and fluorinated compounds while bromine was cleaved from isomers of dibromobenzene and bromofluorobenzene. This ionization technique does not permit the different isomers to be distinguished. Comparable ions and additional clustered ions were obtained using 63Ni ionization. Depending on the chemical constitution, different clustered ions were observed in ion mobility spectra for the separate isomers of dichlorobenzene and dibromobenzene. Corona discharge ionization permits the most sensitive detection of dihalogenated compounds. Only clustered product ions were obtained. Corona discharge ionization enables the classification of different structural isomers of dichlorobenzene, dibromobenzene and bromofluorobenzene.

  14. Coarse grained model for calculating the ion mobility of hydrocarbons

    Science.gov (United States)

    Kuroboshi, Y.; Takemura, K.

    2016-12-01

    Hydrocarbons are widely used as insulating compounds. However, their fundamental characteristics in conduction phenomena are not completely understood. A great deal of effort is required to determine reasonable ionic behavior from experiments because of their complicated procedures and tight controls of the temperature and the purity of the liquids. In order to understand the conduction phenomena, we have theoretically calculated the ion mobilities of hydrocarbons and investigated their characteristics using the coarse grained model in molecular dynamics simulations. We assumed a molecule of hydrocarbons to be a bead and simulated its dependence on the viscosity, electric field, and temperature. Furthermore, we verified the suitability of the conformation, scale size, and long-range interactions for the ion mobility. The results of the simulations show that the ion mobility values agree reasonably well with the values from Walden's rule and depend on the viscosity but not on the electric field. The ion mobility and self-diffusion coefficient exponentially increase with increasing temperature, while the activation energy decreases with increasing molecular size. These values and characteristics of the ion mobility are in reasonable agreement with experimental results. In the future, we can understand not only the ion mobilies of hydrocarbons in conduction, but also we can predict general phenomena in electrochemistry with molecular dynamics simulations.

  15. Ion-molecule clustering in differential mobility spectrometry: lessons learned from tetraalkylammonium cations and their isomers.

    Science.gov (United States)

    Campbell, J Larry; Zhu, Mabel; Hopkins, W Scott

    2014-09-01

    Differential mobility spectrometry (DMS) can distinguish ions based upon the differences in their high- and low-field ion mobilities as they experience the asymmetric waveform applied to the DMS cell. These mobilities are known to be influenced by the ions' structure, m/z, and charge distribution (i.e., resonance structures) within the ions themselves, as well as by the gas-phase environment of the DMS cell. While these associations have been developed over time through empirical observations, the exact role of ion structures or their interactions with clustering molecules remains generally unknown. In this study, that relationship is explored by observing the DMS behaviors of a series of tetraalkylammonium ions as a function of their structures and the gas-phase environment of the DMS cell. To support the DMS experiments, the basin-hopping search strategy was employed to identify candidate cluster structures for density functional theory treatment. More than a million cluster structures distributed across 72 different ion-molecule cluster systems were sampled to determine global minimum structures and cluster binding energies. This joint computational and experimental approach suggests that cluster geometry, in particular ion-molecule intermolecular separation, plays a critical role in DMS.

  16. Tandem ion mobility spectrometry coupled to laser excitation.

    Science.gov (United States)

    Simon, Anne-Laure; Chirot, Fabien; Choi, Chang Min; Clavier, Christian; Barbaire, Marc; Maurelli, Jacques; Dagany, Xavier; MacAleese, Luke; Dugourd, Philippe

    2015-09-01

    This manuscript describes a new experimental setup that allows to perform tandem ion mobility spectrometry (IMS) measurements and which is coupled to a high resolution time-of-flight mass spectrometer. It consists of two 79 cm long drift tubes connected by a dual ion funnel assembly. The setup was built to permit laser irradiation of the ions in the transfer region between the two drift tubes. This geometry allows selecting ions according to their ion mobility in the first drift tube, to irradiate selected ions, and examine the ion mobility of the product ions in the second drift tube. Activation by collision is possible in the same region (between the two tubes) and between the second tube and the time-of-flight. IMS-IMS experiments on Ubiquitin are reported. We selected a given isomer of charge state +7 and explored its structural rearrangement following collisional activation between the two drift tubes. An example of IMS-laser-IMS experiment is reported on eosin Y, where laser irradiation was used to produce radical ions by electron photodetachment starting from doubly deprotonated species. This allowed measuring the collision cross section of the radical photo-product, which cannot be directly produced with an electrospray source.

  17. On-tissue protein identification and imaging by MALDI-ion mobility mass spectrometry.

    Science.gov (United States)

    Stauber, Jonathan; MacAleese, Luke; Franck, Julien; Claude, Emmanuelle; Snel, Marten; Kaletas, Basak Kükrer; Wiel, Ingrid M V D; Wisztorski, Maxence; Fournier, Isabelle; Heeren, Ron M A

    2010-03-01

    MALDI imaging mass spectrometry (MALDI-IMS) has become a powerful tool for the detection and localization of drugs, proteins, and lipids on-tissue. Nevertheless, this approach can only perform identification of low mass molecules as lipids, pharmaceuticals, and peptides. In this article, a combination of approaches for the detection and imaging of proteins and their identification directly on-tissue is described after tryptic digestion. Enzymatic digestion protocols for different kinds of tissues--formalin fixed paraffin embedded (FFPE) and frozen tissues--are combined with MALDI-ion mobility mass spectrometry (IM-MS). This combination enables localization and identification of proteins via their related digested peptides. In a number of cases, ion mobility separates isobaric ions that cannot be identified by conventional MALDI time-of-flight (TOF) mass spectrometry. The amount of detected peaks per measurement increases (versus conventional MALDI-TOF), which enables mass and time selected ion images and the identification of separated ions. These experiments demonstrate the feasibility of direct proteins identification by ion-mobility-TOF IMS from tissue. The tissue digestion combined with MALDI-IM-TOF-IMS approach allows a proteomics "bottom-up" strategy with different kinds of tissue samples, especially FFPE tissues conserved for a long time in hospital sample banks. The combination of IM with IMS marks the development of IMS approaches as real proteomic tools, which brings new perspectives to biological studies.

  18. Shift reagents in ion mobility spectrometry: the effect of the number of interaction sites, size and interaction energies on the mobilities of valinol and ethanolamine.

    Science.gov (United States)

    Fernández-Maestre, Roberto; Meza-Morelos, Dairo; Wu, Ching

    2016-05-01

    Overlapping peaks interfere in ion mobility spectrometry (IMS), but they are separated introducing mobility shift reagents (SR) in the buffer gas forming adducts with different collision cross-sections (size). IMS separations using SR depend on the ion mobility shifts which are governed by adduct's size and interaction energies (stabilities). Mobility shifts of valinol and ethanolamine ions were measured by electrospray-ionization ion mobility-mass spectrometry (MS). Methyl-chloro propionate (M) was used as SR; 2-butanol (B) and nitrobenzene (N) were used for comparison. Density functional theory was used for calculations. B produced the smallest mobility shifts because of its small size. M and N have two strong interaction sites (oxygen atoms) and similar molecular mass, and they should produce similar shifts. For both ethanolamine and valinol ions, stabilities were larger for N adducts than those of M. With ethanolamine, M produced a 68% shift, large compared to that using N, 61%, because M has a third weak interaction site on the chlorine atom and, therefore, M has more interaction possibilities than N. This third site overrode the oxygen atoms' interaction energy that favored the adduction of ethanolamine with N over that with M. On the contrary, with valinol mobility shifts were larger with N than with M (21 vs 18%) because interaction energy favored even more adduction of valinol with N than with M; that is, the interaction energy difference between adducts of valinol with M and N was larger than that between those adducts with ethanolamine, and the third M interaction could not override this larger difference. Mobility shifts were explained based on the number of SR's interaction sites, size of ions and SR, and SR-ion interaction energies. This is the first time that the number of interaction sites is used to explain mobility shifts in SR-assisted IMS. Copyright © 2016 John Wiley & Sons, Ltd.

  19. IR-MALDI-LDI combined with ion mobility orthogonal time-of-flight mass spectrometry.

    Science.gov (United States)

    Woods, Amina S; Ugarov, Michael; Jackson, Shelley N; Egan, Thomas; Wang, Hay-Yan J; Murray, Kermit K; Schultz, J Albert

    2006-06-01

    Most MALDI instrumentation uses UV lasers. We have designed a MALDI-IM-oTOF-MS which employs both a Nd:YAG laser pumped optical parametric oscillator (OPOTEK, lambda = 2.8-3.2 microm at 20 Hz) to perform IR-LDI or IR-MALDI and a Nd:YLF laser (Crystalaser, lambda = 249 nm at 200 Hz) for the UV. Ion mobility (IM) gives a fast separation and analysis of biomolecules from complex mixtures in which ions of similar chemical type fall along well-defined "trend lines". Our data shows that ion mobility allows multiply charged monomers and multimers to be resolved; thus, yielding pure spectra of the singly charged protein ion which are virtually devoid of chemical noise. In addition, we have demonstrated that IR-LDI produced similar results as IR-MALDI for the direct tissue analysis of phospholipids from rat brain.

  20. Detection of Biological Materials Using Ion Mobility Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rodacy, P.J.; Sterling, J.P.; Butler, M.A.

    1999-03-01

    Traditionally, Ion Mobility Spectroscopy has been used to examine ions of relatively low molecular weight and high ion mobility. In recent years, however, biomolecules such as bradykinin, cytochrome c, bovine pancreatic trypsin inhibitor (BPTI), apomyoglobin, and lysozyme, have been successfully analyzed, but studies of whole bio-organisms have not been performed. In this study an attempt was made to detect and measure the mobility of two bacteriophages, {lambda}-phage and MS2 using electrospray methods to inject the viruses into the ion mobility spectrometer. Using data from Yeh, et al., which makes a comparison between the diameter of non-biologic particles and the specific particle mobility, the particle mobility for the MS2 virus was estimated to be 10{sup {minus}2} cm{sup 2}/volt-sec. From this mobility the drift time of these particles in our spectrometer was calculated to be approximately 65 msec. The particle mobility for the {lambda}-phage virus was estimated to be 10{sup {minus}3} cm{sup 2}/volt-sec. which would result in a drift time of 0.7 sec. Spectra showing the presence of a viral peak at the expected drift time were not observed. However, changes in the reactant ion peak that could be directly attributed to the presence of the viruses were observed. Virus clustering, excessive collisions, and the electrospray injection method limited the performance of this IMS. However, we believe that an instrument specifically designed to analyze such bioagents and utilizing other injection and ionization methods will succeed in directly detecting viruses and bacteria.

  1. Ion Mobility Spectrometer / Mass Spectrometer (IMS-MS).

    Energy Technology Data Exchange (ETDEWEB)

    Hunka, Deborah E; Austin, Daniel

    2005-10-01

    The use of Ion Mobility Spectrometry (IMS)in the Detection of Contraband Sandia researchers use ion mobility spectrometers for trace chemical detection and analysis in a variety of projects and applications. Products developed in recent years based on IMS-technology include explosives detection personnel portals, the Material Area Access (MAA) checkpoint of the future, an explosives detection vehicle portal, hand-held detection systems such as the Hound and Hound II (all 6400), micro-IMS sensors (1700), ordnance detection (2500), and Fourier Transform IMS technology (8700). The emphasis to date has been on explosives detection, but the detection of chemical agents has also been pursued (8100 and 6400).Combining Ion Mobility Spectrometry (IMS) with Mass Spectrometry (MS)The IMS-MS combination overcomes several limitations present in simple IMS systems. Ion mobility alone is insufficient to identify an unknown chemical agent. Collision cross section, upon which mobility is based, is not sufficiently unique or predictable a priori to be able to make a confident peak assignment unless the compounds present are already identified. Molecular mass, on the other hand, is much more readily interpreted and related to compounds. For a given compound, the molecular mass can be determined using a pocket calculator (or in one's head) while a reasonable value of the cross-section might require hours of computation time. Thus a mass spectrum provides chemical specificity and identity not accessible in the mobility spectrum alone. In addition, several advanced mass spectrometric methods, such as tandem MS, have been extensively developed for the purpose of molecular identification. With an appropriate mass spectrometer connected to an ion mobility spectrometer, these advanced identification methods become available, providing greater characterization capability.3 AcronymsIMSion mobility spectrometryMAAMaterial Access AreaMSmass spectrometryoaTOForthogonal acceleration time

  2. Direct classification of olive oils by using two types of ion mobility spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Garrido-Delgado, Rocio [Department of Analytical Chemistry, University of Cordoba, Annex C3 Building, Campus of Rabanales, E-14071 Cordoba (Spain); Mercader-Trejo, Flora [Department of Analytical Chemistry, University of Cordoba, Annex C3 Building, Campus of Rabanales, E-14071 Cordoba (Spain); Metrologia de Materiales, Centro Nacional de Metrologia, km. 4.5 Carretera a Los Cues, El Marques, Queretaro (Mexico); Sielemann, Stefanie; Bruyn, Wolfgang de [G.A.S. Gesellschaft fuer analytische Sensorsysteme mbH, BioMedizinZentrumDortmund, Otto-Hahn-Str. 15, 44227 Dortmund (Germany); Arce, Lourdes [Department of Analytical Chemistry, University of Cordoba, Annex C3 Building, Campus of Rabanales, E-14071 Cordoba (Spain); Valcarcel, Miguel, E-mail: qa1meobj@uco.es [Department of Analytical Chemistry, University of Cordoba, Annex C3 Building, Campus of Rabanales, E-14071 Cordoba (Spain)

    2011-06-24

    Graphical abstract: Highlights: > We explore the use of Ion Mobility Spectrometers for classification of olive oils. > Three types of olive oils were analyzed with both devices coupled to headspace system. > The ion mobility data were processed using chemometric to obtain global information. > The classification rate was better using tritium source and separation step prior IMS. - Abstract: In this work, we explored the use of an Ion Mobility Spectrometry (IMS) device with an ultraviolet (UV) source, and of a Gas Chromatographic (GC) column coupled to an IM Spectrometer with a tritium source, for the discrimination of three grades of olive oil, namely: extra virgin olive oil (EVOO), olive oil (OO) and pomace olive oil (POO). The three types of oil were analyzed with both equipment combinations as coupled to a headspace system and the obtained ion mobility data were consecutively processed with various chemometric tools. The classification rate for an independent validation set was 86.1% (confidence interval at 95% [83.4%, 88.5%]) with an UV-IMS and 100% (confidence interval at 95% [87%, 100%]) using a GC-IMS system. The classification rate was improved by using a more suitable ionization source and a pre-separation step prior to the IM analysis.

  3. Entropic electrokinetics: recirculation, particle separation, and negative mobility.

    Science.gov (United States)

    Malgaretti, Paolo; Pagonabarraga, Ignacio; Rubi, J Miguel

    2014-09-19

    We show that when particles are suspended in an electrolyte confined between corrugated charged surfaces, electrokinetic flows lead to a new set of phenomena such as particle separation, mixing for low-Reynolds micro- and nanometric devices, and negative mobility. Our analysis shows that such phenomena arise, for incompressible fluids, due to the interplay between the electrostatic double layer and the corrugated geometrical confinement and that they are magnified when the width of the channel is comparable to the Debye length. Our characterization allows us to understand the physical origin of such phenomena, therefore, shedding light on their possible relevance in a wide variety of situations ranging from nano- and microfluidic devices to biological systems.

  4. Determination of boron in silicates after ion exchange separation

    Science.gov (United States)

    Kramer, H.

    1955-01-01

    Existing methods for the determination of boron in silicates are not entirely satisfactory. Separation as the methyl ester is lengthy and frequently erratic. An accurate and rapid method applicable to glass, mineral, ore, and water samples uses ion exchange to remove interfering cations, and boron is determined titrimetrically in the presence of mannitol, using a pH meter to indicate the end point.

  5. Separation of americium from curium by oxidation and ion exchange.

    Science.gov (United States)

    Burns, Jonathan D; Shehee, Thomas C; Clearfield, Abraham; Hobbs, David T

    2012-08-21

    Nuclear energy has the potential to be a clean alternative to fossil fuels, but in order for it to play a major role in the US, many questions about the back end of the fuel cycle must be addressed. One of these questions is the difficult separation of americium from curium. Here, we report the oxidation of Am in two systems, perchloric acid and nitric acid and the affect of changing the acid has on the oxidation. K(d) values were observed and a direct separation factor was calculated and was seen to be as high as 20 for four metal(IV) pillared phosphate phosphonate inorganic organic hybrid ion exchange materials. These ion exchangers are characterized by very low selectivity for cations with low charge but extremely high uptake of ions of high charge.

  6. Ion mobility spectrometer / mass spectrometer (IMS-MS).

    Energy Technology Data Exchange (ETDEWEB)

    Hunka Deborah Elaine; Austin, Daniel E.

    2005-07-01

    The use of Ion Mobility Spectrometry (IMS) in the Detection of Contraband Sandia researchers use ion mobility spectrometers for trace chemical detection and analysis in a variety of projects and applications. Products developed in recent years based on IMS-technology include explosives detection personnel portals, the Material Area Access (MAA) checkpoint of the future, an explosives detection vehicle portal, hand-held detection systems such as the Hound and Hound II (all 6400), micro-IMS sensors (1700), ordnance detection (2500), and Fourier Transform IMS technology (8700). The emphasis to date has been on explosives detection, but the detection of chemical agents has also been pursued (8100 and 6400). Combining Ion Mobility Spectrometry (IMS) with Mass Spectrometry (MS) is described. The IMS-MS combination overcomes several limitations present in simple IMS systems. Ion mobility alone is insufficient to identify an unknown chemical agent. Collision cross section, upon which mobility is based, is not sufficiently unique or predictable a priori to be able to make a confident peak assignment unless the compounds present are already identified. Molecular mass, on the other hand, is much more readily interpreted and related to compounds. For a given compound, the molecular mass can be determined using a pocket calculator (or in one's head) while a reasonable value of the cross-section might require hours of computation time. Thus a mass spectrum provides chemical specificity and identity not accessible in the mobility spectrum alone. In addition, several advanced mass spectrometric methods, such as tandem MS, have been extensively developed for the purpose of molecular identification. With an appropriate mass spectrometer connected to an ion mobility spectrometer, these advanced identification methods become available, providing greater characterization capability.

  7. Ion chromatography for the separation of heparin and structurally related glycoaminoglycans: A review.

    Science.gov (United States)

    Fasciano, Jennifer M; Danielson, Neil D

    2016-03-01

    The global crisis resulting from adulterated heparin in late 2007 and early 2008 revived the importance of analytical techniques for the purity analysis of heparin products. The utilization of ion chromatography techniques for the separation, detection, and structural determination of heparin and structurally related glycoaminoglycans, including their corresponding oligosaccharides, has become increasingly important. This review summarizes the primary HPLC approaches, particularly strong anion exchange, weak ion exchange, and reversed-phase ion-pair, used for heparin purity analysis as well as structural characterization. Strong anion exchange HPLC has been studied most extensively and currently offers the best separation of crude heparin and heparin-like compounds. Weak anion exchange HPLC has been shown to provide shorter analysis times with lower salt concentrations in the mobile phase but is not as widely developed for the separation of all glycoaminoglycans of interest. Reversed-phase ion-pair HPLC offers fast and effective separations of oligosaccharides derived from glycoaminoglycans that can be coupled to mass spectrometry for structural analysis. However, this method generally does not provide sufficient retention of intact glycoaminoglycans.

  8. Separation processes in biotechnology. Ion-exchange processes.

    Science.gov (United States)

    Shuey, C D

    1990-01-01

    Through the use of several differentiating mechanisms, ion exchangers can separate ionic and nonionic materials, solutions containing only ionic species, and even completely nonionic mixtures. Although the mechanisms are distinct in their mode of operation, the resin characteristics that influence the results are largely the same. A practical understanding of the resin properties involved is all that is necessary to begin to use ion-exchange resins successfully. Ion exchange owes most of its history to water treatment, which has provided the economic and technological driving force in the past for the development of improved resins. However, specialty applications such as those in biotechnology are steadily becoming major factors in industry, perhaps not in shear volumes of resin used, but certainly in the value added by the process. The field of biotechnology no doubt holds many of the exciting new applications for ion exchange.

  9. Corona discharge ion mobility spectrometry at reduced pressures

    Science.gov (United States)

    Tabrizchi, Mahmoud; Rouholahnejad, Fereshteh

    2004-11-01

    Ion mobility spectrometers (IMSs) normally operate at ambient pressure. In this work an IMS cell has been designed and constructed to allow the pressure to be reduced inside the IMS cell. In this cell, corona discharge was employed as the ionization source. Reducing pressure affected both the discharge and the performance of the IMS. The discharge current was observed to increase with reducing pressure while the ignition potential decreased. The ion current received at the collector plate was also increased about 50 times when the pressure was reduced from ambient pressure to 15 Torr. The higher ion current can lead to an extended dynamic range. IMS spectra were recorded at various pressures and the results show that the drift times shift perfectly linear with pressure. This suggests that unlike temperature, pressure correction for ion mobility spectra is as simple as multiplying the drift times by a factor of 760/P.

  10. The dressed mobile atoms and ions

    CERN Document Server

    Amour, B; Guillot, L

    2005-01-01

    We consider free atoms and ions in $\\R^3$ interacting with the quantized electromagnetic field. Because of the translation invariance we consider the reduced hamiltonian associated with the total momentum. After introducing an ultraviolet cutoff we prove that the reduced hamiltonian for atoms has a ground state if the coupling constant and the total momentum are sufficiently small. In the case of ions an extra infrared regularization is needed. We also consider the case of the hydrogen atom in a constant magnetic field. Finally we determine the absolutely continuous spectrum of the reduced hamiltonian. \\end{abstract}

  11. Mesoporous Cladophora cellulose separators for lithium-ion batteries

    Science.gov (United States)

    Pan, Ruijun; Cheung, Ocean; Wang, Zhaohui; Tammela, Petter; Huo, Jinxing; Lindh, Jonas; Edström, Kristina; Strømme, Maria; Nyholm, Leif

    2016-07-01

    Much effort is currently made to develop inexpensive and renewable materials which can replace the polyolefin microporous separators conventionally used in contemporary lithium-ion batteries. In the present work, it is demonstrated that mesoporous Cladophora cellulose (CC) separators constitute very promising alternatives based on their high crystallinity, good thermal stability and straightforward manufacturing. The CC separators, which are fabricated using an undemanding paper-making like process involving vacuum filtration, have a typical thickness of about 35 μm, an average pore size of about 20 nm, a Young's modulus of 5.9 GPa and also exhibit an ionic conductivity of 0.4 mS cm-1 after soaking with 1 M LiPF6 EC: DEC (1/1, v/v) electrolyte. The CC separators are demonstrated to be thermally stable at 150 °C and electrochemically inert in the potential range between 0 and 5 V vs. Li+/Li. A LiFePO4/Li cell containing a CC separator showed good cycling stability with 99.5% discharge capacity retention after 50 cycles at a rate of 0.2 C. These results indicate that the renewable CC separators are well-suited for use in high-performance lithium-ion batteries.

  12. Thin layer chromatography-ion mobility spectrometry (TLC-IMS).

    Science.gov (United States)

    Ilbeigi, Vahideh; Tabrizchi, Mahmoud

    2015-01-06

    Ion mobility spectrometry (IMS) is a fast and sensitive analytical method which operates at the atmospheric pressure. To enhance the capability of IMS for the analysis of mixtures, it is often used with preseparation techniques, such as GC or HPLC. Here, we report for the first time the coupling of the thin-layer chromatography and IMS. A variety of coupling schemes were tried that included direct electrospray from the TLC strip tip, indirect electrospray from a needle connected to the TLC strip, introducing the moving solvent into the injection port, and, the simplest way, offline introduction of scratched or cut pieces of strips into the IMS injection port. In this study a special solvent tank was designed and the TLC strip was mounted horizontally where the solvent would flow down. A very small funnel right below the TLC tip collected the solvent and transferred it to a needle via a capillary tubing. Using the TLC-ESI-IMS technique, acceptable separations were achieved for two component mixtures of morphine-papaverine and acridine-papaverine. A special injection port was designed to host the pieces cut off the TLC. The method was successfully used to identify each spot on the TLC by IMS in a few seconds.

  13. Dividing to unveil protein microheterogeneities: traveling wave ion mobility study.

    Science.gov (United States)

    Halgand, F; Habchi, Johnny; Cravello, Laetitia; Martinho, Marlène; Guigliarelli, Bruno; Longhi, Sonia

    2011-10-01

    Overexpression of a protein in a foreign host is often the only route toward an exhaustive characterization, especially when purification from the natural source(s) is hardly achievable. The key issue in these studies relies on quality control of the purified recombinant protein to precisely determining its identity as well as any undesirable microheterogeneities. While standard proteomics approaches preclude unbiased search for modifications, the optional technique of top-down tandem mass spectrometry (MSMS) requires the use of highly accurate and highly resolved experiments to reveal subtle sequence modifications. In the present study, the top-down MSMS approach combined with traveling wave ion mobility (TWIM) separation was evaluated for its ability to achieve high sequence coverage and to reveal subtle microheterogeneities that were hitherto only accessible with Fourier-transform ion cyclotron resonance-MS instruments. The power of this approach is herein illustrated in an in-depth analysis of both the wild type and K496C variant of the recombinant X domain (XD; aa's 459-507) of the measles virus phosphoprotein expressed in Escherichia coli . Using top-down MSMS combined with TWIM, we show that XD samples occasionally exhibit a microheterogeneity that could not be anticipated from the nucleotide sequence of the encoding constructs and that likely reflects a genetic drift, neutral or not, occurring during expression. In addition, a 1-oxyl-2,2,5,5-tetramethyl-δ3-pyrroline-3-methyl methanethiosulfonate nitroxide probe that was grafted onto the K496C XD variant was shown to undergo oxidation and/or protonation in the electrospray ionization source, leading to artifactual mass increases.

  14. Isotopic separation by ion chromatography; La separation isotopique par chromatographie ionique

    Energy Technology Data Exchange (ETDEWEB)

    Albert, M.G.; Barre, Y.; Neige, R. [CEA Centre d`Etudes de la Vallee du Rhone, 26 - Pierrelatte (France). Dept. de Technologie de l`Enrichissement

    1994-12-31

    The isotopic exchange reaction and the isotopic separation factor are first recalled; the principles of ion chromatography applied to lithium isotope separation are then reviewed (displacement chromatography) and the process is modelled in the view of dimensioning and optimizing the industrial process; the various dimensioning parameters are the isotopic separation factor, the isotopic exchange kinetics and the material flow rate. Effects of the resin type and structure are presented. Dimensioning is also affected by physico-chemical and hydraulic parameters. Industrial implementation features are also discussed. 1 fig., 1 tab., 5 refs.

  15. Preorganized and Immobilized Ligands for Metal Ion Separations

    Energy Technology Data Exchange (ETDEWEB)

    Paine, Robert T. [Univ. of New Mexico, Albuquerque, NM (United States)

    2015-07-01

    The research project, in the period 2003-2015, was focused on the discovery of fundamental new principles in f-element ion coordination chemistry and the application of the new knowledge to the development of advanced detection/separations reagents and methods for these ions. The findings relate to the Nation's efforts to safely and efficiently process nuclear materials. In addition, the project provided training for young scientists needed to maintain the Nation's preeminence in nuclear science.

  16. Travelling-wave ion mobility mass spectrometry and negative ion fragmentation of hybrid and complex N-glycans.

    Science.gov (United States)

    Harvey, David J; Scarff, Charlotte A; Edgeworth, Matthew; Pagel, Kevin; Thalassinos, Konstantinos; Struwe, Weston B; Crispin, Max; Scrivens, James H

    2016-11-01

    Nitrogen collisional cross sections (CCSs) of hybrid and complex glycans released from the glycoproteins IgG, gp120 (from human immunodeficiency virus), ovalbumin, α1-acid glycoprotein and thyroglobulin were measured with a travelling-wave ion mobility mass spectrometer using dextran as the calibrant. The utility of this instrument for isomer separation was also investigated. Some isomers, such as Man3 GlcNAc3 from chicken ovalbumin and Man3 GlcNAc3 Fuc1 from thyroglobulin could be partially resolved and identified by their negative ion fragmentation spectra obtained by collision-induced decomposition (CID). Several other larger glycans, however, although existing as isomers, produced only asymmetric rather than separated arrival time distributions (ATDs). Nevertheless, in these cases, isomers could often be detected by plotting extracted fragment ATDs of diagnostic fragment ions from the negative ion CID spectra obtained in the transfer cell of the Waters Synapt mass spectrometer. Coincidence in the drift times of all fragment ions with an asymmetric ATD profile in this work, and in the related earlier paper on high-mannose glycans, usually suggested that separations were because of conformers or anomers, whereas symmetrical ATDs of fragments showing differences in drift times indicated isomer separation. Although some significant differences in CCSs were found for the smaller isomeric glycans, the differences found for the larger compounds were usually too small to be analytically useful. Possible correlations between CCSs and structural types were also investigated, and it was found that complex glycans tended to have slightly smaller CCSs than high-mannose glycans of comparable molecular weight. In addition, biantennary glycans containing a core fucose and/or a bisecting GlcNAc residue fell on different mobility-m/z trend lines to those glycans not so substituted with both of these substituents contributing to larger CCSs. Copyright © 2016 John Wiley & Sons

  17. T-wave ion mobility-mass spectrometry: basic experimental procedures for protein complex analysis.

    Science.gov (United States)

    Michaelevski, Izhak; Kirshenbaum, Noam; Sharon, Michal

    2010-07-31

    Ion mobility (IM) is a method that measures the time taken for an ion to travel through a pressurized cell under the influence of a weak electric field. The speed by which the ions traverse the drift region depends on their size: large ions will experience a greater number of collisions with the background inert gas (usually N(2;)) and thus travel more slowly through the IM device than those ions that comprise a smaller cross-section. In general, the time it takes for the ions to migrate though the dense gas phase separates them, according to their collision cross-section (Omega). Recently, IM spectrometry was coupled with mass spectrometry and a traveling-wave (T-wave) Synapt ion mobility mass spectrometer (IM-MS) was released. Integrating mass spectrometry with ion mobility enables an extra dimension of sample separation and definition, yielding a three-dimensional spectrum (mass to charge, intensity, and drift time). This separation technique allows the spectral overlap to decrease, and enables resolution of heterogeneous complexes with very similar mass, or mass-to-charge ratios, but different drift times. Moreover, the drift time measurements provide an important layer of structural information, as Omega is related to the overall shape and topology of the ion. The correlation between the measured drift time values and Omega is calculated using a calibration curve generated from calibrant proteins with defined cross-sections(1). The power of the IM-MS approach lies in its ability to define the subunit packing and overall shape of protein assemblies at micromolar concentrations, and near-physiological conditions(1). Several recent IM studies of both individual proteins(2,3) and non-covalent protein complexes(4-9), successfully demonstrated that protein quaternary structure is maintained in the gas phase, and highlighted the potential of this approach in the study of protein assemblies of unknown geometry. Here, we provide a detailed description of IMS

  18. Factors influencing the separation of oligonucleotides using reversed-phase/ion-exchange mixed-mode high performance liquid chromatography columns.

    Science.gov (United States)

    Biba, Mirlinda; Jiang, Eileen; Mao, Bing; Zewge, Daniel; Foley, Joe P; Welch, Christopher J

    2013-08-23

    New mixed-mode columns consisting of reversed-phase and ion-exchange separation modes were evaluated for the analysis of short RNA oligonucleotides (∼20mers). Conventional analysis for these samples typically involves using two complementary methods: strong anion-exchange liquid chromatography (SAX-LC) for separation based on charge, and ion-pair reversed-phase liquid chromatography (IP-RPLC) for separation based on hydrophobicity. Recently introduced mixed-mode high performance liquid chromatography (HPLC) columns combine both reversed-phase and ion-exchange modes, potentially offering a simpler analysis by combining the benefits of both separation modes into a single method. Analysis of a variety of RNA oligonucleotide samples using three different mixed-mode stationary phases showed some distinct benefits for oligonucleotide separation and analysis. When using these mixed-mode columns with typical IP-RPLC mobile phase conditions, such as ammonium acetate or triethylammonium acetate as the primary ion-pair reagent, the separation was mainly based on the IP-RPLC mode. However, when changing the mobile phase conditions to those more typical for SAX-LC, such as salt gradients with NaCl or NaBr, very different separation patterns were observed due to mixed-mode interactions. In addition, the Scherzo SW-C18 and SM-C18 columns with sodium chloride or sodium bromide salt gradients also showed significant improvements in peak shape.

  19. Combined ICR heating antenna for ion separation systems

    Energy Technology Data Exchange (ETDEWEB)

    Timofeev, A. V. [Russian Research Centre Kurchatov Institute (Russian Federation)

    2011-01-15

    A combination of one- and two-wave antennas (one and two turns of conductors around a plasma cylinder, respectively) is proposed. This combined antenna localizes an RF field within itself. It is shown that spent nuclear fuel processing systems based on ICR heating of nuclear ash by such a combined antenna have high productivity. A theory of the RF field excitation in ICR ion separation systems is presented in a simple and compact form.

  20. MINOR ACTINIDE SEPARATIONS USING ION EXCHANGERS OR IONIC LIQUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.; Visser, A.; Bridges, N.

    2011-09-20

    This project seeks to determine if (1) inorganic-based ion exchange materials or (2) electrochemical methods in ionic liquids can be exploited to provide effective Am and Cm separations. Specifically, we seek to understand the fundamental structural and chemical factors responsible for the selectivity of inorganic-based ion-exchange materials for actinide and lanthanide ions. Furthermore, we seek to determine whether ionic liquids can serve as the electrolyte that would enable formation of higher oxidation states of Am and other actinides. Experiments indicated that pH, presence of complexants and Am oxidation state exhibit significant influence on the uptake of actinides and lanthanides by layered sodium titanate and hybrid zirconium and tin phosphonate ion exchangers. The affinity of the ion exchangers increased with increasing pH. Greater selectivity among Ln(III) ions with sodium titanate materials occurs at a pH close to the isoelectric potential of the ion exchanger. The addition of DTPA decreased uptake of Am and Ln, whereas the addition of TPEN generally increases uptake of Am and Ln ions by sodium titanate. Testing confirmed two different methods for producing Am(IV) by oxidation of Am(III) in ionic liquids (ILs). Experimental results suggest that the unique coordination environment of ionic liquids inhibits the direct electrochemical oxidation of Am(III). The non-coordinating environment increases the oxidation potential to a higher value, while making it difficult to remove the inner coordination of water. Both confirmed cases of Am(IV) were from the in-situ formation of strong chemical oxidizers.

  1. Utilizing Ion-Mobility Data to Estimate Molecular Masses

    Science.gov (United States)

    Duong, Tuan; Kanik, Isik

    2008-01-01

    A method is being developed for utilizing readings of an ion-mobility spectrometer (IMS) to estimate molecular masses of ions that have passed through the spectrometer. The method involves the use of (1) some feature-based descriptors of structures of molecules of interest and (2) reduced ion mobilities calculated from IMS readings as inputs to (3) a neural network. This development is part of a larger effort to enable the use of IMSs as relatively inexpensive, robust, lightweight instruments to identify, via molecular masses, individual compounds or groups of compounds (especially organic compounds) that may be present in specific environments or samples. Potential applications include detection of organic molecules as signs of life on remote planets, modeling and detection of biochemicals of interest in the pharmaceutical and agricultural industries, and detection of chemical and biological hazards in industrial, homeland-security, and industrial settings.

  2. The Leuven isotope separator on-line laser ion source

    CERN Document Server

    Kudryavtsev, Y; Franchoo, S; Huyse, M; Gentens, J; Kruglov, K; Müller, W F; Prasad, N V S; Raabe, R; Reusen, I; Van den Bergh, P; Van Duppen, P; Van Roosbroeck, J; Vermeeren, L; Weissman, L

    2002-01-01

    An element-selective laser ion source has been used to produce beams of exotic radioactive nuclei and to study their decay properties. The operational principle of the ion source is based on selective resonant laser ionization of nuclear reaction products thermalized and neutralized in a noble gas at high pressure. The ion source has been installed at the Leuven Isotope Separator On-Line (LISOL), which is coupled on-line to the cyclotron accelerator at Louvain-la-Neuve. sup 5 sup 4 sup , sup 5 sup 5 Ni and sup 5 sup 4 sup , sup 5 sup 5 Co isotopes were produced in light-ion-induced fusion reactions. Exotic nickel, cobalt and copper nuclei were produced in proton-induced fission of sup 2 sup 3 sup 8 U. The b decay of the sup 6 sup 8 sup - sup 7 sup 4 Ni, sup 6 sup 7 sup - sup 7 sup 0 Co, sup 7 sup 0 sup - sup 7 sup 5 Cu and sup 1 sup 1 sup 0 sup - sup 1 sup 1 sup 4 Rh isotopes has been studied by means of beta-gamma and gamma-gamma spectroscopy. Recently, the laser ion source has been used to produce neutron-d...

  3. Biomedical applications of ion mobility-enhanced data-independent acquisition-based label-free quantitative proteomics.

    Science.gov (United States)

    Distler, Ute; Kuharev, Jörg; Tenzer, Stefan

    2014-12-01

    Mass spectrometry-based proteomics greatly benefited from recent improvements in instrument performance and the development of bioinformatics solutions facilitating the high-throughput quantification of proteins in complex biological samples. In addition to quantification approaches using stable isotope labeling, label-free quantification has emerged as the method of choice for many laboratories. Over the last years, data-independent acquisition approaches have gained increasing popularity. The integration of ion mobility separation into commercial instruments enabled researchers to achieve deep proteome coverage from limiting sample amounts. Additionally, ion mobility provides a new dimension of separation for the quantitative assessment of complex proteomes, facilitating precise label-free quantification even of highly complex samples. The present work provides a thorough overview of the combination of ion mobility and data-independent acquisition-based label-free quantification LC-MS and its applications in biomedical research.

  4. Polymers for Traveling Wave Ion Mobility Spectrometry Calibration

    Science.gov (United States)

    Duez, Quentin; Chirot, Fabien; Liénard, Romain; Josse, Thomas; Choi, ChangMin; Coulembier, Olivier; Dugourd, Philippe; Cornil, Jérôme; Gerbaux, Pascal; De Winter, Julien

    2017-07-01

    One of the main issues when using traveling wave ion mobility spectrometry (TWIMS) for the determination of collisional cross-section (CCS) concerns the need for a robust calibration procedure built from referent ions of known CCS. Here, we implement synthetic polymer ions as CCS calibrants in positive ion mode. Based on their intrinsic polydispersities, polymers offer in a single sample the opportunity to generate, upon electrospray ionization, numerous ions covering a broad mass range and a large CCS window for different charge states at a time. In addition, the key advantage of polymer ions as CCS calibrants lies in the robustness of their gas-phase structure with respect to the instrumental conditions, making them less prone to collisional-induced unfolding (CIU) than protein ions. In this paper, we present a CCS calibration procedure using sodium cationized polylactide and polyethylene glycol, PLA and PEG, as calibrants with reference CCS determined on a home-made drift tube. Our calibration procedure is further validated by testing the polymer calibration to determine CCS of numerous different ions for which CCS are reported in the literature. [Figure not available: see fulltext.

  5. Micro faraday-element array detector for ion mobility spectroscopy

    Science.gov (United States)

    Gresham, Christopher A.; Rodacy, Phillip J.; Denton, M. Bonner; Sperline, Roger

    2004-10-26

    An ion mobility spectrometer includes a drift tube having a collecting surface covering a collecting area at one end of the tube. The surface comprises a plurality of closely spaced conductive elements on a non-conductive substrate, each conductive element being electrically insulated from each other element. A plurality of capacitive transimpedance amplifiers (CTIA) adjacent the collecting surface are electrically connected to the plurality of elements, so charge from an ion striking an element is transferred to the capacitor of the connected CTIA. A controller counts the charge on the capacitors over a period of time.

  6. Advancing the High Throughput Identification of Liver Fibrosis Protein Signatures Using Multiplexed Ion Mobility Spectrometry*

    Science.gov (United States)

    Baker, Erin Shammel; Burnum-Johnson, Kristin E.; Jacobs, Jon M.; Diamond, Deborah L.; Brown, Roslyn N.; Ibrahim, Yehia M.; Orton, Daniel J.; Piehowski, Paul D.; Purdy, David E.; Moore, Ronald J.; Danielson, William F.; Monroe, Matthew E.; Crowell, Kevin L.; Slysz, Gordon W.; Gritsenko, Marina A.; Sandoval, John D.; LaMarche, Brian L.; Matzke, Melissa M.; Webb-Robertson, Bobbie-Jo M.; Simons, Brenna C.; McMahon, Brian J.; Bhattacharya, Renuka; Perkins, James D.; Carithers, Robert L.; Strom, Susan; Self, Steven G.; Katze, Michael G.; Anderson, Gordon A.; Smith, Richard D.

    2014-01-01

    Rapid diagnosis of disease states using less invasive, safer, and more clinically acceptable approaches than presently employed is a crucial direction for the field of medicine. While MS-based proteomics approaches have attempted to meet these objectives, challenges such as the enormous dynamic range of protein concentrations in clinically relevant biofluid samples coupled with the need to address human biodiversity have slowed their employment. Herein, we report on the use of a new instrumental platform that addresses these challenges by coupling technical advances in rapid gas phase multiplexed ion mobility spectrometry separations with liquid chromatography and MS to dramatically increase measurement sensitivity and throughput, further enabling future high throughput MS-based clinical applications. An initial application of the liquid chromatography - ion mobility spectrometry-MS platform analyzing blood serum samples from 60 postliver transplant patients with recurrent fibrosis progression and 60 nontransplant patients illustrates its potential utility for disease characterization. PMID:24403597

  7. Advancing the high throughput identification of liver fibrosis protein signatures using multiplexed ion mobility spectrometry.

    Science.gov (United States)

    Baker, Erin Shammel; Burnum-Johnson, Kristin E; Jacobs, Jon M; Diamond, Deborah L; Brown, Roslyn N; Ibrahim, Yehia M; Orton, Daniel J; Piehowski, Paul D; Purdy, David E; Moore, Ronald J; Danielson, William F; Monroe, Matthew E; Crowell, Kevin L; Slysz, Gordon W; Gritsenko, Marina A; Sandoval, John D; Lamarche, Brian L; Matzke, Melissa M; Webb-Robertson, Bobbie-Jo M; Simons, Brenna C; McMahon, Brian J; Bhattacharya, Renuka; Perkins, James D; Carithers, Robert L; Strom, Susan; Self, Steven G; Katze, Michael G; Anderson, Gordon A; Smith, Richard D

    2014-04-01

    Rapid diagnosis of disease states using less invasive, safer, and more clinically acceptable approaches than presently employed is a crucial direction for the field of medicine. While MS-based proteomics approaches have attempted to meet these objectives, challenges such as the enormous dynamic range of protein concentrations in clinically relevant biofluid samples coupled with the need to address human biodiversity have slowed their employment. Herein, we report on the use of a new instrumental platform that addresses these challenges by coupling technical advances in rapid gas phase multiplexed ion mobility spectrometry separations with liquid chromatography and MS to dramatically increase measurement sensitivity and throughput, further enabling future high throughput MS-based clinical applications. An initial application of the liquid chromatography--ion mobility spectrometry-MS platform analyzing blood serum samples from 60 postliver transplant patients with recurrent fibrosis progression and 60 nontransplant patients illustrates its potential utility for disease characterization.

  8. Experimental simulation of negative ion chemistry in Martian atmosphere using ion mobility spectrometry-mass spectrometry

    Science.gov (United States)

    Sabo, Martin; Lichvanová, Zuzana; Orszagh, Juraj; Mason, Nigel; Matejčík, Štefan

    2014-08-01

    We have studied the formation of negative ions in a negative Corona Discharge (CD) fed by CO2/N2 mixtures (with 0, 2, 4, 6, 8, 10% N2) using the technique of ion mobility spectrometry-orthogonal acceleration time of flight mass spectrometry (IMS-oaTOF). The composition of the negative ions was found to be dependent on the initial gas composition, the gas flow regime, the concentrations of neutral reactive species formed in the discharge and the trace amounts on water in the gases were found to play an important role in the negative ions formation. In a pure CO2 discharge operating under standard gas flow conditions of IMS (associated with strong interaction of ions with neutral reactive species formed in discharge) the ions CO3 - (H2O) and CO4 -(H2O) dominated the measured negative ion spectrum while in CO2/N2 mixtures NO3 -(H2O) n , NO3 -(HNO3) ( n = 0, 1) ions prevailed. In the case of reverse gas flow regime (low interaction of ions with neutral reactive species formed in discharge), the negative ions detected were O2 -(H2O) n , and O2 -.CO2(H2O) n both in pure CO2 and N2/CO2 mixtures. The spectra of negative ions recorded for a gas mixture containing 4% N2 in CO2 were compared with theoretical predictions of negative ion composition in the lower atmosphere of Mars.

  9. Evaluation of ion mobility-mass spectrometry for determining the isomeric heterogeneity of oligosaccharide-alditols derived from bovine submaxillary mucin.

    Science.gov (United States)

    Li, Hongli; Bendiak, Brad; Kaplan, Kimberly; Davis, Eric; Siems, William F; Hill, Herbert H

    2013-10-15

    Rapid separation and independent analysis of isomeric species are needed for the structural characterization of carbohydrates in glycomics research. Ion mobility-mass spectrometry techniques were used to examine a series of isomeric neutral oligosaccharide-alditols derived from bovine submaxillary mucin. Several analytical techniques were employed: (1) off line separation of the oligosaccharide-alditol mixture by HPLC; (2) direct and rapid evaluation of isomeric heterogeneity of oligosaccharides by electrospray ionization-ion mobility-time of flight mass spectrometry; and (3) mobility-selected MS(2) and MS(3) to evaluate isomeric mobility peaks by dual gate ion mobility-tandem mass spectrometry. Multiple isomeric ion mobility peaks were observed for the majority of oligosaccharide-alditols, which was achieved on the millisecond time scale after LC separation. Fragmentation spectra obtained from the collision-induced dissociation of isomeric precursor ions could be essentially identical, or dramatically different for a given precursor m/z using the dual-gate ion mobility quadrupole ion trap mass spectrometer. This further confirmed the need for rapid physical resolution of isomeric precursor species prior to their tandem mass spectral analysis.

  10. Ion mobility and transport barriers in the tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, H.; Hazeltine, R.D.; Valanju, P.M. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies; Zhang, Y.Z. [International Centre for Theoretical Physics, Trieste (Italy)

    1993-06-01

    The character of charged particle motion in an axisymmetric toroidal system with a constant radial electric field is investigated both analytically and numerically. Ion radial mobility caused by the combined effects of the radial electric field and charge exchange is found. A simple moment argument in the banana regime matches the simulation results well. Relation of present work and high confinement (H-mode) experiment is also discussed.

  11. Separation of Aliphatic and Aromatic Carboxylic Acids by Conventional and Ultra High Performance Ion Exclusion Chromatography.

    Science.gov (United States)

    Mansour, Fotouh R; Kirkpatrick, Christine L; Danielson, Neil D

    2013-06-01

    An ion exclusion chromatography (IELC) comparison between a conventional ion exchange column and an ultra-high performance liquid chromatography (UHPLC) dynamically surfactant modified C18 column for the separation of an aliphatic carboxylic acid and two aromatic carboxylic acids is presented. Professional software is used to optimize the conventional IELC separation conditions for acetylsalicylic acid and the hydrolysis products: salicylic acid and acetic acid. Four different variables are simultaneously optimized including H2SO4 concentration, pH, flow rate, and sample injection volume. Thirty different runs are suggested by the software. The resolutions and the time of each run are calculated and feed back to the software to predict the optimum conditions. Derringer's desirability functions are used to evaluate the test conditions and those with the highest desirability value are utilized to separate acetylsalicylic acid, salicylic acid, and acetic acid. These conditions include using a 0.35 mM H2SO4 (pH 3.93) eluent at a flow rate of 1 mL min(-1) and an injection volume of 72 μL. To decrease the run time and improve the performance, a UHPLC C18 column is used after dynamic modification with sodium dodecyl sulfate. Using pure water as a mobile phase, a shorter analysis time and better resolution are achieved. In addition, the elution order is different from the IELC method which indicates the contribution of the reversed-phase mode to the separation mechanism.

  12. Ion mobility derived collision cross sections to support metabolomics applications.

    Science.gov (United States)

    Paglia, Giuseppe; Williams, Jonathan P; Menikarachchi, Lochana; Thompson, J Will; Tyldesley-Worster, Richard; Halldórsson, Skarphédinn; Rolfsson, Ottar; Moseley, Arthur; Grant, David; Langridge, James; Palsson, Bernhard O; Astarita, Giuseppe

    2014-04-15

    Metabolomics is a rapidly evolving analytical approach in life and health sciences. The structural elucidation of the metabolites of interest remains a major analytical challenge in the metabolomics workflow. Here, we investigate the use of ion mobility as a tool to aid metabolite identification. Ion mobility allows for the measurement of the rotationally averaged collision cross-section (CCS), which gives information about the ionic shape of a molecule in the gas phase. We measured the CCSs of 125 common metabolites using traveling-wave ion mobility-mass spectrometry (TW-IM-MS). CCS measurements were highly reproducible on instruments located in three independent laboratories (RSD red blood cells using ultra performance liquid chromatography (UPLC) coupled with TW-IM-MS. The mean RSD was cells, an in vitro model used to study cancer development. Experimentally determined and computationally derived CCS values were used as orthogonal analytical parameters in combination with retention time and accurate mass information to confirm the identity of key metabolites potentially involved in cancer. Thus, our results indicate that adding CCS data to searchable databases and to routine metabolomics workflows will increase the identification confidence compared to traditional analytical approaches.

  13. Lifetimes and stabilities of familiar explosive molecular adduct complexes during ion mobility measurements.

    Science.gov (United States)

    McKenzie-Coe, Alan; DeBord, John Daniel; Ridgeway, Mark; Park, Melvin; Eiceman, Gary; Fernandez-Lima, Francisco

    2015-08-21

    Trapped ion mobility spectrometry coupled to mass spectrometry (TIMS-MS) was utilized for the separation and identification of familiar explosives in complex mixtures. For the first time, molecular adduct complex lifetimes, relative stability, binding energies and candidate structures are reported for familiar explosives. Experimental and theoretical results showed that the adduct size and reactivity, complex binding energy and the explosive structure tailor the stability of the molecular adduct complex. The flexibility of TIMS to adapt the mobility separation as a function of the molecular adduct complex stability (i.e., short or long IMS experiments/low or high IMS resolution) permits targeted measurements of explosives in complex mixtures with high confidence levels.

  14. Separation of basic oligopeptides by ion-pairing reversed-phase chromatography

    Science.gov (United States)

    Xie, Wenchun

    The present thesis consist of five chapters. Chapter I introduces background information on the ion-pairing reversed-phase chromatography and liquid chromatography in the critical condition. Chapter II decribes our study on the isocratic separation of oligolysine (dp = 2 to 8) using a fixed content of acetonitrile (ACN) (23%) and different concentrations of HFBA in the mobile phase (0.6-30.6 mM) on a Waters XBridge Shield RP18® column. We found that the retention time of oligolysine increases as the dp increases, because of an increased number of HFBA bound to the peptides. Furthermore, when [HFBA] increased, the retention time increased at different rates. The greater the dp, the faster the rate. Based on a closed pairing model that presumes an equilibrium between an unpaired state and the paired state with a fixed number of HFBA molecules, an equation was derived for the retention factor of oligolysine. In Chapter III, we compare retention behaviors of oligolysine (dp = 2 to 8) and oligoarginine (dp = 2 to 8) when they are separated on the Waters XBridge Shield RP18® using fixed a ACN content (23%) and difference concentrations of HFBA (0.4-30.6 mM) in the mobile phase. The retention time of oligoarginine also increased at different rates as [HFBA] increased. The greater the dp, the faster the rate. The retention time of oligolysine is shorter than that of oligarginine having the dame dp. We applied Eq.1 to analyze the plot of ln k as a function of [HFBA] for each oligopeptide component to obtain the values for n, Kip,m, and βKd,ip. For oligolysine, n increases linearly as dp increase and oligoarginine exhibits an accelerated increase in n as dp rises. The plot of ln βKd,ip against dp followed a linear relationship for both peptides. In Chapter IV, we study the effect of mobile phase composition on the retention of oligolysine (dp = 2 to 8) on the Waters XBridge Shield RP18 ®. The ACN content was changed from 20% to 33% and the HFBA concentration from 0.7 to

  15. The selective separation of Cs and Sr ion on the inorganic ion-exchanger zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hun Hwee; Min, Byeog Heon [Hoseo University, Taegu (Korea)

    1998-04-01

    This study shows the selective separation of Cs and Sr ion on the inorganic ion-exchanger zeolites such as clinoptilolite, Y-type CBV760, CBV780 and A-type 3A. The selective separation of Cs and Sr on these zeolites was examined using batch and continuous column experiments. For the selective separation of Cs and Sr from a synthetic wastewater, adsorption rate of Cs increased in the order, clinoptilolite> 3A>> CBV760> CBV780, adsorption rate of Sr increased in the other, 3A>> clinoptilolite> CBV760> CBV780. For the clinoptilolite, the adsorption rate of Cs reached about 96 {approx} 98% within 3h. The adsorption rate of Sr on 3A reached about 99% within 3h. (author). 40 refs., 27 figs., 4 tabs.

  16. Dynamic multiplexed analysis method using ion mobility spectrometer

    Science.gov (United States)

    Belov, Mikhail E [Richland, WA

    2010-05-18

    A method for multiplexed analysis using ion mobility spectrometer in which the effectiveness and efficiency of the multiplexed method is optimized by automatically adjusting rates of passage of analyte materials through an IMS drift tube during operation of the system. This automatic adjustment is performed by the IMS instrument itself after determining the appropriate levels of adjustment according to the method of the present invention. In one example, the adjustment of the rates of passage for these materials is determined by quantifying the total number of analyte molecules delivered to the ion trap in a preselected period of time, comparing this number to the charge capacity of the ion trap, selecting a gate opening sequence; and implementing the selected gate opening sequence to obtain a preselected rate of analytes within said IMS drift tube.

  17. Separation of seven arsenic species by ion-pair and ion-exchange high performance liquid chromatography

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Hansen, Sven Hedegaard

    1992-01-01

    Arsenite, arsenate, monomethylarsonate, dimethylarsinate, arsenobetaine, arsenocholine and the tetramethylarsonium ion were subjected to ion-exchange and ion-pair reversed phase HPLC. The ion exchange method was superior in selectivity and time of analysis for the arsenic anions. The ammonium ions...... used for the ion-pair method only resulted in separation of some of the anionic arsenic compounds. Flame atomic absorption spectrometry was used for on-line arsenic-specific detection....

  18. Serpentine Ultralong Path with Extended Routing (SUPER) High Resolution Traveling Wave Ion Mobility-MS using Structures for Lossless Ion Manipulations.

    Science.gov (United States)

    Deng, Liulin; Webb, Ian K; Garimella, Sandilya V B; Hamid, Ahmed M; Zheng, Xueyun; Norheim, Randolph V; Prost, Spencer A; Anderson, Gordon A; Sandoval, Jeremy A; Baker, Erin S; Ibrahim, Yehia M; Smith, Richard D

    2017-04-18

    Ion mobility (IM) separations have a broad range of analytical applications, but insufficient resolution often limits their utility. Here, we report on ion mobility separations in a structures for lossless ion manipulations (SLIM) serpentine ultralong path with extended routing (SUPER) traveling wave (TW) ion mobility (IM) module in conjunction with mass spectrometry (MS). Ions were confined in the SLIM by rf fields in conjunction with a DC guard bias, enabling essentially lossless TW transmission over greatly extended paths. The extended routing utilized multiple passes (e.g., ∼1094 m over 81 passes through the 13.5 m serpentine path) and was facilitated by the introduction of a lossless ion switch that allowed ions to be directed to either the MS detector or for another pass through the serpentine separation region, allowing theoretically unlimited IM path lengths. The multipass SUPER IM-MS provided resolution approximately proportional to the square root of the number of passes (or total path length). More than 30-fold higher IM resolution (∼340 vs ∼10) for Agilent tuning mix m/z 622 and 922 ions was achieved for 40 passes compared to commercially available drift tube IM and other TWIM-based platforms. An initial evaluation of the isomeric sugars lacto-N-hexaose and lacto-N-neohexaose showed the isomeric structures to be baseline resolved, and a new conformational feature for lacto-N-neohexaose was revealed after 9 passes. The new SLIM SUPER high resolution TWIM platform has broad utility in conjunction with MS and is expected to enable a broad range of previously challenging or intractable separations.

  19. Prediction of peptide drift time in ion mobility mass spectrometry from sequence-based features

    KAUST Repository

    Wang, Bing

    2013-05-09

    Background: Ion mobility-mass spectrometry (IMMS), an analytical technique which combines the features of ion mobility spectrometry (IMS) and mass spectrometry (MS), can rapidly separates ions on a millisecond time-scale. IMMS becomes a powerful tool to analyzing complex mixtures, especially for the analysis of peptides in proteomics. The high-throughput nature of this technique provides a challenge for the identification of peptides in complex biological samples. As an important parameter, peptide drift time can be used for enhancing downstream data analysis in IMMS-based proteomics.Results: In this paper, a model is presented based on least square support vectors regression (LS-SVR) method to predict peptide ion drift time in IMMS from the sequence-based features of peptide. Four descriptors were extracted from peptide sequence to represent peptide ions by a 34-component vector. The parameters of LS-SVR were selected by a grid searching strategy, and a 10-fold cross-validation approach was employed for the model training and testing. Our proposed method was tested on three datasets with different charge states. The high prediction performance achieve demonstrate the effectiveness and efficiency of the prediction model.Conclusions: Our proposed LS-SVR model can predict peptide drift time from sequence information in relative high prediction accuracy by a test on a dataset of 595 peptides. This work can enhance the confidence of protein identification by combining with current protein searching techniques. 2013 Wang et al.; licensee BioMed Central Ltd.

  20. Nonlinear wavelet compression of ion mobility spectra from ion mobility spectrometers mounted in an unmanned aerial vehicle.

    Science.gov (United States)

    Cao, Libo; Harrington, Peter de B; Harden, Charles S; McHugh, Vincent M; Thomas, Martin A

    2004-02-15

    Linear and nonlinear wavelet compression of ion mobility spectrometry (IMS) data are compared and evaluated. IMS provides low detection limits and rapid response for many compounds. Nonlinear wavelet compression of ion mobility spectra reduced the data to 4-5% of its original size, while eliminating artifacts in the reconstructed spectra that occur with linear compression, and the root-mean-square reconstruction error was 0.17-0.20% of the maximum intensity of the uncompressed spectra. Furthermore, nonlinear wavelet compression precisely preserves the peak location (i.e., drift time). Small variations in peak location may occur in the reconstructed spectra that were linearly compressed. A method was developed and evaluated for optimizing the compression. The compression method was evaluated with in-flight data recorded from ion mobility spectrometers mounted in an unmanned aerial vehicle (UAV). Plumes of dimethyl methylphosphonate were disseminated for interrogation by the UAV-mounted IMS system. The daublet 8 wavelet filter exhibited the best performance for these evaluations.

  1. Separator-Integrated, Reversely Connectable Symmetric Lithium-Ion Battery.

    Science.gov (United States)

    Wang, Yuhang; Zeng, Jiren; Cui, Xiaoqi; Zhang, Lijuan; Zheng, Gengfeng

    2016-02-24

    A separator-integrated, reversely connectable, symmetric lithium-ion battery is developed based on carbon-coated Li3V2(PO4)3 nanoparticles and polyvinylidene fluoride-treated separators. The Li3V2(PO4)3 nanoparticles are synthesized via a facile solution route followed by calcination in Ar/H2 atmosphere. Sucrose solution is used as the carbon source for uniform carbon coating on the Li3V2(PO4)3 nanoparticles. Both the carbon and the polyvinylidene fluoride treatments substantially improve the cycling life of the symmetric battery by preventing the dissolution and shuttle of the electroactive Li3V2(PO4)3. The obtained symmetric full cell exhibits a reversible capacity of ≈ 87 mA h g(-1), good cycling stability, and capacity retention of ≈ 70% after 70 cycles. In addition, this type of symmetric full cell can be operated in both forward and reverse connection modes, without any influence on the cycling of the battery. Furthermore, a new separator integration approach is demonstrated, which enables the direct deposition of electroactive materials for the battery assembly and does not affect the electrochemical performance. A 10-tandem-cell battery assembled without differentiating the electrode polarity exhibits a low thickness of ≈ 4.8 mm and a high output voltage of 20.8 V. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. External Second Gate-Fourier Transform Ion Mobility Spectrometry.

    Energy Technology Data Exchange (ETDEWEB)

    Tarver, Edward E., III

    2005-01-01

    Ion mobility spectrometry (IMS) is recognized as one of the most sensitive and versatile techniques for the detection of trace levels of organic vapors. IMS is widely used for detecting contraband narcotics, explosives, toxic industrial compounds and chemical warfare agents. Increasing threat of terrorist attacks, the proliferation of narcotics, Chemical Weapons Convention treaty verification as well as humanitarian de-mining efforts has mandated that equal importance be placed on the analysis time as well as the quality of the analytical data. (1) IMS is unrivaled when both speed of response and sensitivity has to be considered. (2) With conventional (signal averaging) IMS systems the number of available ions contributing to the measured signal to less than 1%. Furthermore, the signal averaging process incorporates scan-to-scan variations decreasing resolution. With external second gate Fourier Transform ion mobility spectrometry (FT-IMS), the entrance gate frequency is variable and can be altered in conjunction with other data acquisition parameters to increase the spectral resolution. The FT-IMS entrance gate operates with a 50% duty cycle and so affords a 7 to 10-fold increase in sensitivity. Recent data on high explosives are presented to demonstrate the parametric optimization in sensitivity and resolution of our system.

  3. Misfolded amyloid ion channels present mobile beta-sheet subunits in contrast to conventional ion channels.

    Science.gov (United States)

    Jang, Hyunbum; Arce, Fernando Teran; Capone, Ricardo; Ramachandran, Srinivasan; Lal, Ratnesh; Nussinov, Ruth

    2009-12-02

    In Alzheimer's disease, calcium permeability through cellular membranes appears to underlie neuronal cell death. It is increasingly accepted that calcium permeability involves toxic ion channels. We modeled Alzheimer's disease ion channels of different sizes (12-mer to 36-mer) in the lipid bilayer using molecular dynamics simulations. Our Abeta channels consist of the solid-state NMR-based U-shaped beta-strand-turn-beta-strand motif. In the simulations we obtain ion-permeable channels whose subunit morphologies and shapes are consistent with electron microscopy/atomic force microscopy. In agreement with imaged channels, the simulations indicate that beta-sheet channels break into loosely associated mobile beta-sheet subunits. The preferred channel sizes (16- to 24-mer) are compatible with electron microscopy/atomic force microscopy-derived dimensions. Mobile subunits were also observed for beta-sheet channels formed by cytolytic PG-1 beta-hairpins. The emerging picture from our large-scale simulations is that toxic ion channels formed by beta-sheets spontaneously break into loosely interacting dynamic units that associate and dissociate leading to toxic ionic flux. This sharply contrasts intact conventional gated ion channels that consist of tightly interacting alpha-helices that robustly prevent ion leakage, rather than hydrogen-bonded beta-strands. The simulations suggest why conventional gated channels evolved to consist of interacting alpha-helices rather than hydrogen-bonded beta-strands that tend to break in fluidic bilayers. Nature designs folded channels but not misfolded toxic channels.

  4. Ion mobility mass spectrometry of peptide, protein, and protein complex ions using a radio-frequency confining drift cell.

    Science.gov (United States)

    Allen, Samuel J; Giles, Kevin; Gilbert, Tony; Bush, Matthew F

    2016-02-01

    Ion mobility mass spectrometry experiments enable the characterization of mass, assembly, and shape of biological molecules and assemblies. Here, a new radio-frequency confining drift cell is characterized and used to measure the mobilities of peptide, protein, and protein complex ions. The new drift cell replaced the traveling-wave ion mobility cell in a Waters Synapt G2 HDMS. Methods for operating the drift cell and determining collision cross section values using this experimental set up are presented within the context of the original instrument control software. Collision cross sections for 349 cations and anions are reported, 155 of which are for ions that have not been characterized previously using ion mobility. The values for the remaining ions are similar to those determined using a previous radio-frequency confining drift cell and drift tubes without radial confinement. Using this device under 2 Torr of helium gas and an optimized drift voltage, denatured and native-like ions exhibited average apparent resolving powers of 14.2 and 16.5, respectively. For ions with high mobility, which are also low in mass, the apparent resolving power is limited by contributions from ion gating. In contrast, the arrival-time distributions of low-mobility, native-like ions are not well explained using only contributions from ion gating and diffusion. For those species, the widths of arrival-time distributions are most consistent with the presence of multiple structures in the gas phase.

  5. Commercial intermediate pressure MALDI ion mobility spectrometry mass spectrometer capable of producing highly charged laserspray ionization ions.

    Science.gov (United States)

    Inutan, Ellen D; Wang, Beixi; Trimpin, Sarah

    2011-02-01

    The first examples of highly charged ions observed under intermediate pressure (IP) vacuum conditions are reported using laser ablation of matrix/analyte mixtures. The method and results are similar to those obtained at atmospheric pressure (AP) using laserspray ionization (LSI) and/or matrix assisted inlet ionization (MAII). Electrospray ionization (ESI), LSI, and MAII are methods operating at AP and have been shown, with or without the use of a voltage or a laser, to produce highly charged ions with very similar ion abundance and charge states. A commercial matrix-assisted laser desorption/ionization ion mobility spectrometry (IMS) mass spectrometry (MS) instrument (SYNAPT G2) was used for the IP developments. The necessary conditions for producing highly charged ions of peptides and small proteins at IP appear to be a pressure drop region and the use of suitable matrixes and laser fluence. Ionization to produce these highly charged ions under the low pressure conditions of IP does not require specific heating or a special inlet ion transfer region. However, under the current setup, ubiquitin is the highest molecular weight protein observed. These findings are in accord with the need to provide thermal energy in the pressure drop region, similar to LSI and MAII, to improve sensitivity and extend the types of compounds that produce highly charged ions. The practical utility of IP-LSI in combination with IMS-MS is demonstrated for the analysis of model mixtures composed of a lipid, peptides, and a protein. Further, endogenous multiply charged peptides are observed directly from delipified mouse brain tissue with drift time distributions that are nearly identical in appearance to those obtained from a synthesized neuropeptide standard analyzed by either LSI- or ESI-IMS-MS at AP. Efficient solvent-free gas-phase separation enabled by the IMS dimension separates the multiply charged peptides from lipids that remained on the delipified tissue. Lipid and peptide

  6. Determination of Aflatoxins G and GUsing Ion Mobility Spectrometry

    Directory of Open Access Journals (Sweden)

    ALI SHEIBANI

    2012-12-01

    Full Text Available This work describes a rapid and sensitive ion mobility spectrometry method for the determination of aflatoxins G12 (AFG1 and AFG2. The effective instrumental parameters were investigated and optimized. After optimizing, the calibration curves for AFG1 and AFG2 were linear in the range of 1 to 300 ng. Relative standard deviation was 8 % and limit of detection was 0.5 ng. The capability of the proposed method was evaluated for the determination of AFG in spiked pistachio nut as a real sample that satisfactory results were obtained.

  7. Electron attachment and ion mobility in hydrocarbons and related systems

    Energy Technology Data Exchange (ETDEWEB)

    Bakale, G.

    1988-01-01

    During the last two decades, a firm base for the emerging field of liquid state electronics (LSE) has developed through studies of the transport and reaction properties of excess electrons in a variety of liquid-phase systems. Pulse-conductivity techniques were used in many of these studies to measure the mobilities of electrons and ions in pure liquids as well as the rate constants of electron attachment to a wide variety of electron-accepting solutes. Results obtained through such studies have interdisciplinary implications that are described in the discussion that follows which includes examples of the contributions of LSE to physics, chemistry and biology. 42 refs.

  8. Boric acid as a mobile phase additive for high performance liquid chromatography separation of ribose, arabinose and ribulose.

    Science.gov (United States)

    De Muynck, Cassandra; Beauprez, Joeri; Soetaert, Wim; Vandamme, Erick J

    2006-01-01

    A new high performance liquid chromatographic (HPLC) method is described for the analysis of ribose, arabinose and ribulose mixtures obtained from (bio)chemical isomerization processes. These processes gain importance since the molecules can be used for the synthesis of antiviral therapeutics. The HPLC method uses boric acid as a mobile phase additive to enhance the separation on an Aminex HPX-87K column. By complexing with boric acid, the carbohydrates become negatively charged, thus elute faster from the column by means of ion exlusion and are separated because the complexation capacity with boric acid differs from one carbohydrate to another. Excellent separation between ribose, ribulose and arabinose was achieved with concentrations between 0.1 and 10 gL(-1) of discrete sugar.

  9. Serpentine Ultralong Path with Extended Routing (SUPER) High Resolution Traveling Wave Ion Mobility-MS using Structures for Lossless Ion Manipulations

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Liulin; Webb, Ian K.; Garimella, Sandilya V. B.; Hamid, Ahmed M.; Zheng, Xueyun; Norheim, Randolph V.; Prost, Spencer A.; Anderson, Gordon A.; Sandoval, Jeremy A.; Baker, Erin S.; Ibrahim, Yehia M.; Smith, Richard D.

    2017-04-05

    Ion mobility (IM) separations have a broad range of analytical applications, but insufficient resolution limits many applications. Here we report on traveling wave (TW) ion mobility (IM) separations in a Serpentine Ultra-long Path with Extended Routing (SUPER) Structures for Lossless Ion Manipulations (SLIM) module in conjunction with mass spectrometry (MS). The extended routing utilized multiple passes was facilitated by the introduction of a lossless ion switch at the end of the ion path that either directed ions to the MS detector or to another pass through the serpentine separation region, providing theoretically unlimited TWIM path lengths. Ions were confined in the SLIM by rf fields in conjunction with a DC guard bias, enabling essentially lossless TW transmission over greatly extended paths (e.g., ~1094 meters over 81 passes through the 13.5 m serpentine path). In this multi-pass SUPER TWIM provided resolution approximately proportional to the square root of the number of passes (or path length). More than 30-fold higher IM resolution for Agilent tuning mix m/z 622 and 922 ions (~340 vs. ~10) was achieved for 40 passes compared to commercially available drift tube IM and other TWIM-based platforms. An initial evaluation of the isomeric sugars Lacto-N-hexaose and Lacto-N-neohexaose showed the isomeric structures to be baseline resolved, and a new conformational feature for Lacto-N-neohexaose was revealed after 9 passes. The new SLIM SUPER high resolution TWIM platform has broad utility in conjunction with MS and is expected to enable a broad range of previously challenging or intractable separations.

  10. Status report of the Jyvaskyla ion guide isotope separator on-line facility

    NARCIS (Netherlands)

    Penttila, H; Dendooven, P; Honkanen, A; Huhta, M; Jauho, PP; Jokinen, A; Lhersonneau, G; Oinonen, M; Parmonen, JM; Perajarvi, K; Aysto, J

    1997-01-01

    The ion guide isotope separator facility IGISOL of the University of Jyvaskyla has been moved to the new K-130 heavy ion cyclotron laboratory. The totally reconstructed facility is described in detail. The primary beams and targets, helium pumping, separator beam line construction and separator beam

  11. Size Exclusion Chromatography-Ion Mobility-Mass Spectrometry Coupling: a Step Toward Structural Biology.

    Science.gov (United States)

    Van der Rest, Guillaume; Halgand, Frédéric

    2017-09-20

    Noncovalent interactions are essential for the structural organization of biomacromolecules in cells. For this reason, the study of the biophysical, dynamic, and architectural interactions among biomacromolecules is essential. Since mass spectrometry requires compatible solutions while preserving the noncovalent bonding network, we envisioned that size exclusion chromatography coupled with ion mobility and mass spectrometry would be a valuable technique to desalt the initial sample and provide solution and gas-phase structural information in a single stage experiment. Such coupling allowed obtaining information on solution protein complex composition with SEC separation and on authenticity and purity with IMS-MS. Our study demonstrated that such coupling is compatible, useful, as well as suitable for a routine analysis, in pharmaceutical industry, for example. Mobility data were reliable and injected standards allowed calibrating the collision cross-section scale. Graphical Abstract ᅟ.

  12. Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 3. Estimating Surface Area Exposure by Deuterium Uptake

    Science.gov (United States)

    Khakinejad, Mahdiar; Ghassabi Kondalaji, Samaneh; Donohoe, Gregory C.; Valentine, Stephen J.

    2016-03-01

    Gas-phase hydrogen deuterium exchange (HDX), collision cross section (CCS) measurement, and molecular dynamics simulation (MDS) techniques were utilized to develop and compare three methods for estimating the relative surface area exposure of separate peptide chains within bovine insulin ions. Electrosprayed [M - 3H]3- and [M - 5H]5- insulin ions produced a single conformer type with respective collision cross sections of 528 ± 5 Å2 and 808 ± 2 Å2. [M - 4H]4- ions were comprised of more compact (Ω = 676 ± 3 Å2) and diffuse (i.e., more elongated, Ω = 779 ± 3 Å2) ion conformer types. Ions were subjected to HDX in the drift tube using D2O as the reagent gas. Collision-induced dissociation was used to fragment mobility-selected, isotopically labeled [M - 4H]4- and [M - 5H]5- ions into the protein subchains. Deuterium uptake levels of each chain can be explained by limited inter-chain isotopic scrambling upon collisional activation. Using nominal ion structures from MDS and a hydrogen accessibility model, the deuterium uptake for each chain was correlated to its exposed surface area. In separate experiments, the per-residue deuterium content for the protonated and deprotonated ions of the synthetic peptide KKDDDDDIIKIIK were compared. The differences in deuterium content indicated the regional HDX accessibility for cations versus anions. Using ions of similar conformational type, this comparison highlights the complementary nature of HDX data obtained from positive- and negative-ion analysis.

  13. A Device Model for Polymer Light-Emitting Diodes with Mobile Ions

    NARCIS (Netherlands)

    Jong, M.J.M. de; Blom, P.W.M.

    1996-01-01

    A model is presented for the device operation of a polymer light-emitting diode (PLED) with mobile ions. It is calculated that the low efficiency of a PLED with a high injection barrier increases as the ions migrate.

  14. Analysis of Bacterial Lipooligosaccharides by MALDI-TOF MS with Traveling Wave Ion Mobility.

    Science.gov (United States)

    Phillips, Nancy J; John, Constance M; Jarvis, Gary A

    2016-07-01

    Lipooligosaccharides (LOS) are major microbial virulence factors displayed on the outer membrane of rough-type Gram-negative bacteria. These amphipathic glycolipids are comprised of two domains, a core oligosaccharide linked to a lipid A moiety. Isolated LOS samples are generally heterogeneous mixtures of glycoforms, with structural variability in both domains. Traditionally, the oligosaccharide and lipid A components of LOS have been analyzed separately following mild acid hydrolysis, although important acid-labile moieties can be cleaved. Recently, an improved method was introduced for analysis of intact LOS by MALDI-TOF MS using a thin layer matrix composed of 2,4,6-trihydroxyacetophenone (THAP) and nitrocellulose. In addition to molecular ions, the spectra show in-source "prompt" fragments arising from regiospecific cleavage between the lipid A and oligosaccharide domains. Here, we demonstrate the use of traveling wave ion mobility spectrometry (TWIMS) for IMS-MS and IMS-MS/MS analyses of intact LOS from Neisseria spp. ionized by MALDI. Using IMS, the singly charged prompt fragments for the oligosaccharide and lipid A domains of LOS were readily separated into resolved ion plumes, permitting the extraction of specific subspectra, which led to increased confidence in assigning compositions and improved detection of less abundant ions. Moreover, IMS separation of precursor ions prior to collision-induced dissociation (CID) generated time-aligned, clean MS/MS spectra devoid of fragments from interfering species. Incorporating IMS into the profiling of intact LOS by MALDI-TOF MS exploits the unique domain structure of the molecule and offers a new means of extracting more detailed information from the analysis. Graphical Abstract ᅟ.

  15. Analysis of Bacterial Lipooligosaccharides by MALDI-TOF MS with Traveling Wave Ion Mobility

    Science.gov (United States)

    Phillips, Nancy J.; John, Constance M.; Jarvis, Gary A.

    2016-07-01

    Lipooligosaccharides (LOS) are major microbial virulence factors displayed on the outer membrane of rough-type Gram-negative bacteria. These amphipathic glycolipids are comprised of two domains, a core oligosaccharide linked to a lipid A moiety. Isolated LOS samples are generally heterogeneous mixtures of glycoforms, with structural variability in both domains. Traditionally, the oligosaccharide and lipid A components of LOS have been analyzed separately following mild acid hydrolysis, although important acid-labile moieties can be cleaved. Recently, an improved method was introduced for analysis of intact LOS by MALDI-TOF MS using a thin layer matrix composed of 2,4,6-trihydroxyacetophenone (THAP) and nitrocellulose. In addition to molecular ions, the spectra show in-source "prompt" fragments arising from regiospecific cleavage between the lipid A and oligosaccharide domains. Here, we demonstrate the use of traveling wave ion mobility spectrometry (TWIMS) for IMS-MS and IMS-MS/MS analyses of intact LOS from Neisseria spp. ionized by MALDI. Using IMS, the singly charged prompt fragments for the oligosaccharide and lipid A domains of LOS were readily separated into resolved ion plumes, permitting the extraction of specific subspectra, which led to increased confidence in assigning compositions and improved detection of less abundant ions. Moreover, IMS separation of precursor ions prior to collision-induced dissociation (CID) generated time-aligned, clean MS/MS spectra devoid of fragments from interfering species. Incorporating IMS into the profiling of intact LOS by MALDI-TOF MS exploits the unique domain structure of the molecule and offers a new means of extracting more detailed information from the analysis.

  16. Advanced Separators for Lithium-Ion and Lithium-Sulfur Batteries: A Review of Recent Progress.

    Science.gov (United States)

    Xiang, Yinyu; Li, Junsheng; Lei, Jiaheng; Liu, Dan; Xie, Zhizhong; Qu, Deyu; Li, Ke; Deng, Tengfei; Tang, Haolin

    2016-11-09

    Li-ion and Li-S batteries find enormous applications in different fields, such as electric vehicles and portable electronics. A separator is an indispensable part of the battery design, which functions as a physical barrier for the electrode as well as an electrolyte reservoir for ionic transport. The properties of the separators directly influence the performance of the batteries. Traditional polyolefin separators showed low thermal stability, poor wettability toward the electrolyte, and inadequate barrier properties to polysulfides. To improve the performance and durability of Li-ion and Li-S batteries, development of advanced separators is required. In this review, we summarize recent progress on the fabrication and application of novel separators, including the functionalized polyolefin separator, polymeric separator, and ceramic separator, for Li-ion and Li-S batteries. The characteristics, advantages, and limitations of these separators are discussed. A brief outlook for the future directions of the research in the separators is also provided.

  17. Dopant-assisted negative photoionization ion mobility spectrometry for sensitive detection of explosives.

    Science.gov (United States)

    Cheng, Shasha; Dou, Jian; Wang, Weiguo; Chen, Chuang; Hua, Lei; Zhou, Qinghua; Hou, Keyong; Li, Jinghua; Li, Haiyang

    2013-01-02

    Ion mobility spectrometry (IMS) is a key trace detection technique for explosives and the development of a simple, stable, and efficient nonradioactive ionization source is highly demanded. A dopant-assisted negative photoionization (DANP) source has been developed for IMS, which uses a commercial VUV krypton lamp to ionize acetone as the source of electrons to produce negative reactant ions in air. With 20 ppm of acetone as the dopant, a stable current of reactant ions of 1.35 nA was achieved. The reactant ions were identified to be CO(3)(-)(H(2)O)(n) (K(0) = 2.44 cm(2) V(-1) s(-1)) by atmospheric pressure time-of-flight mass spectrometry, while the reactant ions in (63)Ni source were O(2)(-)(H(2)O)(n) (K(0) = 2.30 cm(2) V(-1) s(-1)). Finally, its capabilities for detection of common explosives including ammonium nitrate fuel oil (ANFO), 2,4,6-trinitrotoluene (TNT), N-nitrobis(2-hydroxyethyl)amine dinitrate (DINA), and pentaerythritol tetranitrate (PETN) were evaluated, and the limits of detection of 10 pg (ANFO), 80 pg (TNT), and 100 pg (DINA) with a linear range of 2 orders of magnitude were achieved. The time-of-flight mass spectra obtained with use of DANP source clearly indicated that PETN and DINA can be directly ionized by the ion-association reaction of CO(3)(-) to form PETN·CO(3)(-) and DINA·CO(3)(-) adduct ions, which result in good sensitivity for the DANP source. The excellent stability, good sensitivity, and especially the better separation between the reactant and product ion peaks make the DANP a potential nonradioactive ionization source for IMS.

  18. Experimental and Theoretical Investigation of Sodiated Multimers of Steroid Epimers with Ion Mobility-Mass Spectrometry

    Science.gov (United States)

    Chouinard, Christopher D.; Cruzeiro, Vinícius Wilian D.; Roitberg, Adrian E.; Yost, Richard A.

    2017-02-01

    Ion mobility-mass spectrometry (IM-MS) has recently seen increased use in the analysis of small molecules, especially in the field of metabolomics, for increased breadth of information and improved separation of isomers. In this study, steroid epimers androsterone and trans-androsterone were analyzed with IM-MS to investigate differences in their relative mobilities. Although sodiated monomers exhibited very similar collision cross-sections (CCS), baseline separation was observed for the sodiated dimer species (RS = 1.81), with measured CCS of 242.6 and 256.3 Å2, respectively. Theoretical modeling was performed to determine the most energetically stable structures of solution-phase and gas-phase monomer and dimer structures. It was revealed that these epimers differ in their preferred dimer binding mode in solution phase: androsterone adopts a R=O - Na+ - OH—R' configuration, whereas trans-androsterone adopts a R=O - Na+ - O=R' configuration. This difference contributes to a significant structural variation, and subsequent CCS calculations based on these structures relaxed in the gas phase were in agreement with experimentally measured values (ΔCCS 5%). Additionally, these calculations accurately predicted the relative difference in mobility between the epimers. This study illustrates the power of combining experimental and theoretical results to better elucidate gas-phase structures.

  19. Tandem Mass Spectrometry in Combination with Product Ion Mobility for the Identification of Phospholipids

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Karin A. Zemski; Barkley, Robert M.; Berry, Joseph J.; Hankin, Joseph A.; Hoyes, Emmy; Brown, Jeffery M.; Murphy, Robert C.

    2017-01-03

    Concerted tandem and traveling wave ion mobility mass spectrometry (CTS analysis) is a unique method that results in a four-dimensional data set including nominal precursor ion mass, product ion mobility, accurate mass of product ion, and ion abundance. This nontargeted lipidomics CTS approach was applied in both positive- and negative-ion mode to phospholipids present in human serum, and the data set was used to evaluate the value of product ion mobility in identifying lipids in a complex mixture. It was determined that the combination of diagnostic product ions and unique collisional cross-section values of product ions is a powerful tool in the structural identification of lipids in a complex biological sample.

  20. Analysis of a series of chlorogenic acid isomers using differential ion mobility and tandem mass spectrometry.

    Science.gov (United States)

    Willems, Jamie L; Khamis, Mona M; Mohammed Saeid, Waleed; Purves, Randy W; Katselis, George; Low, Nicholas H; El-Aneed, Anas

    2016-08-24

    Chlorogenic acids are among the most abundant phenolics found in the human diet. Of these, the mono-caffeoylquinic acids are the predominant phenolics found in fruits, such as apples and pears, and products derived from them. In this research, a comprehensive study of the electrospray ionization (ESI) tandem mass spectrometric (MS/MS) dissociation behavior of the three most common mono-caffeoylquinic acids, namely 5-O-caffeoylquinic acid (5-CQA), 3-O-caffeoylquinic acid (3-CQA) and 4-O-caffeoylquinic acid (4-CQA), were determined using both positive and negative ionization. All proposed structures of the observed product ions were confirmed with second-generation MS(3) experiments. Similarities and differences between the dissociation pathways in the positive and negative ion modes are discussed, confirming the proposed structures and the established MS/MS fingerprints. MS/MS dissociation was primarily driven via the cleavage of the ester bond linking the quinic acid moiety to the caffeic acid moiety within tested molecules. Despite being structural isomers with the same m/z values and dissociation behaviors, the MS/MS data in the negative ion mode was able to differentiate the three isomers based on ion intensity for the major product ions, observed at m/z 191, 179 and 173. This differentiation was consistent among various MS instruments. In addition, ESI coupled with high-field asymmetric waveform ion mobility spectrometry-mass spectrometry (ESI-FAIMS-MS) was employed for the separation of these compounds for the first time. By combining MS/MS data and differential ion mobility, a method for the separation and identification of mono-caffeoylquinic in apple/pear juice samples was developed with a run time of less than 1 min. It is envisaged that this methodology could be used to identify pure juices based on their chlorogenic acid profile (i.e., metabolomics), and could also be used to detect juice-to-juice adulteration (e.g., apple juice addition to pear juice).

  1. Ion mobility spectrometry and its applications in detection of chemical warfare agents.

    Science.gov (United States)

    Mäkinen, Marko A; Anttalainen, Osmo A; Sillanpää, Mika E T

    2010-12-01

    When fast detection of chemical warfare agents in the field is required, the ion mobility spectrometer may be the only suitable option. This article provides an essential survey of the different ion mobility spectrometry detection technologies. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.).

  2. Direct analysis of pharmaceutical drug formulations using ion mobility spectrometry/quadrupole-time-of-flight mass spectrometry combined with desorption electrospray ionization.

    Science.gov (United States)

    Weston, Daniel J; Bateman, Robert; Wilson, Ian D; Wood, Tim R; Creaser, Colin S

    2005-12-01

    A novel approach to the rapid analysis of pharmaceutical drug formulations using hyphenated ion mobility spectrometry (IMS) and time-of-flight mass spectrometry (ToF-MS) that requires no sample pretreatment or chromatographic separation is described. A modified quadrupole time-of-flight mass spectrometer containing an ion mobility drift cell was used for gas-phase electrophoretic separation of ions prior to ToF-MS detection. The generation of sample ions directly from tablets and cream formulations was effected by desorption electrospray ionization (DESI) using a modified electrospray ion source. The analysis of a range of over-the-counter and prescription tablet formulations is described, including histamine H2 receptor antagonist (ranitidine), analgesic (paracetamol), opiate (codeine), and aromatase inhibitor anticancer (anastrozole) drugs. The successful determination of active drugs from soft formulations, such as an antiseptic cream (chlorhexidine) and a nicotine-containing skin patch, is also presented. Limits of detection for the active drugs using the DESI/IMS/ToF-MS method fell within the high-picomole to nanomole range. In all cases, the use of ion mobility drift tube separation showed increased selectivity for active drug responses (present as low as 0.14% w/w) over excipient responses such as poly(ethylene glycol). Tandem mass spectrometric analysis of precursor ions separated by IMS allowed positive confirmation of active drugs with little loss of ion mobility efficiency. The ability to analyze hard or soft pharmaceutical formulations directly by DESI combined with ion mobility spectrometry/mass spectrometry in approximately 2 min demonstrates the potential applicability of this novel method to pharmaceutical screening of low-molecular-weight drug formulations with high selectivity over the formulation vehicle.

  3. Ambient temperature nanoelectrospray ion mobility detector for high performance liquid chromatography in determining amines.

    Science.gov (United States)

    Chen, Chuang; Hou, Keyong; Wang, Weiguo; Li, Jinghua; Li, Haiyang

    2014-09-01

    A nanoelectrospray ionization ion mobility spectrometer (nanoESI-IMS) working at ambient pressure and ambient temperature was developed as a detector of high performance liquid chromatography (HPLC) to achieve sensitive detection of amines with no derivatization and meanwhile provide another dimension of separation. The easier desolvation property of the charged droplets formed in nanoESI source enabled complete desolvation of the product ions of sixteen amines and drugs using the nanoESI-IMS at ambient temperature. Working at ambient temperature was good for suppressing the dissociation of thermal volatile ions, such as only the proton adducted molecular ions were observed for morphine in the nanoESI-IMS. Besides, the resolving power of the nanoESI-IMS also showed an increasing tendency as lowering the working temperature, an increment of 19 percent and 10 percent was observed for diethylamine and triethylamine as the temperature dropped from 92°C to 32°C. The resolving power of the nanoESI-IMS at 32°C for the 16 tested compounds was amid 33-44. With the nanoESI-IMS coupled to HPLC, a six-compound mixture including isomers was successfully separated and detected without any derivatization. And linear response ranges of 1 to 20, 0.5 to 20, and 0.8 to 20μgml(-1) and limits of detection of 0.25, 0.15, and 0.17μgml(-1) for triethylamine, diethylamine, and butylamine, respectively, were obtained with the hyphenated system. These results showed the excellent performance of the two-dimensional separation and detection method in direct qualitative and quantitative analyses of amines.

  4. Li mobility in fast ion conductors followed by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, J.

    2010-07-01

    Structural features that enhance Li mobility in fast ion conductors with perovskite (Li{sub 3}xLa{sub 2}/3-xTiO{sub 3} series) and Nasicon structure (Li{sub 1}+xTi{sub 2}-xAl{sub x} (PO{sub 4}){sub 3} series) have been investigated. From the analysis of quadrupolar interactions, the local symmetry and exchange processes between structural sites occupied by lithium have been deduced to investigate local motions of lithium in conduction paths of analyzed compounds. The study of spin-lattice (T{sub 1}) and spin-spin (T{sub 2}) relaxation times made possible the analysis of the temperature dependence of Li residence times at structural sites. The comparison of these values with those deduced from conductivity (ac and dc-measurements) allowed the study of Li-motion mechanisms. The onset of long range motions requires the analysis of low frequency measurements (T{sub 2} relaxation and dc-conductivity). The non- Arrhenius behaviour, often observed in fast ion conductors, has been ascribed to order/disorder transitions. At increasing temperatures, Li motions become less correlated, producing the decrement of activation energy. In analyzed compounds, a direct measurement of diffusion coefficients has been obtained from NMR experiments performed with the pulse field gradient (PFG) technique. Finally, it is emphasized the importance of the vacancy percolation in conductivity processes. (Author)

  5. High efficiency noble gas electron impact ion source for isotope separation

    Energy Technology Data Exchange (ETDEWEB)

    Appelhans, A. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Olson, J. E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Dahl, D. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ward, M. B. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-07-01

    An electron impact ion source has been designed for generation of noble gas ions in a compact isotope separator. The source utilizes a circular filament that surrounds an ionization chamber, enabling multiple passes of electrons through the ionization chamber. This report presents ion optical design and the results of efficiency and sensitivity measurements performed in an ion source test chamber and in the compact isotope separator. The cylindrical design produced xenon ions at an efficiency of 0.37% with a sensitivity of ~24 µA /Pa at 300 µA of electron current.

  6. Combined corona discharge and UV photoionization source for ion mobility spectrometry.

    Science.gov (United States)

    Bahrami, Hamed; Tabrizchi, Mahmoud

    2012-08-15

    An ion mobility spectrometer is described which is equipped with two non-radioactive ion sources, namely an atmospheric pressure photoionization and a corona discharge ionization source. The two sources cannot only run individually but are additionally capable of operating simultaneously. For photoionization, a UV lamp was mounted parallel to the axis of the ion mobility cell. The corona discharge electrode was mounted perpendicular to the UV radiation. The total ion current from the photoionization source was verified as a function of lamp current, sample flow rate, and drift field. Simultaneous operation of the two ionization sources was investigated by recording ion mobility spectra of selected samples. The design allows one to observe peaks from either the corona discharge or photoionization individually or simultaneously. This makes it possible to accurately compare peaks in the ion mobility spectra from each individual source. Finally, the instrument's capability for discriminating two peaks appearing in approximately identical drift times using each individual ionization source is demonstrated.

  7. Correlation of ion-ion interaction with electrical conductivity in solid state polymeric separator for energy storage applications

    Science.gov (United States)

    Sharma, Parul Kumar; Sadiq, M.; Bhatt, Chandni; Sharma, A. L.

    2016-05-01

    In the present study, we report innovative study on the prepared high quality solid state free standing thin polymeric separator. In prepared free standing polymeric separator, polymer (PEO) has been used as host matrix; appropriate bulky anion salt (LiPF6) as conducting species and Nano ceramic filler (BaTiO3) is used to enrich the mechanical and thermal stability of separator used for the device applications. The Fourier Transform Infra-Red (FTIR) result has been analysed properly of the prepared materials to look the microscopic interaction among polymer-ion, ion-ion and polymer-ion-clay interaction. Electrical conductivity results has been recorded using the impedance spectroscopy results which gives the estimated value of the order of ˜10-3 Scm-1 of the nano ceramic doped polymeric separator which is desirable for energy storage application. A fine correlation has been established between the obtained results by this two analysis.

  8. Ion Mobility Studies on the Negative Ion-Molecule Chemistry of Isoflurane and Enflurane

    Science.gov (United States)

    González-Méndez, Ramón; Watts, Peter; Howse, David C.; Procino, Immacolata; McIntyre, Henry; Mayhew, Chris A.

    2017-02-01

    In the present work we present an investigation of the negative ion-molecule chemistry of the anaesthetics isoflurane, ISOF, and enflurane, ENF, in an ion mobility spectrometry/mass spectrometry (IMS/MS), in both air and nitrogen. Hexachloroethane (HCE) was introduced in both air and nitrogen to produce Cl- as a reactant ion. This study was undertaken owing to uncertainties in the chemical processes, which lead to the cluster ions reported in other work (Eiceman et al. Anal. Chem. 61, 1093-1099, 1). In particular for ISOF the product ion observed was ISOF.Cl-, and it was suggested that the Cl- was formed by dissociative electron attachment (DEA) although there was mention of a chlorine containing contaminant. We show in this study that ISOF and ENF do not produce Cl- in an IMS system either by capture of free electrons or reaction with O2 -. This demonstrates that the Cl- containing ions, reported in the earlier study, must have been the result of a chlorine containing contaminant as suggested. The failure of ISOF and ENF to undergo DEA was initially surprising given the high calculated electron affinities, but further calculations showed that this was a result of the large positive vertical attachment energies (VAEs). This experimental work has been supported by electronic structure calculations at the B3LYP level, and is consistent with those obtained in a crossed electron-molecular beam two sector field mass spectrometer. An unusual observation is that the monomer complexes of ISOF and ENF with O2 - are relatively unstable compared with the dimer complexes.

  9. Ion mobility spectrometry for the rapid analysis of over-the-counter drugs and beverages

    Science.gov (United States)

    Fernández-Maestre, Roberto

    2009-01-01

    In the pharmaceutical industry, there are increasing requirements for analytical methods in quality assessment for the production of drugs. In this investigation, ion mobility spectrometry (IMS) was used for the rapid qualitative separation and identification of active ingredients in generic over-the-counter drugs and food additives in beverages. The active ingredients determined in drugs were acetaminophen, aspartame, bisacodyl, caffeine, dextromethorphan, diphenhydramine, famotidine, glucosamine, guaifenesin, loratadine, niacin, phenylephrine, pyridoxine, thiamin, and tetrahydrozoline. Aspartame and caffeine were determined in beverages. Fourteen over-the-counter drugs and beverages were analyzed. Analysis times below 10 s were obtained for IMS, and reduced mobilities were reported for the first time for 12 compounds. A quadrupole mass spectrometer coupled to a mobility spectrometer was used to assure a correct peak assignation. The combination of fast analysis, low cost, and inexpensive maintenance of IMS instruments makes IMS an attractive technique for the qualitative determination of the active ingredients in over-the-counter drugs and food additives in manufacture quality control and cleaning verification for the drug and food industries. PMID:20835390

  10. First observation and mobility measurements of negative ions in superfluid 4He

    NARCIS (Netherlands)

    Kasimov, Aziz; Zühlke, Christiane; Jungmann, Klaus; Zu Putlitz, Gisbert

    2003-01-01

    We present the results of the first mobility measurements in superfluid helium for negative ions of different elements. Various negative ions like Cl-, F- and I- were produced by laser ablation from targets consisting of NaCl, NaF, NaI, LiF and KCl immersed in a 4He bath. In addition to negative ion

  11. Experimental evaluation and optimization of structures for lossless ion manipulations for ion mobility spectrometry with time-of-flight mass spectrometry.

    Science.gov (United States)

    Webb, Ian K; Garimella, Sandilya V B; Tolmachev, Aleksey V; Chen, Tsung-Chi; Zhang, Xinyu; Norheim, Randolph V; Prost, Spencer A; LaMarche, Brian; Anderson, Gordon A; Ibrahim, Yehia M; Smith, Richard D

    2014-09-16

    We report on the performance of structures for lossless ion manipulation (SLIM) as a means for transmitting ions and performing ion mobility separations (IMS). Ions were successfully transferred from an electrospray ionization (ESI) source to the TOF MS analyzer by means of a linear SLIM, demonstrating lossless ion transmission and an alternative arrangement including a 90° turn. First, the linear geometry was optimized for radial confinement by tuning RF on the central "rung" electrodes and potentials on the DC-only guard electrodes. Selecting an appropriate DC guard bias (2-6 V) and RF amplitude (≥160 V(p-p) at 750 kHz) resulted in the greatest ion intensities. Close to ideal IMS resolving power was maintained over a significant range of applied voltages. Second, the 90° turn was optimized for radial confinement by tuning RF on the rung electrodes and DC on the guard electrodes. However, both resolving power and ion transmission showed a dependence on these voltages, and the best conditions for both were >300 V(p-p) RF (685 kHz) and 7-11 V guard DC bias. Both geometries provide IMS resolving powers at the theoretical limit (R ~ 58), showing that degraded resolution from a "racetrack" effect from turning around a corner can be successfully avoided, and the capability also was maintained for essentially lossless ion transmission.

  12. Ion mobility spectrometry-mass spectrometry (IMS-MS) for on- and offline analysis of atmospheric gas and aerosol species

    Science.gov (United States)

    Krechmer, Jordan E.; Groessl, Michael; Zhang, Xuan; Junninen, Heikki; Massoli, Paola; Lambe, Andrew T.; Kimmel, Joel R.; Cubison, Michael J.; Graf, Stephan; Lin, Ying-Hsuan; Budisulistiorini, Sri H.; Zhang, Haofei; Surratt, Jason D.; Knochenmuss, Richard; Jayne, John T.; Worsnop, Douglas R.; Jimenez, Jose-Luis; Canagaratna, Manjula R.

    2016-07-01

    Measurement techniques that provide molecular-level information are needed to elucidate the multiphase processes that produce secondary organic aerosol (SOA) species in the atmosphere. Here we demonstrate the application of ion mobility spectrometry-mass spectrometry (IMS-MS) to the simultaneous characterization of the elemental composition and molecular structures of organic species in the gas and particulate phases. Molecular ions of gas-phase organic species are measured online with IMS-MS after ionization with a custom-built nitrate chemical ionization (CI) source. This CI-IMS-MS technique is used to obtain time-resolved measurements (5 min) of highly oxidized organic molecules during the 2013 Southern Oxidant and Aerosol Study (SOAS) ambient field campaign in the forested SE US. The ambient IMS-MS signals are consistent with laboratory IMS-MS spectra obtained from single-component carboxylic acids and multicomponent mixtures of isoprene and monoterpene oxidation products. Mass-mobility correlations in the 2-D IMS-MS space provide a means of identifying ions with similar molecular structures within complex mass spectra and are used to separate and identify monoterpene oxidation products in the ambient data that are produced from different chemical pathways. Water-soluble organic carbon (WSOC) constituents of fine aerosol particles that are not resolvable with standard analytical separation methods, such as liquid chromatography (LC), are shown to be separable with IMS-MS coupled to an electrospray ionization (ESI) source. The capability to use ion mobility to differentiate between isomers is demonstrated for organosulfates derived from the reactive uptake of isomers of isoprene epoxydiols (IEPOX) onto wet acidic sulfate aerosol. Controlled fragmentation of precursor ions by collisionally induced dissociation (CID) in the transfer region between the IMS and the MS is used to validate MS peak assignments, elucidate structures of oligomers, and confirm the

  13. New Proton-Ionizable, Calixarene-Based Ligands for Selective Metal Ion Separations

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, Richard A.

    2012-06-04

    The project objective was the discovery of new ligands for performing metal ion separations. The research effort entailed the preparation of new metal ion complexing agents and polymers and their evaluation in metal ion separation processes of solvent extraction, synthetic liquid membrane transport, and sorption. Structural variations in acyclic, cyclic, and bicyclic organic ligands were used to probe their influence upon the efficiency and selectivity with which metal ion separations can be performed. A unifying feature of the ligand structures is the presence of one (or more) side arm with a pendent acidic function. When a metal ion is complexed within the central cavity of the ligand, ionization of the side arm(s) produces the requisite anion(s) for formation of an overall electroneutral complex. This markedly enhances extraction/transport efficiency for separations in which movement of aqueous phase anions of chloride, nitrate, or sulfate into an organic medium would be required. Through systematic structural variations, new ligands have been developed for efficient and selective separations of monovalent metal ions (e.g., alkali metal, silver, and thallium cations) and of divalent metal ion species (e.g., alkaline earth metal, lead, and mercury cations). Research results obtained in these fundamental investigations provide important insight for the design and development of ligands suitable for practical metal ion separation applications.

  14. Eco-friendly separation of catechins using cyclodextrins as mobile phase additives in RP-HPLC.

    Science.gov (United States)

    Bi, Wentao; Li, Shengnan; Row, Kyung Ho

    2012-01-01

    New mobile phases for RP-HPLC were developed for the separation of catechin compounds in tea. Cyclodextrin mobile phase additives decreased the use of toxic and inflammable organic solvents without compromising resolution or separation efficiency. To develop a simple greener method for analyzing five tea catechins in RP-HPLC, the mobile phase condition was optimized and the lowest organic modifier proportion with content resolutions and retention factors were obtained. Eco-friendly cyclodextrins were used as mobile phase additives to decrease the proportion of organic modifier and improve resolutions and retention factors. The effects of several physico-chemical parameters on the retention factors were investigate d and the optimum conditions were obtained on a conventional C₁₈ column, where the mobile phase consisted of acetonitrile/water (12/88, v/v) with 1.5 mmol/L β-cyclodextrin at a flow rate of 1.0 mL/min. Cyclodextrins can separate analytes through host-guest complexation, where a transient diastereomeric complex is formed between the cyclodextrin and the analyte. β-Cyclodextrin is the most accessible, the least expensive and generally the most useful cyclodextrin. This work developed a simple eco-friendly method with the lowest concentration of organic solvents. Under the optimal condition, five catechins could be baseline separated within 17 minutes in the isocratic mode. This research exhibited the potential for the separation and determination of other active compounds from natural plants by a greener method. Copyright © 2011 John Wiley & Sons, Ltd.

  15. Thin-film type Li-ion battery, using a polyethylene separator grafted with glycidyl methacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Ko, J.M.; Min, B.G.; Kim, D.-W. [Hanbat University, Taejon (Korea). Department of Chemical Technology; Ryu, K.S.; Kim, K.M.; Lee, Y.G.; Chang, S.H. [Electronic and Telecommunication Research Institute, Taejon (Korea)

    2004-11-30

    For the improvement of organic electrolyte holding ability, the hydrophobic surface of a porous polyethylene (PE)-membrane separator was modified by grafting a hydrophilic monomer, glycidyl methacrylate (GMA), PE-g-GMA, by using electron beam technology, and applied to a thin film type Li-ion battery to elucidate the effect of a surface modification of a PE membrane separator on the cyclic life of Li-ion batteries. The Li-ion battery using the PE-g-GMA membrane separator showed a better cycle life than that of the unmodified PE membrane separator, indicating that the surface hydrophilicity of the PE membrane separator improved the electrolyte holding capability between the electrodes in the Li-ion cell and prevented the electrolyte leakage. (author)

  16. Characterization of TATP gas phase product ion chemistry via isotope labeling experiments using ion mobility spectrometry interfaced with a triple quadrupole mass spectrometer.

    Science.gov (United States)

    Tomlinson-Phillips, Jill; Wooten, Alfred; Kozole, Joseph; Deline, James; Beresford, Pamela; Stairs, Jason

    2014-09-01

    Identification of the fragment ion species associated with the ion reaction mechanism of triacetone triperoxide (TATP), a homemade peroxide-based explosive, is presented. Ion mobility spectrometry (IMS) has proven to be a key analytical technique in the detection of trace explosive material. Unfortunately, IMS alone does not provide chemical identification of the ions detected; therefore, it is unknown what ion species are actually formed and separated by the IMS. In IMS, ions are primarily characterized by their drift time, which is dependent on the ion׳s mass and molecular cross-section; thus, IMS as a standalone technique does not provide structural signatures, which is in sharp contrast to the chemical and molecular information that is generally obtained from other customary analytical techniques, such as NMR, Raman and IR spectroscopy and mass spectrometry. To help study the ion chemistry that gives rise to the peaks observed in IMS, the hardware of two different commercial IMS instruments has been directly coupled to triple quadrupole (QQQ) mass spectrometers, in order to ascertain each ion׳s corresponding mass/charge (m/z) ratios with different dopants at two temperatures. Isotope labeling was then used to help identify and confirm the molecular identity of the explosive fragment and adduct ions of TATP. The m/z values and isotope labeling experiments were used to help propose probable molecular formulas for the ion fragments. In this report, the fragment and adduct ions m/z 58 and 240 of TATP have been confirmed to be [C3H6NH·H](+) and [TATP·NH4](+), respectively; while the fragment ions m/z 73 and 89 of TATP are identified as having the molecular formulas [C4H9NH2](+) and [C4H9O2](+), respectively. It is anticipated that the work in this area will not only help to facilitate improvements in mobility-based detection (IMS and MS), but also aid in the development and optimization of MS-based detection algorithms for TATP.

  17. Waste separation and pretreatment using crystalline silicotitanate ion exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Tadros, M.E.; Miller, J.E. [Sandia National Lab., Albuquerque, NM (United States); Anthony, R.G. [Texas A& M Univ., College Station, TX (United States)

    1997-10-01

    A new class of inorganic ion exchangers called crystalline silicotitanates (CSTs) has been developed jointly by Sandia National Laboratories and Texas A&M University to selectively remove Cs and other radionuclides from a wide spectrum of radioactive defense wastes. The CST exhibits high selectivity and affinity for Cs and Sr under a wide range of conditions. Tests show it can remove part-per-million concentrations of Cs{sup +} from highly alkaline, high-sodium simulated radioactive waste solutions modeled after those at Hanford, Oak Ridge, and Savannah River. The materials exhibit ion exchange properties based on ionic size selectivity. Specifically, crystalline lattice spacing is controlled to be highly selective for Cs ions even in waste streams containing very high (5 to 10 M) concentrations of sodium. The CST technology is being demonstrated with actual waste at several DOE facilities. The use of inorganic ion exchangers. The inorganics are more resistant to chemical, thermal, and radiation degradation. Their high selectivities result in more efficient operations offering the possibility of a simple single-pass operation. In contrast, regenerable organic ion exchangers require additional processing equipment to handle the regeneration liquids and the eluant with the dissolved Cs.

  18. Immobilized aptamer paper spray ionization source for ion mobility spectrometry.

    Science.gov (United States)

    Zargar, Tahereh; Khayamian, Taghi; Jafari, Mohammad T

    2017-01-05

    A selective thin-film microextraction based on aptamer immobilized on cellulose paper was used as a paper spray ionization source for ion mobility spectrometry (PSI-IMS), for the first time. In this method, the paper is not only used as an ionization source but also it is utilized for the selective extraction of analyte, based on immobilized aptamer. This combination integrates both sample preparation and analyte ionization in a Whatman paper. To that end, an appropriate sample introduction system with a novel design was constructed for the paper spray ionization source. Using this system, a continuous solvent flow works as an elution and spray solvent simultaneously. In this method, analyte is adsorbed on a triangular paper with immobilized aptamer and then it is desorbed and ionized by elution solvent and applied high voltage on paper, respectively. The effects of different experimental parameters such as applied voltage, angle of paper tip, distance between paper tip and counter electrode, elution solvent type, and solvent flow rate were optimized. The proposed method was exhaustively validated in terms of sensitivity and reproducibility by analyzing the standard solutions of codeine and acetamiprid. The analytical results obtained are promising enough to ensure the use of immobilized aptamer paper-spray as both the extraction and ionization techniques in IMS for direct analysis of biomedicine. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. An online peak extraction algorithm for ion mobility spectrometry data.

    Science.gov (United States)

    Kopczynski, Dominik; Rahmann, Sven

    2015-01-01

    Ion mobility (IM) spectrometry (IMS), coupled with multi-capillary columns (MCCs), has been gaining importance for biotechnological and medical applications because of its ability to detect and quantify volatile organic compounds (VOC) at low concentrations in the air or in exhaled breath at ambient pressure and temperature. Ongoing miniaturization of spectrometers creates the need for reliable data analysis on-the-fly in small embedded low-power devices. We present the first fully automated online peak extraction method for MCC/IMS measurements consisting of several thousand individual spectra. Each individual spectrum is processed as it arrives, removing the need to store the measurement before starting the analysis, as is currently the state of the art. Thus the analysis device can be an inexpensive low-power system such as the Raspberry Pi. The key idea is to extract one-dimensional peak models (with four parameters) from each spectrum and then merge these into peak chains and finally two-dimensional peak models. We describe the different algorithmic steps in detail and evaluate the online method against state-of-the-art peak extraction methods.

  20. Towards metals analysis using corona discharge ionization ion mobility spectrometry.

    Science.gov (United States)

    Jafari, Mohammad T; Saraji, Mohammad; Sherafatmand, Hossein

    2016-02-25

    For the first time, the capability of corona discharge ionization ion mobility spectrometry (CD-IMS) in the determination of metal complex was evaluated. The extreme simplicity of dispersive liquid-liquid microextraction (DLLME) coupled to the high sensitivity of CD-IMS measurement could make this combination really useful for simple, rapid, and sensitive determination of metals in different samples. In this regard, mercury, as a model metal, was complexed with diethyldithiocarbamate (DEDTC), and then extracted into the carbon tetrachloride using DLLME. Some parameters affecting the extraction efficiency, including the type and volume of the extraction solvent, the type and volume of the disperser solvent, the concentration of the chelating agent, salt addition and, pH were exhaustively investigated. Under the optimized condition, the enrichment factor was obtained to be 142. The linear range of 0.035-10.0 μg mL(-1) with r(2) = 0.997 and the detection limit of 0.010 μg mL(-1) were obtained. The relative standard deviation values were calculated to be lower than 4% and 8% for intra-day and inter-day, respectively. Finally, the developed method was successfully applied for the extraction and determination of mercury in various real samples. The satisfactory results revealed the capability of the proposed method in trace analysis without tedious derivatization or hydride generation.

  1. Novel Nanofiber-based Membrane Separators for Lithium-Ion Batteries

    Science.gov (United States)

    Yanilmaz, Meltem

    Lithium-ion batteries have been widely used in electronic devices including mobile phones, laptop computers, and cameras due to their high specific energy, high energy density, long cycling lifetime, and low self-discharge rate. Nowadays, lithium-ion batteries are finding new applications in electric/hybrid vehicles and energy storage for smart grids. To be used in these new applications, novel battery components are needed so that lithiumion batteries with higher cell performance, better safety, and lower cost can be developed. A separator is an important component to obtain safe batteries and its primary function is to prevent electronic contact between electrodes while regulating cell kinetics and ionic flow. Currently, microporous membranes are the most commonly used separator type and they have good mechanical properties and chemical stability. However, their wettability and thermal stabilities are not sufficient for applications that require high operating temperature and high performance. Due to the superior properties such as large specific surface area, small pore size and high porosity, electrospun nanofiber membranes can be good separator candidate for highperformance lithium-ion batteries. In this work, we focus our research on fabricating nanofiber-based membranes to design new high-performance separators with good thermal stability, as well as superior electrochemical performance compared to microporous polyolefin membranes. To combine the good mechanical strength of PP nonwovens with the excellent electrochemical properties of SiO2/polyvinylidene fluoride (PVDF) composite nanofibers, SiO 2/PVDF composite nanofiber-coated PP nonwoven membranes were prepared. It was found that the addition of SiO2 nanoparticles played an important role in improving the overall performance of these nanofiber-coated nonwoven membranes. Although ceramic/polymer composites can be prepared by encapsulating ceramic particles directly into polymer nanofibers, the performance

  2. Superheated water ion-exchange chromatography: an experimental approach for interpretation of separation selectivity in ion-exchange processes.

    Science.gov (United States)

    Shibukawa, Masami; Shimasaki, Tomomi; Saito, Shingo; Yarita, Takashi

    2009-10-01

    Cation-exchange selectivity for alkali and alkaline-earth metal ions and tetraalkylammonium ions on a strongly acidic sulfonic acid cation-exchange resin has been investigated in the temperature range of 40-175 degrees C using superheated water chromatography. Dependence of the distribution coefficient (ln KD) on the reciprocal of temperature (1/T) is not linear for most of the ions studied, and the selectivity coefficient for a pair of alkali metal ions or that of alkaline-earth metal ions approaches unity as temperature increases. On the other hand, the retention order of tetraalkylammonium ions is reversed at 160 degrees C or above when eluted with Na2SO4 aqueous solution and the larger ions are eluted faster than the smaller ones contrary to the retention order obtained at ambient temperature. The change in ion-exchange selectivity with temperature observed with superheated water chromatography has been discussed on the basis of the effect of temperature on hydration of the ions and specific adsorption or distribution of ionic species between the external solution and ion-exchange resin. In superheated water, the electrostatic interaction or association of the ions with the fixed ion becomes a predominant mechanism resulting in different separation selectivity from that obtained at ambient temperature.

  3. Integrated statistical learning of metabolic ion mobility spectrometry profiles for pulmonary disease identification

    DEFF Research Database (Denmark)

    Hauschild, A.C.; Baumbach, Jan; Baumbach, J.

    2012-01-01

    Exhaled air carries information on human health status. Ion mobility spectrometers combined with a multi-capillary column (MCC/IMS) is a well-known technology for detecting volatile organic compounds (VOCs) within human breath. This technique is relatively inexpensive, robust and easy to use...... sophisticated statistical learning techniques for VOC-based feature selection and supervised classification into patient groups. We analyzed breath data from 84 volunteers, each of them either suffering from chronic obstructive pulmonary disease (COPD), or both COPD and bronchial carcinoma (COPD + BC), as well...... as from 35 healthy volunteers, comprising a control group (CG). We standardized and integrated several statistical learning methods to provide a broad overview of their potential for distinguishing the patient groups. We found that there is strong potential for separating MCC/IMS chromatograms of healthy...

  4. Advancing the High Throughput Identification of Liver Fibrosis Protein Signatures Using Multiplexed Ion Mobility Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Erin Shammel; Burnum-Johnson, Kristin E.; Jacobs, Jon M.; Diamond, Deborah L.; Brown, Roslyn N.; Ibrahim, Yehia M.; Orton, Daniel J.; Piehowski, Paul D.; Purdy, David E.; Moore, Ronald J.; Danielson, William F.; Monroe, Matthew E.; Crowell, Kevin L.; Slysz, Gordon W.; Gritsenko, Marina A.; Sandoval, John D.; Lamarche, Brian L.; Matzke, Melissa M.; Webb-Robertson, Bobbie-Jo M.; Simons, Brenna C.; McMahon, Brian J.; Bhattacharya, Renuka; Perkins, James D.; Carithers, Robert L.; Strom, Susan; Self, Steven; Katze, Michael G.; Anderson, Gordon A.; Smith, Richard D.

    2014-04-01

    Rapid diagnosis of disease states using less invasive, safer, and more clinically acceptable approaches than presently employed is an imperative goal for the field of medicine. While mass spectrometry (MS)-based proteomics approaches have attempted to meet these objectives, challenges such as the enormous dynamic range of protein concentrations in clinically relevant biofluid samples coupled with the need to address human biodiversity have slowed their employment. Herein, we report on the use of a new platform that addresses these challenges by coupling technical advances in rapid gas phase multiplexed ion mobility spectrometry (IMS) separations [1, 2] with liquid chromatography (LC) and MS to dramatically increase measurement sensitivity and throughput, further enabling future MS-based clinical applications. An initial application of the LC-IMS-MS platform for the analysis of blood serum samples from stratified post-liver transplant patients with recurrent fibrosis progression illustrates its potential utility for disease characterization and use in personalized medicine [3, 4].

  5. Surface-Modified Membrane as A Separator for Lithium-Ion Polymer Battery

    Directory of Open Access Journals (Sweden)

    Jun Young Kim

    2010-04-01

    Full Text Available This paper describes the fabrication of novel modified polyethylene (PE membranes using plasma technology to create high-performance and cost-effective separator membranes for practical applications in lithium-ion polymer batteries. The modified PE membrane via plasma modification process plays a critical role in improving wettability and electrolyte retention, interfacial adhesion between separators and electrodes, and cycle performance of lithium-ion polymer batteries. This paper suggests that the performance of lithium-ion polymer batteries can be greatly enhanced by the plasma modification of commercial separators with proper functional materials for targeted application.

  6. An ID/Locator Separation Based Group Mobility Management in Wireless Body Area Network

    Directory of Open Access Journals (Sweden)

    Moneeb Gohar

    2015-01-01

    Full Text Available Mobility management in wireless sensor network is the most important factor to be considered for applications such as healthcare system. Recently, Identifier (ID/Locator (LOC separation based mobility management scheme has been proposed for wireless sensor network. However, it does not perform well in group-based mobility management in wireless body area network, and thus it tends to induce large registration, packet delivery, and handover delays. To overcome these limitations, we propose a group-based mobility management scheme based on ID/LOC separation concept for ID-based communications with location-based routing to reduce the number of control messages. In the proposed scheme, each sensor device has a globally unique device identifier (GDID which contains the information of its home network domain. For handover support, each access gateway maintains its home GDID register (HGR and visiting GDID register (VGR which are used to keep the GDID-locator (LOC mappings for primary mobile devices in the distributed manner. Besides, in the proposed scheme, only the coordinator will send Router Solicitation and Router Advertisement messages to reduce the control messages further. By numerical analysis, we show that the proposed scheme can significantly reduce the registration, packet delivery, and handover delays, compared to the existing schemes.

  7. A Highly Thermostable Ceramic-Grafted Microporous Polyethylene Separator for Safer Lithium-Ion Batteries.

    Science.gov (United States)

    Zhu, Xiaoming; Jiang, Xiaoyu; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2015-11-04

    The safety concern is a critical obstacle to large-scale energy storage applications of lithium-ion batteries. A thermostable separator is one of the most effective means to construct the safe lithium-ion batteries. Herein, we demonstrate a novel ceramic (SiO2)-grafted PE separator prepared by electron beam irradiation. The separator shows similar thickness and pore structure to the bare separator, while displaying strong dimensional thermostability, as the shrinkage ratio is only 20% even at an elevated temperature of 180 °C. Besides, the separator is highly electrochemically inert, showing no adverse effect on the energy and power output of the batteries. Considering the excellent electrochemical and thermal stability, the SiO2-grafted PE separator developed in this work is greatly beneficial for constructing safer lithium-ion batteries.

  8. Feasibility of ultra-performance liquid chromatography-ion mobility-time-of-flight mass spectrometry in analyzing oxysterols.

    Science.gov (United States)

    Kylli, Petri; Hankemeier, Thomas; Kostiainen, Risto

    2017-03-03

    Oxysterols are oxygenated cholesterols that are important in many cell functions and they may also be indicative of certain diseases. The purpose of this work was to study the feasibility of ultra-performance liquid chromatography-ion mobility-time-of-flight mass spectrometry (UPLC-IM-TOFMS) using traveling wave cell in analyzing oxysterols and especially their isomers in biological samples. Oxysterols were analyzed as their p-toluenesulfonyl isocyanate derivatives, which improved the separation of isomeric oxysterols by ion mobility and ionization efficiency in the electrospray ionization step. The UPLC-IM-TOFMS method was shown to be fast and to provide good quantitative performance. The feasibility of the method was demonstrated in the analyses of oxysterols in fibroblast cell samples.

  9. Separation and characterisation of beta2-microglobulin folding conformers by ion-exchange liquid chromatography and ion-exchange liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Bertoletti, Laura; Regazzoni, Luca; Aldini, Giancarlo; Colombo, Raffaella; Abballe, Franco; Caccialanza, Gabriele; De Lorenzi, Ersilia

    2013-04-10

    In this work we present for the first time the use of ion-exchange liquid chromatography to separate the native form and a partially structured intermediate of the folding of the amyloidogenic protein beta2-microglobulin. Using a strong anion-exchange column that accounts for the differences in charge exposure of the two conformers, a LC-UV method is initially optimised in terms of mobile phase pH, composition and temperature. The preferred mobile phase conditions that afford useful information were found to be 35 mM ammonium formate, pH 7.4 at 25°C. The dynamic equilibrium of the two species is demonstrated upon increasing the concentration of acetonitrile in the protein sample. Then, the chromatographic method is transferred to MS detection and the respective charge state distributions of the separated conformers are identified. The LC-MS results demonstrate that one of the conformers is partially unfolded, compared with the native and more compact species. The correspondence with previous results obtained in free solution by capillary electrophoresis suggest that strong ion exchange LC-MS does not alter beta2-microglobulin conformation and maintains the dynamic equilibrium already observed between the native protein and its folding intermediate.

  10. Heavy stable isotope separation by ion cyclotron resonance

    Energy Technology Data Exchange (ETDEWEB)

    Louvet, P.; Compant La Fontaine, A.; Larousse, B.; Patris, M.

    1994-12-31

    The scientific feasibility of the ion cyclotron resonance process (ICR), as well as the technical one, has been investigated carefully for light metallic elements, whose masses lies between 40 and 100/1,2/. The present work deals mainly with the same demonstration for heavier elements such as ytterbium, gadolinium and barium. Recent results, as well as future prospects, are considered here. (authors).

  11. A LASER ION-SOURCE FOR ONLINE MASS SEPARATION

    NARCIS (Netherlands)

    VANDUPPEN, P; DENDOOVEN, P; HUYSE, M; VERMEEREN, L; QAMHIEH, ZN; SILVERANS, RE; VANDEWEERT, E

    1992-01-01

    A laser ion source based on resonance photo ionization in a gas cell is proposed. The gas cell, filled with helium, consists of a target chamber in which the recoil products are stopped and neutralized, and an ionization chamber where the atoms of interest are selectively ionized by the laser light.

  12. Experimental Evaluation and Optimization of Structures for Lossless Ion Manipulations for Ion Mobility Spectrometry with Time-of-Flight Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Ian K.; Garimella, Venkata BS; Tolmachev, Aleksey V.; Chen, Tsung-Chi; Zhang, Xinyu; Norheim, Randolph V.; Prost, Spencer A.; Lamarche, Brian L.; Anderson, Gordon A.; Ibrahim, Yehia M.; Smith, Richard D.

    2014-09-05

    We report on the performance of Structures for Lossless Ion Manipulation (SLIM) devices as a means for transmitting ions and performing ion mobility separations (IMS). Ions were successfully transferred from an electrospray ionization (ESI) source to the TOF MS analyzer by means of a linear SLIM device and an alternative arrangement including a 90° turn. First, the linear geometry was optimized for radial confinement by tuning RF on the central ‘rung’ electrodes and potentials on the DC-only guard electrodes. Selecting an appropriate DC guard bias (2-6 V) and RF amplitude (≥160 Vp-p at 750 kHz) resulted in the greatest ion intensities. Close to ideal IMS resolving power was maintained over a range of applied voltages. Second, the 90° turn was optimized for radial confinement by tuning the RF on the rung electrodes and DC on the guard electrodes; however, both resolving power and ion transmission showed a dependence on these voltages and the best conditions for both were > 300 Vp-p RF (685 kHz) and 7-11 V guard DC bias. Both geometries provide IMS resolving powers at the theoretical limit (R~58), showing that the negative “racetrack” effect from turning around a corner can be successfully avoided, as well as the capability for essentially lossless ion transmission.

  13. Ion mobility-mass spectrometry of phosphorylase B ions generated with supercharging reagents but in charge-reducing buffer.

    Science.gov (United States)

    Hogan, Christopher J; Ogorzalek Loo, Rachel R; Loo, Joseph A; de la Mora, Juan Fernandez

    2010-11-01

    We investigate whether "supercharging" reagents able to shift the charge state distributions (CSDs) of electrosprayed protein ions upward also influence gas-phase protein structure. A differential mobility analyzer and a mass spectrometer are combined in series (DMA-MS) to measure the mass and mobility of monomer and multimeric phosphorylase B ions (monomer molecular weight ∼97 kDa) in atmospheric pressure air. Proteins are electrosprayed from charge-reducing triethylammonium formate in water (pH = 6.8) with and without the addition of the supercharging reagent tetramethylene sulfone (sulfolane). Because the DMA measures ion mobility prior to collisional heating or declustering, it probes the structure of supercharged protein ions immediately following solvent (water) evaporation. As in prior studies, the addition of sulfolane is found to drastically increase both the mean and maximum charge state of phosphorylase B ions. Ions from all protein n-mers were found to yield mobilities that, for a given charge state, were ∼6-10% higher in the absence of sulfolane. We find that the mobility decrease which arises with sulfolane is substantially smaller than that typically observed for folded-to-unfolded transitions in protein ions (where a ∼60% decrease in mobility is typical), suggesting that supercharging reagents do not cause structural protein modifications in solution as large as noted recently by Williams and colleagues [E. R. Williams et al., J. Am. Soc. Mass Spectrom., 2010, 21, 1762-1774]. In fact, the measurements described here indicate that the modest mobility decrease observed can be partly attributed to sulfolane trapping within the protein ions during DMA measurements, and probably also in solution. As the most abundant peaks in measured mass-mobility spectra for ions produced with and without sulfolane correspond to non-covalently bound phosphorylase B dimers, we find that in spite of a change in mobility/cross section, sulfolane addition does not

  14. Separation of ammonia from wastewater using clinoptilolite as ion exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Czaran, E.; Meszaros-Kis, A.; Domokos, E.; Papp, J.

    1988-01-01

    The cation exchange properties of a Hungarian clinoptilolite rock from the Tokaj mountains have been studied. The aim of this work has been to prepare suitable cation containing forms for NH/sub 4//sup +/-removal and regeneration of the NH/sub 4//sup +/-form. The process has been followed from the start with static laboratory experiments through laboratory dynamic measurements up to pilot plant. The static CEC of the clinoptilolite containing rock proved to be 1.2 meq/q. However, under dynamic conditions this value is only 0.2 - 0.3 depending on the circumstances, thus this material is capable of the elimination of 3 - 5 mg NH/sub 3/ per g rock. The exhausted clinoptilolite can be regenerated more efficiently by potassium ions than by the usually applied sodium ions.

  15. Radio-frequency ion deflector for mass separation

    Energy Technology Data Exchange (ETDEWEB)

    Schlösser, Magnus, E-mail: magnus.schloesser@googlemail.com; Rudnev, Vitaly; Ureña, Ángel González, E-mail: laseres@pluri.ucm.es [Unidad de Láseres y Haces Moleculares, Instituto Plurisdisciplinar, Universidad Complutense de Madrid, Madrid 28040 (Spain)

    2015-10-15

    Electrostatic cylindrical deflectors act as energy analyzer for ion beams. In this article, we present that by imposing of a radio-frequency modulation on the deflecting electric field, the ion transmission becomes mass dependent. By the choice of the appropriate frequency, amplitude, and phase, the deflector can be used as mass filter. The basic concept of the new instrument as well as simple mathematic relations are described. These calculations and further numerical simulations show that a mass sensitivity is achievable. Furthermore, we demonstrate the proof-of-principle in experimental measurements, compare the results to those of from a 1 m linear time-of-flight spectrometer, and comment on the mass resolution of the method. Finally, some potential applications are indicated.

  16. Effective Ion Mobility Peak Width as a New Isomeric Descriptor for the Untargeted Analysis of Complex Mixtures Using Ion Mobility-Mass Spectrometry

    Science.gov (United States)

    Farenc, Mathilde; Paupy, Benoit; Marceau, Sabrina; Riches, Eleanor; Afonso, Carlos; Giusti, Pierre

    2017-07-01

    Ion mobility coupled with mass spectrometry was proven to be an efficient way to characterize complex mixtures such as petroleum samples. However, the identification of isomeric species is difficult owing to the molecular complexity of petroleum and no availability of standard molecules. This paper proposes a new simple indicator to estimate the isomeric content of highly complex mixtures. This indicator is based on the full width at half maximum (FWHM) of the extracted ion mobility peak measured in millisecond or square angstrom that is corrected for instrumental factors such as ion diffusion. This value can be easily obtained without precisely identifying the number of isomeric species under the ion mobility peaks. Considering the Boduszynski model, the ion mobility profile for a particular elemental composition is expected to be a continuum of various isomeric species. The drift time-dependent fragmentation profile was studied and confirmed this hypothesis, a continuous evolution of the fragmentation profile showing that the larger alkyl chain species were detected at higher drift time values. This new indicator was proven to be a fast and efficient method to compare vacuum gas oils for which no difference was found using other analytical techniques.

  17. Analysis of paralytic shellfish toxins using high-field asymmetric waveform ion mobility spectrometry with liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Beach, Daniel G; Melanson, Jeremy E; Purves, Randy W

    2015-03-01

    The analysis of paralytic shellfish toxins (PSTs) by liquid chromatography-mass spectrometry remains a challenge because of their high polarity, large number of analogues and the complex matrix in which they occur. Here we investigate the potential utility of high-field asymmetric waveform ion mobility spectrometry (FAIMS) as a gas-phase ion separation tool for analysis of PSTs by mass spectrometry. We investigate the separation of PSTs using FAIMS with two divergent goals: using FAIMS as a primary separation tool for rapid screening by electrospray ionization (ESI)-FAIMS-MS or combined with LC in a multidimensional LC-ESI-FAIMS-MS separation. First, a survey of the parameters that affect the sensitivity and selectivity of PST analysis by FAIMS was carried out using ESI-FAIMS-MS. In particular, the use of acetonitrile as a gas additive in the carrier gas flow offered good separation of all PST epimeric pairs. A second set of FAIMS conditions was also identified, which focussed PSTs to a relatively narrow CV range allowing development of an LC-ESI-FAIMS-MS method for analysis of PST toxins in complex mussel tissue extracts. The quantitative capabilities of this method were evaluated by analysing a PST containing mussel tissue matrix material. Results compared favourably with analysis by an established LC-post-column oxidation-fluorescence method with recoveries ranging from 70 to 106%, although sensitivity was somewhat reduced. The current work represents the first successful separation of PST isomers using ion mobility and shows the promise of FAIMS as a tool for analysis of algal biotoxins in complex samples and outlines some critical requirements for its future improvement.

  18. Surface-Modified Membrane as A Separator for Lithium-Ion Polymer Battery

    OpenAIRE

    Jun Young Kim; Dae Young Lim

    2010-01-01

    This paper describes the fabrication of novel modified polyethylene (PE) membranes using plasma technology to create high-performance and cost-effective separator membranes for practical applications in lithium-ion polymer batteries. The modified PE membrane via plasma modification process plays a critical role in improving wettability and electrolyte retention, interfacial adhesion between separators and electrodes, and cycle performance of lithium-ion polymer batteries. This paper suggests ...

  19. Ancient Pb and Ti mobilization revealed by Scanning Ion Imaging

    Science.gov (United States)

    Kusiak, Monika A.; Whitehouse, Martin J.; Wilde, Simon A.

    2014-05-01

    Zircons from strongly layered early Archean ortho- and paragneisses in ultra-high temperature (UHT) metamorphic rocks of the Napier Complex, Enderby Land, East Antarctica are characterized by complex U-Th-Pb systematics [1,2,3]. A large number of zircons from three samples, Gage Ridge, Mount Sones and Dallwitz Nunatak, are reversely discordant (U/Pb ages older than 207Pb/206Pb ages) with the oldest date of 3.9 Ga [4] (for the grain from Gage Ridge orthogneiss). To further investigate this process, we utilized a novel high spatial resolution Scanning Ion Imaging technique on the CAMECA IMS 1280 at the Natural History Museum in Stockholm. Areas of 70 μm x 70 μm were selected for imaging in mono- and multicollection modes using a ~2 μm rastered primary beam to map out the distribution of 48Ti, 89Y, 180Hf, 232Th, 238U, 204Pb, 206Pb and 207Pb. The ion maps reveal variable distribution of certain elements within analysed grains that can be compared to their CL response. Yttrium, together with U and Th, exhibits zonation visible on the CL images, Hf shows expected minimal variation. Unusual patchiness is visible in the map for Ti and Pb distribution. The bright patches with enhanced signal do not correspond to any zones or to crystal imperfections (e.g. cracks). The presence of patchy titanium is likely to affect Ti-in-zircon thermometry, and patchy Pb affecting 207Pb/206Pb ages, usually considered as more robust for Archean zircons. Using the WinImage program, we produced 207Pb/206Pb ratio maps that allow calculation of 207Pb/206Pb ages for spots of any size within the frame of the picture and at any time after data collection. This provides a new and unique method for obtaining age information from zircon. These maps show areas of enhanced brightness where the 207Pb/206Pb ratio is higher and demonstrate that within these small areas (μm scale) the apparent 207Pb/206Pb age is older, in some of these patches even > 4 Ga. These data are a result of ancient Pb

  20. Detection of emissions from surfaces using ion mobility spectrometry.

    Science.gov (United States)

    Vautz, Wolfgang; Baumbach, Jörg Ingo; Uhde, Erik

    2006-02-01

    Emissions from surfaces (from furniture, wall paintings or floor coverings for instance) significantly influence indoor air quality and therefore the wellbeing or even the health of the occupants. Together with metabolites from mold they are responsible for the well-known "sick building syndrome". Therefore, it is in the interest of the manufacturer as well as of the occupants to have a fast and accurate method for the detection of substances relevant to this syndrome in order to be able to monitor and control product quality and indoor air quality. The use of small and easy-to-transport ion mobility spectrometers that use UV light as the ionization source enables rapid in situ detection of such substances with high selectivity and sensitivity (detection limits in the lower ppb range). If a multicapillary column is used for preseparation as well, the selectivity is increased and the unwanted influence of humidity on the spectra can be eliminated, thus enabling the use of the instruments under normal ambient conditions. Furthermore, the use of air as carrier gas avoids the need for other sources of high-purity gas. An emission cell with a homogeneous and constant air flow over the surface to be investigated was developed in order to ensure reproducible results. Investigations of emissions from wooden surfaces with and without additional contamination as well as from complex mixtures are presented. The results demonstrate that relevant emissions can be identified and quantified with high sensitivity and selectivity in under five minutes. Therefore, the method is useful for indoor air quality monitoring, especially when miniaturized instruments are applied.

  1. Measurement of ion swarm distribution functions in miniature low-temperature co-fired ceramic ion mobility spectrometer drift tubes.

    Science.gov (United States)

    Pfeifer, Kent B; Rumpf, Arthur N

    2005-08-15

    Measurements of the performance of a miniature, portable 12-mm-diameter, 57-mm-length low-temperature cofired ceramic (LTCC) ion mobility spectrometer drift tube were undertaken to verify models of ion transport and determine the physical shape of the ion "swarms" in the LTCC tube. Simplified two-dimensional Gaussian models of ion swarm shape were fit to measured data to extract geometrical shape parameters. Results indicate that tube-transfer function effects that produce asymmetric ion swarms are minimized in the tube reducing temporal dispersion. Data are presented that illustrate the swarm shape as a function of gate time, electric field magnitude, and total charge in the ion swarm. Characterization and understanding of the ion transport mechanisms and effects that limit the resolution and other performance parameters of miniature IMS drift tubes is essential to the development of practical, robust, portable systems for "first responder" and homeland security missions.

  2. Modeling of ion transport through a porous separator in vanadium redox flow batteries

    Science.gov (United States)

    Zhou, X. L.; Zhao, T. S.; An, L.; Zeng, Y. K.; Wei, L.

    2016-09-01

    In this work, we develop a two-dimensional, transient model to investigate the mechanisms of ion-transport through a porous separator in VRFBs and their effects on battery performance. Commercial-available separators with pore sizes of around 45 nm are particularly investigated and effects of key separator design parameters and operation modes are explored. We reveal that: i) the transport mechanism of vanadium-ion crossover through available separators is predominated by convection; ii) reducing the pore size below 15 nm effectively minimizes the convection-driven vanadium-ion crossover, while further reduction in migration- and diffusion-driven vanadium-ion crossover can be achieved only when the pore size is reduced to the level close to the sizes of vanadium ions; and iii) operation modes that can affect the pressure at the separator/electrode interface, such as the electrolyte flow rate, exert a significant influence on the vanadium-ion crossover rate through the available separators, indicating that it is critically important to equalize the pressure on each half-cell of a power pack in practical applications.

  3. First measurement of radioisotopes by collinear laser spectroscopy at an ion-guide separator

    NARCIS (Netherlands)

    Cooke, JL; Billowes, J; Campbell, P; Cochrane, ECA; Cooper, TG; Dendooven, P; Evans, DE; Griffith, JAR; Grant, IS; Honkanen, A; Huhta, M; Levins, JMG; Oinonen, M; Pearson, MR; Penttila, H; Persson, B.L.; Richardson, DS; Tungate, G; Wheeler, PD; Zybert, L; Aysto, J

    1997-01-01

    The first successful application of an ion-guide separator (IGISOL) for collinear laser spectroscopy of radioisotopes has achieved an efficiency comparable with the best obtained with catcher-ionizer facilities. The ion beam energy spread was determined to be less than 6 eV, allowing laser fluoresce

  4. Chromatographic separation process with pellicular ion exchange resins that can be used for ion or isotope separation and resins used in this process. Procede de separation chromatographique au moyen de resines echangeuses d'ions pelliculaires, utilisable notamment pour la separation des isotopes ou des ions, et resines utilisables dans ce procede

    Energy Technology Data Exchange (ETDEWEB)

    Carles, M.; Neige, R.; Niemann, C.; Michel, A.; Bert, M.; Bodrero, S.; Guyot, A.

    1989-01-06

    For separation of uranium, boron or nitrogen isotopes, an isotopic exchange is carried out betwen an isotope fixed on an ion exchange resin and another isotope of the same element in the liquid phase contacting the resin. Pellicular resins are used comprising composite particulates with an inert polymeric core and a surface layer with ion exchange groups.

  5. Development of optimized mobile phases for protein separation by high performance thin layer chromatography.

    Science.gov (United States)

    Biller, Julia; Morschheuser, Lena; Riedner, Maria; Rohn, Sascha

    2015-10-09

    In recent years, protein chemistry tends inexorably toward the analysis of more complex proteins, proteoforms, and posttranslational protein modifications. Although mass spectrometry developed quite fast correspondingly, sample preparation and separation of these analytes is still a major issue and quite challenging. For many years, electrophoresis seemed to be the method of choice; nonetheless its variance is limited to parameters such as size and charge. When taking a look at traditional (thin-layer) chromatography, further parameters such as polarity and different mobile and stationary phases can be utilized. Further, possibilities of detection are manifold compared to electrophoresis. Similarly, two-dimensional separation can be also performed with thin-layer chromatography (TLC). As the revival of TLC developed enormously in the last decade, it seems to be also an alternative to use high performance thin-layer chromatography (HPTLC) for the separation of proteins. The aim of this study was to establish an HPTLC separation system that allows a separation of protein mixtures over a broad polarity range, or if necessary allowing to modify the separation with only few steps to improve the separation for a specific scope. Several layers and solvent systems have been evaluated to reach a fully utilized and optimized separation system. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Selective separation and determination of isoproterenol on thin layers of bismuth silicate ion-exchanger.

    Science.gov (United States)

    Ghoulipour Vanik; Hassankhani-Majd Zahra

    2015-06-01

    A simple and sensitive method for the separation and determination of isoproterenol from other doping drugs has been developed on thin layers of bismuth silicate, a synthetic inorganic ion exchanger as adsorbent in thin layer chromatography (TLC). A mixture of methanol and 0.1 mol/L formic acid (3:7, v/v) was employed as the mobile phase. The development time was 32 min. The quantitative measurement were performed with a Camag TLC Scanner-3 at wavelength (λ) of 410 nm. The isoproterenol recovery in this procedure was 98.9%. The linear correlation coefficient was greater than 0. 987 1 and the relative standard deviation (RSD) was less than 0.94. The limit of detection (LOD) and limit of quantification ( LOQ) were 7.7 x 10(-7) mol/L and 3.85 x 10(-6) mol/L, respectively. This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.

  7. Selective separation and determination of isoproterenol on thin layers of bismuth silicate ion-exchanger

    Institute of Scientific and Technical Information of China (English)

    Vanik GHOULIPOUR; Zahra HASSANKHANI-MAJD

    2015-01-01

    A simple and sensitive method for the separation and determination of isoproterenol from other do-ping drugs has been developed on thin layers of bismuth silicate,a synthetic inorganic ion exchanger as adsor-bent in thin layer chromatography(TLC). A mixture of methanol and 0. 1 mol/L formic acid(3:7,v/v)was employed as the mobile phase. The development time was 32 min. The quantitative measurement were per-formed with a Camag TLC Scanner-3 at wavelength(λ)of 410 nm. The isoproterenol recovery in this procedure was 98. 9%. The linear correlation coefficient was greater than 0. 987 1 and the relative standard deviation (RSD)was less than 0.94. The limit of detection(LOD)and limit of quantification(LOQ)were 7.7×10-7 mol/L and 3. 85 ×10-6 mol/L,respectively. This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.

  8. On the role of local charge carrier mobility in the charge separation mechanism of organic photovoltaics.

    Science.gov (United States)

    Yoshikawa, Saya; Saeki, Akinori; Saito, Masahiko; Osaka, Itaru; Seki, Shu

    2015-07-21

    Although the charge separation (CS) and transport processes that compete with geminate and non-geminate recombination are commonly regarded as the governing factors of organic photovoltaic (OPV) efficiency, the details of the CS mechanism remain largely unexplored. Here we provide a systematic investigation on the role of local charge carrier mobility in bulk heterojunction films of ten different low-bandgap polymers and polythiophene analogues blended with methanofullerene (PCBM). By correlating with the OPV performances, we demonstrated that the local mobility of the blend measured by time-resolved microwave conductivity is more important for the OPV output than those of the pure polymers. Furthermore, the results revealed two separate trends for crystalline and semi-crystalline polymers. This work offers guidance in the design of high-performance organic solar cells.

  9. Tuning of mobile and stationary phase polarity for the separation of polar compounds by SFC.

    Science.gov (United States)

    Ibañez, E; Señoráns, F J

    2000-07-05

    The separation of polar compounds by supercritical-fluid chromatography (SFC) is reviewed. New developments in mobile and stationary phase tuning are reviewed for packed and packed capillary SFC. In terms of mobile phase polarity adjustment, new pure and multiple component fluids are presented. The approach of tuning the polarity of the stationary phase as a way of increasing the range of polar compounds analyzed by SFC using pure CO(2) is discussed using either silica-based or new materials as stationary phase. Chiral, liquid crystal and polymer-based stationary phases coated on particles are widely covered in this review as an interesting approach to separate polar compounds avoiding the major drawbacks associated to the use of modifiers in SFC.

  10. Ionic Liquids as Mobile Phase Additives for Separation of Nucleotides in High-Performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Wen-Zhu(张文珠); HE,Li-Jun(何丽君); LIU,Xia(刘霞); JIANG,Sheng-Xiang(蒋生祥)

    2004-01-01

    Ionic liquids are a type of salts that are liquid at low temperature (< 100 ℃). Because of their some special properties, they have been widely used as new "green solvents" for many chemical reactions and liquid-liquid extraction in the past several years. In this paper, a new method for the separation of nucleotides is developed and the essential feature of the method is that 1-alkyl-3-methylimidazolium salts are used as mobile phase additives, resulting in a baseline separation of nucleotides without need of gradient elution and need of organic solvent addition as currently used in RP-HPLC. This study shows the potential application of ionic liquids as mobile phase additives in reversed-phase liquid chromatography.

  11. Controller Development for a Separate Meter-In Separate Meter-Out Fluid Power Valve for Mobile Applications

    DEFF Research Database (Denmark)

    Nielsen, Brian

    by a single pump the fluid is distributed through valves. A valve works by controlling a fluid stream through the valve by varying the opening of an orifice. The disadvantage by this is that when controlling the fluid flow rate a pressure drop is created across the orifice. This results in a throttle loss......, which is commonly used in many types of mobile applications, is a 4-way proportional valve. In this type of valve two fluid streams are controlled: One fluid stream from a pump to a fluid consumer and one fluid stream from the fluid consumer to a fluid reservoir. In a 4-way proportional valve...... it is necessary to use a separate control of the two fluid streams to minimise the throttling losses. The purpose of the research documented in this dissertation is to investigate how a 4-way proportional valve may be build to fulfil the increasing demands with regard to energy efficiency and functionality...

  12. Separation of Radioactive Elements Using Nitrogen Oxygen Donor Macrocyclic Ion Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Joong; Shim, Min Sook [Korea University, Seoul (Korea, Republic of); Kim, Jeong; Lee, Myung No [Seonam University, Namwon (Korea, Republic of)

    1997-07-01

    The study for the selective separation and recovery of Pd{sup 2+} ion lead to following results. The four kinds of stationary phase, SGB-NTOE, SGB-NTOT, SGB-NEOD, and SGB-NTOD, were synthesized to react NOTE, NTOT, NEOD, and NTOD with 3-glycidyloxypropyltrimethoxy silane and silica gel. Using these macrocycles, selective separation of Hg(II), Pt(II), and Pd(II) from alkali earth and transition metal ions were possible by column chromatography. Maximum separation capability was appeared in SGB-NTOT and it took 12 hours for complete separation of Pd{sup 2+} ion with the column which inner diameter was 24 cm. The results of the study for the selective separation of Cs{sup +} and Sr{sup 2+} are as follows: Sr{sup 2+} ion was effectively separated through liquid membrane with CR22BB and the relative transport ration of Sr{sup 2+}/Na{sup +} was 15. Cs{sup +} ion was effectively separated through liquid membrane with CR22BB(OH)Ph and the relative transport ration of Cs{sup +}/Na{sup +} was 3.4. 9 refs., 7 tabs., 15 figs. (author)

  13. Relating chromatographic retention and electrophoretic mobility to the ion distribution within electrosprayed droplets.

    Science.gov (United States)

    Bökman, C Fredrik; Bylund, Dan; Markides, Karin E; Sjöberg, Per J R

    2006-03-01

    Ions that are observed in a mass spectrum obtained with electrospray mass spectrometry can be assumed to originate preferentially from ions that have a high distribution to the surface of the charged droplets. In this study, a relation between chromatographic retention and electrophoretic mobility to the ion distribution (derived from measured signal intensities in mass spectra and electrospray current) within electrosprayed droplets for a series of tetraalkylammonium ions, ranging from tetramethyl to tetrapentyl, is presented. Chromatographic retention in a reversed-phase system was taken as a measure of the analyte's surface activity, which was found to have a large influence on the ion distribution within electrosprayed droplets. In addition, different transport mechanisms such as electrophoretic migration and diffusion can influence the surface partitioning coefficient. The viscosity of the solvent system is affected by the methanol content and will influence both diffusion and ion mobility. However, as diffusion and ion mobility are proportional to each other, we have, in this study, chosen to focus on the ion mobility parameter. It was found that the influence of ion mobility relative to surface activity on the droplet surface partitioning of analyte ions decreases with increasing methanol content. This effect is most probably coupled to the decrease in droplet size caused by the decreased surface tension at increasing methanol content. The same observation was made upon increasing the ionic strength of the solvent system, which is also known to give rise to a decreased initial droplet size. The observed effect of ionic strength on the droplet surface partitioning of analyte ions could also be explained by the fact that at higher ionic strength, a larger number of ions are initially closer to the droplet surface and, thus, the contribution of ionic transport from the bulk liquid to the liquid/air surface interface (jet and droplet surface), attributable to

  14. [Separation of zoledronic acid and its related substances by ion-pair reversed-phase high performance liquid chromatography].

    Science.gov (United States)

    Zhang, Xiaoqing; Jiang, Ye; Xu, Zhiru

    2004-07-01

    A rapid and simple ion-pair reversed-phase high performance liquid chromatographic method (HPLC) has been established for the routine analysis of zoledronic acid and its related substances. The chromatographic conditions were optimized based on the satisfactory separation of zoledronic acid from imidazol-1-ylacetic acid, their retention times and peak shape. The excellent separation of zoledronic acid from its related substances, including the remaining imidazol-1-ylacetic acid used in the synthesis of zoledronic acid and other impurities of oxidation and decomposition, was achieved within 9 min on a Hypersil C8 column with UV detection at 220 nm. The mobile phase was a mixture of methanol (20%) and 5 mmo/L phosphate buffer (80%) that contains 6 mmol/L tetrabutylammonium bromide. The resolution factor of zoledronic acid from its adjacent peak was more than 2.5. This is a simple and rapid method for the routine assay of zoledronic acid.

  15. Robust creation of entanglement between ions in spatially separate cavities.

    Science.gov (United States)

    Browne, Daniel E; Plenio, Martin B; Huelga, Susana F

    2003-08-08

    We present a protocol that allows the generation of a maximally entangled state between individual atoms held in spatially separate cavities. Assuming perfect detectors and neglecting spontaneous emission from the atoms, the resulting idealized scheme is deterministic. Under more realistic conditions, when the atom-cavity interaction departs from the strong coupling regime, and considering imperfect detectors, we show that the scheme is robust against experimental inefficiencies and yields probabilistic entanglement of very high fidelity.

  16. Robust creation of entanglement between ions in spatially separate cavities

    CERN Document Server

    Plenio, M B; Huelga, S F

    2003-01-01

    We present a protocol that allows the generation of a maximally entangled state between individual atoms held in spatially separate cavities. Assuming perfect detectors and neglecting spontaneous emission from the atoms, the resulting idealized scheme is deterministic. Under more realistic conditions, when the the atom-cavity interaction departs from the strong coupling regime, and considering imperfect detectors, we show that the scheme is robust against experimental inefficiencies and yields probabilistic entanglement of very high fidelity.

  17. Calcium Activities During Different Ion Exchange Separation Procedures

    Science.gov (United States)

    Zhang, Z.; Zhu, H.; Liu, Y.; Liu, F.; Zhang, C.; Sun, W.

    2014-12-01

    Calcium is a major element and participates in many geological processes. Investigations on stable calcium isotopic compositions of natural geological samples provide a great powerful tool to understand all kinds of those geological processes from a view of the field of isotope geochemistry. With the development of modern instruments and chemical separation techniques, calcium isotopic compositions could be determined even more precisely if the column chemistry brings no deviation. Usually, Calcium is separated from matrix elements using cation resin columns and the related chemical separation techniques seem to be robust. However, more detailed work still need to be done on matrix effects and calcium isotopic fractionations on column chemistry or during elution processes. If calcium is run on TIMS instruments, the interference effect could be lower and easier controlled, thus, the requirement to the chemistry is relatively not critic, but calcium fractionation on filaments could be much difficult to monitor. If calcium is run on MC-ICP-MS instruments, the interference effect could be huge and is really difficult to be recognized and subtracted, the requirement to the chemistry is much more critical in order to get a real result of the sample, but the instrument fractionation could be easier to monitor. Here we investigate calcium activities on several kinds of cation resins under different column/acid conditions. We seek to find a good balance between recovery and interference effect on column chemistry and are intend to set up a better chemical separation procedure to satisfy the instrument requirements for calcium. In addition, Calcium isotopic fractionation on column will also be discussed further here based on our previous and ongoing results.

  18. Experimental research on benzene detection using ion mobility spectrometer with a laser ionization source

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-yun; KONG Xiang-he; JI Ren-dong; ZHANG Shu-dong

    2006-01-01

    An ion mobility spectrometer equipped with a laser ionization source is used for the sensitive detection of benzene.Mobility spectra of the benzene are presented.We also discussed the mobility spectra at various concentrations and drift voltages.Detection limits are determined to be in the upper ppbv range.In the end,the advantages and possibilities of this technique are briefly discussed.

  19. Study and optimization of key parameters of a laser ablation ion mobility spectrometer

    Science.gov (United States)

    Ni, Kai; Li, Jianan; Tang, Binchao; Shi, Yuan; Yu, Quan; Qian, Xiang; Wang, Xiaohao

    2016-11-01

    Ion Mobility Spectrometry (IMS), having an advantage in real-time and on-line detection, is an atmospheric pressure detecting technique. LA-IMS (Laser Ablation Ion Mobility Spectrometry) uses Nd-YAG laser as ionization source, whose energy is high enough to ionize metal. In this work, we tested the signal in different electric field intensity by a home-made ion mobility spectrometer, using silicon wafers the sample. The transportation of metal ions was match with the formula: Td = d/K • 1/E, when the electric field intensity is greater than 350v/cm. The relationship between signal intensity and collection angle (the angle between drift tube and the surface of the sample) was studied. With the increasing of the collection angle, signal intensity had a significant increase; while the variation of incident angle of the laser had no significant influence. The signal intensity had a 140% increase when the collection angle varied from 0 to 45 degree, while the angle between the drift tube and incident laser beam keeping the same as 90 degree. The position of ion gate in LA-IMS(Laser Ablation Ion Mobility Spectrometry) is different from the traditional ones for the kinetic energy of the ions is too big, if the distance between ion gate and sampling points less than 2.5cm the ion gate will not work, the ions could go through ion gate when it closed. The SNR had been improved by define the signal when the ion gate is closed as background signal, the signal noise including shock wave and electrical field perturbation produced during the interaction between laser beam and samples is eliminated when the signal that the ion gate opened minus the background signal.

  20. Continuous Separation of Cesium Based on NiHCF/PTCF Electrode by Electrochemically Switched Ion Exchange

    Institute of Scientific and Technical Information of China (English)

    孙斌; 郝晓刚; 王忠德; 张忠林; 刘世斌; 官国清

    2012-01-01

    Nickel hexacyanoferrate (NiHCF) film was synthesized on porous three-dimensional carbon felt (PTCF) substrate by repetitious batch chemical depositions, and the NiHCF/PTCF electrode was used as electrochemically switched ion exchange (ESIX) electrode in a packed bed for continuous separation for cesium ions. The morphologies of the prepared electrodes were characterized by scanning electron microscopy and the effects of solution concentration on the ion-exchange capacity of the electrodes were investigated by cyclic voltammetry technique. Cycling stability and long-term storage stability of NiHCF/PTCF electrodes were also studied. The NiHCF/PTCF electrodes with excellent ion-exchange ability were used to assemble a diaphragm-isolated ESIX reactor for cesium separation. Continuous separation of cesium and regeneration of NiHCF/PTCF electrode based on the diaphragm-isolated reactor were performed in a laboratory-scale two-electrode system.

  1. Electrodialysis-ion exchange for the separation of dissolved salts

    Energy Technology Data Exchange (ETDEWEB)

    Baroch, C.J. [Wastren, Inc., Westminster, CO (United States); Grant, P.J. [Wastren, Inc., Hummelstown, PA (United States)

    1995-10-01

    The Department of Energy generates and stores a significant quantity of low level, high level, and mixed wastes. As some of the DOE facilities are decontaminated and decommissioned, additional and possibly different forms of wastes will be generated. A significant portion of these wastes are aqueous streams containing acids, bases, and salts, or are wet solids containing inorganic salts. Some of these wastes are quite dilute solutions, whereas others contain large quantities of nitrates either in the form of dissolved salts or acids. Many of the wastes are also contaminated with heavy metals, radioactive products, or organics. Some of these wastes are in storage because a satisfactory treatment and disposal processes have not been developed. There is considerable interest in developing processes that remove or destroy the nitrate wastes. Electrodialysis-Ion Exchange (EDIX) is a possible process that should be more cost effective in treating aqueous waste steams. This report describes the EDIX process.

  2. Method and system for producing hydrogen using sodium ion separation membranes

    Science.gov (United States)

    Bingham, Dennis N; Klingler, Kerry M; Turner, Terry D; Wilding, Bruce M; Frost, Lyman

    2013-05-21

    A method of producing hydrogen from sodium hydroxide and water is disclosed. The method comprises separating sodium from a first aqueous sodium hydroxide stream in a sodium ion separator, feeding the sodium produced in the sodium ion separator to a sodium reactor, reacting the sodium in the sodium reactor with water, and producing a second aqueous sodium hydroxide stream and hydrogen. The method may also comprise reusing the second aqueous sodium hydroxide stream by combining the second aqueous sodium hydroxide stream with the first aqueous sodium hydroxide stream. A system of producing hydrogen is also disclosed.

  3. Novel additives for the separation of organic acids by ion-pair chromatography

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper proposes the use of novel surfactant additives for the separation of organic acids by ion-pair chromatography and studies the influences of surfactants on the chromatographic separation behaviors.Researches have been carried out on both silica gel matrix and polymer supporters in order to compare the two ordinary kinds of stationary phases,and the phenomenon is similar. Separation is based on differences in the stabilities of analyte-additive complexes in solution.Retention times of analytes c...

  4. Mussel-inspired polydopamine-treated polyethylene separators for high-power Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ryou, Myung-Hyun; Park, Jung-Ki [Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea, Republic of); Lee, Yong Min [Department of Applied Chemistry, Hanbat National University, Daejeon, 305-719 (Korea, Republic of); Choi, Jang Wook [Graduate School of EEWS, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea, Republic of)

    2011-07-19

    Polydopamine-treated polyethylene (PE) separators for high-power lithium ion batteries are developed. A simple dipping process makes the PE surfaces hydrophilic and thus enhances the power capabilities remarkably compared to those of the control cases with bare PE separators. The original mechanical and thermal properties of the PE separators are preserved. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. First observation and mobility measurements of negative ions in superfluid He-4

    NARCIS (Netherlands)

    Kasimova, A; Zuhlke, C; Jungmann, K; Putlitz, GZ

    2003-01-01

    We present the results of the first mobility measurements in superfluid helium for negative ions of different elements. Various negative ions like Cl-, F- and I- were produced by laser ablation from targets consisting of NaCl, NaF, NaI, LiF and KCl immersed in a He-4 bath. In addition to negative io

  6. First observation and mobility measurements of negative ions in superfluid He-4

    NARCIS (Netherlands)

    Kasimova, A; Zuhlke, C; Jungmann, K; Putlitz, GZ

    We present the results of the first mobility measurements in superfluid helium for negative ions of different elements. Various negative ions like Cl-, F- and I- were produced by laser ablation from targets consisting of NaCl, NaF, NaI, LiF and KCl immersed in a He-4 bath. In addition to negative

  7. Development of an Ion Mobility Spectrometry-Orbitrap Mass Spectrometer Platform

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Yehia M.; Garimella, Sandilya V. B.; Prost, Spencer A.; Wojcik, Roza; Norheim, Randolph V.; Baker, Erin S.; Rusyn, Ivan; Smith, Richard D.

    2016-12-20

    Complex samples benefit from multidimensional measurements where higher resolution enables more complete characterization of biological and environmental systems. To address this challenge, we developed a drift tube-based ion mobility spectrometry-Orbitrap mass spectrometer (IMS-Orbitrap MS) platform. To circumvent the time scale disparity between the fast IMS separation and the much slower Orbitrap MS acquisition, we utilized a dual gate and pseudorandom sequences to multiplexed injection of ions and allowing operation in signal averaging (SA), single multiplexing (SM) and double multiplexing (DM) IMS modes to optimize the signal-to-noise ratio of the measurements. For the SM measurements, a previously developed algorithm was used to reconstruct the IMS data. A new algorithm was developed for the DM analyses involving a two-step process that first recovers the SM data and then decodes the SM data. The algorithm also performs multiple refining procedures in order to minimize demultiplexing artifacts. The new IMS-Orbitrap MS platform was demonstrated by the analysis of proteomic and petroleum samples, where the integration of IMS and high mass resolution proved essential for accurate assignment of molecular formulae.

  8. Electrochemical selective ion separation in capacitive deionization with sodium manganese oxide.

    Science.gov (United States)

    Kim, Seonghwan; Yoon, Hansun; Shin, Dongyoon; Lee, Jaehan; Yoon, Jeyong

    2017-11-15

    Electrochemical selective ion separation via capacitive deionization, for example, separation of lithium resource from brine, using lithium ion batteries is proposed and demonstrated to have the potential for separating specific ions selectively from a solution containing diverse ions. This separation method is of great industrial concern because of applicability in various fields such as deionization, water softening, purification, heavy metal removal, and resource recovery. Nevertheless, besides the selectivity of materials for lithium ion batteries toward Li(+), there is very little investigation on the selectivity of the materials for sodium ion batteries toward Na(+). Here, the electrochemical selectivity of sodium manganese oxide (Na0.44MnO2), one of the most widely used material in sodium ion batteries, for Na(+) and other cations (K(+), Mg(2+), and Ca(2+)) is investigated. Selective Na(+) separation using the system consisting of Na0.44MnO2 and a Ag/AgCl electrode is successfully demonstrated from a solution containing diverse cations (Na(+), K(+), Mg(2+), and Ca(2+)) via a two-step process that involves a capturing step (charging process) and a releasing step (discharging process). The results showed that Na0.44-xMnO2 has over 13 times higher selectivity for Na(+) than for K(+) and 6-8times higher selectivity for Na(+) than for Mg(2+) and Ca(2+) in the electrolyte containing equal concentrations of the respective ions. Additionally, as a practical demonstration, Na(+) was successfully separated from an industrial raw material used for pure KOH production (estimated ratio of Na(+):K(+)=1:200). Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Data for Users of Handheld Ion Mobility Spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Keith A. Daum; Sandra L. Fox

    2008-05-01

    Chemical detection technology end-user surveys conducted by Idaho National Laboratory (INL) in 2005 and 2007 indicated that first responders believed manufacturers’ claims for instruments sometimes were not supported in field applications, and instruments sometimes did not meet their actual needs. Based on these findings, the Department of Homeland Security (DHS) asked INL to conduct a similar survey for handheld ion mobility spectrometers (IMS), which are used by a broad community of first responders as well as for other applications. To better access this broad community, the INL used the Center for Technology Commercialization, Inc. (CTC), Public Safety Technology Center (PSTC) to set up an online framework to gather information from users of handheld IMS units. This framework (Survey Monkey) was then used to perform an online Internet survey, augmented by e-mail prompts, to get information from first responders and personnel from various agencies about their direct experience with handheld IMS units. Overall, 478 individuals responded to the survey. Of these, 174 respondents actually owned a handheld IMS. Performance and satisfaction data from these 174 respondents are captured in this report. The survey identified the following observations: • The most common IMS unit used by respondents was the Advanced Portable Detector (APD 2000), followed by ChemRae, Sabre 4000, Sabre 2000, Draeger Multi IMS, Chemical Agent Monitor-2, Chemical Agent Monitor, Vapor Tracer, and Vapor Tracer 2. • The primary owners were HazMat teams (20%), fire services (14%), local police (12%), and sheriffs’ departments (9%). • IMS units are seldom used as part of an integrated system for detecting and identifying chemicals but instead are used independently. • Respondents are generally confused about the capabilities of their IMS unit. This is probably a result of lack of training. • Respondents who had no training or fewer than 8 hours were not satisfied with the overall

  10. Electrode-supported thin α-alumina separators for lithium-ion batteries

    Science.gov (United States)

    Mi, Wanliang; Sharma, Gaurav; Dong, Xueliang; Jin, Yi; Lin, Y. S.

    2016-02-01

    Lithium ion batteries with an inorganic separator offer improved safety and enhanced reliability. The free-standing inorganic separators recently studied for lithium ion batteries are brittle and expensive. To address these issues, this paper reports the synthesis of a new and stable electrode-supported separator using a low-cost ceramic powder. Thin and porous α-Al2O3 separator films of thicknesses down to 40 μm were coated on Li4Ti5O12 (LTO) electrode by blade-coating a slurry of α-Al2O3, water and a small amount of polyvinyl alcohol (PVA). The performance of the LTO/Li cells with coated α-Al2O3 separator improves with decreasing PVA content. Cells with coated α-Al2O3 separator containing 0.4wt% PVA exhibit similar discharge capacity but better rate capability than those with commercial polypropylene (PP) or thick sintered α-Al2O3 separator. The coated α-Al2O3 separator does not react with LTO even after many charge/discharge cycles. Fabrication of the electrode-supported α-Al2O3 separator is scalable and cost-effective, offering high potential for practical application in industrial lithium ion battery manufacturing.

  11. Rate-dependent performance of ion chambers for particle-ID at the GSI fragment separator

    Energy Technology Data Exchange (ETDEWEB)

    Hucka, Jan-Paul; Allred, Timothy; Enders, Joachim [Institut fuer Kernphysik, TU Darmstadt (Germany); Gernhaeuser, Roman; Maurus, Steffen [Physik Department, TU Muenchen (Germany); Nociforo, Chiara; Pietri, Stephane; Prochazka, Andrej [GSI Helmholtzzentrum fuer Schwerionenforschung (Germany)

    2015-07-01

    At the GSI Fragment Separator (FRS), multi-sampling ion chambers (MUSIC) employing a Frisch grid are used for charge identification of secondary ion beams. At the FAIR Super-FRS, higher rates are expected, and an event-by-event determination of the charge of secondary ions will be needed at rates of several 100000 events per second. The comparison of results from test measurements for the MUSIC performance with that of a recently constructed tilted-electrode gas ion chamber (TEGIC), which was designed similar to the one discussed, is presented.

  12. Production of intense metallic ion beams in order of isotopic separations; Production de faisceaux intenses d'ions metalliques en vue de la separation des isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Sarrouy, J.L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    We describe an isotope separator with magnetic sector of 60 deg that permits, with a process of neutralization of the space charge, to use efficiently intense ion beams. The sources of realized ions provide ionic debits of 10 mA. This present work deals who to obtain intense ion beams (10 to 15 mA), different processes of ion currents measurement, as well as the study of the phenomenon of space charge neutralization. The second part of this memory will be on the survey and the adaptation on the source of various type of oven permitting to spray and to ionize metals directly. By order of increasing difficulty of vaporization, we reached the chromium. (M.B.) [French] 0n decrit un separateur d'isotope a secteur magnetique de 60 deg qui permet, grace a un procede de neutralisation de la charge d'espace, d'utiliser efficacement des faisceaux d'ions intenses. Les sources d'ions realisees fournissent des debits ioniques de 10 mA. Ce present travail porte sur l'obtention de faisceaux d'ions faisceaux d'ions intenses (10 a 15 mA), des differents procedes de mesures des courants d'ions, ainsi que l'etude du phenomene de neutralisation de charge d'espace. La deuxieme partie de ce memoire portera sur l'etude et l'adaptation sur la source de divers type de four permettant de vaporiser et d'ioniser directement les metaux. Par ordre de difficulte croissantes de vaporisations, nous avons atteint le chrome. (M.B.)

  13. Production of intense metallic ion beams in order of isotopic separations; Production de faisceaux intenses d'ions metalliques en vue de la separation des isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Sarrouy, J.L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    We describe an isotope separator with magnetic sector of 60 deg that permits, with a process of neutralization of the space charge, to use efficiently intense ion beams. The sources of realized ions provide ionic debits of 10 mA. This present work deals who to obtain intense ion beams (10 to 15 mA), different processes of ion currents measurement, as well as the study of the phenomenon of space charge neutralization. The second part of this memory will be on the survey and the adaptation on the source of various type of oven permitting to spray and to ionize metals directly. By order of increasing difficulty of vaporization, we reached the chromium. (M.B.) [French] 0n decrit un separateur d'isotope a secteur magnetique de 60 deg qui permet, grace a un procede de neutralisation de la charge d'espace, d'utiliser efficacement des faisceaux d'ions intenses. Les sources d'ions realisees fournissent des debits ioniques de 10 mA. Ce present travail porte sur l'obtention de faisceaux d'ions faisceaux d'ions intenses (10 a 15 mA), des differents procedes de mesures des courants d'ions, ainsi que l'etude du phenomene de neutralisation de charge d'espace. La deuxieme partie de ce memoire portera sur l'etude et l'adaptation sur la source de divers type de four permettant de vaporiser et d'ioniser directement les metaux. Par ordre de difficulte croissantes de vaporisations, nous avons atteint le chrome. (M.B.)

  14. Effects of mobile vacancies on the dynamics of ordering and phase separation in nonconserved multicomponent systems

    DEFF Research Database (Denmark)

    Gilhøj, Henriette; Jeppesen, Claus; Mouritsen, Ole G.

    1995-01-01

    The effects of mobile vacancies on the dynamics of ordering processes and phase separation in multicomponent systems are studied via Monte Carlo simulations of a two-dimensional seven-state ferromagnetic Potts model with varying degrees of site dilution. The model displays phase equilibria...... corresponding to a dilute Potts-disordered (fluid) phase and a dilute Potts-ordered phase (solid), as well as a broad region of coexistence between the fluid and the solid phase. Temperature quenches into the dilute Potts-ordered phase as well as into the phase-separated region are considered under...... the condition of conserved vacancy density and nonconserved Potts order. The dynamics of ordering and phase separation is found to follow algebraic growth laws with exponent values that depend on the phase to which the quench is performed. Strong transient effects are observed in the dilute Potts-ordered phase...

  15. SEPARATION OF METAL IONS AS CHELATES OF 1N2,7O3,6S IN THE PRESENCE OR ABSSENCE OF TBA+ BY CAPILLARY ELECTROPHORESIS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Separation and determination of metal ions based on the formation of chelate anions with 1-Nitroso-2,7-dihydrexynaphthalene-3,6-di sulfonic acid(1N2,7O3,6S) was studied by using HPCE of the nine metal ions exami ned, the ions that can be detected sensitively with 1-Nitroso-2,7-dihydrexyna phtha lene-3,6-disulfonic acid were Fe2+,Co2+,Cu2+,Ni2+,Zn 2+ and Pd2+. The cobalt chelate could exist in two oxidation stat es of cobalt. When TBA+ were added in electrophoretic solutions, the drastic c ha nges in electrophoretic mobilities of chelate were observed, which was due to th e ion association between chelates anions and TBA+. The ion association consta nts of chelate anions with TBA+ were determined by using the change in electro p horetic mobilities of chelates, metal ions tested were separated within 10 min u sing 30cm silica capillary(50 m i.d).

  16. Exhaled breath analysis for lung cancer detection using ion mobility spectrometry.

    Directory of Open Access Journals (Sweden)

    Hiroshi Handa

    Full Text Available Conventional methods for lung cancer detection including computed tomography (CT and bronchoscopy are expensive and invasive. Thus, there is still a need for an optimal lung cancer detection technique.The exhaled breath of 50 patients with lung cancer histologically proven by bronchoscopic biopsy samples (32 adenocarcinomas, 10 squamous cell carcinomas, 8 small cell carcinomas, were analyzed using ion mobility spectrometry (IMS and compared with 39 healthy volunteers. As a secondary assessment, we compared adenocarcinoma patients with and without epidermal growth factor receptor (EGFR mutation.A decision tree algorithm could separate patients with lung cancer including adenocarcinoma, squamous cell carcinoma and small cell carcinoma. One hundred-fifteen separated volatile organic compound (VOC peaks were analyzed. Peak-2 noted as n-Dodecane using the IMS database was able to separate values with a sensitivity of 70.0% and a specificity of 89.7%. Incorporating a decision tree algorithm starting with n-Dodecane, a sensitivity of 76% and specificity of 100% was achieved. Comparing VOC peaks between adenocarcinoma and healthy subjects, n-Dodecane was able to separate values with a sensitivity of 81.3% and a specificity of 89.7%. Fourteen patients positive for EGFR mutation displayed a significantly higher n-Dodecane than for the 14 patients negative for EGFR (p<0.01, with a sensitivity of 85.7% and a specificity of 78.6%.In this prospective study, VOC peak patterns using a decision tree algorithm were useful in the detection of lung cancer. Moreover, n-Dodecane analysis from adenocarcinoma patients might be useful to discriminate the EGFR mutation.

  17. An electrospray ionization-ion mobility spectrometer as detector for high- performance liquid chromatography.

    Science.gov (United States)

    Zühlke, Martin; Riebe, Daniel; Beitz, Toralf; Löhmannsröben, Hans-Gerd; Zenichowski, Karl; Diener, Marc; Linscheid, Michael W

    2015-01-01

    The application of electrospray ionization (ESI) ion mobility (IM) spectrometry on the detection end of a high-performance liquid chromatograph has been a subject of study for some time. So far, this method has been limited to low flow rates or has required splitting of the liquid flow. This work presents a novel concept of an ESI source facilitating the stable operation of the spectrometer at flow rates between 10 μL mn(-1) and 1500 μL min(-1) without flow splitting, advancing the T-cylinder design developed by Kurnin and co-workers. Flow rates eight times faster than previously reported were achieved because of a more efficient dispersion of the liquid at increased electrospray voltages combined with nebulization by a sheath gas. Imaging revealed the spray operation to be in a rotationally symmetric multijet mode. The novel ESI-IM spectrometer tolerates high water contents (≤90%) and electrolyte concentrations up to 10mM, meeting another condition required of high-performance liquid chromatography (HPLC) detectors. Limits of detection of 50 nM for promazine in the positive mode and 1 μM for 1,3-dinitrobenzene in the negative mode were established. Three mixtures of reduced complexity (five surfactants, four neuroleptics, and two isomers) were separated in the millisecond regime in stand-alone operation of the spectrometer. Separations of two more complex mixtures (five neuroleptics and 13 pesticides) demonstrate the application of the spectrometer as an HPLC detector. The examples illustrate the advantages of the spectrometer over the established diode array detector, in terms of additional IM separation of substances not fully separated in the retention time domain as well as identification of substances based on their characteristic Ims.

  18. Supercritical fluid chromatographic resolution of water soluble isomeric carboxyl/amine terminated peptides facilitated via mobile phase water and ion pair formation.

    Science.gov (United States)

    Patel, M A; Riley, F; Ashraf-Khorassani, M; Taylor, L T

    2012-04-13

    Both analytical scale and preparative scale packed column supercritical fluid chromatography (SFC) have found widespread applicability for chiral separations of multiple polar pharmaceutical candidates. However, SFC is rapidly becoming an achiral technique. More specifically, ion pair SFC is finding greater utility for separation of ionic analytes such as amine salts and organic sulfonates. The key to this success is, in part, the incorporation of additives such as trifluoroacetic acid and ammonium acetate into the mobile phase in association with a wide variety of both bonded silica stationary phases and high purity bare silica. Ion pairing SFC coupled with evaporative light scattering detection and mass spectrometric detection is presented here for the separation of water soluble, uncapped, isomeric peptide pairs that differ in amino acid arrangement. The separation is best achieved on either diol-bonded silica or bare silica with 1-5% (w/w) water as a significant ingredient in the mobile phase. Nitrogenous stationary phases such as 2-ethylpyridine, which had been very successful for the separation of capped peptides failed to yield the desired separation regardless of the mobile phase composition. A HILIC type retention mechanism is postulated for the separation of both isomeric uncapped peptide pairs.

  19. Quantitative detection of benzene in toluene- and xylene-rich atmospheres using high-kinetic-energy ion mobility spectrometry (IMS).

    Science.gov (United States)

    Langejuergen, Jens; Allers, Maria; Oermann, Jens; Kirk, Ansgar; Zimmermann, Stefan

    2014-12-02

    One major drawback of ion mobility spectrometry (IMS) is the dependence of the response to a certain analyte on the concentration of water or the presence of other compounds in the sample gas. Especially for low proton affine analytes, e.g., benzene, which often exists in mixtures with other volatile organic compounds, such as toluene and xylene (BTX), a time-consuming preseparation is necessary. In this work, we investigate BTX mixtures using a compact IMS operated at decreased pressure (20 mbar) and high kinetic ion energies (HiKE-IMS). The reduced electric field in both the reaction tube and the drift tube can be independently increased up to 120 Td. Under these conditions, the water cluster distribution of reactant ions is shifted toward smaller clusters independent of the water content in the sample gas. Thus, benzene can be ionized via proton transfer from H3O(+) reactant ions. Also, a formation of benzene ions via charge transfer from NO(+) is possible. Furthermore, the time for interaction between ions and neutrals of different analytes is limited to such an extent that a simultaneous quantification of benzene, toluene, and xylene is possible from low ppbv up to several ppmv concentrations. The mobility resolution of the presented HiKE-IMS varies from R = 65 at high field (90 Td) to R = 73 at lower field (40 Td) in the drift tube, which is sufficient to separate the analyzed compounds. The detection limit for benzene is 29 ppbv (2 s of averaging) with 3700 ppmv water, 12.4 ppmv toluene, and 9 ppmv xylene present in the sample gas. Furthermore, a less-moisture-dependent benzene measurement with a detection limit of 32 ppbv with ca. 21 000 ppmv (90% relative humidity (RH) at 20 °C) water present in the sample gas is possible evaluating the signal from benzene ions formed via charge transfer.

  20. Mobility of O$_2^-$ ions in supercritical Ar: Experiment and Molecular Dynamics Simulations

    CERN Document Server

    Borghesani, A F

    2008-01-01

    A new analysis and new Molecular Dynamics (MD) simulations of the measurements of the mobility $\\mu_{i}$ of O$_{2}^{-} $ ions in dense supercritical Ar gas are reported. $\\mu_{i}$ shows a marked dependence on the distance from the critical temperature $T_{c}.$ A mobility defect appears as a function of the gas density and its maximum value occurs below the critical density. The locus of points of maximum mobility defect in the $P-T$ plane appears on the extrapolation of the coexistence curve into the single-phase region. MD simulations quantitatively reproduce the mobility defect near $T_{c}.$

  1. Comprehensive theoretical analysis and experimental exploration of ultrafast microchip-based high-field asymmetric ion mobility spectrometry (FAIMS) technique.

    Science.gov (United States)

    Li, Lingfeng; Wang, Yonghuan; Chen, Chilai; Wang, Xiaozhi; Luo, Jikui

    2015-06-01

    High-field asymmetric ion mobility spectrometry (FAIMS) has become an efficient technique for separation and characterization of gas-phase ions at ambient pressure, which utilizes the mobility differences of ions at high and low fields. Micro FAIMS devices made by micro-electromechanical system technology have small gaps of the channels, high electric field and good installation precision, as thus they have received great attentions. However, the disadvantage of relatively low resolution limits their applications in some areas. In this study, theoretical analysis and experimental exploration were carried out to overcome the disadvantage. Multiple scans, characteristic decline curves of ion transmission and pattern recognitions were proposed to improve the performance of the microchip-based FAIMS. The results showed that although micro FAIMS instruments as a standalone chemical analyzer suffer from low resolution, by using one or more of the methods proposed, they can identify chemicals precisely and provide quantitative analysis with low detection limit in some applications. Copyright © 2015 John Wiley & Sons, Ltd.

  2. Adjusting mobility scales of ion mobility spectrometers using 2,6-DtBP as a reference compound.

    Science.gov (United States)

    Viitanen, A-K; Mauriala, T; Mattila, T; Adamov, A; Pedersen, C S; Mäkelä, J M; Marjamäki, M; Sysoev, A; Keskinen, J; Kotiaho, T

    2008-09-15

    Performance of several time-of-flight (TOF) type ion mobility spectrometers (IMS) was compared in a joint measurement campaign and their mobility scales were adjusted based on the measurements. A standard reference compound 2,6-di-tert butylpyridine (2,6-DtBP) was used to create a single peak ion mobility distribution with a known mobility value. The effective length of the drift tube of each device, considered here as an instrument constant, was determined based on the measurements. Sequentially, two multi-peaked test compounds, DMMP and DIMP, were used to verify the performance of the adjustment procedure in a wider mobility scale. By determining the effective drift tube lengths using 2,6-DtBP, agreement between the devices was achieved. The determination of effective drift tube lengths according to standard reference compound was found to be a good method for instrument inter-comparison. The comparison procedure, its benefits and shortcomings as well as dependency on accuracy of literature value are discussed along with the results.

  3. Coherent Diabatic Ion Transport and Separation in a Multi-Zone Trap Array

    CERN Document Server

    Bowler, R; Lin, Y; Tan, T R; Hanneke, D; Jost, J D; Home, J P; Leibfried, D; Wineland, D J

    2015-01-01

    We investigate the motional dynamics of single and multiple ions during transport between and separation into spatially distinct locations in a multi-zone linear Paul trap. A single 9Be+ ion in a 2 MHz harmonic well located in one zone was laser-cooled to near its ground state of motion and transported 370 micrometers by moving the well to another zone. This was accomplished in 8 microseconds, corresponding to 16 periods of oscillation. Starting from a state with n=0.1 quanta, during transport the ion was excited to a displaced coherent state with n=1.6 quanta but on completion was returned close to its motional ground state with n=0.2. Similar results were achieved for the transport of two ions. We also separated chains of up to 9 ions from one potential well to two distinct potential wells. With two ions this was accomplished in 55 microseconds, with final excitations of about 2 quanta for each ion. Fast coherent transport and separation can significantly reduce the time overhead in certain architectures fo...

  4. Enhanced capacity and stability for the separation of cesium in electrically switched ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Tawfic, A.F.; Dickson, S.E.; Kim, Y. [McMaster University, Hamilton, ON (Canada); Mekky, W. [AMEC NSS, Power and Process America, Toronto (Canada)

    2015-03-15

    Electrically switched ion exchange (ESIX) can be used to separate ionic contaminants from industrial wastewater, including that generated by the nuclear industry. The ESIX method involves sequential application of reduction and oxidation potentials to an ion exchange film to induce the respective loading and unloading of cesium. This technology is superior to conventional methods (e.g electrodialysis reversal or reverse osmosis) as it requires very little energy for ionic separation. In previous studies, ESIX films have demonstrated relatively low ion exchange capacities and limited film stabilities over repeated potential applications. In this study, the methodology for the deposition of electro-active films (nickel hexacyanoferrate) on nickel electrodes was modified to improve the ion exchange capacity for cesium removal using ESIX. Cyclic voltammetry was used to investigate the ion exchange capacity and stability. Scanning electron microscopy (SEM) was used to characterize the modified film surfaces. Additionally, the films were examined for the separation of cesium ions. This modified film preparation technique enhanced the ion exchange capacity and improves the film stability compared to previous methods for the deposition of ESIX films. (authors)

  5. Prawn Shell Derived Chitin Nanofiber Membranes as Advanced Sustainable Separators for Li/Na-Ion Batteries.

    Science.gov (United States)

    Zhang, Tian-Wen; Shen, Bao; Yao, Hong-Bin; Ma, Tao; Lu, Lei-Lei; Zhou, Fei; Yu, Shu-Hong

    2017-08-09

    Separators, necessary components to isolate cathodes and anodes in Li/Na-ion batteries, are consumed in large amounts per year; thus, their sustainability is a concerning issue for renewable energy storage systems. However, the eco-efficient and environmentally friendly fabrication of separators with a high mechanical strength, excellent thermal stability, and good electrolyte wettability is still challenging. Herein, we reported the fabrication of a new type of separators for Li/Na-ion batteries through the self-assembly of eco-friendly chitin nanofibers derived from prawn shells. We demonstrated that the pore size in the chitin nanofiber membrane (CNM) separator can be tuned by adjusting the amount of pore generation agent (sodium dihydrogen citrate) in the self-assembly process of chitin nanofibers. By optimizing the pore size in CNM separators, the electrochemical performance of the LiFePO4/Li half-cell with a CNM separator is comparable to that with a commercialized polypropylene (PP) separator. More attractively, the CNM separator showed a much better performance in the LiFePO4/Li cell at 120 °C and Na3V2(PO4)3/Na cell than the PP separator. The proposed fabrication of separators by using natural raw materials will play a significant contribution to the sustainable development of renewable energy storage systems.

  6. Performance, resolving power, and radial ion distributions of a prototype nanoelectrospray ionization resistive glass atmospheric pressure ion mobility spectrometer.

    Science.gov (United States)

    Kwasnik, Mark; Fuhrer, Katrin; Gonin, Marc; Barbeau, Katherine; Fernandez, Facundo M

    2007-10-15

    In this article, we describe and characterize a novel ion mobility spectrometer constructed with monolithic resistive glass desolvation and drift regions. This instrument is equipped with switchable corona discharge and nanoelectrospray ionization sources and a Faraday plate detector. Following description of the instrument, pulsing electronics, and data acquisition system, we examine the effects of drift gas flow rate and temperature, and of the aperture grid to anode distance on the observed resolving power and sensitivity. Once optimum experimental parameters are identified, different ion gate pulse lengths, and their effect on the temporal spread of the ion packet were investigated. Resolving power ranged from an average value of 50 ms/ms for a 400-micros ion gate pulse, up to an average value of 68 ms/ms for a 100-micros ion gate pulse, and a 26-cm drift tube operated at 383 V cm(-1). Following these experiments, the radial distribution of ions in the drift region of the spectrometer was studied by using anodes of varying sizes, showing that the highest ionic density was located at the center of the drift tube. Finally, we demonstrate the applicability of this instrument to the study of small molecules of environmental relevance by analyzing a commercially available siderophore, deferoxamine mesylate, in both the free ligand and Fe-bound forms. Ion mobility experiments showed a dramatic shift to shorter drift times caused by conformational changes upon metal binding, in agreement with previous reversed-phase liquid chromatography observations.

  7. Characterization of Polyolefin Pyrolysis Species Produced Under Ambient Conditions by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry and Ion Mobility-Mass Spectrometry

    Science.gov (United States)

    Farenc, Mathilde; Witt, Matthias; Craven, Kirsten; Barrère-Mangote, Caroline; Afonso, Carlos; Giusti, Pierre

    2017-03-01

    Polyolefins such as polyethylene (PE) and polypropylene (PP) are often characterized from their pyrolysis products by Py-MS. Nowadays the development of plasma-based direct probe atmospheric pressure sources allow the direct analysis of these polymers. These sources operate at atmospheric pressure, which implies a limited control of the ionization conditions. It was shown that side reactions could occur with species present in air, such as O2, which may lead to the formation of oxidized compounds. In this work, ion mobility-mass spectrometry (IM-MS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR) were used for the exhaustive characterization of the PP and PE pyrolysis ions produced using plasma-based atmospheric pressure ion sources. Both PP and PE yielded distributions of pyrolysis products presenting different amounts of unsaturation but also different numbers of oxygen atoms. In addition, the ions produced from PP presented a lower collision cross-section (CCS) than those produced from PE. In the same way, both PP and PE present repeated patterns separated by 14 m/z in the bidimensional drift time versus m/z plots. Within these plots, several trend lines can be evidenced, which are specific of each polymer investigated. Differences were observed between isotactic and atactic samples concerning the pyrolysis profile relative abundance and collision cross-section.

  8. Characterization of Polyolefin Pyrolysis Species Produced Under Ambient Conditions by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry and Ion Mobility-Mass Spectrometry

    Science.gov (United States)

    Farenc, Mathilde; Witt, Matthias; Craven, Kirsten; Barrère-Mangote, Caroline; Afonso, Carlos; Giusti, Pierre

    2017-01-01

    Polyolefins such as polyethylene (PE) and polypropylene (PP) are often characterized from their pyrolysis products by Py-MS. Nowadays the development of plasma-based direct probe atmospheric pressure sources allow the direct analysis of these polymers. These sources operate at atmospheric pressure, which implies a limited control of the ionization conditions. It was shown that side reactions could occur with species present in air, such as O2, which may lead to the formation of oxidized compounds. In this work, ion mobility-mass spectrometry (IM-MS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR) were used for the exhaustive characterization of the PP and PE pyrolysis ions produced using plasma-based atmospheric pressure ion sources. Both PP and PE yielded distributions of pyrolysis products presenting different amounts of unsaturation but also different numbers of oxygen atoms. In addition, the ions produced from PP presented a lower collision cross-section (CCS) than those produced from PE. In the same way, both PP and PE present repeated patterns separated by 14 m/z in the bidimensional drift time versus m/z plots. Within these plots, several trend lines can be evidenced, which are specific of each polymer investigated. Differences were observed between isotactic and atactic samples concerning the pyrolysis profile relative abundance and collision cross-section.

  9. Preparation of thermal resistant-enhanced separators for lithium ion battery by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Joon Yong; Shin, Junhwa; Nho, Youngchang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-03-15

    Micro-porous membrane made of polyethylene (PE) or polypropylene (PP) is most widely used as physical separators between the cathode and anode in lithium secondary batteries. However, the polymer membranes so soften or melt when the temperature reaches 130 .deg. C or higher because of thermal shrinkage of the polyolefin separators, and thaw low thermal stability may cause internal short circuiting or lead to thermal runaway. In this study, to realize a highly safe battery, we prepared three type separators as crosslinked PE separator, polymer-coated PE separator, and ceramic-coated PE separators, for lithium secondary battery by electron beam irradiation. We prepared crosslinked PE separators with the improved thermal stability by irradiating a commercial PE separator with an electron beam. A polymer-coated PE separator was prepared by a dip-coating of PVDF-HFP/PEGDMA on both sides of a PE separator followed by an electron beam irradiation. Ceramic-coated PE separator was prepared by coating ceramic particles on a PE separator followed by an electron beam irradiation. The prepared separators were characterized with FT-IR, SEM, electrolyte uptake, ion conductivity, thermal shrinkage and battery performance test.

  10. Deformation and failure characteristics of four types of lithium-ion battery separators

    Science.gov (United States)

    Zhang, Xiaowei; Sahraei, Elham; Wang, Kai

    2016-09-01

    Mechanical properties and failure mechanisms of battery separators play a crucial role in integrity of Lithium-ion batteries during an electric vehicle crash event. In this study, four types of commonly used battery separators are characterized and their mechanical performance, strength, and failure are compared. This includes two dry-processed polyethylene (PE) and trilayer separators, a wet-processed ceramic-coated separator, and a nonwoven separator. In detail, uniaxial tensile tests were performed along machine direction (MD), transverse direction (TD) and diagonal direction (DD). Also, through-thickness compression tests and biaxial punch tests were conducted. Comprehensive mechanical tests revealed interesting deformation and failure patterns under extreme mechanical loads. Last, a finite element model of PE separator was developed in LSDYNA based on the uniaxial tensile and through-thickness compression test data. The model succeeded in predicting the response of PE separator under punch tests with different sizes of punch head.

  11. Effects of separator breakdown on abuse response of 18650 Li-ion cells

    Science.gov (United States)

    Roth, E. P.; Doughty, D. H.; Pile, D. L.

    The thermal abuse tolerance of Li-ion cells depends not only on the stability of the active materials in the anode and cathode but also on the stability of the separator which prevents direct interaction between these electrodes. Separator response has been measured as a function of temperature and high voltage both for isolated materials and in full 18650 cells. Separators with different compositions and properties were measured to determine the effect of separator melt integrity on cell response under abusive conditions. These studies were performed as part of the U.S. Department of Energy (DOE) Advanced Technology Development (ATD) Program.

  12. Development of a four-zone carousel process packed with metal ion-imprinted polymer for continuous separation of copper ions from manganese ions, cobalt ions, and the constituent metal ions of the buffer solution used as eluent.

    Science.gov (United States)

    Jo, Se-Hee; Park, Chanhun; Yi, Sung Chul; Kim, Dukjoon; Mun, Sungyong

    2011-08-19

    A three-zone carousel process, in which Cu(II)-imprinted polymer (Cu-MIP) and a buffer solution were employed as adsorbent and eluent respectively, has been developed previously for continuous separation of Cu²⁺ (product) from Mn²⁺ and Co²⁺ (impurities). Although this process was reported to be successful in the aforementioned separation task, the way of using a buffer solution as eluent made it inevitable that the product stream included the buffer-related metal ions (i.e., the constituent metal ions of the buffer solution) as well as copper ions. For a more perfect recovery of copper ions, it would be necessary to improve the previous carousel process such that it can remove the buffer-related metal ions from copper ions while maintaining the previous function of separating copper ions from the other 2 impure heavy-metal ions. This improvement was made in this study by proposing a four-zone carousel process based on the following strategy: (1) the addition of one more zone for performing the two-step re-equilibration tasks and (2) the use of water as the eluent of the washing step in the separation zone. The operating conditions of such a proposed process were determined on the basis of the data from a series of single-column experiments. Under the determined operating conditions, 3 runs of carousel experiments were carried out. The results of these experiments revealed that the feed-loading time was a key parameter affecting the performance of the proposed process. Consequently, the continuous separation of copper ions from both the impure heavy-metal ions and the buffer-related metal ions could be achieved with a purity of 91.9% and a yield of 92.8% by using the proposed carousel process based on a properly chosen feed-loading time.

  13. Ion mobility tandem mass spectrometry enhances performance of bottom-up proteomics.

    Science.gov (United States)

    Helm, Dominic; Vissers, Johannes P C; Hughes, Christopher J; Hahne, Hannes; Ruprecht, Benjamin; Pachl, Fiona; Grzyb, Arkadiusz; Richardson, Keith; Wildgoose, Jason; Maier, Stefan K; Marx, Harald; Wilhelm, Mathias; Becher, Isabelle; Lemeer, Simone; Bantscheff, Marcus; Langridge, James I; Kuster, Bernhard

    2014-12-01

    One of the limiting factors in determining the sensitivity of tandem mass spectrometry using hybrid quadrupole orthogonal acceleration time-of-flight instruments is the duty cycle of the orthogonal ion injection system. As a consequence, only a fraction of the generated fragment ion beam is collected by the time-of-flight analyzer. Here we describe a method utilizing postfragmentation ion mobility spectrometry of peptide fragment ions in conjunction with mobility time synchronized orthogonal ion injection leading to a substantially improved duty cycle and a concomitant improvement in sensitivity of up to 10-fold for bottom-up proteomic experiments. This enabled the identification of 7500 human proteins within 1 day and 8600 phosphorylation sites within 5 h of LC-MS/MS time. The method also proved powerful for multiplexed quantification experiments using tandem mass tags exemplified by the chemoproteomic interaction analysis of histone deacetylases with Trichostatin A.

  14. Preparation and characterization of a Lithium-ion battery separator from cellulose nanofibers

    Directory of Open Access Journals (Sweden)

    Hongfeng Zhang

    2015-10-01

    Full Text Available Optimizing the desired properties for stretch monolayer separators used in Lithium-ion batteries has been a challenge. In the present study a cellulose nanofiber/PET nonwoven composite separator is successfully fabricated, using a wet-laid nonwoven (papermaking process, which can attain optimal properties in wettability, mechanical strength, thermal resistance, and electrochemical performance simultaneously. The PET nonwoven material, which is fabricated from ultrafine PET fibers by a wet-laid process, is a mechanical support layer. The porous structure of the composite separator was created by cellulose nanofibers coating the PET in a papermaking process. Cellulose nanofibers (CNFs, which are an eco-friendly sustainable resource, have been drawing considerable attention due to their astounding properties, such as: incredible specific surface area, thermal and chemical stability, high mechanical strength and hydrophilicity. The results show that the CNF separator exhibits higher porosity (70% than a PP (polypropylene separator (40%. The CNF separator can also be wetted by electrolyte in a few seconds while a PP separator cannot be entirely wetted after 1 min. The CNF separator has an electrolyte uptake of 250%, while a PP separator has only 65%. Another notable finding is that the CNF separator has almost no shrinkage when exposed to 180 °C for 1 h, whereas a PP separator shrinks by more than 50%. Differential Scanning Calorimetry (DSC shows that the CNF separator has a higher melting point than a PP separator. These findings all indicate that the CNF 29 separator will be more favorable than stretch film for use in Lithium-ion batteries.

  15. Collisional Cross-Sections with T-Wave Ion Mobility Spectrometry without Experimental Calibration

    Science.gov (United States)

    Mortensen, Daniel N.; Susa, Anna C.; Williams, Evan R.

    2017-07-01

    A method for relating traveling-wave ion mobility spectrometry (TWIMS) drift times with collisional cross-sections using computational simulations is presented. This method is developed using SIMION modeling of the TWIMS potential wave and equations that describe the velocity of ions in gases induced by electric fields. The accuracy of this method is assessed by comparing the collisional cross-sections of 70 different reference ions obtained using this method with those obtained from static drift tube ion mobility measurements. The cross-sections obtained here with low wave velocities are very similar to those obtained using static drift (average difference = 0.3%) for ions formed from both denaturing and buffered aqueous solutions. In contrast, the cross-sections obtained with high wave velocities are significantly greater, especially for ions formed from buffered aqueous solutions. These higher cross-sections at high wave velocities may result from high-order factors not accounted for in the model presented here or from the protein ions unfolding during TWIMS. Results from this study demonstrate that collisional cross-sections can be obtained from single TWIMS drift time measurements, but that low wave velocities and gentle instrument conditions should be used in order to minimize any uncertainties resulting from high-order effects not accounted for in the present model and from any protein unfolding that might occur. Thus, the method presented here eliminates the need to calibrate TWIMS drift times with collisional cross-sections measured using other ion mobility devices.

  16. Mathematical modeling of salt-gradient ion-exchange simulated moving bed chromatography for protein separations

    Institute of Scientific and Technical Information of China (English)

    卢建刚

    2004-01-01

    The salt-gradient operation mode used in ion-exchange simulated moving bed chromatography (SMBC) can improve the efficiency of protein separations. A detailed model that takes into account any kind of adsorption/ion-exchange equilibrium, salt gradient, size exclusion, mass transfer resistance, and port periodic switching mechanism, was developed to simulate the complex dynamics. The model predictions were verified by the experimental data on upward and downward gradients for protein separations reported in the literature. All design and operating parameters (number, configuration, length and diameter of columns, particle size, switching period, flow rates of feed, raffinate, desorbent and extract, protein concentrations in feed, different salt concentrations in desorbent and feed) can be chosen correctly by numerical simulation. This model can facilitate the design, operation, optimization, control and scale-up of salt-gradient ion-exchange SMBC for protein separations.

  17. Ion-exchange chromatography separation applied to mineral recycle in closed systems

    Science.gov (United States)

    Ballou, E.; Spitze, L. A.; Wong, F. W.; Wydeven, T.; Johnson, C. C.

    1981-01-01

    As part of the controlled ecological life support system (CELSS) program, a study is being made of mineral separation on ion-exchange columns. The purpose of the mineral separation step is to allow minerals to be recycled from the oxidized waste products of plants, man, and animals for hydroponic food production. In the CELSS application, relatively large quantities of minerals in a broad concentration range must be recovered by the desired system, rather than the trace quantities and very low concentrations treated in analytical applications of ion-exchange chromatography. Experiments have been carried out to assess the parameters pertinent to the scale-up of ion-exchange chromatography and to determine feasibility. Preliminary conclusions are that the column scale-up is in a reasonable size range for the CELSS application. The recycling of a suitable eluent, however, remains a major challenge to the suitability of using ion exchange chromatography in closed systems.

  18. Separations of Metal Ions Using Ionic Liquids:The Challenges of Multiple Mechanisms

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Ionic liquids are a distinct sub-set of liquids, comprising only of cations and anions, often with negligible vapor pressure. As a result of the low or non-volatility of these fluids, ionic liquids are often considered in liquid/liquid separation schemes where the goal is to replace volatile organic solvents. Unfortunately,it is often not yet recognized that the ionic nature of these solvents can result in a variety of extraction mechanisms, including solvent ion-pair extraction, ion exchange, and simultaneous combinations of these.This paper discusses current ionic liquid-based separations research where the effects of the nature of the solvent ions, ligands, and metal ion species were studied in order to be able to understand the nature of the challenges in utilizing ionic liquids for practical applications.

  19. Effects of ion mobility and positron fraction on solitary waves in weak relativistic electron-positron-ion plasma

    CERN Document Server

    Lu, Ding; Xie, Bai-Song

    2013-01-01

    Effects of ion mobility and positron fraction on solitary waves of envelop of laser field and potential of electrostatic field in weak relativistic electron-positron-ion plasma are investigated. The parameter region for the existence of solitary waves is obtained analytically, and the reasonable choice of parameters is clarified. Both cases of mobile and immobile ions are considered. It is found that the amplitudes of solitary waves in the former case are larger compared to the latter case. For small plasma density, the localized solitary wave solutions in terms of approximate perturbation analytical method are consistent well with that by exact numerical calculations. However as the plasma density increases the analytical method loses its validity more and more. The influence of the positron fraction on the amplitudes of solitary waves shows a monotonous increasing relation. Implication of our results to the particle acceleration is also discussed briefly.

  20. Effects of ion mobility and positron fraction on solitary waves in weak relativistic electron-positron-ion plasma

    Science.gov (United States)

    Lu, Ding; Li, Zi-Liang; Xie, Bai-Song

    2013-09-01

    The effects of ion mobility and positron fraction on the solitary waves of the laser field envelope and the potential of the electrostatic field in weak relativistic electron-positron-ion plasma are investigated. The parameter region for the existence of solitary waves is obtained analytically, and a reasonable choice of parameters is clarified. Both cases of mobile and immobile ions are considered. It is found that the amplitudes of solitary waves in the former case are larger compared to the latter case. For small plasma density, the localized solitary wave solutions in terms of the approximate perturbation analytical method are very consistent with those by exact numerical calculations. However, as the plasma density increases the analytical method loses its validity more and more. The influence of the positron fraction on the amplitudes of solitary waves shows a monotonous increasing relation. The implications of our results to particle acceleration are also discussed briefly.

  1. Tailoring orthogonal proteomic routines to understand protein separation during ion exchange chromatography.

    Science.gov (United States)

    Cabrera, Rosa; Zhelyazkova, Petya; Galvis, Leonardo; Fernandez-Lahore, Marcelo

    2008-07-01

    Surface charge, molecular weight, and folding state are known to influence protein chromatographic behaviour onto ion exchangers. Experimentally, information related to such factors can be gathered via 2-DE methods. The application of 2-D PAGE under denaturing/reducing conditions was already shown to reveal separation trends within a large protein population from cell extracts. However, ion-exchange chromatography normally runs under native conditions. A tailored protocol consisting in a first separation based on IEF on Immobiline strips under native conditions followed by a second dimension SDS-PAGE run was adopted. The chromatographic versus electrophoretic separation behaviours of two model proteins, thaumatin (TAU) and BSA, were compared to better understand which proteomic routine would be better suited to anticipate IEX chromatographic separations. It was observed that the information contained in the pI value obtained with the adapted 2-DE protocol showed better correlation with the IEX chromatographic behaviour. On the other hand, chromatographic separations performed in the presence of urea as a denaturant have demonstrated the potential influence of hydrodynamic radius/conformation on protein separation. Moreover, the information provided by such 2-D system correlated well with the chromatographic behaviour of an additional set of pure proteins. An initial prediction of protein ion-exchange chromatographic behaviour could be possible utilizing an experimental approach based on 2-DE running under milder chemical conditions. This technique provides information that more closely resembles the separation behaviour observed with a complex biotechnological feedstock.

  2. The investigation of ionization conditions in the trace amounts detection of heterocyclic compounds by ion mobility spectrometry and mass spectrometry

    Science.gov (United States)

    Shaltaeva, Y. R.; Sysoev, A. A.; Poteshin, S. S.; Negru, K. I.; Grishin, S. S.; Trefilova, V. V.; Zuev, M. I.; Baberkina, E. P.

    2016-10-01

    The first part of paper is devoted to the detection of New Psychoactive Substances by ion mobility mass spectrometry study. In the second part of the paper presents a promising approach to prevent the spread of narcotic substances, consisting in the use of field-portable ion mobility spectrometers and finding the correlation between the peaks of the spectrograms of ion mobility and the chemical structure of the compound.

  3. Identity Efficiency for High-Performance Ambient Pressure Ion Mobility Spectrometry.

    Science.gov (United States)

    Kanu, A Bakarr; Leal, Anne

    2016-03-15

    A new approach to reduce the false-positive responses commonly encountered in the field when drugs and explosives are detected is reported for an electrospray ionization high-performance ion mobility spectrometry (ESI-HPIMS). In this article, we report on the combination of reduced mobility and the width-at-half-height of a peak to give a new parameter called conditional reduced mobility (CRM). It was found that the CRM was capable of differentiating between real drugs peaks from that of a false-positive peak and may help to reduce false-positive rates. This effect was demonstrated using 11 drugs (amphetamine, cannabidiol, cocaine, codeine, heroine, methamphetamine, morphine, phentermine, L-phenylepherine, proglitazone, and rosiglitazone) and seven interferences chosen from off-the-shelf products. This report determined and compared CRM, resolving power (R(m)), and diffusion-limited conditional theoretical reduced mobility (DLCTRM) for ESI-HPIMS. The most important parameters for determining CRM are reduced mobility and width-at-half-height of a peak. There is a specific optimum voltage, gate pulse width, resolving power, and now CRM for each ion. DLCTRM indicate the optimum reduced mobility that is not normally possible under field conditions. CRM predicts the condition at which a target compound can be differentiated from a false-positive response. This was possible because different ions exhibits different drifting patterns and hence a different peak broadening phenomenon inside an ion mobility tube. Reduced mobility for target compounds reported were reproducible to within 2% for ESI-HPIMS. The estimated resolving power for the ESI-HPIMS used in this study was 61 ± 0.22. Conditional reduced mobility introduced in this paper show differences between target compounds and false-positive peaks as high as 74%, as was the case for cannabidiol and interference #1 at 70 μs gate pulse width.

  4. Ion chromatographic separation of inorganic ions using a combination of hydrophilic interaction chromatographic column and cation-exchange resin column.

    Science.gov (United States)

    Arai, Kaori; Mori, Masanobu; Hironaga, Takahiro; Itabashi, Hideyuki; Tanaka, Kazuhiko

    2012-04-01

    A combination of hydrophilic interaction chromatographic (HILIC) column and a weakly acidic cation-exchange resin (WCX) column was used for simultaneous separation of inorganic anions and cations by ion chromatography (IC). Firstly, the capability of HILIC column for the separation of analyte ions was evaluated under acidic eluent conditions. The columns used were SeQuant ZIC-HILIC (ZIC-HILIC) with a sulfobetaine-zwitterion stationary phase (ZIC-HILIC) and Acclaim HILIC-10 with a diol stationary phase (HILIC-10). When using tartaric acid as the eluent, the HILIC columns indicated strong retentions for anions, based on ion-pair interaction. Especially, HILIC-10 could strongly retain anions compared with ZIC-HILIC. The selectivity for analyte anions of HILIC-10 with 5 mmol/L tartaric acid eluent was in the order of I(-) > NO3(-) > Br(-) > Cl(-) > H2PO4(-). However, since HILIC-10 could not separate analyte cations, a WCX column (TSKgel Super IC-A/C) was connected after the HILIC column in series. The combination column system of HILIC and WCX columns could successfully separate ten ions (Na+, NH4+, K+, Mg2+, Ca2+, H2PO4(-), Cl(-), Br(-), NO3(-) and I(-)) with elution of 4 mmol/L tartaric acid plus 8 mmol/L 18-crown-6. The relative standard deviations (RSDs) of analyte ions by the system were in the ranges of 0.02% - 0.05% in retention times and 0.18% - 5.3% in peak areas through three-time successive injections. The limits of detection at signal-to-noise ratio of 3 were 0.24 - 0.30 micromol/L for the cations and 0.31 - 1.2 micromol/L for the anions. This system was applied for the simultaneous determination of the cations and the anions in a vegetable juice sample with satisfactory results.

  5. Ion imprinted polymeric nanoparticles for selective separation and sensitive determination of zinc ions in different matrices.

    Science.gov (United States)

    Shamsipur, Mojtaba; Rajabi, Hamid Reza; Pourmortazavi, Seied Mahdi; Roushani, Mahmoud

    2014-01-01

    Preparation of Zn(2+) ion-imprinted polymer (Zn-IIP) nanoparticles is presented in this report. The Zn-IIP nanoparticles are prepared by dissolving stoichiometric amounts of zinc nitrate and selected chelating ligand, 3,5,7,20,40-pentahydroxyflavone, in 15 mL ethanol-acetonitrile (2:1; v/v) mixture as a porogen solvent in the presence of ethylene glycol-dimethacrylate (EGDMA) as cross-linking, methacrylic acid (MAA) as functional monomer, and 2,2-azobisisobutyronitrile (AIBN) as initiator. After polymerization, Cavities in the polymer particles corresponding to the Zn(2+) ions were created by leaching the polymer in HCl aqueous solution. The synthesized IIPs were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, fluorescence spectroscopy and thermal analysis techniques. Also, the pH range for rebinding of Zn(2+) ion on the IIP and equilibrium binding time were optimized, using flame atomic absorption spectrometry. In selectivity study, it was found that imprinting results increased affinity of the material toward Zn(2+) ion over other competitor metal ions with the same charge and close ionic radius. The prepared IIPs were repeatedly used and regenerated for six times without any significant decrease in polymer binding affinities. Finally, the prepared sorbent was successfully applied to the selective recognition and determination of zinc ion in different real samples.

  6. Separation and Concentration of Indium from Leaching Solution Containing Indium, Antimony and Iron Ions

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Processing conditions of effectively separating indium from the leaching solution of a smelting antimony slag were studied. For the leaching solution containing indium and antimony and iron ions, indium was separated by extracting with HDEHP-kerosine solution, washing antimony and iron ions with oxalic acid solution and stripping indium with a dilute solution of hydrochloric acid. InCl3 solution with purity above 90% is obtained. Indium can be enriched through a circulation of stripping with a dilute HCl solution. The concentration of InCl3 solution is about 25~30 g/L.

  7. Rapid separation of desloratadine and related compounds in solid pharmaceutical formulation using gradient ion-pair chromatography.

    Science.gov (United States)

    Zheng, Jinjian; Rustum, Abu M

    2010-01-01

    We reported the development of an ion-pair chromatographic method to separate desloratadine and all known related compounds in Clarinex Tablets, which use desloratadine as active pharmaceutical ingredient (API). For the first time, baseline separation for desloratadine and all known related compounds was achieved by utilizing a YMC-Pack Pro C(18) column (150 mm x 4.6 mm I.D., 3 microm particle size, 120A pore size) and a gradient elution method. The mobile phase A contains 3 mM sodium dodecylsulfate (SDS), 15 mM sodium citrate buffer at pH 6.2, and 40 mM sodium sulfate, while the mobile phase B is acetonitrile. Chromsword, an artificial intelligence method development tool, was used to optimize several key chromatographic parameters simultaneously including buffer pH/solvent strength, and temperature/gradient profile. The resolution of desloratadine and desloratadine 3,4-dehydropiperidine derivative, one of the critical pairs was improved by adding 40 mM sodium sulfate. Ultraviolet detection at 267 nm was used to achieve the detection for desloratadine and all compounds. This method has been successfully validated according to ICH guidelines in terms of linearity, accuracy, quantitation limit/detection limit, precision, specificity and robustness. It could be used as a stability indicating method for desloratadine drug substances or drug products that use desloratadine as active pharmaceutical ingredient.

  8. Separation of Ni and Co by D2EHPA in the Presence of Citrate Ion

    Science.gov (United States)

    Nadimi, Hamed; Haghshenas Fatmehsari, Davoud; Firoozi, Sadegh

    2017-10-01

    Recycling processes for the recovery of metallic content from the electronic wastes are environmentally friendly and economical. This paper reports a method for the recovery and separation of Ni and Co from the sulfate solution by the use of D2EHPA. In this regard, the influence of citrate ion, as a carboxylate ligand, was examined in the separation conditions of Ni and Co via D2EHPA (a poor selective extractant for Ni and Co separation). It was found that the Δ {pH}_{0.5}^{Ni-Co} (the difference between pH values corresponding to 50 pct extraction of metallic ion) increases to 1.5 at the citrate concentration of 0.05 M; this Δ {pH}_{0.5}^{Ni-Co} value is much higher than that obtained in the absence of citrate ion (0.1). Fourier Transform Infrared Spectroscopy (FT-IR) indicated that the citrate ion is co-absorbed during the metallic ions absorption by D2EHPA meaning that the metal-organic complexes contain Co/Ni and citrate ion. Also, the stoichiometric coefficients of the Ni and Co extraction reaction were proposed by applying the slope analysis method.

  9. Polydopamine coated electrospun poly(vinyldiene fluoride) nanofibrous membrane as separator for lithium-ion batteries

    Science.gov (United States)

    Cao, Chengying; Tan, Lei; Liu, Weiwei; Ma, Jiquan; Li, Lei

    2014-02-01

    In this study, polydopamine (PDA) coated electrospun poly(vinyldiene fluoride) (PVDF) nanofibrous membranes used as separator for lithium-ion batteries are successfully prepared. Their morphology, chemical and electrochemical characterization are investigated. The morphology and porosity measurements of the membranes show that the PDA coating does not harm to the structure of the electrospun PVDF nanofibrous membranes. Due to the PDA coating, it makes the PVDF surface hydrophilic and thus increases the electrolyte uptake and ionic conductivity, resulting in the enhanced performance of batteries. The battery using the PDA coated PVDF nanofibrous separator exhibits better cycling performance and higher power capability than that the battery using the bare PVDF nanofibrous separator. This study underlines that the PDA-coating treatment provides a promising process for the fabrication of advanced electrospun nanofibers separator in the lithium-ion battery applications.

  10. Facile and Nonradiation Pretreated Membrane as a High Conductive Separator for Li-Ion Batteries.

    Science.gov (United States)

    Li, Bao; Li, Yongjun; Dai, Dongmei; Chang, Kun; Tang, Hongwei; Chang, Zhaorong; Wang, Chunru; Yuan, Xiao-Zi; Wang, Haijiang

    2015-09-16

    Polyolefin membranes are widely used as separators in commercialized Li-ion batteries. They have less polarized surfaces compared with polarized molecules of electrolyte, leading to a poor wetting state for separators. Radiation pretreatments are often adopted to solve such a problem. Unfortunately, they can only activate several nanometers deep from the surface, which limits the performance improvement. Here we report a facile and scalable method to polarize polyolefin membranes via a chemical oxidation route. On the surfaces of pretreated membrane, layers of poly(ethylene oxide) and poly(acrylic acid) can easily be coated, thus resulting in a high Li-ion conductivity of the membrane. Assembled with this decorated separator in button cells, both high-voltage (Li1.2Mn0.54Co0.13Ni0.13O2) and moderate-voltage (LiFePO4) cathode materials show better electrochemical performances than those assembled with pristine polyolefin separators.

  11. Battery Separator Characterization and Evaluation Procedures for NASA's Advanced Lithium-Ion Batteries

    Science.gov (United States)

    Baldwin, Richard S.; Bennet, William R.; Wong, Eunice K.; Lewton, MaryBeth R.; Harris, Megan K.

    2010-01-01

    To address the future performance and safety requirements for the electrical energy storage technologies that will enhance and enable future NASA manned aerospace missions, advanced rechargeable, lithium-ion battery technology development is being pursued within the scope of the NASA Exploration Technology Development Program s (ETDP's) Energy Storage Project. A critical cell-level component of a lithium-ion battery which significantly impacts both overall electrochemical performance and safety is the porous separator that is sandwiched between the two active cell electrodes. To support the selection of the optimal cell separator material(s) for the advanced battery technology and chemistries under development, laboratory characterization and screening procedures were established to assess and compare separator material-level attributes and associated separator performance characteristics.

  12. Direct Separation of Molybdenum from Solid Uranium Matrices Employing Pyrohydrolysis, a Green Separation Method, and Its Determination by Ion Chromatography.

    Science.gov (United States)

    Mishra, Vivekchandra G; Thakur, Uday K; Shah, Dipti J; Gupta, Neeraj K; Jeyakumar, Subbiah; Tomar, Bhupendra S; Ramakumar, Karanam L

    2015-11-01

    Pyrohydrolysis is a well-established separation method, and it is being used as a sample preparation method for several materials for further determination of non-metals such as halogens, boron, and sulfur. Analytes are retained in a diluted solution that is suitable for carrying out analysis by several determination techniques and minimizing the use of concentrated reagents. Pyrohydrolysis separation of metals has not been reported yet. The present study demonstrates the pyrohydrolysis separation of Mo as MoO4(2-) from uranium materials and its subsequent determination using ion chromatography coupled with suppressed conductivity detector. With use of TGA and XRD the volatilization behavior of Mo was studied. Important parameters for the pyrohydrolysis method required for the quantitative separation of Mo were evaluated. The precision of the method was better than 5% at 25 ppm of Mo. The accuracy was evaluated by analysis of a CRM (U3O8-ILCE-IV). The method was applied to determine Mo in ammonium diuranate samples, where the conventional methods suffer from the loss of Mo.

  13. Separation of silver ions and starch modified silver nanoparticles using high performance liquid chromatography with ultraviolet and inductively coupled mass spectrometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, Traci A.; Saadawi, Ryan; Zhang, Peng; Caruso, Joseph A., E-mail: joseph.caruso@uc.edu; Landero-Figueroa, Julio

    2014-10-01

    The production of commercially available products marketed to contain silver nanoparticles is rapidly increasing. Species-specific toxicity is a phenomenon associated with many elements, including silver, making it imperative to develop a method to identify and quantify the various forms of silver (namely, silver ions vs. silver nanoparticles) possibly present in these products. In this study a method was developed using high performance liquid chromatography (HPLC) with ultraviolet (UV–VIS) and inductively coupled mass spectrometric (ICP-MS) detection to separate starch stabilized silver nanoparticles (AgNPs) and silver ions (Ag{sup +}) by cation exchange chromatography with 0.5 M nitric acid mobile phase. The silver nanoparticles and ions were baseline resolved with an ICP-MS response linear over four orders of magnitude, 0.04 mg kg{sup −1} detection limit, and 90% chromatographic recovery for silver solutions containing ions and starch stabilized silver nanoparticles smaller than 100 nm.

  14. Separation of silver ions and starch modified silver nanoparticles using high performance liquid chromatography with ultraviolet and inductively coupled mass spectrometric detection

    Science.gov (United States)

    Hanley, Traci A.; Saadawi, Ryan; Zhang, Peng; Caruso, Joseph A.; Landero-Figueroa, Julio

    2014-10-01

    The production of commercially available products marketed to contain silver nanoparticles is rapidly increasing. Species-specific toxicity is a phenomenon associated with many elements, including silver, making it imperative to develop a method to identify and quantify the various forms of silver (namely, silver ions vs. silver nanoparticles) possibly present in these products. In this study a method was developed using high performance liquid chromatography (HPLC) with ultraviolet (UV-VIS) and inductively coupled mass spectrometric (ICP-MS) detection to separate starch stabilized silver nanoparticles (AgNPs) and silver ions (Ag+) by cation exchange chromatography with 0.5 M nitric acid mobile phase. The silver nanoparticles and ions were baseline resolved with an ICP-MS response linear over four orders of magnitude, 0.04 mg kg- 1 detection limit, and 90% chromatographic recovery for silver solutions containing ions and starch stabilized silver nanoparticles smaller than 100 nm.

  15. Polymethylmethacrylate/Polyacrylonitrile Membranes via Centrifugal Spinning as Separator in Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Meltem Yanilmaz

    2015-04-01

    Full Text Available Electrospun nanofiber membranes have been extensively studied as separators in Li-ion batteries due to their large porosity, unique pore structure, and high electrolyte uptake. However, the electrospinning process has some serious drawbacks, such as low spinning rate and high production cost. The centrifugal spinning technique can be used as a fast, cost-effective and safe technique to fabricate high-performance fiber-based separators. In this work, polymethylmethacrylate (PMMA/polyacrylonitrile (PAN membranes with different blend ratios were produced via centrifugal spinning and characterized by using different electrochemical techniques for use as separators in Li-ion batteries. Compared with commercial microporous polyolefin membrane, centrifugally-spun PMMA/PAN membranes had larger ionic conductivity, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. Centrifugally-spun PMMA/PAN membrane separators were assembled into Li/LiFePO4 cells and these cells delivered high capacities and exhibited good cycling performance at room temperature. In addition, cells using centrifugally-spun PMMA/PAN membrane separators showed superior C-rate performance compared to those using microporous polypropylene (PP membranes. It is, therefore, demonstrated that centrifugally-spun PMMA/PAN membranes are promising separator candidate for high-performance Li-ion batteries.

  16. Comparison of liquid and supercritical fluid chromatography mobile phases for enantioselective separations on polysaccharide stationary phases.

    Science.gov (United States)

    Khater, Syame; Lozac'h, Marie-Anne; Adam, Isabelle; Francotte, Eric; West, Caroline

    2016-10-07

    Analysis and production of enantiomerically pure compounds is a major topic of interest when active pharmaceutical ingredients are concerned. Enantioselective chromatography has become a favourite both at the analytical and preparative scales. High-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC) are dominating the scene and are often seen as complementary techniques. Nowadays, for economic and ecologic reasons, SFC may be preferred over normal-phase HPLC (NPLC) as it allows significant reductions in solvent consumption. However, the transfer of NPLC methods to SFC is not always straightforward. In this study, we compare the retention of achiral molecules and separation of enantiomers under supercritical fluid (carbon dioxide with ethanol or isopropanol) and liquid normal-phase (heptane with ethanol or isopropanol) elution modes with polysaccharide stationary phases in order to explore the differences between the retention and enantioseparation properties between the two modes. Chemometric methods (namely quantitative structure-retention relationships and discriminant analysis) are employed to compare the results obtained on a large set of analytes (171 achiral probes and 97 racemates) and gain some understanding on the retention and separation mechanisms. The results indicate that, contrary to popular belief, carbon dioxide - solvent SFC mobile phases are often weaker eluents than liquid mobile phases. It appears that SFC and NPLC elution modes provide different retention mechanisms. While some enantioseparations are unaffected, facilitating the transfer between the two elution modes, other enantioseparations may be drastically different due to different types and strength of interactions contributing to enantioselectivity.

  17. Interfacing an ion mobility spectrometry based explosive trace detector to a triple quadrupole mass spectrometer.

    Science.gov (United States)

    Kozole, Joseph; Stairs, Jason R; Cho, Inho; Harper, Jason D; Lukow, Stefan R; Lareau, Richard T; DeBono, Reno; Kuja, Frank

    2011-11-15

    Hardware from a commercial-off-the-shelf (COTS) ion mobility spectrometry (IMS) based explosive trace detector (ETD) has been interfaced to an AB/SCIEX API 2000 triple quadrupole mass spectrometer. To interface the COTS IMS based ETD to the API 2000, the faraday plate of the IMS instrument and the curtain plate of the mass spectrometer were removed from their respective systems and replaced by a custom faraday plate, which was fabricated with a hole for passing the ion beam to the mass spectrometer, and a custom interface flange, which was designed to attach the IMS instrument onto the mass spectrometer. Additionally, the mass spectrometer was modified to increase the electric field strength and decrease the pressure in the differentially pumped interface, causing a decrease in the effect of collisional focusing and permitting a mobility spectrum to be measured using the mass spectrometer. The utility of the COTS-ETD/API 2000 configuration for the characterization of the gas phase ion chemistry of COTS-ETD equipment was established by obtaining mass and tandem mass spectra in the continuous ion flow and selected mobility monitoring operating modes and by obtaining mass-selected ion mobility spectra for the explosive standard 2,4,6 trinitrotoluene (TNT). This analysis confirmed that the product ion for TNT is [TNT - H](-), the predominant collision-induced dissociation pathway for [TNT- H](-) is the loss of NO and NO(2), and the reduced mobility value for [TNT - H](-) is 1.54 cm(2)V(-1) s(-1). Moreover, this analysis was attained for sample amounts of 1 ng and with a resolving power of 37. The objective of the research is to advance the operational effectiveness of COTS IMS based ETD equipment by developing a platform that can facilitate the understanding of the ion chemistry intrinsic to the equipment.

  18. Determining the mobility of ions by transient current measurements at high voltages.

    Science.gov (United States)

    Kohn, Peter; Schröter, Klaus; Thurn-Albrecht, Thomas

    2007-08-24

    We present polarization and transient current experiments that allow an independent determination of the charge carrier density and the mobility of ions in polymer electrolytes at low charge carrier density. The method relies on a complete depletion of ions in the bulk electrolyte achieved by applying high voltages. Based on a qualitative model for the charge dynamics in this nonlinear regime, the method is exemplarily applied to a system of polymethylmethacrylate doped with small amounts of a lithium salt. The independently obtained values for the ionic mobility, the charge carrier density, and the conductivity are consistent for all salt concentrations studied. Criteria for the applicability of the method are discussed.

  19. Photo and Collision Induced Isomerization of a Cyclic Retinal Derivative: An Ion Mobility Study.

    Science.gov (United States)

    Coughlan, Neville J A; Scholz, Michael S; Hansen, Christopher S; Trevitt, Adam J; Adamson, Brian D; Bieske, Evan J

    2016-09-01

    A cationic degradation product, formed in solution from retinal Schiff base (RSB), is examined in the gas phase using ion mobility spectrometry, photoisomerization action spectroscopy, and collision induced dissociation (CID). The degradation product is found to be N-n-butyl-2-(β-ionylidene)-4-methylpyridinium (BIP) produced through 6π electrocyclization of RSB followed by protonation and loss of dihydrogen. Ion mobility measurements show that BIP exists as trans and cis isomers that can be interconverted through buffer gas collisions and by exposure to light, with a maximum response at λ = 420 nm.Graphical Abstract.

  20. Electron attachment rate constant measurement by photoemission electron attachment ion mobility spectrometry (PE-EA-IMS)

    Science.gov (United States)

    Su, Desheng; Niu, Wenqi; Liu, Sheng; Shen, Chengyin; Huang, Chaoqun; Wang, Hongmei; Jiang, Haihe; Chu, Yannan

    2012-12-01

    Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS), with a source of photoelectrons induced by vacuum ultraviolet radiation on a metal surface, has been developed to study electron attachment reaction at atmospheric pressure using nitrogen as the buffer gas. Based on the negative ion mobility spectra, the rate constants for electron attachment to tetrachloromethane and chloroform were measured at ambient temperature as a function of the average electron energy in the range from 0.29 to 0.96 eV. The experimental results are in good agreement with the data reported in the literature.

  1. Multiple Gas-Phase Conformations of a Synthetic Linear Poly(acrylamide) Polymer Observed Using Ion Mobility-Mass Spectrometry

    Science.gov (United States)

    Haler, Jean R. N.; Far, Johann; Aqil, Abdelhafid; Claereboudt, Jan; Tomczyk, Nick; Giles, Kevin; Jérôme, Christine; De Pauw, Edwin

    2017-08-01

    Ion mobility-mass spectrometry (IM-MS) has emerged as a powerful separation and identification tool to characterize synthetic polymer mixtures and topologies (linear, cyclic, star-shaped,…). Electrospray coupled to IM-MS already revealed the coexistence of several charge state-dependent conformations for a single charge state of biomolecules with strong intramolecular interactions, even when limited resolving power IM-MS instruments were used. For synthetic polymers, the sample's polydispersity allows the observation of several chain lengths. A unique collision cross-section (CCS) trend is usually observed when increasing the degree of polymerization (DP) at constant charge state, allowing the deciphering of different polymer topologies. In this paper, we report multiple coexisting CCS trends when increasing the DP at constant charge state for linear poly(acrylamide) PAAm in the gas phase. This is similar to observations on peptides and proteins. Biomolecules show in addition population changes when collisionally heating the ions. In the case of synthetic PAAm, fragmentation occurred before reaching the energy for conformation conversion. These observations, which were made on two different IM-MS instruments (SYNAPT G2 HDMS and high resolution multi-pass cyclic T-Wave prototype from Waters), limit the use of ion mobility for synthetic polymer topology interpretations to polymers where unique CCS values are observed for each DP at constant charge state. [Figure not available: see fulltext.

  2. Lithium-sodium separation by ion-exchange. Particular study of a pulsed column; La separation lithium-sodium par echange d'ions. Etude particuliere d'une colonne a impulsions

    Energy Technology Data Exchange (ETDEWEB)

    Auvert, H. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1968-07-01

    A study is made of the operational conditions and constraints in the case of a moving-bed ion-exchange column subjected to pulses. The example chosen to illustrate its application concerns the lithium-sodium separation in a hydroxide medium (LiOH, NaOH). In the first part, the physico-chemical characteristics of the exchange and the kinetic characteristics of the exchange-reaction are considered. In the second part, the operation of the pulsed column is studied. Using the results obtained in the first part, the conditions required for study state operation are determined. When this is obtained, it is possible to calculate the height equivalent of the theoretical plate (HETP) of the installation. A study is also made of 'sliding', a phenomenon peculiar to pulsed columns. The results obtained show that it is possible, using laboratory tests, to determine the characteristics and the operational condition of a moving-bed ion-exchange column. (author) [French] On se propose d'etudier les conditions et les servitudes de fonctionnement d'une colonne d'echangeurs d'ions a lit mobile, fonctionnant par 'impulsions'. L'exemple d'application choisi est la separation lithium-sodium en milieu hydroxyde (LiOH, NaOH). Dans une premiere partie, on etudie successivement les caracteristiques physico-chimiques de l'echange envisage et les caracteristiques cinetiques de la reaction d'echange mise en oeuvre. Dans une seconde partie on etudie le fonctionnement de la colonne a impulsions. A partir des resultats acquis dans la premiere partie, on determine les conditions necessaires a l'obtention d'un regime permanent. Lorsque celui-ci est atteint en colonne, les performances obtenues permettent de calculer la hauteur equivalente a un plateau theorique (HEPT) de l'installation. On etudie par ailleurs l'influence du 'glissement', phenomene inherent au fonctionnement de la colonne a impulsions. L

  3. Measurements of ion mobility in argon and neon based gas mixtures

    Science.gov (United States)

    Deisting, Alexander; Garabatos, Chilo; Szabo, Alexander; Vranic, Danilo

    2017-02-01

    As gaseous detectors are operated at high rates of primary ionisation, ions created in the detector have a considerable impact on the performance of the detector. The upgraded ALICE Time Projection Chamber (TPC) will operate during LHC Run 3 with a substantial space charge density of positive ions in the drift volume. In order to properly simulate such space charges, knowledge of the ion mobility K is necessary. To this end, a small gaseous detector was constructed and the ion mobility of various gas mixtures was measured. To validate the corresponding signal analysis, simulations were performed. Results are shown for several argon and neon based mixtures with different CO2 fractions. A decrease of K was measured for increasing water content.

  4. Measurements of ion mobility in argon and neon based gas mixtures

    CERN Document Server

    Deisting, Alexander; Szabo, Alexander; Vranic, Danilo

    2016-01-01

    As gaseous detectors are operated at high rates of primary ionisation, ions created in the detector have a considerable impact on the performance of the detector. The upgraded ALICE Time Projection Chamber (TPC) will operate during LHC Run$\\,3$ with a substantial space charge density of positive ions in the drift volume. In order to properly simulate such space charges, knowledge of the ion mobility $K$ is necessary. To this end, a small gaseous detector was constructed and the ion mobility of various gas mixtures was measured. To validate the corresponding signal analysis, simulations were performed. Results are shown for several argon and neon based mixtures with different $\\textrm{CO}_2$ fractions. A decrease of $K$ was measured for increasing water content.

  5. High-field asymmetric waveform ion mobility spectrometry with solvent vapor addition: a potential greener bioanalytical technique.

    Science.gov (United States)

    Tsai, Chia-Wei; Yost, Richard A; Garrett, Timothy J

    2012-06-01

    Green chemistry is a way to avoid threats to human health and the environment in chemical processes, including analytical methodology. According to the 12 principles provided by ACS Green Chemistry Institute, first described by Anastas and Warner, prevention of waste generation should be first considered as an alternative to ways of treating waste. Therefore, analytical techniques that may reduce solvent waste are of great interest towards greener analysis. High-field asymmetric waveform ion mobility spectrometry (FAIMS) utilizes electrical fields to achieve separation, post an ionization source, and could provide an alternative method for separation and reduce solvent use in comparison with traditional HPLC methodologies. In this article, the operational principles and developments of FAIMS will be discussed, including the advantages of adding solvent vapor to the carrier gas. In addition, applications and challenges of implementing FAIMS technology will also be discussed.

  6. Influence of phase separation for surfactant driven pattern formation during ion beam erosion

    Energy Technology Data Exchange (ETDEWEB)

    Hofsaess, Hans; Zhang, Kun; Vetter, Ulrich; Bobes, Omar; Pape, Andre; Gehrke, Hans-Gregor; Broetzmann, Marc [II. Physikalisches Institut, Goettingen Univ. (Germany)

    2012-07-01

    We will present results on metal surfactant driven self-organized pattern formation on surfaces by ion beam erosion, with a focus on the role of phase separation for the initial steps of pattern formation. Si substrates were irradiated with 5 keV Xe ions at normal incidence and ion fluences up to 5.10{sup 17} Xe/cm{sup 2} under continuous deposition of surfactant atoms. In the absence of such surfactants uniform flat surfaces are obtained, while in the presence of Fe and Mo surfactants pronounced patterns like dots, combinations of dots and ripples with wavelengths around 100 nm are generated. The surfactant coverage and deposition direction determine the pattern type and the pattern orientation, respectively. A critical steady-state coverage for onset of dot formation and onset of ripple formation is in the range of 10{sup 15} and 5.10{sup 15} Xe/cm{sup 2}. The steady-state surface region consists of a thin amorphous metal silicide layer with high metal concentration in the ripple and dot regions. Pattern formation is explained by ion induced diffusion and phase separation of the initially flat amorphous silicide layer and subsequent ion beam erosion with composition dependent sputter yield. To investigate the role of initial phase separation we additionally compare the pattern formation for different other metal surfactants.

  7. Effect of urea on protein separation by ion-exchange chromatography.

    Science.gov (United States)

    Khademi, Fatemeh; Mostafaie, Ali

    2010-05-01

    Ion-exchange chromatography (IEC) is the most frequently used chromatographic technique for the separation of proteins and peptides. In this article, the effects of urea on IEC separation of kiwifruit actinidin, egg white and urinary proteins were examined. The purity and relative amount of each protein in different conditions (in the presence or absence of urea) were compared with each other. The three parameters, including resolution, selectivity and efficiency of column in the presence of urea, were calculated and compared with the absence of urea. The results revealed that urea improved the purity of proteins and the resolution, selectivity and efficiency of IEC in separation of studied proteins.

  8. Synthesis of Anomeric Methyl Fructofuranosides and Their Separation on an Ion-Exchange Resin

    Science.gov (United States)

    Nurminen, Erkki; Poijarvi, Paivi; Koskua, Katja; Hovinen, Jari

    2007-01-01

    Treatment of d-fructose with methanol in the presence of acid as a catalyst gives a mixture of methyl-[beta]-d-fructopyranoside, methyl-[alpha]-D-fructofuranoside, and methyl-[beta]-d-fructofuranoside, which were separated on an ion exchange column and characterized polarimetrically.

  9. Direct detection of trimethylamine in meat food products using ion mobility spectrometry.

    Science.gov (United States)

    Bota, Gheorghe M; Harrington, Peter B

    2006-01-15

    Biogenic amines are degradation products generated by bacteria in meat products. These amines can indicate bacterial contamination or have a carcinogenic effect to humans consuming spoiled meats; therefore, their rapid detection is essential. Trimethylamine (TMA) is a good target for the detection of biogenic amines because its volatility. TMA was directly detected in meat food products using ion mobility spectrometry (IMS). TMA concentrations were measured in chicken meat juice for a quantitative evaluation of the meat decaying process. The lowest detected TMA concentration in chicken juice was 0.6+/-0.2 ng and the lowest detected signal for TMA in a standard aqueous solution was 0.6 ng. IMS data were processed using partial least squares (PLS) and Fuzzy rule-building expert system (FuRES). Using these two chemometric methods, trimethylamine concentrations of different days of meat spoilage can be separated, indicating the decaying of meat products. Comparing the two methods, FuRES provided a better classification of different days of meat spoilage.

  10. A nanoscale soft-ionization membrane: A novel ionizer for ion mobility spectrometers for space applications

    Science.gov (United States)

    Hartley, Frank T.; Kanik, Isik

    2002-11-01

    The Jet Propulsion Laboratory (JPL) has developed a novel nanometer-thick "Soft Ionization Membrane" (SIM) which is capable of ionizing nearly 100% of the gases that pass through it. Both sides of the membrane are coated with a metallic conducting film. A modest potential of less than 10 Volts across the membrane produces an electric field in excess of 107 V/cm over a region that is smaller than the mean free path of gas molecules which ionizes the neutral molecules that passing through. Because the region of high electric field is smaller than the mean free path of gas molecules, there are virtually no high energy collisions and the system does not suffer from the fatal problem of avalanche breakdown. The soft ionization mechanism does not fracture the medium or cause any secondary ionization. Thus, a truly new ionization technique is enabled by a simple nanoscale micromachined device. The SIM is tiny, rugged and well suited for a wide variety of applications ranging from space micropropulsion systems to miniature analytical separation devices. In this paper we focus our attention on ion mobility spectrometers (IMSs) as a potential candidate to be incorporated with SIM.

  11. Atmospheric Pressure Chemical Ionization Sources Used in The Detection of Explosives by Ion Mobility Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Waltman, Melanie J. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2010-05-01

    Explosives detection is a necessary and wide spread field of research. From large shipping containers to airline luggage, numerous items are tested for explosives every day. In the area of trace explosives detection, ion mobility spectrometry (IMS) is the technique employed most often because it is a quick, simple, and accurate way to test many items in a short amount of time. Detection by IMS is based on the difference in drift times of product ions through the drift region of an IMS instrument. The product ions are created when the explosive compounds, introduced to the instrument, are chemically ionized through interactions with the reactant ions. The identity of the reactant ions determines the outcomes of the ionization process. This research investigated the reactant ions created by various ionization sources and looked into ways to manipulate the chemistry occurring in the sources.

  12. Modulation of electrical mobility in Au ion irradiated titanium oxide with crystal field splitting

    Science.gov (United States)

    Park, Hyun-Woo; Jun, Byung-Hyuk; Choi, Dukhyun; Chung, Kwun-Bum

    2016-11-01

    Electrical modulation of radio frequency (RF) sputtered TiO2- x films were investigated as a function of Au swift heavy ion irradiation dose at room temperature. The prepared TiO2- x films were irradiated with 130 MeV Au swift heavy ion in the range from 1 × 1011 to 5 × 1012 ions/cm2. As the Au ion irradiation dose increased up to 1 × 1012 ions/cm2, the electrical mobility of TiO2- x films were dramatically increased 3.07 × 102 cm2 V-1 s-1 without the change of carrier concentration. These changes in electrical properties of Au irradiated TiO2- x film, are related to the modification of electronic structure such as crystal field splitting of Ti 3d orbital hybridization and sub-band edge states below the conduction band as a function of Au swift heavy ion irradiation dose.

  13. Lithium-ion battery electrolyte mobility at nano-confined graphene interfaces

    OpenAIRE

    Moeremans, Boaz; Cheng, Hsiu-Wei; Hu, Qingyun; Garces, Hector F.; Padture, Nitin P.; Renner, Frank Uwe; Valtiner, Markus

    2016-01-01

    Interfaces are essential in electrochemical processes, providing a critical nanoscopic design feature for composite electrodes used in Li-ion batteries. Understanding the structure, wetting and mobility at nano-confined interfaces is important for improving the efficiency and lifetime of electrochemical devices. Here we use a Surface Forces Apparatus to quantify the initial wetting of nanometre-confined graphene, gold and mica surfaces by Li-ion battery electrolytes. Our results indicate pref...

  14. Separation of hemicellulose-derived saccharides from wood hydrolysate by lime and ion exchange resin.

    Science.gov (United States)

    Wang, Xiaojun; Zhuang, Jingshun; Fu, Yingjuan; Tian, Guoyu; Wang, Zhaojiang; Qin, Menghua

    2016-04-01

    A combined process of lime treatment and mixed bed ion exchange was proposed to separate hemicellulose-derived saccharides (HDS) from prehydrolysis liquor (PHL) of lignocellulose as value added products. The optimization of lime treatment achieved up to 44.2% removal of non-saccharide organic compounds (NSOC), mainly colloidal substances, with negligible HDS degradation at 0.5% lime level and subsequent neutralization by phosphoric acid. The residual NSOC and calcium ions in lime-treated PHL were eliminated by mixed bed ion exchange. The breakthrough curves of HDS and NSOC showed selective retention toward NSOC, leading to 75% HDS recovery with 95% purity at 17 bed volumes of exchange capacity. In addition, macroporous resin showed higher exchange capacity than gel resin as indicated by the triple processing volume. The remarkable selectivity of the combined process suggested the feasibility for HDS separation from PHL.

  15. Development of a low-energy radioactive ion beam facility for the MARA separator

    Science.gov (United States)

    Papadakis, Philippos; Moore, Iain; Pohjalainen, Ilkka; Sarén, Jan; Uusitalo, Juha

    2016-12-01

    A low-energy radioactive ion beam facility for the production and study of nuclei produced close to the proton drip line is under development at the Accelerator Laboratory of the University of Jyväskylä, Finland. The facility will take advantage of the mass selectivity of the recently commissioned MARA vacuum-mode mass separator. The ions selected by MARA will be stopped and thermalised in a small-volume gas cell prior to extraction and further mass separation. The gas cell design allows for resonance laser ionisation/spectroscopy both in-gas-cell and in-gas-jet. The facility will include experimental setups allowing ion counting, mass measurement and decay spectroscopy.

  16. Nuclear astrophysics and the Daresbury Recoil Separator at the Holifield Radioactive Ion Beam Facility

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.S.

    1997-12-01

    The Daresbury Recoil Separator (DRS) has been installed for nuclear astrophysics research at Oak Ridge National Laboratory`s Holifield Radioactive Ion Beam Facility. It will be used for direct measurements of capture reactions on radioactive ions which occur in stellar explosions such as novae, supernovae and X-ray bursts. These measurements will be made in inverse kinematics with radioactive heavy ion beams incident on hydrogen and helium targets, and the DRS will separate the capture reaction recoils from the intense flux of beam particles. Details of the new DRS experimental equipment and preliminary results from the first commissioning experiments with stable beams are described, along with the plans for the first measurements with radioactive beams. Other astrophysics research efforts at ORNL--in theoretical astrophysics, nuclear astrophysics data evaluation, heavy element nucleosynthesis, theoretical atomic astrophysics, and atomic astrophysics data--are also briefly described.

  17. Development of a low-energy radioactive ion beam facility for the MARA separator

    Energy Technology Data Exchange (ETDEWEB)

    Papadakis, Philippos, E-mail: philippos.papadakis@jyu.fi; Moore, Iain; Pohjalainen, Ilkka; Sarén, Jan; Uusitalo, Juha [University of Jyväskylä, Department of Physics (Finland)

    2016-12-15

    A low-energy radioactive ion beam facility for the production and study of nuclei produced close to the proton drip line is under development at the Accelerator Laboratory of the University of Jyväskylä, Finland. The facility will take advantage of the mass selectivity of the recently commissioned MARA vacuum-mode mass separator. The ions selected by MARA will be stopped and thermalised in a small-volume gas cell prior to extraction and further mass separation. The gas cell design allows for resonance laser ionisation/spectroscopy both in-gas-cell and in-gas-jet. The facility will include experimental setups allowing ion counting, mass measurement and decay spectroscopy.

  18. Development of a low-energy radioactive ion beam facility for the MARA separator

    CERN Document Server

    Papadakis, Philippos; Pohjalainen, Ilkka; Sarén, Jan; Uusitalo, Juha

    2016-01-01

    A low-energy radioactive ion beam facility for the production and study of nuclei produced close to the proton drip line is under development at the Accelerator Laboratory of the University of Jyv\\"askyl\\"a, Finland. The facility will take advantage of the mass selectivity of the recently commissioned MARA vacuum-mode mass separator. The ions selected by MARA will be stopped and thermalised in a small-volume gas cell prior to extraction and further mass separation. The gas cell design allows for resonance laser ionisation/spectroscopy both in-gas-cell and in-gas-jet. The facility will include experimental setups allowing ion counting, mass measurement and decay spectroscopy.

  19. Pharmaceutical metabolite profiling using quadrupole/ion mobility spectrometry/time-of-flight mass spectrometry.

    Science.gov (United States)

    Chan, Eric C Y; New, Lee Sun; Yap, Chun Wei; Goh, Lin Tang

    2009-02-01

    The use of hybrid quadrupole ion mobility spectrometry time-of-flight mass spectrometry (Q/IMS/TOFMS) in the metabolite profiling of leflunomide (LEF) and acetaminophen (APAP) is presented. The IMS drift times (T(d)) of the drugs and their metabolites were determined in the IMS/TOFMS experiments and correlated with their exact monoisotopic masses and other in silico generated structural properties, such as connolly molecular area (CMA), connolly solvent-excluded volume (CSEV), principal moments of inertia along the X, Y and Z Cartesian coordinates (MI-X, MI-Y and MI-Z), inverse mobility and collision cross-section (CCS). The correlation of T(d) with these parameters is presented and discussed. IMS/TOF tandem mass spectrometry experiments (MS(2) and MS(3)) were successfully performed on the N-acetyl-p-benzoquinoneimine glutathione (NAPQI-GSH) adduct derived from the in vitro microsomal metabolism of APAP. As comparison, similar experiments were also performed using hybrid triple quadrupole linear ion trap mass spectrometry (QTRAPMS) and quadrupole time-of-flight mass spectrometry (QTOFMS). The abilities to resolve the product ions of the metabolite within the drift tube and fragment the ion mobility resolved product ions in the transfer travelling wave-enabled stacked ring ion guide (TWIG) demonstrated the potential applicability of the Q/IMS/TOFMS technique in pharmaceutical metabolite profiling.

  20. Tunable separation of anions and cations by column switching in ion chromatography.

    Science.gov (United States)

    Amin, Muhammad; Lim, Lee Wah; Takeuchi, Toyohide

    2007-03-15

    A convenient ion chromatography method has been proposed for the routine and simple determination of anions (Cl(-), SO(4)(2-) and NO(3)(-)) and/or cations (Na(+), NH(4)(+), K(+), Mg(2+) and Ca(2+)) using a single pump, a single eluent and a single detector. The present system used cation-exchange and anion-exchange columns connected in series via two 6-port switching valves or a single 10-port valve. The connection order of the ion-exchange columns could be varied by switching the valve(s). The present system therefore allowed the separation of either cations or anions in a single chromatographic run. While one ion-exchange column is being operated, the other ion-exchange column is being conditioned, i.e., the columns are always ready for analysis at any time. When 2.4mM 5-sulfosalicylic acid was used as the eluent, the three anions and the five cations could be separated on the anion-exchange column and cation-exchange column, respectively. In order to obtain the separations of the target ions, the injection valve was placed between the two columns. Complete separations of the above anions or cations were demonstrated within 10min each. The detection limits at S/N=3 were 19-50ppb (mug/l) for cations and 10-14ppb for anions. The relative standard deviations of the analyte ions were less than 1.1, 2.9 and 2.8% for retention time, peak area and peak height, respectively. This proposed technique was applied to the determination of common anions and cations in river water samples.

  1. Ion exchange separation of chromium from natural water matrix for stable isotope mass spectrometric analysis

    Science.gov (United States)

    Ball, J.W.; Bassett, R.L.

    2000-01-01

    A method has been developed for separating the Cr dissolved in natural water from matrix elements and determination of its stable isotope ratios using solid-source thermal-ionization mass spectrometry (TIMS). The separation method takes advantage of the existence of the oxidized form of Cr as an oxyanion to separate it from interfering cations using anion-exchange chromatography, and of the reduced form of Cr as a positively charged ion to separate it from interfering anions such as sulfate. Subsequent processing of the separated sample eliminates residual organic material for application to a solid source filament. Ratios for 53Cr/52Cr for National Institute of Standards and Technology Standard Reference Material 979 can be measured using the silica gel-boric acid technique with a filament-to-filament standard deviation in the mean 53Cr/52Cr ratio for 50 replicates of 0.00005 or less. (C) 2000 Elsevier Science B.V. All rights reserved.

  2. Fast separation of hen egg white protein with a phosphorylcholine type zwitterionic ion chromatography stationary phase

    Institute of Scientific and Technical Information of China (English)

    Qian Qu; Xiu Juan Yu; Xi Wu; Fei Shi; Li Li Wang

    2012-01-01

    In this work,a kind of preparation method of zwitterionic ion chromatography (ZIC) stationary phase modified with phosphorylcholine (PC) was obtained by hydrolyzing after bonding phosphorylcholine dichloride to diol-silica to better explore the characteristics of the PC groups as ZIC stationary phase ligand in simultaneous separation of acidic proteins and basic proteins.The results showed that two kinds of acidic proteins and three kinds of basic proteins can be separated completely,meanwhile,hen egg white was separated and purified and three kinds of egg white components ovalbumin,G2 ovoglobulin and ovotransfemin proteins were separated completely by one single step on PC-ZIC column,the purity of all proteins reached above 95%.PC-ZIC stationary phase was successfully improved with better separation capacity and selectivity than previously reported in this paper.

  3. Separation of polar betalain pigments from cacti fruits of Hylocereus polyrhizus by ion-pair high-speed countercurrent chromatography.

    Science.gov (United States)

    Wybraniec, Sławomir; Stalica, Paweł; Jerz, Gerold; Klose, Bettina; Gebers, Nadine; Winterhalter, Peter; Spórna, Aneta; Szaleniec, Maciej; Mizrahi, Yosef

    2009-10-09

    Polar betacyanin pigments together with betaxanthins from ripe cactus fruits of Hylocereus polyrhizus (Cactaceae) were fractionated by means of preparative ion-pair high-speed countercurrent chromatography (IP-HSCCC) also using the elution-extrusion (EE) approach for a complete pigment recovery. HSCCC separations were operated in the classical 'head-to-tail' mode with an aqueous mobile phase. Different CCC solvent systems were evaluated in respect of influence and effectiveness of fractionation capabilities to separate the occurring pigment profile of H. polyrhizus. For that reason, the additions of two different volatile ion-pair forming perfluorinated carboxylic acids (PFCA) were investigated. For a direct comparison, five samples of Hylocereus pigment extract were run on preparative scale (900 mg) in 1-butanol-acetonitrile-aqueous TFA 0.7% (5:1:6, v/v/v) and the modified systems tert.-butyl methyl ether-1-butanol-acetonitrile-aqueous PFCA (2:2:1:5, v/v/v/v) using 0.7% and 1.0% trifluoroacetic acid (TFA) or heptafluorobutyric acid (HFBA) in the aqueous phase, respectively. The chemical affinity to the organic stationary CCC solvent phases and in consequence the retention of these highly polar betalain pigments was significantly increased by the use of the more lipophilic fluorinated ion-pair reagent HFBA instead of TFA. The HFBA additions separated more effectively the typical cacti pigments phyllocactin and hylocerenin from betanin as well as their iso-forms. Unfortunately, similar K(D) ratios and selectivity factors alpha around 1.0-1.1 in all tested solvent systems proved that the corresponding diastereomers, 15S-type pigments cannot be resolved from the 15R-epimers (iso-forms). Surprisingly, additions of the stronger ion-pair reagent (HFBA) resulted in a partial separation of hylocerenin from phyllocactin which were not resolved in the other solvent systems. The pigments were detected by means of HPLC-DAD and HPLC-electrospray ionization-MS using also

  4. Studies on Molecular and Ion Transport in Silicalite Membranes and Applications as Ion Separator for Redox Flow Battery

    Science.gov (United States)

    Yang, Ruidong

    Microporous zeolite membranes have been widely studied for molecular separations based on size exclusion or preferential adsorption-diffusion mechanisms. The MFI-type zeolite membranes were also demonstrated for brine water desalination by molecular sieving effect. In this research, the pure silica MFI-type zeolite (i.e. silicalite) membrane has been for the first time demonstrated for selective permeation of hydrated proton (i.e. H3O+) in acidic electrolyte solutions. The silicalite membrane allows for permeation of H 3O+ ions, but is inaccessible to the large hydrated multivalent vanadium ions due to steric effect. The silicalite membrane has been further demonstrated as an effective ion separator in the all-vanadium redox flow battery (RFB).The silicalite is nonionic and its proton conductivity relies on the electric field-driven H3O+ transport through the sub nanometer-sized pores under the RFB operation conditions. The silicalite membrane displayed a significantly reduced self-discharge rate because of its high proton-to-vanadium ion transport selectivity. However, the nonionic nature of the silicalite membrane and very small diffusion channel size render low proton conductivity and is therefore inefficient as ion exchange membranes (IEMs) for practical applications. The proton transport efficiency may be improved by reducing the membrane thickness. However, the zeolite thin films are extremely fragile and must be supported on mechanically strong and rigid porous substrates. In this work, silicalite-Nafion composite membranes were synthesized to achieve a colloidal silicalite skin on the Nafion thin film base. The "colloidal zeolite-ionic polymer" layered composite membrane combines the advantages of high proton-selectivity of the zeolite layer and the mechanical flexibility and low proton transport resistance of the ionic polymer membrane. The composite membrane exhibited higher proton/vanadium ion separation selectivity and lower electrical resistance than

  5. Distinguishing d - and l -aspartic and isoaspartic acids in amyloid β peptides with ultrahigh resolution ion mobility spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xueyun; Deng, Liulin; Baker, Erin M.; Ibrahim, Yehia M.; Petyuk, Vladislav A.; Smith, Richard D.

    2017-01-01

    Ion mobility spectrometry (IMS) was utilized to separate Aβ peptide variants containing isomeric asparic and isoaspartic acid residues with either al- ord-form. The abundance of each variant is of great interest in Alzheimer's disease studies and also to evaluate how often these modifications are occurring in other environmental and biological samples.

  6. Investigation of isomeric flavanol structures in black tea thearubigins using ultraperformance liquid chromatography coupled to hybrid quadrupole/ion mobility/time of flight mass spectrometry.

    Science.gov (United States)

    Yassin, Ghada H; Grun, Christian; Koek, Jean H; Assaf, Khaleel I; Kuhnert, Nikolai

    2014-11-01

    Ultra performance liquid chromatography (UPLC) when coupled to ion mobility (IMS)/orthogonal acceleration time of flight mass spectrometry is a suitable technique for analyzing complex mixtures such as the black tea thearubigins. With the aid of this advanced instrumental analysis, we were able to separate and identify different isomeric components in the complex mixture which could previously not be differentiated by a conventional high performance liquid chromatography/tandem mass spectrometry. In this study, the difference between isomeric structures theasinensins, proanthocyanidins B-type and rutin (quercetin-3O-rutinoside) were studied, and these are present abundantly in many botanical sources. The differentiation between these structures was accomplished according to their acquired mobility drift times differing from the traditional investigations in mass spectrometry, where calculation of theoretical collisional cross sections allowed assignment of the individual isomeric structures. The present work demonstrates UPLC-IMS-MS as an efficient technology for isolating and separating isobaric and isomeric structures existing in complex mixtures discriminating between them according to their characteristic fragment ions and mobility drift times. Therefore, a rational assignment of isomeric structures in many phenolic secondary metabolites based on the ion mobility data might be useful in mass spectrometry-based structure analysis in the future.

  7. Synergistic thermal stabilization of ceramic/co-polyimide coated polypropylene separators for lithium-ion batteries

    Science.gov (United States)

    Lee, Yunju; Lee, Hoogil; Lee, Taejoo; Ryou, Myung-Hyun; Lee, Yong Min

    2015-10-01

    To improve the safety of lithium-ion batteries (LIBs), co-polyimide (PI) P84 was introduced as a polymeric binder for Al2O3/polymer composite surface coatings on polypropylene (PP) separators. By monitoring the dimensional shrinkage of the PP separators at high temperatures, we verified a synergistic thermal stabilization effect between the Al2O3 ceramic and the PI polymeric binder. Although PI was thermally stable up to 300 °C, a coating consisting solely of PI did not impede the PP separator dimensional changes (-22% at 150 °C). On the other hand, the Al2O3/PI-coated PP separators efficiently impeded the thermal shrinkage (-10% at 150 °C). In contrast, an Al2O3/poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) combination lowered the thermal stability of the PP separators (-33% at 150 °C). As a result, the Al2O3/PI-coated PP separators remarkably suppressed the internal short-circuit of the unit half-cells associated with separator thermal shrinkage (100 min at 160 °C), whereas the PVdF-HFP retained only 40 min under identical conditions. The Al2O3/PI-coated PP separators achieved rate capabilities and cell performances similar to those of the bare PP separators.

  8. Thermomechanical analysis and durability of commercial micro-porous polymer Li-ion battery separators

    Science.gov (United States)

    Love, Corey T.

    2011-03-01

    Static and dynamic thermomechanical analysis was performed with a dynamic mechanical analyzer (DMA) to identify thermal and mechanical transitions for commercially available polymer separators under mechanical loading. Clear transitions in deformation mode were observed at elevated temperatures. These transitions identified the onset of separator "shutdown" which occurred at temperatures below the polymer melting point. Mechanical loading direction was critical to the overall integrity of the separator. Anisotropic separators (Celgard 2320, 2400 and 2500) were mechanically limited when pulled in tensile in the transverse direction. The anisotropy of these separators is a result of the dry technique used to manufacture the micro-porous membranes. Separators prepared using the wet technique (Entek Gold LP) behaved more uniformly, or biaxially, where all mechanical properties were nearly identical within the separator plane. The information provided by the DMA can also be useful for predicting the long-term durability of polymer separators in lithium-ion batteries exposed to electrolyte (solvent and salt), thermal fluctuations and electrochemical cycling. Small losses in mechanical integrity were observed for separators exposed to the various immersion environments over the 4-week immersion time.

  9. Resonance ionization laser ion sources for on-line isotope separators (invited).

    Science.gov (United States)

    Marsh, B A

    2014-02-01

    A Resonance Ionization Laser Ion Source (RILIS) is today considered an essential component of the majority of Isotope Separator On Line (ISOL) facilities; there are seven laser ion sources currently operational at ISOL facilities worldwide and several more are under development. The ionization mechanism is a highly element selective multi-step resonance photo-absorption process that requires a specifically tailored laser configuration for each chemical element. For some isotopes, isomer selective ionization may even be achieved by exploiting the differences in hyperfine structures of an atomic transition for different nuclear spin states. For many radioactive ion beam experiments, laser resonance ionization is the only means of achieving an acceptable level of beam purity without compromising isotope yield. Furthermore, by performing element selection at the location of the ion source, the propagation of unwanted radioactivity downstream of the target assembly is reduced. Whilst advances in laser technology have improved the performance and reliability of laser ion sources and broadened the range of suitable commercially available laser systems, many recent developments have focused rather on the laser/atom interaction region in the quest for increased selectivity and/or improved spectral resolution. Much of the progress in this area has been achieved by decoupling the laser ionization from competing ionization processes through the use of a laser/atom interaction region that is physically separated from the target chamber. A new application of gas catcher laser ion source technology promises to expand the capabilities of projectile fragmentation facilities through the conversion of otherwise discarded reaction fragments into high-purity low-energy ion beams. A summary of recent RILIS developments and the current status of laser ion sources worldwide is presented.

  10. Electrochemical membrane reactor: In situ separation and recovery of chromic acid and metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Jeeshan; Tripathi, Bijay P.; Saxena, Arunima; Shahi, Vinod K. [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)

    2007-08-01

    An electrochemical membrane reactor with three compartments (anolyte, catholyte and central compartment) based on in-house-prepared cation- and anion-exchange membrane was developed to achieve in situ separation and recovery of chromic acid and metal ions. The physicochemical and electrochemical properties of the ion-exchange membrane under standard operating conditions reveal its suitability for the proposed reactor. Experiments using synthetic solutions of chromate and dichromate of different concentrations were carried out to study the feasibility of the process. Electrochemical reactions occurring at the cathode and anode under operating conditions are proposed. It was observed that metal ion migrated through the cation-exchange membrane from central compartment to catholyte and OH{sup -} formation at the cathode leads to the formation of metal hydroxide. Simultaneously, chromate ion migrated through the anion-exchange membrane from central compartment to the anolyte and formed chromic acid by combining H{sup +} produced their by oxidative water splitting. Thus a continuous decay in the concentration of chromate and metal ion was observed in the central compartment, which was recovered separately in the anolyte and catholyte, respectively, from their mixed solution. This process was completely optimized in terms of operating conditions such as initial concentration of chromate and metal ions in the central compartment, the applied cell voltage, chromate and metal ion flux, recovery percentage, energy consumption, and current efficiency. It was concluded that chromic acid and metal ions can be recovered efficiently from their mixed solution leaving behind the uncharged organics and can be reused as their corresponding acid and base apart from the purifying water for further applications. (author)

  11. Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 1. Peptides to Proteins

    Science.gov (United States)

    Donohoe, Gregory C.; Khakinejad, Mahdiar; Valentine, Stephen J.

    2015-04-01

    Ion mobility spectrometry (IMS) coupled with hydrogen deuterium exchange (HDX)-mass spectrometry (MS) has been used to study the conformations of negatively-charged peptide and protein ions. Results are presented for ion conformers of angiotensin 1, a synthetic peptide (SP), bovine insulin, ubiquitin, and equine cytochrome c. In general, the SP ion conformers demonstrate a greater level of HDX efficiency as a greater proportion of the sites undergo HDX. Additionally, these ions exhibit the fastest rates of exchange. Comparatively, the angiotensin 1 ions exhibit a lower rate of exchange and HDX level presumably because of decreased accessibility of exchange sites by charge sites. The latter are likely confined to the peptide termini. Insulin ions show dramatically reduced HDX levels and exchange rates, which can be attributed to decreased conformational flexibility resulting from the disulfide bonds. For the larger ubiquitin and protein ions, increased HDX is observed for larger ions of higher charge state. For ubiquitin, a conformational transition from compact to more elongated species (from lower to higher charge states) is reflected by an increase in HDX levels. These results can be explained by a combination of interior site protection by compact conformers as well as decreased access by charge sites. The elongated cytochrome c ions provide the largest HDX levels where higher values correlate with charge state. These results are consistent with increased exchange site accessibility by additional charge sites. The data from these enhanced IMS-HDX experiments are described in terms of charge site location, conformer rigidity, and interior site protection.

  12. X-ray spectroscopic signatures of ion species separation in ICF implosions on OMEGA

    Science.gov (United States)

    Hakel, Peter; Hsu, Scott; Herrmann, Hans; Kim, Yong Ho; Schmitt, Mark; Kagan, Grigory; McEvoy, Aaron; Colgan, James; Fontes, Christopher; Kilcrease, David; Sherrill, Manolo; Rauenzahn, Rick

    2015-11-01

    This work aims to provide a direct measurement of the species separation through experimental inference of the ion density profiles, and comparisons of the data with simulations that explicitly model multi-ion-species diffusion. We also describe the development of a new code capable of modeling x-ray spectral emission from ICF capsules that accounts for the effects of spatial gradients in species distributions throughout the target. This new code named FESTR also allows the inclusion of NLTE, opacity, and Stark broadening effects on x-ray spectral line emissions. We show preliminary results from an OMEGA campaign to obtain direct measurements of ion species separation via advanced analysis of x-ray spectroscopy and spectrally resolved imaging data. These were symmetric direct-drive implosions of CH capsules with deuterium and trace argon gas fills. The implosions were designed to be in a collisional, diffusive regime and to take advantage of interspecies diffusion between the D and Ar driven by temperature gradients in the hot spot. X-ray spectral line emissions and narrowband images from He-like and H-like Ar ions are used to infer the spatial separation of Ar from D.

  13. Ion chromatographic separation of inorganic ions using a combination of hydrophilic interaction chromatographic column and cation-exchange resin column

    Institute of Scientific and Technical Information of China (English)

    Kaori ARAI; Masanobu MORI; Takahiro HIRONAGA; Hideyuki ITABASHI; Kazuhiko TANAKA

    2012-01-01

    A combination of hydrophilic interaction chromatographic ( HILIC ) column and a weakly acidic cation-exchange resin (WCX) column was used for simultaneous separation of inorganic anions and cations by ion chromatography ( IC ).Firstly,the capability of HILIC column for the separation of analyte ions was evaluated under acidic eluent conditions.The columns used were SeQuant ZIC-HILIC (ZIC-HILIC) with a sulfobetainezwitterion stationary phase (ZIC-HILIC) and Acclaim HILIC-10 with a diol stationary phase (HILIC-10).When using tartaric acid as the eluent,the HILIC columns indicated strong retentions for anions,based on ion-pair interaction.Especially,HILIC-10 could strongly retain anions compared with ZIC-HILIC. The selectivity for analyte anions of HILIC-10 with 5 mmol/L tartaric acid eluent was in the order of I- > NO3- > Br- > Cl- >H2PO4-.However,since HILIC-10 could not separate analyte cations,a WCX column (TSKgel Super IC-A/C) was connected after the HILIC column in series.The combination column system of HILIC and WCX columns could successfully separate ten ions (Na+,NH4+,K+,Mg2+,Ca2+,H2PO4-,Cl-,Br-,NO3- and I-) with elution of 4 mmol/L tartaric acid plus 8 mmol/L 18-crown-6.The relative standard deviations (RSDs) of analyte ions by the system were in the ranges of 0.02% - 0.05% in retention times and 0.18% - 5.3% in peak areas through three-time successive injections.The limits of detection at signal-to-noise ratio of 3 were 0.24 - 0.30 μmol/L for the cations and 0.31 - 1.2 μmol/L for the anions.This system was applied for the simultaneous determination of the cations and the anions in a vegetable juice sample with satisfactory results.

  14. Effect of the difference in ion mobilities on traveling-wave electro-osmosis

    CERN Document Server

    Gonzalez, Antonio; Garcia-Sanchez, Pablo; Castellanos, Antonio

    2008-01-01

    We analyze the AC electro-osmotic motion of a 1:1 aqueous solution, taking into account the difference in mobilities and diffusion coefficients between positive and negative ions. This model serves to understand the behavior of common systems as a solution of NaCl in water. We pay special attention to two cases. First, the case of slightly different mobilities, that can model a KCl solution. Second, the case of a strongly asymmetric solution, with an almost vanishing mobility, applicable to the case of a salt where the negative ion is much more massive than the positive one. For all the cases, we perform the mathematical description and linear analysis of the problem, in order to establish the dependence of the induced velocity with the frequency, wavelength and amplitude of the applied voltage.

  15. Determination of biogenic amines in canned fish samples using head-space solid phase microextraction based on nanostructured polypyrrole fiber coupled to modified ionization region ion mobility spectrometry.

    Science.gov (United States)

    Parchami, Razieh; Kamalabadi, Mahdie; Alizadeh, Naader

    2017-01-20

    The head-space solid phase microextraction (HS-SPME) was applied to extraction and determination of histamine (HIS), putrescine (PUT), cadaverine (CAD), tyramine (TYR) in canned fish samples by ion mobility spectrometry (IMS) without any derivatization process. HIS and CAD have the same mobilities in nitrogen as buffer gas and their corresponding peaks are severely overlapped in ion mobility spectrum. Peak separation was acquired in the presence of 18-crown-6 vapor as complexation reagent into carrier gas and modified ionization region of IMS (MIR-IMS) at optimum flow rate. The interaction between 18-crown-6 and the mentioned amines forms nanocluster product ions with different cross section areas and ion mobilities. The effects of main extraction parameters on the efficiency of HS-SPME-MIR-IMS were investigated and optimized. Relative standard deviations (RSD%) of the biogenic amines determination at 50μgL(-1) concentration level were obtained in range 5.7%-6.3%. Limits of detection for analytes were in the range of 0.6-1ngg(-1). HS-SPME-MIR-IMS results indicate that the proposed method can be successfully used in biogenic amines analysis in water and food samples. Method validation was conducted by comparing our results with those obtained through GC-MS method.

  16. Carbon dots rooted agarose hydrogel hybrid platform for optical detection and separation of heavy metal ions.

    Science.gov (United States)

    Gogoi, Neelam; Barooah, Mayuri; Majumdar, Gitanjali; Chowdhury, Devasish

    2015-02-11

    A robust solid sensing platform for an on-site operational and accurate detection of heavy metal is still a challenge. We introduce chitosan based carbon dots rooted agarose hydrogel film as a hybrid solid sensing platform for detection of heavy metal ions. The fabrication of the solid sensing platform is centered on simple electrostatic interaction between the NH3+ group present in the carbon dots and the OH- groups present in agarose. Simply on dipping the hydrogel film strip into the heavy metal ion solution, in particular Cr6+, Cu2+, Fe3+, Pb2+, Mn2+, the strip displays a color change, viz., Cr6+→yellow, Cu2+→blue, Fe3+→brown, Pb2+→white, Mn2+→tan brown. The optical detection limit of the respective metal ion is found to be 1 pM for Cr6+, 0.5 μM for Cu2+, and 0.5 nM for Fe3+, Pb2+, and Mn2+ by studying the changes in UV-visible reflectance spectrum of the hydrogel film. Moreover, the hydrogel film finds applicability as an efficient filtration membrane for separation of these quintet heavy metal ions. The strategic fundamental feature of this sensing platform is the successful capability of chitosan to form colored chelates with transition metals. This proficient hybrid hydrogel solid sensing platform is thus the most suitable to employ as an on-site operational, portable, cheap colorimetric-optical detector of heavy metal ion with potential skill in their separation. Details of the possible mechanistic insight into the colorimetric detection and ion separation are also discussed.

  17. Simulation model for overloaded monoclonal antibody variants separations in ion-exchange chromatography.

    Science.gov (United States)

    Guélat, Bertrand; Ströhlein, Guido; Lattuada, Marco; Delegrange, Lydia; Valax, Pascal; Morbidelli, Massimo

    2012-08-31

    A model was developed for the design of a monoclonal antibody charge variants separation process based on ion-exchange chromatography. In order to account for a broad range of operating conditions in the simulations, an explicit pH and salt concentration dependence has been included in the Langmuir adsorption isotherm. The reliability of this model was tested using experimental chromatographic retention times as well as information about the structural characteristics of the different charge variants, e.g. C-terminal lysine groups and deamidated groups. Next, overloaded isocratic elutions at various pH and salt concentrations have been performed to determine the saturation capacity of the ion-exchanger. Furthermore, the column simulation model was applied for the prediction of monoclonal antibody variants separations with both pH and salt gradient elutions. A good prediction of the elution times and peak shapes was observed, even though none of the model parameters was adjusted to fit the experimental data. The trends in the separation performance obtained through the simulations were generally sufficient to identify the most promising operating conditions. The predictive column simulation model thus developed in this work, including a set of parameters determined through specific independent experiments, was experimentally validated and offers a useful basis for a rational optimization of monoclonal antibody variants separation processes on ion-exchange chromatography.

  18. Boehmite particle coating modified microporous polyethylene membrane: A promising separator for lithium ion batteries

    Science.gov (United States)

    Yang, Chongwen; Tong, Hua; Luo, Chuanpeng; Yuan, Shuanglong; Chen, Guorong; Yang, Yunxia

    2017-04-01

    To exploit high-quality separators for lithium ion batteries, current research activities are mainly focused on the modification of microporous polyolefin membranes by coating them with inorganic particles to achieve comprehensive improvements in their thermal stability, electrochemical compatibility, and overcharge protection. Here, we report a separator made by coating boehmite (AlOOH) particles on microporous polyethylene (PE) membranes. Compared to the commercially applied coating materials, e.g., aluminum oxide (Al2O3), AlOOH allows for a substantial reduction in the coating thickness, while ensuring excellent thermal stability of the modified PE membrane. Our study shows that this is due to the formation of an interlocking interface structure that interconnects the PE membrane and AlOOH coating layer as soon as PE melts at about 140 °C, preventing the modified PE membrane from shrinking at subsequently elevated temperatures. The modified PE membrane exhibits suitable electrolyte wettability to facilitate ion transport through it. Thus, the lithium ion batteries employing it as a separator could attain substantially improved electrochemical performance. Furthermore, the AlOOH-coated PE separator was also found to provide an excellent overcharge protection.

  19. Collision Cross Sections for 20 Protonated Amino Acids: Fourier Transform Ion Cyclotron Resonance and Ion Mobility Results

    Science.gov (United States)

    Anupriya; Jones, Chad A.; Dearden, David V.

    2016-08-01

    We report relative dephasing cross sections for the 20 biogenic protonated amino acids measured using the cross sectional areas by Fourier transform ion cyclotron resonance (CRAFTI) technique at 1.9 keV in the laboratory reference frame, as well as momentum transfer cross sections for the same ions computed from Boltzmann-weighted structures determined using molecular mechanics. Cross sections generally increase with increasing molecular weight. Cross sections for aliphatic and aromatic protonated amino acids are larger than the average trend, suggesting these side chains do not fold efficiently. Sulfur-containing protonated amino acids have smaller than average cross sections, reflecting the mass of the S atom. Protonated amino acids that can internally hydrogen-bond have smaller than average cross sections, reflecting more extensive folding. The CRAFTI measurements correlate well with results from drift ion mobility (IMS) and traveling wave ion mobility (TWIMS) spectrometric measurements; CRAFTI results correlate with IMS values approximately as well as IMS and TWIMS values from independent measurements correlate with each other. Both CRAFTI and IMS results correlate well with the computed momentum transfer cross sections, suggesting both techniques provide accurate molecular structural information. Absolute values obtained using the various methods differ significantly; in the case of CRAFTI, this may be due to errors in measurements of collision gas pressure, measurement of excitation voltage, and/or dependence of cross sections on kinetic energy.

  20. Desorption electrospray ionization (DESI) with atmospheric pressure ion mobility spectrometry for drug detection.

    Science.gov (United States)

    Roscioli, Kristyn M; Tufariello, Jessica A; Zhang, Xing; Li, Shelly X; Goetz, Gilles H; Cheng, Guilong; Siems, William F; Hill, Herbert H

    2014-04-01

    Desorption electrospray ionization (DESI) was coupled to an ambient pressure drift tube ion mobility time-of-flight mass spectrometer (IM-TOFMS) for the direct analysis of active ingredients in pharmaceutical samples. The DESI source was also coupled with a standalone IMS demonstrating potential of portable and inexpensive drug-quality testing platforms. The DESI-IMS required no sample pretreatment as ions were generated directly from tablets and cream formulations. The analysis of a range of over-the-counter and prescription tablet formations was demonstrated for amphetamine (methylphenidate), antidepressant (venlafaxine), barbiturate (Barbituric acid), depressant (alprazolam), narcotic (3-methylmorphine) and sympatholytic (propranolol) drugs. Active ingredients from soft and liquid formulations, such as Icy Hot cream (methyl salicylate) and Nyquil cold medicine (acetaminophen, dextromethorphan, doxylamine) were also detected. Increased sensitivity for selective drug responses was demonstrated through the formation of sodiated adduct ions by introducing small quantities of NaCl into the DESI solvent. Of the drugs and pharmaceuticals tested in this study, 68% (22 total samples) provided a clear ion mobility response at characteristic mobilities either as (M + H)(+), (M - H)(-), or (M + Na)(+) ions.

  1. First measurement of radioisotopes by collinear laser spectroscopy at an ion-guide separator

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, J.L.; Cochrane, E.C.A.; Evans, D.E.; Griffith, J.A.R.; Persson, J.R.; Richardson, D.S.; Tungate, G.; Zybert, L. [School of Physics and Space Research, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Billowes, J.; Campbell, P.; Cooper, T.G.; Grant, I.S.; Levins, J.M.G.; Pearson, M.R.; Wheeler, P.D. [Schuster Laboratory, University of Manchester, Manchester M13 9PL (United Kingdom); Dendooven, P.; Honkanen, A.; Huhta, M.; Oinonen, M.; Penttilae, H.; Aeystoe, J. [Accelerator Laboratory, University of Jyvaeskylae, PL 35, Jyvaeskylae SF - 403 51 (Finland)

    1997-11-01

    The first successful application of an ion-guide separator (IGISOL) for collinear laser spectroscopy of radioisotopes has achieved an efficiency comparable with the best obtained with catcher-ionizer facilities. The ion beam energy spread was determined to be less than 6 eV, allowing laser fluorescence resonance signals for the {sup 140,142,144}Ba radioisotopes to be detected with high resolution and sensitivity. Applications of this technique to measuring nuclear properties of refractory elements and short lived isomers promises to be particularly advantageous. (author). Letter-to-the-editor.

  2. Misfolded Amyloid Ion Channels Present Mobile β-Sheet Subunits in Contrast to Conventional Ion Channels

    OpenAIRE

    Jang, Hyunbum; Arce, Fernando Teran; Capone, Ricardo; Ramachandran, Srinivasan; Lal, Ratnesh; Nussinov, Ruth

    2009-01-01

    In Alzheimer's disease, calcium permeability through cellular membranes appears to underlie neuronal cell death. It is increasingly accepted that calcium permeability involves toxic ion channels. We modeled Alzheimer's disease ion channels of different sizes (12-mer to 36-mer) in the lipid bilayer using molecular dynamics simulations. Our Aβ channels consist of the solid-state NMR-based U-shaped β-strand-turn-β-strand motif. In the simulations we obtain ion-permeable channels whose subunit mo...

  3. PERVAPORATION SEPARATION OF WATER-ACETIC ACID MIXTURES THROUGH AN-co-AA MEMBRANES TREATED WITH RARE EARTH METAL IONS

    Institute of Scientific and Technical Information of China (English)

    SHEN Zhiquan; ZHANG Fuyao; ZHANG Yifeng

    1995-01-01

    Pervaporation separation of water-acetic acid mixtures through Poly (AN-co-AA)membranes and rare earth metal ions treated Poly(AN-co-AA)membranes was investigated for the first time. The results showed that the treatment with rare earth metal ions could greatly improve the characteristics of the separation of water-acetic acid mixtures.

  4. Expanded polytetrafluoroethylene reinforced polyvinylidenefluoride-hexafluoropropylene separator with high thermal stability for lithium-ion batteries

    Science.gov (United States)

    Xiong, Ming; Tang, Haolin; Wang, Yadong; Lin, Yu; Sun, Meiling; Yin, Zhuangfei; Pan, Mu

    2013-11-01

    PVDF-HFP/ePTFE composite separator with high thermal stability and low thermal shrinkage characteristic has been developed. The PVDF-HFP acts to absorb the electrolyte and shutdown at elevated temperature. The thermally stable ePTFE matrix is adopted to improve the mechanical strength and sustain the insulation after the shutdown. This novel separator presents good ion conductivity (up to 1.29 mS cm-1) and has a low thermal shrinkage of 8.8% at 162 °C. The composite separator shutdown at 162 °C and keep its integrity before 329 °C. Cells based on the composite separator show excellent capacities at high rate discharge and stable cycling performance.

  5. In situ separation of lactic acid from fermentation broth using ion exchange resins.

    Science.gov (United States)

    Ataei, Seyed Ahmad; Vasheghani-Farahani, Ebrahim

    2008-11-01

    Lactic acid fermentation is an end product inhibited reaction. In situ separation of lactic acid from fermentation broth using ion exchange resins was investigated and compared with conventional fermentation system. Amberlite resin (IRA-400, Cl-) was used to separate lactic acid from fermentation broth and pH was controlled online with an automatic pH controller. The effect of process variables on lactic acid production by Lactobacillus casei in whey permeate was studied. The maximum productivity was obtained at pH=6.1, T=37 degrees C and impeller speed=200 rpm. The maximum concentration of lactic acid at optimum condition was found to be 37.4 g/L after 38 h of fermentation using in situ separation system. The productivity of in situ separation system was five times increased in comparison with conventional system.

  6. Electrospun polyimide nanofiber-based nonwoven separators for lithium-ion batteries

    Science.gov (United States)

    Miao, Yue-E.; Zhu, Guan-Nan; Hou, Haoqing; Xia, Yong-Yao; Liu, Tianxi

    2013-03-01

    Polyimide (PI) nanofiber-based nonwovens have been fabricated via electrospinning for the separators of lithium-ion batteries (LIBs). Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and hot oven tests show that the PI nanofiber-based nonwovens are thermally stable at a high temperature of 500 °C while the commercial Celgard membrane exhibits great shrinkage at 150 °C and even goes melting over 167 °C, indicating a superior thermal stability of PI nanofiber-based nonwovens than that of the Celgard membrane. Moreover, the PI nanofiber-based nonwovens exhibit better wettability for the polar electrolyte compared to the Celgard membrane. The PI nanofiber-based nonwoven separators are also evaluated to have higher capacity, lower resistance and higher rate capability compared to the Celgard membrane separator, which proves that they are ideal candidates for separators of high-performance rechargeable LIBs.

  7. Electrospray ionization ion mobility mass spectrometry provides novel insights into the pattern and activity of fetal hippocampus gangliosides.

    Science.gov (United States)

    Sarbu, Mirela; Vukelić, Željka; Clemmer, David E; Zamfir, Alina D

    2017-08-01

    Gangliosides (GGs), a particular class of glycosphingolipids ubiquitously found in tissues and body fluids, exhibit the highest expression in the central nervous system, especially in brain. GGs are involved in crucial processes, such as neurogenesis, synaptogenesis, synaptic transmission, cell adhesion, growth and proliferation. For these reasons, efforts are constantly invested into development and refinement of specific methods for GG analysis. We have recently shown that ion mobility separation (IMS) mass spectrometry (MS) has the capability to provide consistent compositional and structural information on GGs at high sensitivity, resolution and mass accuracy. In the present paper, we have implemented IMS MS for the first time in the study of a highly complex native GG mixture extracted and purified from human fetal hippocampus. As compared to previous studies, where no separation techniques prior to MS were applied, IMS MS technique has not just generated valuable novel information on the GG pattern characteristic for hippocampus in early developmental stage, but also provided data related to the GG molecular involvement in the synaptic functions by the discovery of 25 novel structures modified by CH3COO(-). The detection and identification in fetal hippocampus of a much larger number of GG species than ever reported before was possible due to the ion mobility separation according to the charge state, the carbohydrate chain length and the degree of sialylation. By applying IMS in conjunction with collision induced dissociation (CID) tandem MS (MS/MS), novel GG species modified by CH3COO(-) attachment, discovered here for the first time, were sequenced and structurally investigated in details. The present findings, based on IMS MS, provide a more reliable insight into the expression and role of gangliosides in human hippocampus, with a particular emphasis on their cholinergic activity at this level. Copyright © 2017 Elsevier B.V. and Société Française de

  8. Comprehensive analysis of fatty alcohol ethoxylates by ultra high pressure hydrophilic interaction chromatography coupled with ion mobility spectrometry mass spectrometry using a custom-designed sub-2 μm column.

    Science.gov (United States)

    Ma, Qiang; Ma, Wei; Chen, Xi; Wang, Ziming; Bai, Hua; Zhang, Lanwei; Li, Wentao; Wang, Chao; Li, Xinshi

    2015-06-01

    Comprehensive analysis of fatty alcohol ethoxylates has been conducted by coupling ultra high pressure hydrophilic interaction chromatography and ion mobility spectrometry mass spectrometry. A custom-designed sub-2 μm column was used for the chromatographic separation of fatty alcohol ethoxylates by hydrophilic interaction chromatography. Ion mobility spectrometry provided a post-ionization resolution during a very short period of 6.4 ms. Distinguishable families of singly, doubly, and triply charged fatty alcohol ethoxylates were clearly observed. By virtue of the combination of hydrophilic interaction chromatography and ion mobility spectrometry, comprehensive resolution based on both hydrophobicity difference and mobility disparity has been achieved for fatty alcohol ethoxylates. The orthogonality of the developed separation and analysis system was evaluated with the correlation coefficient and peak spreading angle of 0.0224 and 88.72°, respectively. The actual peak capacity obtained was individually 40 and 193 times than those when hydrophilic interaction chromatography and ion mobility spectrometry were used alone. The collision cross-sections of fatty alcohol ethoxylates were calculated by calibrating the traveling wave ion mobility device with polyalanine.

  9. Experimental Findings On Minor Actinide And Lanthanide Separations Using Ion Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D. T.; Shehee, T. C.; Clearfield, A.

    2013-09-17

    This project seeks to determine if inorganic or hybrid inorganic ion-exchange materials can be exploited to provide effective americium and curium separations. Specifically, we seek to understand the fundamental structural and chemical factors responsible for the selectivity of the tested ion-exchange materials for actinide and lanthanide ions. During FY13, experimental work focused in the following areas: (1) investigating methods to oxidize americium in dilute nitric acid with subsequent ion-exchange performance measurements of ion exchangers with the oxidized americium and (2) synthesis, characterization and testing of ion-exchange materials. Ion-exchange materials tested included alkali titanates, alkali titanosilicates, carbon nanotubes and group(IV) metal phosphonates. Americium oxidation testing sought to determine the influence that other redox active components may have on the oxidation of Am(III). Experimental findings indicated that Pu(IV) is oxidized to Pu(VI) by peroxydisulfate, but there are no indications that the presence of plutonium affects the rate or extent of americium oxidation at the concentrations of peroxydisulfate being used. Tests also explored the influence of nitrite on the oxidation of Am(III). Given the formation of Am(V) and Am(VI) in the presence of nitrite, it appears that nitrite is not a strong deterrent to the oxidation of Am(III), but may be limiting Am(VI) by quickly reducing Am(VI) to Am(V). Interestingly, additional absorbance peaks were observed in the UV-Vis spectra at 524 and 544 nm in both nitric acid and perchloric acid solutions when the peroxydisulfate was added as a solution. These peaks have not been previously observed and do not correspond to the expected peak locations for oxidized americium in solution. Additional studies are in progress to identify these unknown peaks. Three titanosilicate ion exchangers were synthesized using a microwave-accelerated reaction system (MARS) and determined to have high affinities

  10. Plasma catecholamines in hypertension and pheochromocytoma determined using ion-pair reversed-phase chromatography with amperometric detection: investigation of the separation mechanism and clinical methodology.

    Science.gov (United States)

    Krstulović, A M; Dziedzic, S W; Bertani-Dziedzic, L; DiRico, D E

    1981-11-06

    The retention behavior of catecholamines (CAs) in ion-pair reversed-phase chromatography is examined. From the effects of pH, ionic strength and a secondary ion-pairing reagent (citric acid), under our chromatographic conditions, the retention behavior can be explained by assuming a mixed ion-exchange mechanism with octyl sulfate and citrate, on the column and in the mobile phase, respectively. The developed separation method was applied to the analysis of CAs in plasma samples purified by alumina adsorption and detected amperometrically. This method provides the basis for the determination of the short-term magnitude of CA response to physical and physiological interventions, as well as the baseline CA levels in essential hypertension and pheochromocytoma. The results seen for norepinephrine and epinephrine are consistent with eh funcitonal roles of these CAs as hormones or peripheral transmitters.

  11. Electrospun montmorillonite modified poly(vinylidene fluoride) nanocomposite separators for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Changjiang; Yang, Shuli; Zhao, Xinfei [College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Du, Pingfan, E-mail: dupf@zstu.edu.cn [College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Key Laboratory of Advanced Textile Materials and Manufacturing Technology (Ministry of Education), Zhejiang Sci-Tech University, Hangzhou 310018 (China); Xiong, Jie, E-mail: jxiong@zstu.edu.cn [College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Key Laboratory of Advanced Textile Materials and Manufacturing Technology (Ministry of Education), Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2016-07-15

    Highlights: • Composite separators of PVDF and MMT for lithium-ion batteries were electrospun. • Thermal dimensional stability and tensile property of composite separators get improved. • Presence of montmorillonite promotes electrical properties of PVDF fibrous separators. • Batteries consisting of PVDF/MMT-5% separator achieve the best performance. - Abstract: Composite separators of poly(vinylidene fluoride) (PVDF) with different contents of montmorillonite (MMT) for Li-ion batteries have been fabricated by electrospinning. The morphology, function group, crystallinity, and mechanical properties of membranes were investigated by scanning electron microscope (SEM), Fourier Transform infrared spectra (FT-IR), differential scanning calorimetry (DSC), and tensile test, respectively. Interlayer spacing of MMT in polymer was characterized by X-ray diffraction (XRD). In addition, the results of electrochemical measurements suggest that PVDF/MMT-5% composite membrane has maximum ionic conductivity of 4.2 mS cm{sup −1}, minimum interfacial resistance of 97 Ω, and excellent electrochemical stability. The cell comprising PVDF/MMT-5% composite membrane shows higher capacity and more stable cycle performance than the one using commercial Celgard PP membrane.

  12. A review on the separators of liquid electrolyte Li-ion batteries

    Science.gov (United States)

    Zhang, Sheng Shui

    This paper reviews the separators used in liquid electrolyte Li-ion batteries. According to the structure and composition of the membranes, the battery separators can be broadly divided as three groups: (1) microporous polymer membranes, (2) non-woven fabric mats and (3) inorganic composite membranes. The microporous polymer membranes are characterised by their thinness and thermal shutdown properties. The non-woven mats have high porosity and a low cost, while the composite membranes have excellent wettability and exceptional thermal stability. The manufacture, characteristics, performance and modifications of these separators are introduced and discussed. Among numerous battery separators, the thermal shutdown and ceramic separators are of special importance in enhancing the safety of Li-ion batteries. The former consists of either a polyethylene (PE)-polypropylene (PP) multilayer structure or a PE-PP blend which increases safety by allowing meltdown of the PE to close the ionic conduction pathways at a temperature below that at which thermal runway occurs. Whereas the latter comprises nano-size ceramic materials coated on two sides of a flexible and highly porous non-woven matrix which enhances the safety by retaining extremely stable dimensions even at very high temperatures to prevent the direct contact of the electrodes.

  13. Selective separation of sodium ions from a mixture with phenylalanine by Donnan dialysis with a profiled sulfogroup cation exchange membrane

    Science.gov (United States)

    Vasil'eva, V. I.; Goleva, E. A.

    2013-11-01

    The possibility of separating ions of metal from a mixture with ampholyte (an amino acid) by Donnan dialysis with an MK-40 sulfogroup cation exchange membrane is demonstrated. Conditions ensuring the selectivity and intensity of the mass transfer of sodium ions from a mixture with bipolar phenylalanine ions into a diffusate containing hydrochloric acid through a cation exchange membrane are found.

  14. Feasibility of corona discharge ion mobility spectrometry for direct analysis of samples extracted by dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Jafari, Mohammad T; Riahi, Farhad

    2014-05-23

    The capability of corona discharge ionization ion mobility spectrometry (CD-IMS) for direct analysis of the samples extracted by dispersive liquid-liquid microextraction (DLLME) was investigated and evaluated, for the first time. To that end, an appropriate new injection port was designed and constructed, resulting in possibility of direct injection of the known sample volume, without tedious sample preparation steps (e.g. derivatization, solvent evaporation, and re-solving in another solvent…). Malathion as a test compound was extracted from different matrices by a rapid and convenient DLLME method. The positive ion mobility spectra of the extracted malathion were obtained after direct injection of carbon tetrachloride or methanol solutions. The analyte responses were compared and the statistical results revealed the feasibility of direct analysis of the extracted samples in carbon tetrachloride, resulting in a convenient methodology. The coupled method of DLLME-CD-IMS was exhaustively validated in terms of sensitivity, dynamic range, recovery, and enrichment factor. Finally, various real samples of apple, river and underground water were analyzed, all verifying the feasibility and success of the proposed method for the easy extraction of the analyte using DLLME separation before the direct analysis by CD-IMS.

  15. Analysis of heterogeneous water vapor uptake by metal iodide cluster ions via differential mobility analysis-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Oberreit, Derek [Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Fluid Measurement Technologies, Inc., Saint Paul, Minnesota 55110 (United States); Rawat, Vivek K.; Larriba-Andaluz, Carlos; Ouyang, Hui; McMurry, Peter H.; Hogan, Christopher J., E-mail: hogan108@umn.edu [Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2015-09-14

    The sorption of vapor molecules onto pre-existing nanometer sized clusters is of importance in understanding particle formation and growth in gas phase environments and devising gas phase separation schemes. Here, we apply a differential mobility analyzer-mass spectrometer based approach to observe directly the sorption of vapor molecules onto iodide cluster ions of the form (MI){sub x}M{sup +} (x = 1-13, M = Na, K, Rb, or Cs) in air at 300 K and with water saturation ratios in the 0.01-0.64 range. The extent of vapor sorption is quantified in measurements by the shift in collision cross section (CCS) for each ion. We find that CCS measurements are sensitive enough to detect the transient binding of several vapor molecules to clusters, which shift CCSs by only several percent. At the same time, for the highest saturation ratios examined, we observed CCS shifts of up to 45%. For x < 4, cesium, rubidium, and potassium iodide cluster ions are found to uptake water to a similar extent, while sodium iodide clusters uptake less water. For x ≥ 4, sodium iodide cluster ions uptake proportionally more water vapor than rubidium and potassium iodide cluster ions, while cesium iodide ions exhibit less uptake. Measured CCS shifts are compared to predictions based upon a Kelvin-Thomson-Raoult (KTR) model as well as a Langmuir adsorption model. We find that the Langmuir adsorption model can be fit well to measurements. Meanwhile, KTR predictions deviate from measurements, which suggests that the earliest stages of vapor uptake by nanometer scale species are not well described by the KTR model.

  16. Specific chemical reactivities of spatially separated 3-aminophenol conformers with cold Ca$^+$ ions

    CERN Document Server

    Chang, Yuan-Pin; Küpper, Jochen; Rösch, Daniel; Wild, Dieter; Willitsch, Stefan

    2013-01-01

    Many molecules exhibit multiple rotational isomers (conformers) that interconvert thermally and are difficult to isolate. Consequently, a precise characterization of their role in chemical reactions has proven challenging. We have probed the reactivity of specific conformers using an experimental technique based on their spatial separation in a molecular beam by electrostatic deflection. The separated conformers react with a target of Coulomb-crystallized ions in a trap. In the reaction of Ca$^+$ with 3-aminophenol, we find a twofold larger rate constant for the \\textit{cis}- compared to the \\textit{trans}-conformer (differentiated by the O-H bond orientation). This result is explained by conformer-specific differences in the long-range ion-molecule interaction potentials. Our approach demonstrates the possibility of controlling reactivity through selection of conformational states.

  17. Influence of the coupling between an atmospheric pressure ion mobility spectrometer and the low pressure ion inlet of a mass spectrometer on the mobility measurement

    Directory of Open Access Journals (Sweden)

    Gunzer Frank

    2016-01-01

    Full Text Available Ion mobility spectrometers (IMS are versatile gas analyzers. Due to their small size and robustness, combined with a very high sensitivity, they are often used in gas sensing applications such as environmental monitoring. In order to improve the selectivity, they are typically combined with a mass spectrometer (MS. Since IMS works at atmospheric pressure, and MS works at vacuum, a special interface reducing the pressure over normally two stages has to be used. In this paper the influence of this coupling of different pressure areas on the IMS signal will be analyzed with help of finite elements method simulations.

  18. Affecting proton mobility in activated peptide and whole protein ions via lysine guanidination.

    Science.gov (United States)

    Pitteri, Sharon J; Reid, Gavin E; McLuckey, Scott A

    2004-01-01

    We have evaluated the effect of lysine guanidination in peptides and proteins on the dissociation of protonated ions in the gas phase. The dissociation of guanidinated model peptide ions compared to their unmodified forms showed behavior consistent with concepts of proton mobility as a major factor in determining favored fragmentation channels. Reduction of proton mobility associated with lysine guanidination was reflected by a relative increase in cleavages occurring C-terminal to aspartic acid residues as well as increases in small molecule losses. To evaluate the effect of guanidination on the dissociation behavior of whole protein ions, bovine ubiquitin was selected as a model. Essentially, all of the amide bond cleavages associated with the +10 charge state of fully guanidinated ubiquitin were observed to occur C-terminal to aspartic acid residues, unlike the dissociation behavior of the +10 ion of the unmodified protein, where competing cleavage N-terminal to proline and nonspecific amide bond cleavages were also observed. The +8 and lower charge states of the guanidinated protein showed prominent losses of small neutral molecules. This overall fragmentation behavior is consistent with current hypotheses regarding whole protein dissociation that consider proton mobility and intramolecular charge solvation as important factors in determining favored dissociation channels, and are also consistent with the fragmentation behaviors observed for the guanidinated model peptide ions. Further evaluation of the utility of condensed phase guanidination of whole proteins is necessary but the results described here confirm that guanidination can be an effective strategy for enhancing C-terminal aspartic acid cleavages. Gas phase dissociation exclusively at aspartic acid residues, especially for whole protein ions, could be useful in identifying and characterizing proteins via tandem mass spectrometry of whole protein ions.

  19. Separation of Co(II) ions from water resources by natural zeolite (clinoptilolite)

    OpenAIRE

    Jakupi, Shaban; Lisickov, Kiril; Golomeova, Mirjana; Atkovska, Katerina; Marinkovski, Mirko

    2016-01-01

    The contemporary trends in green separation processes impose the need for application of natural, low-cost and high-efficiency selective adsorbents within the processes for the treatment of drinking water supplies. Lately, nano-porous inorganic sorbents represent an ongoing trend for elimination of heavy metals from water resources. Natural zeolite clinoptilolite was used as a potential raw material for the purpose of removal of Co ions from model solutions. The experimental results were obta...

  20. Unified superresolution experiments and stochastic theory provide mechanistic insight into protein ion-exchange adsorptive separations

    OpenAIRE

    Kisley, Lydia; Chen, Jixin; Mansur, Andrea P.; Shuang, Bo; Kourentzi, Katerina; Poongavanam, Mohan-Vivekanandan; Chen, Wen-Hsiang; Dhamane, Sagar; Willson, Richard C.; Landes, Christy F.

    2014-01-01

    Adsorption of proteins underlies the purification of biopharmaceuticals, as well as therapeutic apheresis, immunoassays, and biosensors. In particular, separation of proteins by interactions with charged ligands on surfaces (ion-exchange chromatography) is an essential tool of the modern pharmaceutical industry. By quantifying the interactions of single proteins with individual charged ligands, we demonstrate that clusters of charges are necessary to create functional adsorption sites and tha...

  1. Boron Separation by the Two-step Ion-Exchange for the Isotopic Measurement of Boron

    Institute of Scientific and Technical Information of China (English)

    WANG,Qing-Zhong(王庆忠); XIAO,Ying-Kai(肖应凯); WANG,Yun-Hui(王蕴惠); ZHANG,Chong-Geng(张崇耿); WEI,Hai-Zhen(魏海珍)

    2002-01-01

    An improved procedure for extraction and purification of boron from natural samples is presented. The separation and purification of boron was carried out using a boron-specific resin, Amberlite IRA743, and a mixed ion exchange resin,Dowex 50W × 8 and Ion Exchanger Ⅱ resin. Using the mixed ion exchange resin which adsorbs all cations and anions except boron, the HCl and other cations and anions left in eluant from the Amberlite IRA 743 were removed effectively. In this case, boron loss can be avoided because the boron-bearing solution does not have to be evaporated to reach dryness to dislodge HCl. The boron recovery ranged from 97.6% to 102% in this study. The isotopic fractionation of boron can be negligible within the precision of the isotopic measurement. The results show that boron separation for the isotopic measurement by using both Amberlite IRA 743 resin and the mixed rein is more effective than that using Amberlite IRA 743 resin alone. The boron in samples of brine, seawater, rock, coral and foraminifer were separated by this procedure. Boron isotopic compositions of these samples were measured by thermal ionization mass spectrometry in this study.

  2. Scaled-up separation of cellobiohydrolase1 from a cellulase mixture by ion-exchange chromatography.

    Science.gov (United States)

    Ye, Zhuoliang; Lane, Andrew N; Willing, Gerold A; Berson, R Eric

    2011-01-01

    Enzymatic hydrolysis of cellulose often involves cellulases produced by Trichoderma reesei, of which cellobiohydrolase1 (CBH1) is the most abundant (about 60% of total cellulases) and plays an important role in the hydrolysis of crystalline cellulose. A method for separating sufficient quantities from the bulk cellulase cocktail is highly desirable for many studies, such as those that aim to characterize binding and hydrolysis kinetics of CBH1. In this work, CBH1 was separated from other Spezyme CP cellulases by ion-exchange chromatography using an efficient modification of a smaller scale process. The ion-exchange column was connected to a vacuum manifold system to provide a steady flow through parallel columns and thus achieve scale-up for enzyme separation. With five 5-mL columns running in parallel, about 55 mg of CBH1 was separated from 145 mg of Spezyme CP in a single separation. Step elution was used to replace the continuous gradient used at smaller scale. The purified CBH1 was collected in the fraction eluted with a buffer containing 0.33 M salt and showed comparable purity and activity as the enzyme purified by a fast protein liquid chromatography system. The stability of separated CBH1 was studied for up to 2 days and good thermal stability was observed. Separated CBH1 also showed both high adsorption to bacterial microcrystalline cellulose with ~4 μmol/g maximum adsorption and a K(a) of 5.55 ± 2.34 μM(-1) , and good hydrolytic activity based on atomic force microscopy observations that show a reduction in fiber height.

  3. Separation and quantitation of methenamine in urine by ion-pair extraction.

    Science.gov (United States)

    Strom, J G; Jun, H W

    1986-04-01

    An ion-pair extraction technique is described for separating methenamine, a urinary tract antibacterial agent, from formaldehyde in human urine samples. Separation conditions are developed from extraction constants for the methenamine-bromocresol green ion-pair. The technique involves adsorption of the ion-pair onto a silica cartridge and elution with methylene chloride:1-pentanol (95:5). Methenamine is freed from the ion-pair by the addition of excess tetrabutylammonium iodide and converted to formaldehyde (determined spectrophotometrically) by reaction with ammonia and acetylacetone. Linear standard plots were obtained from urine containing methenamine which was diluted to 10-160 micrograms/mL. The lower limit of detection was 6 micrograms/mL of methenamine. Absolute recovery from urine was greater than or equal to 94.5%. The precision (CV) of detection of methenamine in the presence of formaldehyde was less than 2%, and less than or equal to 4.5% for the detection of formaldehyde in the presence of methenamine. No interferences were noted. The applicability of the method was demonstrated by analysis of human urine levels of both methenamine and formaldehyde following oral administration of a methenamine salt to a volunteer.

  4. First laser ions at an off-line mass separator of the ISAC facility at TRIUMF

    CERN Document Server

    Rauth, C; Horn, R; Lassen, J; Bricault, P; Wendt, K; 10.1016/j.nimb.2003.08.029

    2004-01-01

    For efficient and in particular for selective production of radioactive ion beams at on-line mass separator facilities the technique of resonance ionization laser ion sources (RILlS) has become the most powerful tool. In facilities like ISOLDE at CERN they nowadays represent the most commonly used type of ion source for rare short-lived isotopes, delivering highest suppression of isobaric contaminations. For a first off-line demonstration preparing the development and installation of such a laser ion source at the new ISAC facility at TRIUMF in Vancouver (Canada), an all solid state laser system developed at the University of Mainz (Germany), was transferred and tested there at an off-line test separator. The laser system consists of three tunable titanium:sapphire lasers with a repetition rate of 12 kHz, pulse length of ~30 ns, up to 2.5 W output power in the infrared to red spectral region and features additional frequency doubling units. With this system first RILIS studies were performed in a number of el...

  5. Development of an ion mobility spectrometer with UV ionization source to detect ketones and BTX

    Science.gov (United States)

    Ni, Kai; Guo, Jingran; Ou, Guangli; Lei, Yu; Wang, Xiaohao

    2014-11-01

    Ion mobility spectrometry (IMS) is an attractive material analysis technology for developing a miniaturized volatile organic compounds (VOCs) on-site monitoring sensor. Having simple instrumentation, IMS is especially suitable when portability and sensitivity are required. In this work, we designed an ion mobility spectrometer with UV ionization. The geometric parameters of the UV-IMS were optimized based on a numerical simulation. The simulation results demonstrated that the drift electric field in the drift region was approximately homogenous and in the reaction region had an ion focusing effect, which could improve the sensitivity and resolving power of the IMS. The UV-IMS has been constructed and used to detect VOCs, such as acetone, benzene, toluene and m-xylene (BTX). The resolution of these substance measured from the UV-IMS in the atmospheric conditions are about 30 and the limit of detection (LOD) is low to ppmv. The ion mobility module and electric circuit are integrated in a main PCB, which can facilitate mass production and miniaturization. The present UV-IMS is expected to become a tool of choice for the on-site monitoring for VOCs.

  6. Analysis of CD34+ cell collection using two mobilization regimens for newly diagnosed multiple myeloma patients reveals the separate impact of mobilization and collection variables.

    Science.gov (United States)

    Abuabdou, Ahmed; Rosenbaum, Eric R; Usmani, Saad Zafar; Barlogie, Bart; Cottler-Fox, Michele

    2014-10-01

    Mobilization regimens for CD34+ cells have generally been judged successful based on the number of cells collected without evaluating mobilization separately from collection. Using retrospective data for patients who collected CD34+ cells on Total Therapy protocols 3a/3b (VTD-PACE) and Total Therapy 4/5 using a novel regimen that added low dose melphalan to VTD-PACE (MVTD-PACE), we analyzed mobilization and collection variables separately. A significant difference favoring MVDT-PACE was found in mean CD34+ cells/µL on day 2 of collection and in mean ratio of CD34+ cells/µL on day 2 to day 1. However, because apheresis variables and growth factor dose during collection were manipulated to optimize individual collections, the two regimens were not significantly different when the mean total CD34+ cells ×10(6) /kg collected was compared. Thus, when evaluating a chemotherapy regimen or new growth factor for mobilization, it is important to realize that total CD34+ cells collected is dependent on both mobilization and collection variables.

  7. Unfolding of Hydrated Alkyl Diammonium Cations Revealed by Cryogenic Ion Mobility-Mass Spectrometry.

    Science.gov (United States)

    Servage, Kelly A; Fort, Kyle L; Silveira, Joshua A; Shi, Liuqing; Clemmer, David E; Russell, David H

    2015-07-22

    Hydration of the ammonium ion plays a key role in determining the biomolecular structure as well as local structure of water in aqueous environments. Experimental data obtained by cryogenic ion mobility-mass spectrometry (cryo-IM-MS) show that dehydration of alkyl diammonium cations induces a distinct unfolding transition at a critical number of water molecules, n = 21 to 23, n = 24 to 26, and n = 27 to 29, for 1,7-diaminoheptane, 1,8-diaminooctane, and 1,10-diaminodecane, respectively. Results are also presented that reveal compelling evidence for unique structural transitions of hydrated ammonium ions associated with the development of the hydrogen-bond network around individual charged groups. The ability to track the evolution of structure upon stepwise dehydration provides direct insight into the intricate interplay between solvent-molecule interactions that are responsible for defining conformations. Such insights are potentially valuable in understanding how ammonium ion solvation influences conformation(s) of larger biomolecules.

  8. Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries.

    Science.gov (United States)

    Hofmann, Andreas; Kaufmann, Christoph; Müller, Marcus; Hanemann, Thomas

    2015-08-27

    In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE) and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte-separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4-400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3-38.1 mN∙m(-1). It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations.

  9. Utilization of a diol-stationary phase column in ion chromatographic separation of inorganic anions.

    Science.gov (United States)

    Arai, Kaori; Mori, Masanobu; Kozaki, Daisuke; Nakatani, Nobutake; Itabashi, Hideyuki; Tanaka, Kazuhiko

    2012-12-28

    We describe the ion chromatographic separation of inorganic anions using a diol-stationary phase column (-CH(OH)CH(2)OH; diol-column) without charged functional groups. Anions were separated using acidic eluent as in typical anion-exchange chromatography. The retention volumes of anions on the diol-column increased with increasing H(+) concentration in the eluent. The anion-exchange capacities of diol-columns in the acidic eluent (pH 2.8) were larger than that of zwitterionic stationary phase column but smaller than that of an anion-exchange column. The separation of anions using the diol-column was strongly affected by the interaction of H(+) ions with the diol-functional groups and by the types of the eluents. In particular, the selection of the eluent was very important for controlling the retention time and resolution. Good separation was obtained using a diol-column (HILIC-10) with 5 mM phthalic acid as eluent. The limits of detection at a signal-to-noise ratio of 3 ranged from 1.2 to 2.7 μM with relative standard deviations (RSD, n=5) of 0.04-0.07% for the retention time and 0.4-2.0% for the peak areas. This method was successfully applied to the determination of H(2)PO(4)(-), Cl(-), and NO(3)(-) in a liquid fertilizer sample.

  10. Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Andreas Hofmann

    2015-08-01

    Full Text Available In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte–separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4–400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3–38.1 mN∙m−1. It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations.

  11. Reactant ion chemistry for detection of TNT, RDX, and PETN using an ion mobility spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Klassen, S.E.; Rodacy, P.; Silva, R.

    1997-09-01

    This report describes the responses of three energetic materials (TNT, RDX, and PETN) to varying reactant ion chemistries and IMS cell temperatures. The following reactant ion chemistries were evaluated; air-dry; air-wet; methylene chloride-dry; methylene chloride-wet; methylene bromide-dry; nitrogen dioxide-wet; sulfur dioxide-wet. The temperature was varied between 160 - 220{degrees}C.

  12. Recovery of lithium and cobalt from waste lithium ion batteries of mobile phone

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Manis Kumar, E-mail: mkjha@nmlindia.org; Kumari, Anjan; Jha, Amrita Kumari; Kumar, Vinay; Hait, Jhumki; Pandey, Banshi Dhar

    2013-09-15

    Graphical abstract: Recovery of valuable metals from scrap batteries of mobile phone. - Highlights: • Recovery of Co and Li from spent LIBs was performed by hydrometallurgical route. • Under the optimum condition, 99.1% of lithium and 70.0% of cobalt were leached. • The mechanism of the dissolution of lithium and cobalt was studied. • Activation energy for lithium and cobalt were found to be 32.4 kJ/mol and 59.81 kJ/mol, respectively. • After metal recovery, residue was washed before disposal to the environment. - Abstract: In view of the stringent environmental regulations, availability of limited natural resources and ever increasing need of alternative energy critical elements, an environmental eco-friendly leaching process is reported for the recovery of lithium and cobalt from the cathode active materials of spent lithium-ion batteries of mobile phones. The experiments were carried out to optimize the process parameters for the recovery of lithium and cobalt by varying the concentration of leachant, pulp density, reductant volume and temperature. Leaching with 2 M sulfuric acid with the addition of 5% H{sub 2}O{sub 2} (v/v) at a pulp density of 100 g/L and 75 °C resulted in the recovery of 99.1% lithium and 70.0% cobalt in 60 min. H{sub 2}O{sub 2} in sulfuric acid solution acts as an effective reducing agent, which enhance the percentage leaching of metals. Leaching kinetics of lithium in sulfuric acid fitted well to the chemical controlled reaction model i.e. 1 − (1 − X){sup 1/3} = k{sub c}t. Leaching kinetics of cobalt fitted well to the model ‘ash diffusion control dense constant sizes spherical particles’ i.e. 1 − 3(1 − X){sup 2/3} + 2(1 − X) = k{sub c}t. Metals could subsequently be separated selectively from the leach liquor by solvent extraction process to produce their salts by crystallization process from the purified solution.

  13. Separation of sulfite, sulfate, and thiosulfate by ion chromatography with gradient elution

    Energy Technology Data Exchange (ETDEWEB)

    Sunden, T. (Univ. of Umea, Sweden); Lindgren, M.; Cedergren, A.; Siemer, D.D.

    1983-01-01

    A simple gradient apparatus, consisting of a peristaitic pump in addition to a standard high-pressure pump, is described. The device is used to make a single-run ion chromotographic separation of sulfite, sulfate, and thiosulfate in less than 15 min. This separation required a step gradient with 4.8 mM NaHCO/sub 3//4.7 mM Na/sub 2/CO/sub 3/ as start eluent and 6.9 mM NaHCO/sub 3//8.6 mM Na/sub 2/CO/sub 3/ is final eluent when two (4 x 50) mm Dionex anion precolumns in series were used as separator. The eluent compositions were simplex optimized.

  14. Charged Polymer-Coated Separators by Atmospheric Plasma-Induced Grafting for Lithium-Ion Batteries.

    Science.gov (United States)

    Han, Mina; Kim, Dong-Won; Kim, Yeong-Cheol

    2016-10-05

    A simple and fast method of atmospheric plasma-induced grafting was applied over a polyethylene membrane to enhance its performance as a separator for lithium-ion batteries. The process of grafting has formed a thin, durable, and uniform layer on the surface of the porous membrane. The charges of grafted polymers affected the performance of batteries in many ways besides the change of hydrophilicity. Negative charges in polymers improve the capacity retention of batteries and the uniformity of the SEI layer. On the other hand, the electrostatic attraction between different charges contributed to small increases of thermal stability and mechanical strength of separators. Polyampholyte was grafted by using the mixtures of monomers, and the composition of the grafted layer was optimized. The formation of stable uniform SEI layers and the marked improvement in capacity retention were observed in the full cell tests of the lithium battery with the polyampholyte-grafted separators when the polyampholyte has a negative net charge.

  15. Utilization of deep eutectic solvents as novel mobile phase additives for improving the separation of bioactive quaternary alkaloids.

    Science.gov (United States)

    Tan, Ting; Zhang, Mingliang; Wan, Yiqun; Qiu, Hongdeng

    2016-01-01

    Deep eutectic solvents (DESs) were used as novel mobile phase additives to improve chromatographic separation of four quaternary alkaloids including coptisine chloride, sanguinarine, berberine chloride and chelerythrine on a C18 column. DESs as a new class of ionic liquids are renewably sourced, environmentally benign, low cost and easy to prepare. Seven DESs were obtained by mixing different hydrogen acceptors and hydrogen-bond donors. The effects of organic solvents, the concentration of DESs, the types of DESs and the pH values of the buffer solution on the separation of the analytes were investigated. The composition of acetonitrile and 1.0% deep eutectic solvents aqueous solution (pH 3.3, adjusted with hydrochloric acid) in a 32:68 (v/v) ratio was used as optimized mobile phase, with which four quaternary alkaloids were well separated. When a small amount of DESs was added in the mobile phase for the separation of alkaloids on the C18 column, noticeable improvements were distinctly observed such as decreasing peak tailing and improving resolution. The separation mechanism mediated by DESs as mobile phase additives can be attributed to combined effect of both hydrogen acceptors and hydrogen-bond donors. For example, choline chloride can effectively cover the residual silanols on silica surface and ethylene glycol can reduce the retention time of analytes. The proposed method has been applied to determine BerbC in Lanqin Chinese herbal oral solution and BerbC tablet. Utilization of DESs in mobile phase can efficiently improve separation and selectivity of analytes from complex samples.

  16. Express analysis of explosives, chemical warfare agents and drugs with multicapillary column gas chromatography and ion mobility increment spectrometry.

    Science.gov (United States)

    Buryakov, Igor A

    2004-02-05

    Description of a gas chromatograph designed for express analysis of explosives (2,4-dinitrotoluene, 2,4,6-trinitrotoluene, pentaerythritol tetranitrate), chemical warfare agents (mustard gas, lewisite, sarin) and drugs (heroin, cocaine hydrochloride, crack) is given. The devices comprises a multicapillary chromatographic column and an ion mobility increment spectrometer (MCC-IMIS). The main analytical characteristics of an IMIS (estimated detection limit (DL), linear dynamic range (LDR), speed of response) and a chromatographic column (separation power, degree of separation, a number of possible peaks at a chromatogram section, divided by analysis time) are determined. The maximum value of DL equal to 5 pg/ml was registered for cis-alpha-LW, and the lowest one of 0.001 pg/ml was for cocaine. The maximum value of LDR equal to 1000 was registered for sarin and the lowest one of 150 was for the ions of lewisite. Speed of response of one compound detection with the IMIS was 0.7 s.

  17. High temperature stable Li-ion battery separators based on polyetherimides with improved electrolyte compatibility

    Science.gov (United States)

    l'Abee, Roy; DaRosa, Fabien; Armstrong, Mark J.; Hantel, Moritz M.; Mourzagh, Djamel

    2017-03-01

    We report (electro-)chemically stable, high temperature resistant and fast wetting Li-ion battery separators produced through a phase inversion process using novel polyetherimides (PEI) based on bisphenol-aceton diphthalic anhydride (BPADA) and para-phenylenediamine (pPD). In contrast to previous studies using PEI based on BPADA and meta-phenylenediamine (mPD), the separators reported herein show limited swelling in electrolytes and do not require fillers to render sufficient mechanical strength and ionic conductivity. In this work, the produced 15-25 μm thick PEI-pPD separators show excellent electrolyte compatibility, proven by low degrees of swelling in electrolyte solvents, low contact angles, fast electrolyte wicking and high electrolyte uptake. The separators cover a tunable range of morphologies and properties, leading to a wide range of ionic conductivities as studied by Electrochemical Impedance Spectroscopy (EIS). Dynamic Mechanical Analysis (DMA) demonstrated dimensional stability up to 220 °C. Finally, single layer graphite/lithium nickel manganese cobalt oxide (NMC) pouch cells were assembled using this novel PEI-pPD separator, showing an excellent capacity retention of 89.3% after 1000 1C/2C cycles, with a mean Coulombic efficiency of 99.77% and limited resistance build-up. We conclude that PEI-pPD is a promising new material candidate for high performance separators.

  18. Novel Ceramic-Grafted Separator with Highly Thermal Stability for Safe Lithium-Ion Batteries.

    Science.gov (United States)

    Jiang, Xiaoyu; Zhu, Xiaoming; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2017-08-09

    The separator is a critical component of lithium-ion batteries (LIBs), which not only allows ionic transport while it prevents electrical contact between electrodes but also plays a key role for thermal safety performance of LIBs. However, commercial separators for LIBs are typically microporous polyolefin membranes that pose challenges for battery safety, due to shrinking and melting at elevated temperature. Here, we demonstrate a strategy to improve the thermal stability and electrolyte affinity of polyethylene (PE) separators. By simply grafting the vinylsilane coupling reagent on the surface of the PE separator by electron beam irradiation method and subsequent hydrolysis reaction into the Al(3+) solution, an ultrathin Al2O3 layer is grafted on the surface of the porous polymer microframework without sacrificing the porous structure and increasing the thickness. The as-synthesized Al2O3 ceramic-grafted separator (Al2O3-CGS) shows almost no shrinkage at 150 °C and decreases the contact angle of the conventional electrolyte compared with the bare PE separator. Notably, the full cells with the Al2O3-CGSs exhibit better cycling performance and rate capability and also provide stable open circuit voltage even at 170 °C, indicating its promising application in LIBs with high safety and energy density.

  19. Development of Advanced Nuclide Separation and Recovery Methods using Ion-Exchanhge Techniques in Nuclear Backend

    Science.gov (United States)

    Miura, Hitoshi

    The development of compact separation and recovery methods using selective ion-exchange techniques is very important for the reprocessing and high-level liquid wastes (HLLWs) treatment in the nuclear backend field. The selective nuclide separation techniques are effective for the volume reduction of wastes and the utilization of valuable nuclides, and expected for the construction of advanced nuclear fuel cycle system and the rationalization of waste treatment. In order to accomplish the selective nuclide separation, the design and synthesis of novel adsorbents are essential for the development of compact and precise separation processes. The present paper deals with the preparation of highly functional and selective hybrid microcapsules enclosing nano-adsorbents in the alginate gel polymer matrices by sol-gel methods, their characterization and the clarification of selective adsorption properties by batch and column methods. The selective separation of Cs, Pd and Re in real HLLW was further accomplished by using novel microcapsules, and an advanced nuclide separation system was proposed by the combination of selective processes using microcapsules.

  20. Analysis of explosives using corona discharge ionization combined with ion mobility spectrometry-mass spectrometry.

    Science.gov (United States)

    Lee, Jihyeon; Park, Sehwan; Cho, Soo Gyeong; Goh, Eun Mee; Lee, Sungman; Koh, Sung-Suk; Kim, Jeongkwon

    2014-03-01

    Corona discharge ionization combined with ion mobility spectrometry-mass spectrometry (IMS-MS) was utilized to investigate five common explosives: cyclonite (RDX), trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), cyclotetramethylenetetranitramine (HMX), and 2,4-dinitrotoluene (DNT). The MS scan and the selected ion IMS analyses confirmed the identities of the existing ion species and their drift times. The ions observed were RDX·NO3(-), TNT(-), PETN·NO3(-), HMX·NO3(-), and DNT(-), with average drift times of 6.93 ms, 10.20 ms, 9.15 ms, 12.24 ms, 11.30 ms, and 8.89 ms, respectively. The reduced ion mobility values, determined from a standard curve calculated by linear regression of (normalized drift times)(-1) versus literature K0 values, were 2.09, 1.38, 1.55, 1.15, 1.25, and 1.60 cm(2) V(-1) s(-1), respectively. The detection limits were found to be 0.1 ng for RDX, 10 ng for TNT, 0.5 ng for PETN, 5.0 ng for HMX, and 10 ng for DNT. Simplified chromatograms were observed when nitrogen, as opposed to air, was used as the drift gas, but the detection limits were approximately 10 times worse (i.e., less sensitivity of detection). © 2013 Elsevier B.V. All rights reserved.

  1. Investigation of the lithium ion mobility in cyclic model compounds and their ion conduction properties

    Energy Technology Data Exchange (ETDEWEB)

    Thielen, Joerg

    2011-07-27

    In view of both, energy density and energy drain, rechargeable lithium ion batteries outperform other present accumulator systems. However, despite great efforts over the last decades, the ideal electrolyte in terms of key characteristics such as capacity, cycle life, and most important reliable safety, has not yet been identified. Steps ahead in lithium ion battery technology require a fundamental understanding of lithium ion transport, salt association, and ion solvation within the electrolyte. Indeed, well defined model compounds allow for systematic studies of molecular ion transport. Thus, in the present work, based on the concept of immobilizing ion solvents, three main series with a cyclotriphosphazene (CTP), hexaphenylbenzene (HBP), and tetramethylcyclotetrasiloxane (TMS) scaffold were prepared. Lithium ion solvents, among others ethylene carbonate (EC), which has proven to fulfill together with propylene carbonate safety and market concerns in commercial lithium ion batteries, were attached to the different cores via alkyl spacers of variable length. All model compounds were fully characterized, pure and thermally stable up to at least 235 C, covering the requested broad range of glass transition temperatures from -78.1 C up to +6.2 C. While the CTP models tend to rearrange at elevated temperatures over time, which questions the general stability of alkoxide related (poly)phosphazenes, both, the HPB and CTP based models show no evidence of core stacking. In particular the CTP derivatives represent good solvents for various lithium salts, exhibiting no significant differences in the ionic conductivity {sigma}{sub dc} and thus indicating comparable salt dissociation and rather independent motion of cations and ions. In general, temperature-dependent bulk ionic conductivities investigated via impedance spectroscopy follow a William-Landel-Ferry (WLF) type behavior. Modifications of the alkyl spacer length were shown to influence ionic conductivities only in

  2. Methods development for separation of inorganic anions, organic acids and bases, and neutral organic compounds by ion chromatography and capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie [Iowa State Univ., Ames, IA (United States)

    1999-04-01

    A novel anion-exchange resin containing three amine groups was prepared by reaction of a chloromethylated polystyrene-divinylbenzene (PS-DVB) resin with diethylenetriamine. After being protonated by contact with an aqueous acid, this resin can be used for ion chromatographic separation of anions. The charge on the resins can be varied from +1 to +3 by changing the mobile phase pH. The selectivity of the new ion exchangers for various inorganic anions was quite different from that of conventional anion exchangers. The performance of this new anion exchanger was studied by changing the pH and the concentration of the eluent, and several different eluents were used with some common anions as testing analytes. Conductivity detection and UV-visible detection were applied to detect the anions after separation. The new resin can also be used for HPLC separation of neutral organic compounds. Alkylphenols and alkylbenzenes were separated with this new polymeric resin, and excellent separations were obtained under simple conditions. This report contains Chapter 1: General introduction and Chapter 6: General conclusions.

  3. Study of selective heating at ion cyclotron resonance for the plasma separation process

    Science.gov (United States)

    Compant La Fontaine, A.; Pashkovsky, V. G.

    1995-12-01

    The plasma separation process by ion cyclotron resonance heating (ICRH) is studied both theoretically and experimentally on two devices: the first one called ERIC (Ion Cyclotron Resonance Experiment) at Saclay (France) [P. Louvet, Proceedings of the 2nd Workshop on Separation Phenomena in Liquids and Gases, Versailles, France, 1989, edited by P. Louvet, P. Noe, and Soubbaramayer (Centre d'Etudes Nucléaires de Saclay and Cité Scientifique Parcs et Technopoles, Ile de France Sud, France, 1989), Vol. 1, p. 5] and the other one named SIRENA at the Kurchatov Institute, Moscow, Russia [A. I. Karchevskii et al., Plasma Phys. Rep. 19, 214 (1993)]. The radio frequency (RF) transversal magnetic field is measured by a magnetic probe both in plasma and vacuum and its Fourier spectrum versus the axial wave number kz is obtained. These results are in agreement with the electromagnetic (EM) field calculation model based on resolution of Maxwell equations by a time-harmonic scheme studied here. Various axial boundary conditions models used to compute the EM field are considered. The RF magnetic field is weakly influenced by the plasma while the electric field components are strongly disturbed due to space-charge effects. In the plasma the transversal electric field is enhanced and the kz spectrum is narrower than in vacuum. The calculation of the resonant isotope heating is made by the Runge-Kutta method. The influence of ion-ion collisions, inhomogeneity of the static magnetic field B0, and the RF transversal magnetic field component on the ion acceleration is examined. These results are successfully compared with experiments of a minor isotope 44Ca heating measurements, made with an energy analyzer.

  4. Study of selective heating at ion cyclotron resonance for the plasma separation process

    Energy Technology Data Exchange (ETDEWEB)

    Compant La Fontaine, A. [Direction du Cycle du Combustible/Departement des Procedes d` Enrichissement, Service de Physique, d` Experimentation et d` Analyse, Commissariat a l` Energie Atomique, Centre d` Etudes de Saclay, 91191 Gif-sur-Yvette Cedex (France); Pashkovsky, V.G. [Molecular Physics Institute, RRC Kurchatov Institute 123182, Moscow (Russian Federation)

    1995-12-01

    The plasma separation process by ion cyclotron resonance heating (ICRH) is studied both theoretically and experimentally on two devices: the first one called ERIC (Ion Cyclotron Resonance Experiment) at Saclay (France) [P. Louvet, {ital Proceedings} {ital of} {ital the} 2{ital nd} {ital Workshop} {ital on} {ital Separation} {ital Phenomena} {ital in} {ital Liquids} {ital and} {ital Gases}, Versailles, France, 1989, edited by P. Louvet, P. Noe, and Soubbaramayer (Centre d`Etudes Nucleaires de Saclay and Cite Scientifique Parcs et Technopoles, Ile de France Sud, France, 1989), Vol. 1, p. 5] and the other one named SIRENA at the Kurchatov Institute, Moscow, Russia [A. I. Karchevskii {ital et} {ital al}., Plasma Phys. Rep. {bold 19}, 214 (1993)]. The radio frequency (RF) transversal magnetic field is measured by a magnetic probe both in plasma and vacuum and its Fourier spectrum versus the axial wave number {ital k}{sub {ital z}} is obtained. These results are in agreement with the electromagnetic (EM) field calculation model based on resolution of Maxwell equations by a time-harmonic scheme studied here. Various axial boundary conditions models used to compute the EM field are considered. The RF magnetic field is weakly influenced by the plasma while the electric field components are strongly disturbed due to space-charge effects. In the plasma the transversal electric field is enhanced and the {ital k}{sub {ital z}} spectrum is narrower than in vacuum. The calculation of the resonant isotope heating is made by the Runge--Kutta method. The influence of ion--ion collisions, inhomogeneity of the static magnetic field {ital B}{sub 0}, and the RF transversal magnetic field component on the ion acceleration is examined. These results are successfully compared with experiments of a minor isotope {sup 44}Ca heating measurements, made with an energy analyzer. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  5. Synthetic, structural, and theoretical investigations of alkali metal germanium hydrides--contact molecules and separated ions.

    Science.gov (United States)

    Teng, Weijie; Allis, Damian G; Ruhlandt-Senge, Karin

    2007-01-01

    The preparation of a series of crown ether ligated alkali metal (M=K, Rb, Cs) germyl derivatives M(crown ether)nGeH3 through the hydrolysis of the respective tris(trimethylsilyl)germanides is reported. Depending on the alkali metal and the crown ether diameter, the hydrides display either contact molecules or separated ions in the solid state, providing a unique structural insight into the geometry of the obscure GeH3- ion. Germyl derivatives displaying M--Ge bonds in the solid state are of the general formula [M([18]crown-6)(thf)GeH3] with M=K (1) and M=Rb (4). The compounds display an unexpected geometry with two of the GeH3 hydrogen atoms closely approaching the metal center, resulting in a partially inverted structure. Interestingly, the lone pair at germanium is not pointed towards the alkali metal, rather two of the three hydrides are approaching the alkali metal center to display M--H interactions. Separated ions display alkali metal cations bound to two crown ethers in a sandwich-type arrangement and non-coordinated GeH3- ions to afford complexes of the type [M(crown ether)2][GeH3] with M=K, crown ether=[15]crown-5 (2); M=K, crown ether=[12]crown-4 (3); and M=Cs, crown ether=[18]crown-6 (5). The highly reactive germyl derivatives were characterized by using X-ray crystallography, 1H and 13C NMR, and IR spectroscopy. Density functional theory (DFT) and second-order Møller-Plesset perturbation theory (MP2) calculations were performed to analyze the geometry of the GeH3- ion in the contact molecules 1 and 4.

  6. Lithium-ion battery electrolyte mobility at nano-confined graphene interfaces

    Science.gov (United States)

    Moeremans, Boaz; Cheng, Hsiu-Wei; Hu, Qingyun; Garces, Hector F.; Padture, Nitin P.; Renner, Frank Uwe; Valtiner, Markus

    2016-08-01

    Interfaces are essential in electrochemical processes, providing a critical nanoscopic design feature for composite electrodes used in Li-ion batteries. Understanding the structure, wetting and mobility at nano-confined interfaces is important for improving the efficiency and lifetime of electrochemical devices. Here we use a Surface Forces Apparatus to quantify the initial wetting of nanometre-confined graphene, gold and mica surfaces by Li-ion battery electrolytes. Our results indicate preferential wetting of confined graphene in comparison with gold or mica surfaces because of specific interactions of the electrolyte with the graphene surface. In addition, wetting of a confined pore proceeds via a profoundly different mechanism compared with wetting of a macroscopic surface. We further reveal the existence of molecularly layered structures of the confined electrolyte. Nanoscopic confinement of less than 4-5 nm and the presence of water decrease the mobility of the electrolyte. These results suggest a lower limit for the pore diameter in nanostructured electrodes.

  7. Clone-Based Mobile Agent Itinerary Planning Using Separate Trees For Data Fusion In WSNS

    Directory of Open Access Journals (Sweden)

    Soheil Javadi

    2012-09-01

    Full Text Available Recent studies demonstrate that Mobile Agent (MA approach could be more effective than conventional client-server model in Wireless Sensor Network (WSN. Particularly, itinerary planning for MAs is a significant aspect of these approaches. Tree-based methods have been widely used for this purpose where many agents are dispatched simultaneously. Most of tree-based methods try to construct an optimal/suboptimal tree in terms of an objective function. In contrast, in this paper we introduce a new approach that tries to separate the MA dispatching and data fusion operations by considering two itinerary trees which results in more flexibility to regulate the itinerary plan. Based on this idea, we propose an algorithm called Two Trees Clone-based Itinerary (TTCI which constructs two trees, one serves to distribute MA in the network and another to fuse back the sensed data. By experimental results, we demonstrate the performance improvement of TTCI algorithm in terms of overall energy consumption in comparison with the previous schemes. Meanwhile, the TTCI keeps the delay low.

  8. EM∩IM: software for relating ion mobility mass spectrometry and electron microscopy data.

    Science.gov (United States)

    Degiacomi, Matteo T; Benesch, Justin L P

    2016-01-07

    We present EM∩IM, software that allows the calculation of collision cross-sections from electron density maps obtained for example by means of transmission electron microscopy. This allows the assessment of structures other than those described by atomic coordinates with ion mobility mass spectrometry data, and provides a new means for contouring and validating electron density maps. EM∩IM thereby facilitates the use of data obtained in the gas phase within structural biology studies employing diverse experimental methodologies.

  9. Multi-Capillary Column-Ion Mobility Spectrometry of Volatile Metabolites Emitted by Saccharomyces Cerevisiae

    OpenAIRE

    Christoph Halbfeld; Ebert, Birgitta E.; Blank, Lars M.

    2014-01-01

    Volatile organic compounds (VOCs) produced during microbial fermentations determine the flavor of fermented food and are of interest for the production of fragrances or food additives. However, the microbial synthesis of these compounds from simple carbon sources has not been well investigated so far. Here, we analyzed the headspace over glucose minimal salt medium cultures of Saccharomyces cerevisiae using multi-capillary column-ion mobility spectrometry (MCC-IMS). The high sensitivity and f...

  10. Unified superresolution experiments and stochastic theory provide mechanistic insight into protein ion-exchange adsorptive separations.

    Science.gov (United States)

    Kisley, Lydia; Chen, Jixin; Mansur, Andrea P; Shuang, Bo; Kourentzi, Katerina; Poongavanam, Mohan-Vivekanandan; Chen, Wen-Hsiang; Dhamane, Sagar; Willson, Richard C; Landes, Christy F

    2014-02-11

    Chromatographic protein separations, immunoassays, and biosensing all typically involve the adsorption of proteins to surfaces decorated with charged, hydrophobic, or affinity ligands. Despite increasingly widespread use throughout the pharmaceutical industry, mechanistic detail about the interactions of proteins with individual chromatographic adsorbent sites is available only via inference from ensemble measurements such as binding isotherms, calorimetry, and chromatography. In this work, we present the direct superresolution mapping and kinetic characterization of functional sites on ion-exchange ligands based on agarose, a support matrix routinely used in protein chromatography. By quantifying the interactions of single proteins with individual charged ligands, we demonstrate that clusters of charges are necessary to create detectable adsorption sites and that even chemically identical ligands create adsorption sites of varying kinetic properties that depend on steric availability at the interface. Additionally, we relate experimental results to the stochastic theory of chromatography. Simulated elution profiles calculated from the molecular-scale data suggest that, if it were possible to engineer uniform optimal interactions into ion-exchange systems, separation efficiencies could be improved by as much as a factor of five by deliberately exploiting clustered interactions that currently dominate the ion-exchange process only accidentally.

  11. Unified superresolution experiments and stochastic theory provide mechanistic insight into protein ion-exchange adsorptive separations

    Science.gov (United States)

    Kisley, Lydia; Chen, Jixin; Mansur, Andrea P.; Shuang, Bo; Kourentzi, Katerina; Poongavanam, Mohan-Vivekanandan; Chen, Wen-Hsiang; Dhamane, Sagar; Willson, Richard C.; Landes, Christy F.

    2014-01-01

    Chromatographic protein separations, immunoassays, and biosensing all typically involve the adsorption of proteins to surfaces decorated with charged, hydrophobic, or affinity ligands. Despite increasingly widespread use throughout the pharmaceutical industry, mechanistic detail about the interactions of proteins with individual chromatographic adsorbent sites is available only via inference from ensemble measurements such as binding isotherms, calorimetry, and chromatography. In this work, we present the direct superresolution mapping and kinetic characterization of functional sites on ion-exchange ligands based on agarose, a support matrix routinely used in protein chromatography. By quantifying the interactions of single proteins with individual charged ligands, we demonstrate that clusters of charges are necessary to create detectable adsorption sites and that even chemically identical ligands create adsorption sites of varying kinetic properties that depend on steric availability at the interface. Additionally, we relate experimental results to the stochastic theory of chromatography. Simulated elution profiles calculated from the molecular-scale data suggest that, if it were possible to engineer uniform optimal interactions into ion-exchange systems, separation efficiencies could be improved by as much as a factor of five by deliberately exploiting clustered interactions that currently dominate the ion-exchange process only accidentally. PMID:24459184

  12. Isotopic separation through ion cyclotron-resonance: results from the ERIC experiment; La separation isotopique par resonance cyclotron ionique: resultats obtenus avec l`experience ERIC

    Energy Technology Data Exchange (ETDEWEB)

    Compant la Fontaine, A.; Louvet, P. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Procedes d`Enrichissement

    1994-12-31

    Stable isotope separation by the means of ion cyclotron-resonance is studied at CEA since 1981. Results from the ERIC experiments are of two types: parameter measurements which help characterizing the plasma and optimizing the process, and isotopic separation results. For example, the selective feature of isotope heating was verified in the cases of zinc and calcium using an electrostatic analyzer. The separation factors of various elements (calcium, zinc, barium, chromium...) are depending on the mass relative difference of the isotopes to be separated, difference which must be large compared to the magnetic field inhomogeneities and the Doppler broadening. 2 figs., 1 tab., 3 refs.

  13. Analyses of mouse breath with ion mobility spectrometry: a feasibility study.

    Science.gov (United States)

    Vautz, Wolfgang; Nolte, Jürgen; Bufe, Albrecht; Baumbach, Jörg I; Peters, Marcus

    2010-03-01

    Exhaled breath can provide comprehensive information about the metabolic state of the subject. Breath analysis carried out during animal experiments promises to increase the information obtained from a particular experiment significantly. This feasibility study should demonstrate the potential of ion mobility spectrometry for animal breath analysis, even for mice. In the framework of the feasibility study, an ion mobility spectrometer coupled with a multicapillary column for rapid preseparation was used to analyze the breath of orotracheally intubated spontaneously breathing mice during anesthesia for the very first time. The sampling procedure was validated successfully. Furthermore, the breath of four mice (2 healthy control mice, 2 with allergic airway inflammation) was analyzed. Twelve peaks were identified directly by comparison with a database. Additional mass spectrometric analyses were carried out for validation and for identification of unknown signals. Significantly different patterns of metabolites were detected in healthy mice compared with asthmatic mice, thus demonstrating the feasibility of analyzing mouse breath with ion mobility spectrometry. However, further investigations including a higher animal number for validation and identification of unknown signals are needed. Nevertheless, the results of the study demonstrate that the method is capable of rapid analyses of the breath of mice, thus significantly increasing the information obtained from each particular animal experiment.

  14. A compact high-resolution X-ray ion mobility spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Reinecke, T.; Kirk, A. T.; Heptner, A.; Niebuhr, D.; Böttger, S.; Zimmermann, S. [Department of Sensors and Measurement Technology, Institute of Electrical Engineering and Measurement Technology, Leibniz Universität Hannover, Appelstr. 9A, 30167 Hannover (Germany)

    2016-05-15

    For the ionization of gaseous samples, most ion mobility spectrometers employ radioactive ionization sources, e.g., containing {sup 63}Ni or {sup 3}H. Besides legal restrictions, radioactive materials have the disadvantage of a constant radiation with predetermined intensity. In this work, we replaced the {sup 3}H source of our previously described high-resolution ion mobility spectrometer with 75 mm drift tube length with a commercially available X-ray source. It is shown that the current configuration maintains the resolving power of R = 100 which was reported for the original setup containing a {sup 3}H source. The main advantage of an X-ray source is that the intensity of the radiation can be adjusted by varying its operating parameters, i.e., filament current and acceleration voltage. At the expense of reduced resolving power, the sensitivity of the setup can be increased by increasing the activity of the source. Therefore, the performance of the setup can be adjusted to the specific requirements of any application. To investigate the relation between operating parameters of the X-Ray source and the performance of the ion mobility spectrometer, parametric studies of filament current and acceleration voltage are performed and the influence on resolving power, peak height, and noise is analyzed.

  15. Polyvinylidene fluoride membrane by novel electrospinning system for separator of Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Cuiru [Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China); Jia, Zhidong; Guan, Zhicheng; Wang, Liming [Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China); Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China)

    2009-04-01

    The remarkable characteristics of nanofibers mats electrospun are large surface area to volume ratio and high porosity, which are crucial to increase the ionic conductivity of membrane full of liquid electrolyte, in this aspect, electrospinning is prior to the other methods, such as dry method, wet method, etc. Therefore, fabricating the separator of Li-ion batteries by electrospinning is potential and promising. The PVDF membranes were fabricated by electrospinning. The experiment demonstrated that the main deficiency in the fabricating separators process by electrospinning was low mechanical property, which induced partial short circuits inside the cells. Several methods were presented to enhance the mechanical strength. The experiments demonstrated that the higher the solution concentration was, the stronger the mechanical strength was, and the higher the voltage was, the stronger the mechanical strength was. Additionally, the spherical hat collection target instead of conditional plane target was applied in the electrospinning system, as a result, the thickness of the membrane was more uniform and the fiber diameter was also more uniform. Therefore, the charge and discharge capacity of the coin type cell composed of the separator collected by spherical hat target exceeded the plane target, and the electrospinning separators exceeded the commercial polypropylene separator. (author)

  16. Polyvinylidene fluoride membrane by novel electrospinning system for separator of Li-ion batteries

    Science.gov (United States)

    Yang, Cuiru; Jia, Zhidong; Guan, Zhicheng; Wang, Liming

    The remarkable characteristics of nanofibers mats electrospun are large surface area to volume ratio and high porosity, which are crucial to increase the ionic conductivity of membrane full of liquid electrolyte, in this aspect, electrospinning is prior to the other methods, such as dry method, wet method, etc. Therefore, fabricating the separator of Li-ion batteries by electrospinning is potential and promising. The PVDF membranes were fabricated by electrospinning. The experiment demonstrated that the main deficiency in the fabricating separators process by electrospinning was low mechanical property, which induced partial short circuits inside the cells. Several methods were presented to enhance the mechanical strength. The experiments demonstrated that the higher the solution concentration was, the stronger the mechanical strength was, and the higher the voltage was, the stronger the mechanical strength was. Additionally, the spherical hat collection target instead of conditional plane target was applied in the electrospinning system, as a result, the thickness of the membrane was more uniform and the fiber diameter was also more uniform. Therefore, the charge and discharge capacity of the coin type cell composed of the separator collected by spherical hat target exceeded the plane target, and the electrospinning separators exceeded the commercial polypropylene separator.

  17. Electrically driven ion separations and nanofiltration through membranes coated with polyelectrolyte multilayers

    Science.gov (United States)

    White, Nicholas

    Polyelectrolyte multilayer (PEM) films deposited using the layer-by-layer (LBL) method are attractive for their simple deposition, tailorable nature, scalability, and charge or size-based selectivity for solutes. This dissertation explores ion separations in electrodialysis (ED) and solute removal through nanofiltration with PEMs deposited on polymer membranes. ED membranes typically exhibit modest selectivities between monovalent and divalent ions. In contrast, this work shows that K+/Mg 2+ ED selectivities reach values >1000 when using Nafion 115 cation-exchange membranes coated with multilayer poly(4-styrenesulfonate) (PSS)/protonated poly(allylamine) (PAH) films. For comparison, the corresponding K+ /Mg2+ selectivity of bare Nafion 115 is 20,000, presumably because the applied current is below the limiting value for K+ and H+ transport is negligible at this high K+ concentration. The high selectivities of these membranes may enable electrodialysis applications such as purification of salts that contain divalent or trivalent ions. The high ED selectivities of (PAH/PSS)5PAH-coated Nafion membranes translate to separations with Li+/Co2+ and K +/La3+. Even with adsorption of only 3 polyelectrolyte layers, Nafion membranes exhibit a Li+/Co2+ selectivity >23. However, the resistance to monovalent-ion passage does not decrease significantly with fewer polyelectrolyte layers. At overlimiting currents, hydroxides from water splitting form insoluble metal hydroxides to foul the membrane. With 0.1 M source-phase salt concentrations, transference numbers for monovalent cations approach unity and selectivities are >5000 because the diffusion-limited K+ or Li+ currents exceed the applied current. However, ED selectivities gradually decline with time. Thus, future research should aim to increase membrane stability and limiting currents to fully exploit the remarkable selectivity of these membranes. PEMs deposited on commercial ultrafiltration (UF) membranes also show high

  18. Recoil separators for radiative capture using radioactive ion beams. Recent advances and detection techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Chris [TRIUMF, Vancouver, BC (Canada); Greife, Uwe; Hager, Ulrike [Colorado School of Mines, Golden, CO (United States)

    2014-06-15

    Radiative capture reactions involving the fusion of hydrogen or helium are ubiquitous in the stellar history of the universe, and are some of the most important reactions in the processes that govern nucleosynthesis and energy generation in both static and explosive scenarios. However, radiative capture reactions pose some of the most difficult experimental challenges due to extremely small cross sections. With the advent of recoil separators and techniques in inverse kinematics, it is now possible to measure radiative capture reactions on very short-lived radioactive nuclei, and in the presence of high experimental backgrounds. In this paper we review the experimental needs for making measurements of astrophysical importance on radiative capture reactions. We also review some of the important historical advances in the field of recoil separators as well as describe current techniques and performance milestones, including descriptions of some of the separators most recently working at radioactive ion beam facilities, such as DRAGON at TRIUMF and the DRS at the Holifield Radioactive Ion Beam Facility. We will also summarize some of the scientific highlight measurements at the RIB facilities. (orig.)

  19. Characterization of magnetic ion-exchange composites for protein separation from biosuspensions.

    Science.gov (United States)

    Käppler, Tobias E; Hickstein, Birgit; Peuker, Urs A; Posten, Clemens

    2008-06-01

    Downstream processing is a major issue in biotechnological production. A multitude of unit operations with nonsatisfying yield are often used to reach the desired product purity. Direct recovery technologies such as high-gradient magnetic fishing (HGMF) are advantageous because of their ability to separate the desired product in early stages from crude cultivation broths. However, the use of magnetic particles to capture valuable biotechnological products is often linked to the drawback that support particles are expensive and not available in greater quantities. This current work presents new composite magnetic particles that can be used in biotechnology. They are manufactured by a spray drying process. During this process, the nanosized magnetite particles as well as functional ion-exchange nanoparticles are integrated into one particle in which they are linked by a matrix polymer. The production procedure is flexible, scalable, and therefore economical. These particles have good adsorption capacities of up to 85 mg/g adsorbed protein and good binding kinetics. They are resistant to harsh conditions such as short ultrasonic treatment or extreme pHs. In order to test their usefulness in biosuspensions, model proteins were separated using these particles. The anion and cation exchanger particles separated lysozyme (LZ) or BSA from cultivation suspensions. The selectivity of recovery was dependent on other proteins present as is usual for ion-exchange binding mechanisms.

  20. Laser desorption-ion mobility spectrometry as a useful tool for imaging of thin layer chromatography surface.

    Science.gov (United States)

    Ilbeigi, Vahideh; Sabo, Martin; Valadbeigi, Younes; Matejcik, Stefan; Tabrizchi, Mahmoud

    2016-08-12

    We present a novel method for coupling thin layer chromatography (TLC) with ion mobility spectrometry (IMS) using laser desorption technique (LD). After separation of the compounds by TLC, the TLC surface was sampled by the LD-IMS without any further manipulation or preparation. The position of the laser was fixed and the TLC plate was moved in desired directions by the motorized micro-positioning stage. The method was successfully applied to analyze the TLC plates containing explosives (tri nitro toluene, 1,3,5-trinitro- 1,3,5-triazacyclohexane, pentaerythritol tetranitrate, 2,4-dinitro toluene and 3,4-dinitro toluene), amino acids (alanine, proline and isoleucine), nicotine and diphenylamine mixtures and detection limits for these compounds were determined. Combination of TLC with LD-IMS technique offers additional separation dimension, allowing separation of overlapping TLC analytes. The time for TLC sampling by LD-IMS was less than 80s. The scan rate for LD is adjustable so that fast and effective analysis of the mixtures is possible with the proposed method. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Structural analysis of ruthenium-arene complexes using ion mobility mass spectrometry, collision-induced dissociation, and DFT.

    Science.gov (United States)

    Czerwinska, Izabella; Far, Johann; Kune, Christopher; Larriba-Andaluz, Carlos; Delaude, Lionel; De Pauw, Edwin

    2016-04-21

    Ion mobility mass spectrometry (IM-MS) and collision-induced dissociation (CID) techniques were used to investigate the influence of the phosphine ligand on the physicochemical properties of [RuCl2(p-cymene)(PCy3)] (), [RuCl2(p-cymene)(PPh3)] (), and [RuCl2(p-cymene)(PTA)] () in the gas phase (PTA is 1,3,5-triaza-7-phosphaadamantane). Electrospray ionization of complexes and led to the corresponding [RuCl(p-cymene)(PR3)](+) ions via the dissociation of a chlorido ligand, whereas RAPTA-C () afforded two molecular ions by in-source oxidation ([Ru(III)Cl2(p-cymene)(PTA)](+)) or protonation ([RuCl2(p-cymene)(PTA+H)](+)). Control experiments showed that the balance between these two ionization paths was strongly influenced by the nature of the solvent used for infusion. Collision cross sections (CCSs) of the four molecular ions accurately reflected the variations of steric bulk inferred from the Tolman steric parameters (θ) of the phosphine ligands. Moreover, DFT calculations combined with a model based on the kinetic theory of gases (the trajectory method of the IMoS software) afforded reliable CCS predictions. The almost two times higher dipole moment of [RuCl2(p-cymene)(PTA+H)](+) (μ = 13.75 D) compared to [Ru(III)Cl2(p-cymene)(PTA)](+) (μ = 7.18 D) was held responsible for increased ion-induced dipole interactions with a polarizable drift gas such as N2. Further experiments with He and CO2 confirmed that increasing the polarizability of the buffer gas improved the separation between the two molecular ions derived from complex . The fragmentation patterns of complexes were determined by CID. The sequence of collision voltages at which 50% of a precursor ion dissociates (V50) recorded for the molecular ions derived from compounds was in good agreement with simple electronic considerations based on the donor strength of the phosphine ligand. Thus, the CCS and V50 parameters used to determine the shape and stability of ionic species in the gas phase are complementary

  2. Application of linear pH gradients for the modeling of ion exchange chromatography: Separation of monoclonal antibody monomer from aggregates.

    Science.gov (United States)

    Kluters, Simon; Wittkopp, Felix; Jöhnck, Matthias; Frech, Christian

    2016-02-01

    The mobile phase pH is a key parameter of every ion exchange chromatography process. However, mechanistic insights into the pH influence on the ion exchange chromatography equilibrium are rare. This work describes a mechanistic model capturing salt and pH influence in ion exchange chromatography. The pH dependence of the characteristic protein charge and the equilibrium constant is introduced to the steric mass action model based on a protein net charge model considering the number of amino acids interacting with the stationary phase. This allows the description of the adsorption equilibrium of the chromatographed proteins as a function of pH. The model parameters were determined for a monoclonal antibody monomer, dimer, and a higher aggregated species based on a manageable set of pH gradient experiments. Without further modification of the model parameters the transfer to salt gradient elution at fixed pH is demonstrated. A lumped rate model was used to predict the separation of the monoclonal antibody monomer/aggregate mixture in pH gradient elution and for a pH step elution procedure-also at increased protein loadings up to 48 g/L packed resin. The presented model combines both salt and pH influence and may be useful for the development and deeper understanding of an ion exchange chromatography separation.

  3. Renewable and superior thermal-resistant cellulose-based composite nonwoven as lithium-ion battery separator.

    Science.gov (United States)

    Zhang, Jianjun; Liu, Zhihong; Kong, Qingshan; Zhang, Chuanjian; Pang, Shuping; Yue, Liping; Wang, Xuejiang; Yao, Jianhua; Cui, Guanglei

    2013-01-01

    A renewable and superior thermal-resistant cellulose-based composite nonwoven was explored as lithium-ion battery separator via an electrospinning technique followed by a dip-coating process. It was demonstrated that such nanofibrous composite nonwoven possessed good electrolyte wettability, excellent heat tolerance, and high ionic conductivity. The cells using the composite separator displayed better rate capability and enhanced capacity retention, when compared to those of commercialized polypropylene separator under the same conditions. These fascinating characteristics would endow this renewable composite nonwoven a promising separator for high-power lithium-ion battery.

  4. Characterization of Polylactides with Different Stereoregularity Using Electrospray Ionization Ion Mobility Mass Spectrometry

    Science.gov (United States)

    Kim, Kihyun; Lee, Jong Wha; Chang, Taihyun; Kim, Hugh I.

    2014-10-01

    We investigated the effect of stereoregularity on the gas-phase conformations of linear and cyclic polylactides (PLA) using electrospray ionization ion mobility mass spectrometry (ESI-IM-MS) combined with molecular dynamics simulations. IM-MS analysis of PLA ions shows intriguing difference between the collision cross section (ΩD) value of poly-L-lactide (PLLA) and poly-LD-lactide (PLDLA) ions with respect to their chain architecture and stereoregularity. In the singly sodiated linear PLA ( l-PLA•Na+) case, both l-PLLA and l-PLDLA up to 11mer have very similar ΩD values, but the ΩD values of l-PLLA are greater than that of l-PLDLA ions for larger ions. In the case of cyclic PLA ( c-PLA), c-PLLA•Na+ is more compact than c-PLDLA•Na+ for short PLA ions. However, c-PLLA exhibits larger ΩD value than c-PLDLA for PLA ions longer than 13mer. The origin of difference in the ΩD values was investigated using theoretical investigation of PLAs in the gas phase. The gas-phase conformation of PLA ions is influenced by Na+-oxygen coordination and the weak intramolecular hydrogen bond interaction, which are more effectively formed in more flexible chains. Therefore, the less flexible PLLA has a larger ΩD value than PLDLA. However, for short c-PLA, concomitant maximization of both Na+-oxygen coordination and hydrogen bond interaction is difficult due to the constricted chain freedom, which makes the ΩD value of PLAs in this range show a different trend compared with other PLA ions. Our study facilitates the understanding of correlation between stereoregularity of PLAs and their structure, providing potential utility of IM-MS to characterize stereoisomers of polymers.

  5. Analysis of antibiotics from liquid sample using electrospray ionization-ion mobility spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li Shu; Jia Jian; Gao Xiaoguang; He Xiuli [State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China); Li Jianping, E-mail: jpli@mail.ie.ac.cn [State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer The reduced mobilities of 18 antibiotics are determined. Black-Right-Pointing-Pointer Establishing antibiotic mass-mobility correlation using (12,4) potential model. Black-Right-Pointing-Pointer Multi-component characteristics of antibiotics can be revealed using ESI-IMS. Black-Right-Pointing-Pointer Most mixtures of antibiotics can be analyzed using ESI-IMS. Black-Right-Pointing-Pointer The detection limit of amoxicillin is 70 pg. - Abstract: The recent findings of antibiotic residues in aquatic environment at trace level have gained much concern for the detrimental effect on ecological and human health due to bacterial resistance. Here, the feasibility of using electrospray ionization ion mobility spectrometry (ESI-IMS) for analysis antibiotics in liquid sample is demonstrated. Reduced mobilities and collision cross sections of 18 antibiotics are experimentally measured and compared with theoretical values according to mass-mobility correlation. Gentamicin is used as an example to investigate the capability of ESI-IMS for multi-component analysis of antibiotics. Mixtures of antibiotics at different concentrations are analyzed. The estimated detection limit for amoxicillin is 0.7 mg L{sup -1} (70 pg) and the linear range of response maintains over two orders. This method will be a potential technique for the analysis of antibiotics in aquatic environment.

  6. Influence of Equilibration Time in Solution on the Inclusion/Exclusion Topology Ratio of Host-Guest Complexes Probed by Ion Mobility and Collision-Induced Dissociation.

    Science.gov (United States)

    Carroy, Glenn; Daxhelet, Charlotte; Lemaur, Vincent; De Winter, Julien; De Pauw, Edwin; Cornil, Jérôme; Gerbaux, Pascal

    2016-03-18

    Host-guest complexes are formed by the creation of multiple noncovalent bonds between a large molecule (the host) and smaller molecule(s) or ion(s) (the guest(s)). Ion-mobility separation coupled with mass spectrometry nowadays represents an ideal tool to assess whether the host-guest complexes, when transferred to the gas phase upon electrospray ionization, possess an exclusion or inclusion nature. Nevertheless, the influence of the solution conditions on the nature of the observed gas-phase ions is often not considered. In the specific case of inclusion complexes, kinetic considerations must be taken into account beside thermodynamics; the guest ingression within the host cavity can be characterized by slow kinetics, which makes the complexation reaction kinetically driven on the timescale of the experiment. This is particularly the case for the cucurbituril family of macrocyclic host molecules. Herein, we selected para-phenylenediamine and cucurbit[6]uril as a model system to demonstrate, by means of ion mobility and collision-induced dissociation measurements, that the inclusion/exclusion topology ratio varies as a function of the equilibration time in solution prior to the electrospray process.

  7. Evolution of glassy polymers used for gas separation following ion beam irradiation

    Science.gov (United States)

    Ilconich, Jeffery B.

    Commercial gas separation membranes are typically polymeric because of low cost, processibility and wide range of available properties. However, while much work has been done to develop improved polymers for membranes, these materials have limitations for many applications. Therefore, much work has been focused in post-formation modification of polymer membrane. In this work, two very different polymers were modified by ion irradiation to evaluate the evolution in chemical structure, microstructure and permeation properties. A specific focus was on the impact of ion choice on properties of a specific polymer. The first part of study focused on evolution in a typical commercial membrane polymer, polysulfone, following H+ irradiation. Ion irradiation of polysulfone resulted in significant evolution in chemical structure at intermediate H+ doses. There was a general decrease in permeance with little improvement in selectivity following irradiation. Modification of asymmetric polysulfone membranes by H+ and C- irradiation resulted in significant damage to the porous substrate of the membranes. Therefore, these membranes exhibited larger decreases in permeance then could be attributed to changes in the selective layer. The polyimide, 6FDA-6FpDA, was irradiated with three different ions, (H+, N+ and F+) to investigate impact of ion mass and energy transfer mechanisms. As expected the polymer responded different to the different ions at similar overall doses and total energy transfer. In general, more damage to the polymer matrix was achieved with larger mass ions. The larger relative evolution to microstructure was attributed to the greater nuclear loss mechanism for N+ and F+ relative to H+. Significant evolution in permeation properties corresponded to this change in chemical structure and microstructure. While the ions exhibited similar trends in evolution in permeation properties, there were large differences in scale of modification. For example, at high dose H

  8. A comparison of the ion chemistry for mono-substituted toluenes and anilines by three methods of atmospheric pressure ionization with ion mobility spectrometry.

    Science.gov (United States)

    Borsdorf, H; Neitsch, K; Eiceman, G A; Stone, J A

    2009-06-15

    Ion mobility spectra for a series of mono-substituted toluenes and a series of mono-substituted anilines were obtained using three different methods of atmospheric pressure ionization including photoionization, chemical ionization from a (63)Ni source, and chemical ionization from a corona discharge source. The product ion peak intensities were measured as functions of analyte concentration at 323 K in a purified air atmosphere. Two, and sometimes three, product ion peaks were observed in spectra from chemical ionization with the (63)Ni source and it is suggested that the major peak, due to the protonated molecule, arose in both series by proton transfer from H3O+(H2O)n. The second peak with diminished intensity and longer drift time than the protonated molecule can be seen with the toluenes and was understood to be the NO+ adduct, formed from the reactant ion NO+(H2O)n. Electron transfer from the anilines to the latter ion yields the molecular ions, identified by having the same reduced mobility coefficients as the molecular ions produced by photoionization. The structure of these product ions was determined by investigations using the coupling of ion mobility spectrometry with atmospheric pressure photoionization and mass spectrometry (APPI-IMS-MS). The relative abundances of both the NO+ adducts with the toluenes and the molecular ions with the anilines are enhanced with a corona discharge source where relatively more NO+(H2O)n is produced than in a (63)Ni source. Ab initio calculations show that only the protonated anilines of all the product ions are significantly hydrated with 1 ppm(v) of moisture in the supporting atmosphere of the ion mobility spectrometer.

  9. Combined Use of Post-Ion Mobility/Collision-Induced Dissociation and Chemometrics for b Fragment Ion Analysis

    Science.gov (United States)

    Zekavat, Behrooz; Miladi, Mahsan; Becker, Christopher; Munisamy, Sharon M.; Solouki, Touradj

    2013-09-01

    Although structural isomers may yield indistinguishable ion mobility (IM) arrival times and similar fragment ions in tandem mass spectrometry (MS), it is demonstrated that post-IM/collision-induced dissociation MS (post-IM/CID MS) combined with chemometrics can enable independent study of the IM-overlapped isomers. The new approach allowed us to investigate the propensity of selected b type fragment ions from AlaAlaAlaHisAlaAlaAla-NH2 (AAA(His)AAA) heptapeptide to form different isomers. Principle component analysis (PCA) of the unresolved post-IM/CID profiles indicated the presence of two different isomer types for b4 +, b5 +, and b6 + and a single isomer type for b7 + fragments of AAA(His)AAA. We employed a simple-to-use interactive self-modeling mixture analysis (SIMPLISMA) to calculate the total IM profiles and CID mass spectra of b fragment isomers. The deconvoluted CID mass spectra showed discernible fragmentation patterns for the two isomers of b4 +, b5 +, and b6 + fragments. Under our experimental conditions, calculated percentages of the "cyclic" isomers (at the 95 % confidence level for n = 3) for b4 +, b5 +, and b6 + were 61 (± 5) %, 36 (± 5) %, and 48 (± 2) %, respectively. Results from the SIMPLISMA deconvolution of b5 + species resembled the CID MS patterns of fully resolved IM profiles for the two b5 + isomers. The "cyclic" isomers for each of the two-component b fragment ions were less susceptible to ion fragmentation than their "linear" counterparts.

  10. Production of chemically reactive radioactive ion beams through on-line separation; Production de faisceaux d'ions radioactifs chimiquement reactifs par separation en ligne

    Energy Technology Data Exchange (ETDEWEB)

    Joinet, A

    2003-10-01

    The ISOL (isotope separation on line) allows the production of secondary radioactive ion beams through spallation or fragmentation or fission reactions that take place in a thick target bombarded by a high intensity primary beam. The challenge is to increase the intensity and purity of the radioactive beam. The optimization of the system target/source requires the right choice of material for the target by taking into account the stability of the material, its reactivity and the ionization method used. The target is an essential part of the system because radioactive elements are generated in it and are released more or less quickly. Tests have been made in order to select the best fitted material for the release of S, Se, Te, Ge and Sn. Materials tested as target filling are: ZrO{sub 2}, Nb, Ti, V,TiO{sub 2}, CeO{sub x}, ThO{sub 2}, C, ZrC{sub 4} and VC). Other molecules such as: COSe, COS, SeS, COTe, GeS, SiS, SnS have been studied to ease the extraction of recoil nuclei (Se, S, Te, Ge and Sn) produced inside the target.

  11. Ceramic separators based on Li+-conducting inorganic electrolyte for high-performance lithium-ion batteries with enhanced safety

    Science.gov (United States)

    Jung, Yun-Chae; Kim, Seul-Ki; Kim, Moon-Sung; Lee, Jeong-Hye; Han, Man-Seok; Kim, Duck-Hyun; Shin, Woo-Cheol; Ue, Makoto; Kim, Dong-Won

    2015-10-01

    Flexible ceramic separators based on Li+-conducting lithium lanthanum zirconium oxide are prepared as thin films and directly applied onto negative electrode to produce a separator-electrode assembly with good interfacial adhesion and low interfacial resistances. The ceramic separators show an excellent thermal stability and high ionic conductivity as compared to conventional polypropylene separator. The lithium-ion batteries assembled with graphite negative electrode, Li+-conducting ceramic separator and LiCoO2 positive electrode exhibit good cycling performance in terms of discharge capacity, capacity retention and rate capability. It is also demonstrated that the use of a ceramic separator can greatly improve safety over cells employing a polypropylene separator, which is highly desirable for lithium-ion batteries with enhanced safety.

  12. Ion mobility spectrometry-mass spectrometry studies of ion processes in air at atmospheric pressure and their application to thermal desorption of 2,4,6-trinitrotoluene

    Science.gov (United States)

    Sabo, Martin; Malásková, Michaela; Matejčík, Štefan

    2014-02-01

    In this study we have investigated the negative reactant ion formation in a negative corona discharge (CD) using the corona discharge ion mobility spectrometry orthogonal acceleration time-of-flight (CD-IMS-oaTOF) technique. The reactant ions were formed in the CD operating in the reverse gas flow mode at an elevated temperature of 363.5 K in synthetic and ambient air. Under these conditions mainly O_{2}^{-} and their clusters were formed. We have also studied the influence of CCl4 admixture to air (dopant gas) on the composition of the reactant ions, which resulted in the formation of Cl- and its clusters with a reduced ion mobility of 3.05 cm2 V-1 s-1 as a major reactant ion peak. Additional IMS peaks with reduced ion mobilities of 2.49, 2.25 and 2.03 cm2 V-1 s-1 were detected, and Cl- · (NO2) and Cl- · (NO)n(n = 2, 3) anions were identified. The negative reactant ions were used to detect 2,4,6 trinitrotoluene (TNT) using the thermal desorption (TD) technique using a CD-IMS instrument. Using TD sampling and a negative CD ion source doped by CCl4 we have achieved a limit of detection of 350 pg for direct surface analysis of TNT.

  13. Separation of 1,3-Propanediol from Aqueous Solutions by Ion Exchange Chromatography

    Directory of Open Access Journals (Sweden)

    Rukowicz Beata

    2014-06-01

    Full Text Available 1,3-propanediol is a promising monomer with many applications and can be produced by bioconversion of renewable resources. The separation of this product from fermentation broth is a difficult task. In this work, the application of cation exchange resin for the separation of 1,3-propanediol from model aqueous solution was examined. The best effect of separation of 1,3-propanediol from glycerol using sorption method was obtained for H+ resin form, although the observed partition coefficient of 1,3-propanediol was low. On the basis of the results of the sorption of 1,3-propanediol, the ionic forms of the resin were selected and used in the next experiments (H+, Ca2+, Ag+, Na+, Pb2+, Zn2+. The best results in ion exchange chromatography were obtained for cation exchange resin in H+ and Ca2+ form. The use of smaller particle size of resin and a longer length of the column allows to obtain better separation of mixtures.

  14. Separation of pegylated recombinant proteins and isoforms on CIM ion exchangers.

    Science.gov (United States)

    Gašperšič, Jernej; Podgornik, Aleš; Kramberger, Petra; Jarc, Marko; Jančar, Janez; Žorž, Mirjan; Krajnc, Nika Lendero

    2016-10-15

    Protein pegylation is a process of covalent attachment of a polyethylene glycol (PEG) group to the protein tertiary structure that can "mask" the agent from the immune system and also increases the hydrodynamic size of the agent. Usually the pegylation prolongs the protein stability in the organism due to reduced renal clearance and provides superior water solubility to hydrophobic molecules. The mono-pegylated form of protein is usually prefered for medical applications. Different conditions with different PEG reagents have to be tested to find optimal pegylation procedure with specific protein. The goal of this study was to prepare screening method for separation of random mono-pegylated protein. Cytochrome C and beta lactoglobulin were pegylated with four reagents and a complete screening of several chromatographic monoliths in ion exchange mode with different buffers was performed to optimaly separate each mono-pegylated protein. The screening method was developed that produces optimal separation of target pegylated protein on CIM monoliths. Because of short chromatographic run time, CIM monoliths are perfect candidates to test alot of parameters. The results obtained show that each protein has its own unique separation parameters (pH, ionexchange ligand, buffer type). Two biopharmaceuticals were isolated using protocol: super human leptin antagonist (SHLA) was purified from inclusion bodies and mono-pegylated super mouse leptin antagonist (SMLA) from pegylated mixture. During study it was observed that the convective interaction media (CIM) monoliths additionally discriminate between protein isoforms pegylated on different sites in 3D structure of the protein.

  15. Short communication: separation and quantification of caseins and casein macropeptide using ion-exchange chromatography.

    Science.gov (United States)

    Holland, B; Rahimi Yazdi, S; Ion Titapiccolo, G; Corredig, M

    2010-03-01

    The aim of this work was to improve an existing method to separate and quantify the 4 major caseins from milk samples (i.e., containing whey proteins) using ion-exchange chromatography. The separation process was carried out using a mini-preparative cation exchange column (1 or 5mL of column volume), using urea acetate as elution buffer at pH 3.5 with a NaCl gradient. All 4 major caseins were separated, and the purity of each peak was assessed using sodium dodecyl sulfate-PAGE. Purified casein fractions were also added to raw milk to confirm their elution volumes. The quantification was carried out using purified caseins in buffer as well as added directly to fresh skim milk. This method can also be employed to determine the decrease in kappa-casein and the release of the casein-macropeptide during enzymatic hydrolysis using rennet. In this case, the main advantage of using this method is the lack of organic solvents compared with the conventional method for separation of macropeptide (using reversed phase HPLC).

  16. PVDF-HFP/ether-modified polysiloxane membranes obtained via airbrush spraying as active separators for application in lithium ion batteries.

    Science.gov (United States)

    Seidel, S M; Jeschke, S; Vettikuzha, P; Wiemhöfer, H-D

    2015-08-04

    Improved hybrid polymer electrolyte membranes are introduced based on ether-modified polysiloxanes and poly(vinylidene fluoride-co-hexafluoropropylene) yielding a safe separator membrane, which is able to be sprayed directly onto lithium ion battery active materials, with an active role for enhanced ion transport.

  17. SEPARATION AND PURIFICATION OF LIGNIN BY MEANS OF ION EXCHANGE PROCESS

    Institute of Scientific and Technical Information of China (English)

    XUHede; LIANGHao; 等

    1993-01-01

    The effect of resin structure on desalination of lignin solution was investigated,the optimal structure of resin is as follows;cross linking degree as 4%,ratio of cationogen to anionogen is near 1.with such resin the desalination of lignin was produced very well because the resin has both molecule sieving and ion retardation properties.The sulfonation degress of lignin and total salt content of lignin solution were determinred with ion exchange technique,the relative error less than 1%.The salt content of small molecule in the lignin solution was calculated from sulfonation degree of lignin and total salt.Among gel and macroporous resins the best separation of lignin from reducing sugar was achieved with interpenetrating sulfonated resin 2×1.5×1.The separation of lignin with interpenetrating resin was carried out simultaneously with fractionation of lignin,the effect of fractionation with macroporous sulfonated resin is better than that with interpenetrating resin,but the former has a definite sorption of lignin which decreased the recovery of lignin.

  18. High charge carrier mobility and efficient charge separation in highly soluble perylenetetracarboxyl-diimides

    NARCIS (Netherlands)

    Günbaş, D.D.; Xue, C.; Patwardhan,S.; Fravventura, M.C.; Zhang, H.; Jager, W.F.; Sudhölter, E.J.R.; Laurens D. A.; Siebbeles, L.D.A.; Savenije, T.J.; Jin, S.; Grozema, F.C.

    2014-01-01

    In this communication we report on the synthesis and charge mobility of highly soluble perylenebisimid derivatives.We show that introduction of alkylester side chains results in compounds combining a high solubility with charge mobilities up to 0.22 cm2 V_1 s_1. These materials are therefore interes

  19. Separated effects of ions, metastables and photons on the properties of barrier layers on polymers

    Science.gov (United States)

    Biskup, Beatrix; Boeke, Marc; Benedikt, Jan; von Keudell, Achim

    2016-09-01

    Analyses of a-C:H /a-Si:H multilayers on polymer substrates indicated that prolonged ion bombardment influences negatively the properties of the barrier layer, while a short plasma pretreatment can improve the barrier effect. This work is motivated by these results and investigates the influence of different reactive plasma components, namely ions, metastables and VUV-photons, on the properties of the grown barrier layer. To separate the different species and their influence on plasma pretreatment and film growth, we build a grid system, which repels the ions from the substrate, so that only metastables and VUV-photons have an effect on the layer. An integral part of this investigation is, to measure the photon fluxes to the substrate by an intensity calibrated VUV monochromator. For that, a differentially pumped monochromator with a spectral range 30 - 300 nm is used, where the two most prominent argon lines at 104.9 and 106.8 nm can be measured. In this approach we are able to study the different effects of the plasma species and also possible synergy effects, to improve the properties of the barrier layer. This work is supported by the DFG within the SFB-TR 87.

  20. Dopant titrating ion mobility spectrometry for trace exhaled nitric oxide detection.

    Science.gov (United States)

    Peng, Liying; Hua, Lei; Li, Enyou; Wang, Weiguo; Zhou, Qinghua; Wang, Xin; Wang, Changsong; Li, Jinghua; Li, Haiyang

    2015-01-05

    Ion mobility spectrometry (IMS) is a promising non-invasive tool for the analysis of exhaled gas and exhaled nitric oxide (NO), a biomarker for diagnosis of respiratory diseases. However, the high moisture in exhaled gas always brings about extra overlapping ion peaks and results in poor identification ability. In this paper, p-benzoquinone (PBQ) was introduced into IMS to eliminate the interference of overlapping ion peaks and realize the selective identification of NO. The overlapping ions caused by moisture were titrated by PBQ and then converted to hydrated PBQ anions (C6H4[Formula: see text](H2O)n). The NO concentration could be determined by quantifying gas phase hydrated nitrite anions (N[Formula: see text](H2O)n), product ions of NO. Under optimized conditions, a limit of detection (LOD) of about 1.4 ppbv and a linear range of 10-200 ppbv were obtained for NO even in 100% relative humidity (RH) purified air. Furthermore, this established method was applied to measure hourly the exhaled NO of eight healthy volunteers, and real-time monitoring the exhaled NO of an esophageal carcinoma patient during radical surgery. These results revealed the potential of the current dopant titrating IMS method in the measurement of exhaled NO for medical disease diagnosis.

  1. Online Hydrogen-Deuterium Exchange Traveling Wave Ion Mobility Mass Spectrometry (HDX-IM-MS): a Systematic Evaluation

    Science.gov (United States)

    Cryar, Adam; Groves, Kate; Quaglia, Milena

    2017-06-01

    Hydrogen-deuterium exchange mass spectrometry (HDX-MS) is an important tool for measuring and monitoring protein structure. A bottom-up approach to HDX-MS provides peptide level deuterium uptake values and a more refined localization of deuterium incorporation compared with global HDX-MS measurements. The degree of localization provided by HDX-MS is proportional to the number of peptides that can be identified and monitored across an exchange experiment. Ion mobility spectrometry (IMS) has been shown to improve MS-based peptide analysis of biological samples through increased separation capacity. The integration of IMS within HDX-MS workflows has been commercialized but presently its adoption has not been widespread. The potential benefits of IMS, therefore, have not yet been fully explored. We herein describe a comprehensive evaluation of traveling wave ion mobility integrated within an online-HDX-MS system and present the first reported example of UDMSE acquisition for HDX analysis. Instrument settings required for optimal peptide identifications are described and the effects of detector saturation due to peak compression are discussed. A model system is utilized to confirm the comparability of HDX-IM-MS and HDX-MS uptake values prior to an evaluation of the benefits of IMS at increasing sample complexity. Interestingly, MS and IM-MS acquisitions were found to identify distinct populations of peptides that were unique to the respective methods, a property that can be utilized to increase the spatial resolution of HDX-MS experiments by >60%. [Figure not available: see fulltext.

  2. Ion mobility mass spectrometry as a potential tool to assign disulfide bonds arrangements in peptides with multiple disulfide bridges.

    Science.gov (United States)

    Echterbille, Julien; Quinton, Loïc; Gilles, Nicolas; De Pauw, Edwin

    2013-05-07

    Disulfide bridges play a major role in defining the structural properties of peptides and proteins. However, the determination of the cysteine pairing is still challenging. Peptide sequences are usually achieved using tandem mass spectrometry (MS/MS) spectra of the totally reduced unfolded species, but the cysteine pairing information is lost. On the other hand, MS/MS experiments performed on native folded species show complex spectra composed of nonclassical ions. MS/MS alone does not allow either the cysteine pairing or the full sequence of an unknown peptide to be determined. The major goal of this work is to set up a strategy for the full structural characterization of peptides including disulfide bridges annotation in the sequence. This strategy was developed by combining ion mobility spectrometry (IMS) and collision-induced dissociation (CID). It is assumed that the opening of one S-S bridge in a peptide leads to a structural evolution which results in a modification of IMS drift time. In the presence of multiple S-S bridges, the shift in arrival time will depend on which disulfide(s) has (have) been reduced and on the shape adopted by the generated species. Due to specific fragmentations observed for each species, CID experiments performed after the mobility separation could provide not only information on peptide sequence but also on the localization of the disulfide bridges. To achieve this goal, synthetic peptides containing two disulfides were studied. The openings of the bridges were carried out following different experimental conditions such as reduction, reduction/alkylation, or oxidation. Due to disulfide scrambling highlighted with the reduction approaches, oxidation of S-S bonds into cysteic acids appeared to be the best strategy. Cysteine connectivity was then unambiguously determined for the two peptides, without any disulfide scrambling interference.

  3. Development of long-lived radionuclide partitioning technology - Preparation of ion exchanges for selective separation of radioactive elements

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Joong; Jeong, Hae In; Shim, Min Sook [Korea University, Seoul (Korea, Republic of); Kim, Jeong [Seonam University, Namwon (Korea, Republic of)

    1995-07-01

    Ion exchanger contained nitrogen-oxygen donor macrocyclic units was synthesized, and immobilization process was carried out by adsorption of the exchanger to silica gel. The binding constants were measured with acid concentration. From the binding constants, selectivity for Pt(II) ion and acid concentration of eluents were determined. The most optimum conditions for the separation were also determined from investigating the effects of amount of immobile phase and column length. And liarit aza-crown ethers were synthesized and selectively separated Cs/Sr ion from mixed metal solution. 37= refs., 24 tabs., 40 figs. (author)

  4. Experimental Ion Mobility measurements in Ne-CO$_2$ and CO$_2$-N$_2$ mixtures

    CERN Document Server

    Encarnação, P.M.C.C.; Veenhof, R.; Neves, P.N.B.; Santos, F.P.; Trindade, A.M.F.; Borges, F.I.G.M.; Conde, C.A.N.

    2016-01-01

    In this paper we present the experimental results for the mobility, K0, of ions in neon-carbon dioxide (Ne-CO2) and carbon dioxide-nitrogen (CO2-N2) gaseous mixtures for total pressures ranging from 8–12 Torr, reduced electric fields in the 10–25 Td range, at room temperature. Regarding the Ne-CO2 mixture only one peak was observed for CO2 concentrations above 25%, which has been identified as an ion originated in CO2, while below 25% of CO2 a second-small peak appears at the left side of the main peak, which has been attributed to impurities. The mobility values for the main peak range between 3.51 ± 0.05 and 1.07 ± 0.01 cm2V−1s−1 in the 10%-99% interval of CO2, and from 4.61 ± 0.19 to 3.00 ± 0.09 cm2V−1s−1 for the second peak observed (10%–25% of CO2). For the CO2-N2, the time-of-arrival spectra displayed only one peak for CO2 concentrations above 10%, which was attributed to ions originated in CO2, namely CO2+(CO2), with a second peak appearing for CO2 concentrations below 10%. This secon...

  5. [Influences of ion-suppressors on retention behaviors of nine food additives in reversed-phase high performance liquid chromatographic separation].

    Science.gov (United States)

    Zhao, Yonggang; Chen, Xiaohong; Li, Xiaoping; Yao, Shanshan; Jin, Micong

    2011-10-01

    The influences of ion-suppressors on retention behaviors of nine food additives, i.e., acesulfame, saccharin, caffeine, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid and neotame in reversed-phase high performance liquid chromatographic (RP-HPLC) separation were investigated. The organic modification effects of acids, i. e. , trifluoroacetic acid (TFA) and buffer salts, i. e. , TFA-ammonium acetate (AmAc) were studied emphatically. The relationships between retention factors of solutes and volume percentages of ion-suppressors in the mobile phase systems of acetonitrile-TFA aqueous solution and acetonitrile-TFA-AmAc aqueous solution were quantitatively established, separately. The separation of nine food additives was completed by a gradient elution with acetonitrile-TFA (0.01%, v/v)-AmAc (2. 5 mmol/L) aqueous solution as the mobile phases. An RP-HPLC method was established for the simultaneous determination of nine food additives in red wine. In the range of 10. 0 - 100. 0 mg/L, nine food additives showed good linearity with the correlation coefficients ( r2 ) larger than 0. 999 1. The limits of detection (LODs) were in the range of 0. 33 - 2. 36 mg/L and the limits of quantification (LOQs) were in the range of 1. 11 - 7. 80 mg/L. The spiked recoveries were between 87. 61% and 108. 4% with the relative standard deviations (RSDs) of 2. 2% -9. 4%. These results are of referential significance for the rapid establishment and accu- rate optimization of RP-HPLC separation for the simultaneous determination of food additives in other foods.

  6. Anion and cation mixed-bed ion exchange for enhanced multidimensional separations of peptides and phosphopeptides.

    Science.gov (United States)

    Motoyama, Akira; Xu, Tao; Ruse, Cristian I; Wohlschlegel, James A; Yates, John R

    2007-05-15

    Shotgun proteomics typically uses multidimensional LC/MS/MS analysis of enzymatically digested proteins, where strong cation-exchange (SCX) and reversed-phase (RP) separations are coupled to increase the separation power and dynamic range of analysis. Here we report an on-line multidimensional LC method using an anion- and cation-exchange mixed bed for the first separation dimension. The mixed-bed ion-exchange resin improved peptide recovery over SCX resins alone and showed better orthogonality to RP separations in two-dimensional separations. The Donnan effect, which was enhanced by the introduction of fixed opposite charges in one column, is proposed as the mechanism responsible for improved peptide recovery by producing higher fluxes of salt cations and lower populations of salt anions proximal to the SCX phase. An increase in orthogonality was achieved by a combination of increased retention for acidic peptides and moderately reduced retention of neutral to basic peptides by the added anion-exchange resin. The combination of these effects led to approximately 100% increase in the number of identified peptides from an analysis of a tryptic digest of a yeast whole cell lysate. The application of the method to phosphopeptide-enriched samples increased by 94% phosphopeptide identifications over SCX alone. The lower pKa of phosphopeptides led to specific enrichment in a single salt step resolving acidic phosphopeptides from other phospho- and non-phosphopeptides. Unlike previous methods that use anion exchange to alter selectivity or enrich phosphopeptides, the proposed format is unique in that it works with typical acidic buffer systems used in electrospray ionization, making it feasible for online multidimensional LC/MS/MS applications.

  7. Two Azimuthally Separated Regions of Cusp Ion Injection Observed via Energetic Neutral Atoms

    Science.gov (United States)

    Abe, M.; Taguchi, S.; Collier, M. R.; Moore, T. E.

    2011-01-01

    The low-energy neutral atom (LENA) imager on the IMAGE spacecraft can detect energetic neutral atoms produced by ion injection into the cusp through a charge exchange with the Earth's hydrogen exosphere. We examined the occurrence of the LENA cusp signal during positive IMF B(sub z) in terms of the arrival direction and the IMF clock angle theta(sub CA). Results of statistical analyses show that the occurrence frequency is high on the postnoon side when theta(sub CA) is between approximately 20 degrees and approximately 50 degrees. This is ascribed to ion injection caused by cusp reconnection typical of positive IMF B(sub z). Our results also show that there is another situation of high occurrence frequency, which can be identified with theta(sub CA) of approximately 30 degrees to approximately 80 degrees. When theta(sub CA) is relatively large (60 degrees - 80 degrees), occurrence frequencies are high at relatively low latitudes over a wide extent spanning both prenoon and postnoon sectors. This feature suggests that the ion injection is caused by reconnection at the dayside magnetopause. Its postnoon side boundary shifts toward the prenoon as theta(sub CA) decreases. When theta(sub CA) is less than approximately 50 degrees, the high occurrence frequency exists well inside the prenoon sector, which is azimuthally separated from the postnoon region ascribed to cusp reconnection. The prenoon region, which is thought due to ion injection caused by dayside reconnection, may explain the recent report that proton aurora brightening occurs in the unanticipated prenoon sector of the northern high-latitude ionosphere for IMF B(sub y) greater than 0 and B(sub z) greater than 0.

  8. The effect of magnetite nanoparticles synthesis conditions on their ability to separate heavy metal ions

    Directory of Open Access Journals (Sweden)

    Bobik Magdalena

    2017-06-01

    Full Text Available Magnetite nanoparticles have become a promising material for scientific research. Among numerous technologies of their synthesis, co-precipitation seems to be the most convenient, less time-consuming and cheap method which produces fine and pure iron oxide particles applicable to environmental issues. The aim of the work was to investigate how the co-precipitation synthesis parameters, such as temperature and base volume, influence the magnetite nanoparticles ability to separate heavy metal ions. The synthesis were conducted at nine combinations of different ammonia volumes - 8 cm3, 10 cm3, 15 cm3 and temperatures - 30°C, 60°C, 90°C for each ammonia volume. Iron oxides synthesized at each combination were examined as an adsorbent of seven heavy metals: Cr(VI, Pb(II, Cr(III, Cu(II, Zn(II, Ni(II and Cd(II. The representative sample of magnetite was characterized using XRD, SEM and BET methods. It was observed that more effective sorbent for majority of ions was produced at 30°C using 10 cm3 of ammonia. The characterization of the sample produced at these reaction conditions indicate that pure magnetite with an average crystallite size of 23.2 nm was obtained (XRD, the nanosized crystallites in the sample were agglomerated (SEM and the specific surface area of the aggregates was estimated to be 55.64 m2·g-1 (BET. The general conclusion of the work is the evidence that magnetite nanoparticles have the ability to adsorb heavy metal ions from the aqueous solutions. The effectiveness of the process depends on many factors such as kind of heavy metal ion or the synthesis parameters of the sorbent.

  9. Monitoring the Effect of Metal Ions on the Mobility of Artemia salina Nauplii.

    Science.gov (United States)

    Kokkali, Varvara; Katramados, Ioannis; Newman, Jeffrey D

    2011-03-28

    This study aims to measure the effect of toxic aqueous solutions of metals on the mobility of Artemia salina nauplii by using digital image processing. The instrument consists of a camera with a macro lens, a dark chamber, a light source and a laptop computer. Four nauplii were inserted into a macro cuvette, which contained copper, cadmium, iron and zinc ions at various concentrations. The nauplii were then filmed inside the dark chamber for two minutes and the video sequence was processed by a motion tracking algorithm that estimated their mobility. The results obtained by this system were compared to the mortality assay of the Artemia salina nauplii. Despite the small number of tested organisms, this system demonstrates great sensitivity in quantifying the mobility of the nauplii, which leads to significantly lower EC50 values than those of the mortality assay. Furthermore, concentrations of parts per trillion of toxic compounds could be detected for some of the metals. The main novelty of this instrument relies in the sub-pixel accuracy of the tracking algorithm that enables robust measurement of the deterioration of the mobility of Artemia salina even at very low concentrations of toxic metals.

  10. Rapid analysis of pesticide residues in drinking water samples by dispersive solid-phase extraction based on multiwalled carbon nanotubes and pulse glow discharge ion source ion mobility spectrometry.

    Science.gov (United States)

    Zou, Nan; Gu, Kejia; Liu, Shaowen; Hou, Yanbing; Zhang, Jialei; Xu, Xiang; Li, Xuesheng; Pan, Canping

    2016-03-01

    An analytical method based on dispersive solid-phase extraction with a multiwalled carbon nanotubes sorbent coupled with positive pulse glow discharge ion mobility spectrometry was developed for analysis of 30 pesticide residues in drinking water samples. Reduced ion mobilities and the mass-mobility correlation of 30 pesticides were measured. The pesticides were divided into five groups to verify the separation capability of pulse glow discharge in mobility spectrometry. The extraction conditions such as desorption solvent, ionic strength, conditions of adsorption and desorption, the amounts of multiwalled carbon nanotubes, and solution pH were optimized. The enrichment factors of pesticides were 5.4- to 48.7-fold (theoretical enrichment factor was 50-fold). The detection limits of pesticides were 0.01∼0.77 μg/kg. The linear range was 0.005-0.2 mg/L for pesticide standard solutions, with determination coefficients from 0.9616 to 0.9999. The method was applied for the analysis of practical and spiked drinking water samples. All results were confirmed by high-performance liquid chromatography with tandem mass spectrometry. The proposed method was proven to be a commendably rapid screening qualitative and semiquantitative technique for the analysis of pesticide residues in drinking water samples on site.

  11. High Precision Measurements of Carbon Disulfide Negative Ion Mobility and Diffusion

    CERN Document Server

    Snowden-Ifft, D P

    2013-01-01

    High precision measurements were made of mobility, lateral and longitudinal diffusion of CS2 negative ions in 40 Torr CS2 and 30 - 10 Torr CS2 - CF4. The mobility was found to be be 363.1 +/- 0.5 Torr cm2 / s V in CS2 and 408.0 +/- 0.8 Torr cm2 / s V in the CS2 - CF4 gas mixture. The lateral diffusion temperatures for these two gases (295 +/- 15 K and 297 +/- 6 K) were found to be in good agreement with room temperature. By contrast longitudinal diffusion temperature was found to be slightly elevated (319 +/- 10 (stat) +/- 8 (sys) K and 310 +/- 20 (stat) +/- 6 (sys) K) though given the errors, room temperature diffusion can not be ruled out. For lateral diffusion significant capture distances (0.21 +/- 0.07 mm and 0.15 +/- 0.03 mm) were measured while for longitudinal diffusion the results were not conclusive.

  12. Plasma Modified Polypropylene Membranes as the Lithium-Ion Battery Separators

    Science.gov (United States)

    Wang, Zhengduo; Zhu, Huiqin; Yang, Lizhen; Wang, Xinwei; Liu, Zhongwei; Chen, Qiang

    2016-04-01

    To reduce the thermal shrinkage of the polymeric separators and improve the safety of the Li-ion batteries, plasma treatment and plasma enhanced vapor chemical deposition (PECVD) of SiOx-like are carried out on polypropylene (PP) separators, respectively. Critical parameters for separator properties, such as the thermal shrinkage rate, porosity, wettability, and mechanical strength, are evaluated on the plasma treated PP membranes. O2 plasma treatment is found to remarkably improve the wettability, porosity and electrolyte uptake. PECVD SiOx-like coatings are found to be able to effectively reduce the thermal shrinkage rate of the membranes and increase the ionic conductivity. The electrolyte-philicity of the SiOx-like coating surface can be tuned by the varying O2 content in the gas mixture during the deposition. Though still acceptable, the mechanical strength is reduced after PECVD, which is due to the plasma etching. supported by National Natural Science Foundation of China (Nos. 11175024, 11375031), the Beijing Institute of Graphic and Communication Key Project of China (No. 23190113051), the Shenzhen Science and Technology Innovation Committee of China (No. JCYJ20130329181509637), BJNSFC (No. KZ201510015014), and the State Key Laboratory of Electrical Insulation and Power Equipment of China (No. EIPE15208)

  13. Ion-exchange vs reversed-phase chromatography for separation and determination of basic psychotropic drugs.

    Science.gov (United States)

    Petruczynik, Anna; Wróblewski, Karol; Deja, Michał; Waksmundzka-Hajnos, Monika

    2015-11-01

    Ion exchange chromatography, an alternative to reversed-phase (RP) chromatography, is described in this paper. We aimed to obtain optimal conditions for the separation of basic drugs because silica-based RP stationary phases show silanol effect and make the analysis of basic analytes hardly possible. The retention, separation selectivity, symmetry of peaks and system efficiency were examined in different eluent systems containing different types of buffers at acidic pH and with the addition of organic modifiers: methanol and acetonitrile. The obtained results reveal a large influence of the salt cation used for buffer preparation and the type of organic modifier on the retention behavior of the analytes. These results were also compared with those obtained on an XBridge C18 column. The obtained results demonstrated that SCX stationary phases can be successfully used as alternatives to C18 stationary phases in the separation of basic compounds. The most selective and efficient chromatographic systems were applied for the quantification of some psychotropic drugs in fortified human serum samples.

  14. Lithium Thiophosphate Compounds as Stable High Rate Li-Ion Separators

    Energy Technology Data Exchange (ETDEWEB)

    Apblett, Christopher A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    Battery separators based upon lithium thiophosphate (LiPS4) have previously been demonstrated at UC Boulder, but the thickness of the separators was too high to be of practical use in a lithium ion battery. The separators are solid phase, which makes them intrinsically less prone to thermal runaway and thereby improves safety. Results of attempting to develop sputtered thin film layers of this material by starting with targets of pure Li, Li2S, and P2S5 are reported. Sputtering rates and film quality and composition are discussed, along with efforts to use Raman spectroscopy to determine quantitative film composition. The latter is a rate limiting step in the investigation of these films, as they are typically thin and require long times to get to sufficient thickness to be analyzed using traditional methods, whereas Raman is particularly well suited to this analysis, if it can be made quantitative. The final results of the film deposition methods are reported, and a path towards new films is discussed. Finally, it should be noted that this program originally began with one graduate student working on the program, but this student ultimately chose to not continue with a PhD. A second student took over in the middle of the effort, and a new program has been proposed with a significantly altered chemistry to take the program in a new direction.

  15. Nanoparticle-coated separators for lithium-ion batteries with advanced electrochemical performance

    KAUST Repository

    Fang, Jason

    2011-01-01

    We report a simple, scalable approach to improve the interfacial characteristics and, thereby, the performance of commonly used polyolefin based battery separators. The nanoparticle-coated separators are synthesized by first plasma treating the membrane in oxygen to create surface anchoring groups followed by immersion into a dispersion of positively charged SiO 2 nanoparticles. The process leads to nanoparticles electrostatically adsorbed not only onto the exterior of the surface but also inside the pores of the membrane. The thickness and depth of the coatings can be fine-tuned by controlling the ζ-potential of the nanoparticles. The membranes show improved wetting to common battery electrolytes such as propylene carbonate. Cells based on the nanoparticle-coated membranes are operable even in a simple mixture of EC/PC. In contrast, an identical cell based on the pristine, untreated membrane fails to be charged even after addition of a surfactant to improve electrolyte wetting. When evaluated in a Li-ion cell using an EC/PC/DEC/VC electrolyte mixture, the nanoparticle-coated separator retains 92% of its charge capacity after 100 cycles compared to 80 and 77% for the plasma only treated and pristine membrane, respectively. © the Owner Societies 2011.

  16. On-line coupling of an ion chromatograph to the ICP-MS: Separations with a cation exchange chromatography column

    Energy Technology Data Exchange (ETDEWEB)

    Roellin, Stefan [Studsvik Nuclear AB, Nykoeping (Sweden)

    1999-12-01

    An ion chromatography system was coupled on-line to the ICP-MS. All separations were made with a cation exchange chromatography column. Fundamental laws about elution parameters affecting individual retention times and elution forms are explained by applying a proper ion exchange mechanism for the isocratic elution (separations with constant eluent concentration) of mono-, di-, tri-, and tetravalent cations and the actinide species MO{sub 2}{sup +} and MO{sub 2}{sup 2+}. A separation method with two eluents has been investigated to separate mono- from divalent ions in order to separate isobaric overlaps of Rb/Sr and Cs/Ba. The ions normally formed by actinides in aqueous solutions in the oxidation states III to VI are M{sup 3+}, M{sup 4+}, MO{sub 2}{sup +} and MO{sub 2}{sup 2+} respectively. Elution parameters were investigated to separate all four actinide species from each other in order to separate isobaric overlaps of the actinides Np, Pu, U and Am. A major question of concern over the possible release of actinides to the environment is the speciation of actinides within their four possible oxidation states. To check the possibility of speciation analysis with ion chromatography, a separation method was investigated to separate U{sup 4+} and UO{sub 2}{sup 2+} without changing the redox species composition during the separation. First results of Pu speciation analysis showed that Pu could be eluted as three different species. Pu(VI) was always eluting at the same time as Np(V). This was surprising as Pu(VI) is expected to have the same chemical characteristics as U(VI) and thus was expected to elute at the same time as U(VI)

  17. Applicability of ion mobility spectrometry for detection of quarantine pests in wood

    Science.gov (United States)

    Ewing, K. J.; Sanghera, J.; Myers, S. W.; Ervin, A. M.; Carey, C.; Gleason, G.; Mosser, L.; Levy, L.; Hennessey, M. K.; Bulluck, R.

    2016-05-01

    Visual inspection is the most commonly used method for detecting quarantine pests in agricultural cargo items at ports. For example, solid wood packing material (SWPM) at ports may be a pathway for wood pests and is a frequent item of inspection at ports. The inspection process includes examination of the external surface of the item and often destructive sampling to detect internal pest targets. There are few tools available to inspectors to increase the efficiency of inspection and reduce the labor involved. Ion mobility spectrometry (IMS) has promise as an aid for inspection. Because pests emit volatile organic compounds (VOCs) such as hormone like substances, Ion Mobility Spectrometry (IMS) was investigated for possible utility for detecting pests during inspection. SWPM is a major pest pathway in trade, and fumigation of many kinds of wood, including SWPM, with methyl bromide (MeBr) following a published schedule1 is regularly conducted for phytosanitary reasons prior to shipment to the United States. However, the question remains as to how long the methyl bromide remains in the wood samples after fumigation such that it could act as an interferent to the detection of pest related VOC emissions. This work investigates the capability of ion mobility spectrometry to detect the presence of residual methyl bromide in fumigated maple and poplar wood samples at different times post fumigation up to 118 days after fumigation. Data show that MeBr can be detected in the less dense poplar wood up to 118 days after fumigation while MeBr can be detected in the denser maple wood 55 days after fumigation.

  18. Observation of Interspecies Ion Separation in Inertial-Confinement-Fusion Implosions via Imaging X-Ray Spectroscopy

    CERN Document Server

    Hsu, S C; Hakel, P; Vold, E L; Schmitt, M J; Hoffman, N M; Rauenzahn, R M; Kagan, G; Tang, X -Z; Mancini, R C; Kim, Y; Herrmann, H W

    2016-01-01

    We report direct experimental evidence of interspecies ion separation in direct-drive, inertial-confinement-fusion experiments on the OMEGA laser facility. These experiments, which used plastic capsules with D$_2$/Ar gas fill (1% Ar by atom), were designed specifically to reveal interspecies ion separation by exploiting the predicted, strong ion thermo-diffusion between ion species of large mass and charge difference. Via detailed analyses of imaging x-ray-spectroscopy data, we extract Ar-atom-fraction radial profiles at different times, and observe both enhancement and depletion compared to the initial 1%-Ar gas fill. The experimental results are interpreted with radiation-hydrodynamic simulations that include recently implemented, first-principles models of interspecies ion diffusion. The experimentally inferred Ar-atom-fraction profiles agree reasonably, but not exactly, with calculated profiles associated with the incoming and rebounding first shock.

  19. Mixed mobile ion effect on a.c. conductivity of boroarsenate glasses

    Indian Academy of Sciences (India)

    M Purnima; Shashidhar Bale; Ch Srinivasu; M A Samee; Syed Rahman

    2012-06-01

    In this article we report the study of mixed mobile ion effect (MMIE) in boroarsenate glasses. DSC and a.c. electrical conductivity studies have been carried out for MgO–(25−)Li2O–50B2O3–25As2O3 glasses. It is observed that strength of MMIE in a.c. conductivity is less pronounced with increase in temperature and frequency. The results were explained on the basis of structural model (SM) proposed by Swenson and his co-workers supporting molecular dynamic results.

  20. Development of a portable preconcentrator/ion mobility spectrometer system for the trace detection of narcotics

    Energy Technology Data Exchange (ETDEWEB)

    Parmeter, J.E.; Custer, C.A.

    1997-08-01

    This project was supported by LDRD funding for the development and preliminary testing of a portable narcotics detection system. The system developed combines a commercial trace detector known as an ion mobility spectrometer (IMS) with a preconcentrator originally designed by Department 5848 for the collection of explosives molecules. The detector and preconcentrator were combined along with all necessary accessories onto a push cart, thus yielding a fully portable detection unit. Preliminary testing with both explosives and narcotics molecules shown that the system is operational, and that it can successfully detect drugs as marijuana, methamphetamine (speed), and cocaine based on their characteristics IMS signatures.

  1. Application of Ion Mobility Spectrometry (IMS) in forensic chemistry and toxicology with focus on biological matrices

    Science.gov (United States)

    Bernhard, Werner; Keller, Thomas; Regenscheit, Priska

    1995-01-01

    The IMS (Ion Mobility Spectroscopy) instrument 'Ionscan' takes advantage of the fact that trace quantities of illicit drugs are adsorbed on dust particles on clothes, in cars and on other items of evidence. The dust particles are collected on a membrane filter by a special attachment on a vacuum cleaner. The sample is then directly inserted into the spectrometer and can be analyzed immediately. We show casework applications of a forensic chemistry and toxicology laboratory. One new application of IMS in forensic chemistry is the detection of psilocybin in dried mushrooms without any further sample preparation.

  2. Determination of Uric Acid in Human Urine by Ion-exclusion Chromatography with UV Detection Using Pure Water as Mobile Phase

    Institute of Scientific and Technical Information of China (English)

    侯升杰; 杨成对; 王辉; 田中一彦; 丁明玉

    2012-01-01

    A simple, rapid and accurate ion-exclusion chromatographic method coupled with a UV detector for the determination of uric acid in human urine samples has been developed. The separation was carried out on an ion-exclusion column using only pure water as mobile phase. The detection wavelength was 254 nm and urine sample was injected directly without any pretreatment. Furthermore, the retention behavior of uric acid on the ion-exclusion column was researched when pure water and 1 mmol·L-1 HCI were used as mobile phase, respectively. The stability of uric acid was also further investigated within 28 days, In this method, the linear range of the calibration curve for uric acid was 0.25--100 mg·L-1, and the detection limit calculated at S/N=3 was 0.02mg·L-1 The proposed ion-exclusion chromatographic method has been used for the determination of uric acid in human urine.

  3. A facile approach to make high performance nano-fiber reinforced composite separator for lithium ion batteries

    Science.gov (United States)

    Huang, Xiaosong

    2016-08-01

    The separator is a porous membrane located between the negative and the positive electrodes. In this work, a nano-fiber reinforced composite separator was developed. Compared with the commercial polyolefin separator, the composite separator showed superior (a) dimensional stability at elevated temperatures relative to conventional separators and (b) wettability by the liquid electrolyte. After being saturated with a commercial LiPF6-ethylene carbonate-dimethyl carbonate electrolyte, the composite separator enabled a high effective ionic conductivity (σeff) of 1.25 mS/cm. A stable cycle performance and an improved rate capability have been observed in the coin cells with the composite separator. This initial study shows that this type of composite membranes can be a promising alternative separator for lithium ion batteries.

  4. Poly(m-phenylene isophthalamide) separator for improving the heat resistance and power density of lithium-ion batteries

    Science.gov (United States)

    Zhang, Hong; Zhang, Yin; Xu, Tiange; John, Angelin Ebanezar; Li, Yang; Li, Weishan; Zhu, Baoku

    2016-10-01

    A microporous poly(m-phenylene isophthalamide) (PMIA) separator with high safety (high-heat resistance and self extinguishing), high porosity and excellent liquid electrolyte wettability was prepared by the traditional nonsolvent introduced phase separation process. Due to the high-heat resistance of PMIA material, the as-prepared separator exhibited a negligible thermal shrank ratio at 160 °C for 1 h. Meanwhile, benefiting from its high porosity and excellent wettability in liquid electrolyte, the liquid electrolyte uptake and the ionic conductivity of the separator were higher than that of the commercial PP-based separators. Furthermore, the cell assembled with this separator showed better cycling performance and superior rate capacity compared to those with PP-based separators. These results suggested that the PMIA separator is very attractive for high-heat resistance and high-power density lithium-ion batteries.

  5. Multiproduct high-resolution monoclonal antibody charge variant separations by pH gradient ion-exchange chromatography.

    Science.gov (United States)

    Farnan, Dell; Moreno, G Tony

    2009-11-01

    In the biotechnology industry, ion-exchange chromatography is widely used for profiling the charge heterogeneity of proteins, including monoclonal antibodies. Ionic strength based ion exchange separations, while having excellent resolving power and robustness, are product specific and time-consuming to develop. In the present work, a pH gradient based separation using a cation exchange column is described and shown to be a multiproduct charge sensitive separation method for monoclonal antibodies. Simple mixtures of defined buffer components were used to generate the pH-gradients that separate closely related antibody species. The form of the pH gradient was controlled and optimized by the pump as well as the buffer composition if necessary. During this work, the buffer compositions for the separation were optimized in parallel for several MAbs. The data shows that the multiproduct method is optimal for all of the MAbs studied. Operational aspects of the separation such as column chemistry, column length, and sample matrix indicate a very robust method. The pH gradient ion-exchange method is demonstrated to have significant resolving power and peak capacities far in excess of what we would expect for ionic strength elution ion-exchange. Data obtained demonstrates that the separation is relatively insensitive to column length. Direct analysis (no buffer exchange) of samples in matrixes consistent with in-process manufacturing pools is demonstrated. Such a capability is extremely useful for the high throughput evaluation of in-process and final product samples.

  6. Formation of oxides and segregation of mobile atoms during SIMS profiling of Si with oxygen ions

    Energy Technology Data Exchange (ETDEWEB)

    Petravic, M.; Williams, J.S.; Svensson, B.G.; Conway, M. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences

    1993-12-31

    An oxygen beam is commonly used in secondary ion mass spectroscopy (SIMS) analysis to enhance the ionization probability for positive secondary ions. It has been observed, however, that this technique produces in some cases a great degradation of depth resolution. The most pronounced effects have been found for impurities in silicon under oxygen bombardment at angles of incidence smaller than {approx} 30 deg from the surface normal. A new approach is described which involved broadening of SIMS profiles for some mobile atoms, such as Cu, Ni and Au, implanted into silicon. The anomalously large broadening is explained in terms of segregation at a SiO{sub 2}/Si interface formed during bombardment with oxygen at impact angles less than 30 deg. 2 refs., 1 tab., 4 figs.

  7. Ion Mobility-Mass Spectrometry Differentiates Protein Quaternary Structures Formed in Solution and in Electrospray Droplets.

    Science.gov (United States)

    Han, Linjie; Ruotolo, Brandon T

    2015-07-01

    Electrospray ionization coupled to mass spectrometry is a key technology for determining the stoichiometries of multiprotein complexes. Despite highly accurate results for many assemblies, challenging samples can generate signals for artifact protein-protein binding born of the crowding forces present within drying electrospray droplets. Here, for the first time, we study the formation of preferred protein quaternary structures within such rapidly evaporating nanodroplets. We use ion mobility and tandem mass spectrometry to investigate glutamate dehydrogenase dodecamers and serum amyloid P decamers as a function of protein concentration, along with control experiments using carefully chosen protein analogues, to both establish the formation of operative mechanisms and assign the bimodal conformer populations observed. Further, we identify an unprecedented symmetric collision-induced dissociation pathway that we link directly to the quaternary structures of the precursor ions selected.

  8. Ion mobility spectrometry: A personal view of its development at UCSB.

    Science.gov (United States)

    Bowers, Michael T

    2014-09-15

    Ion mobility is not a newly discovered phenomenon. It has roots going back to Langevin at the beginning of the 20th century. Our group initially got involved by accident around 1990 and this paper is a brief account of what has transpired here at UCSB the past 25 years in response to this happy accident. We started small, literally, with transition metal atomic ions and transitioned to carbon clusters, synthetic polymers, most types of biological molecules and eventually peptide and protein oligomeric assembly. Along the way we designed and built several generations of instruments, a process that is still ongoing. And perhaps most importantly we have incorporated theory with experiment from the beginning; a necessary wedding that allows an atomistic face to be put on the otherwise interesting but not fully informative cross section measurements.

  9. Fabrication of porous carbon/TiO₂ composites through polymerization-induced phase separation and use as an anode for Na-ion batteries.

    Science.gov (United States)

    Lee, Jeongwoo; Chen, Yu-Ming; Zhu, Yu; Vogt, Bryan D

    2014-12-10

    Polymerization-induced phase separation of nanoparticle-filled solution is demonstrated as a simple approach to control the structure of porous composites. These composites are subsequently demonstrated as the active component for sodium ion battery anode. To synthesize the composites, we dissolved/dispersed titanium oxide (anatase) nanoparticles (for sodium insertion) and poly(hydroxybutyl methacrylate) (PHBMA, porogen) in furfuryl alcohol (carbon precursor) containing a photoacid generator (PAG). UV exposure converts the PAG to a strong acid that catalyzes the furfuryl alcohol polymerization. This polymerization simultaneously decreases the miscibility of the PHBMA and reduces the mobility in the mixture to kinetically trap the phase separation. Carbonization of this polymer composite yields a porous nanocomposite. This nanocomposite exhibits nearly 3-fold greater gravimetric capacity in Na-ion batteries than the same titanium oxide nanoparticles that have been coated with carbon. This improved performance is attributed to the morphology as the carbon content in the composite is five times that of the coated nanoparticles. The porous composite materials exhibit stable cyclic performance. Moreover, the battery performance using materials from this polymerization-induced phase separation method is reproducible (capacity within 10% batch-to-batch). This simple fabrication methodology may be extendable to other systems and provides a facile route to generate reproducible hierarchical porous morphology that can be beneficial in energy storage applications.

  10. Characterization of Membrane Protein-Lipid Interactions by Mass Spectrometry Ion Mobility Mass Spectrometry

    Science.gov (United States)

    Liu, Yang; Cong, Xiao; Liu, Wen; Laganowsky, Arthur

    2016-12-01

    Lipids in the biological membrane can modulate the structure and function of integral and peripheral membrane proteins. Distinguishing individual lipids that bind selectively to membrane protein complexes from an ensemble of lipid-bound species remains a daunting task. Recently, ion mobility mass spectrometry (IM-MS) has proven to be invaluable for interrogating the interactions between protein and individual lipids, where the complex undergoes collision induced unfolding followed by quantification of the unfolding pathway to assess the effect of these interactions. However, gas-phase unfolding experiments for membrane proteins are typically performed on the entire ensemble (apo and lipid bound species), raising uncertainty to the contribution of individual lipids and the species that are ejected in the unfolding process. Here, we describe the application of mass spectrometry ion mobility mass spectrometry (MS-IM-MS) for isolating ions corresponding to lipid-bound states of a model integral membrane protein, ammonia channel (AmtB) from Escherichia coli. Free of ensemble effects, MS-IM-MS reveals that bound lipids are ejected as neutral species; however, no correlation was found between the lipid-induced stabilization of complex and their equilibrium binding constants. In comparison to data obtained by IM-MS, there are surprisingly limited differences in stability measurements from IM-MS and MS-IM-MS. The approach described here to isolate ions of membrane protein complexes will be useful for other MS methods, such as surface induced dissociation or collision induced dissociation to determine the stoichiometry of hetero-oligomeric membrane protein complexes.

  11. Distance Geometry Protocol to Generate Conformations of Natural Products to Structurally Interpret Ion Mobility-Mass Spectrometry Collision Cross Sections

    Science.gov (United States)

    2015-01-01

    Ion mobility-mass spectrometry (IM-MS) allows the separation of ionized molecules based on their charge-to-surface area (IM) and mass-to-charge ratio (MS), respectively. The IM drift time data that is obtained is used to calculate the ion-neutral collision cross section (CCS) of the ionized molecule with the neutral drift gas, which is directly related to the ion conformation and hence molecular size and shape. Studying the conformational landscape of these ionized molecules computationally provides interpretation to delineate the potential structures that these CCS values could represent, or conversely, structural motifs not consistent with the IM data. A challenge in the IM-MS community is the ability to rapidly compute conformations to interpret natural product data, a class of molecules exhibiting a broad range of biological activity. The diversity of biological activity is, in part, related to the unique structural characteristics often observed for natural products. Contemporary approaches to structurally interpret IM-MS data for peptides and proteins typically utilize molecular dynamics (MD) simulations to sample conformational space. However, MD calculations are computationally expensive, they require a force field that accurately describes the molecule of interest, and there is no simple metric that indicates when sufficient conformational sampling has been achieved. Distance geometry is a computationally inexpensive approach that creates conformations based on sampling different pairwise distances between the atoms within the molecule and therefore does not require a force field. Progressively larger distance bounds can be used in distance geometry calculations, providing in principle a strategy to assess when all plausible conformations have been sampled. Our results suggest that distance geometry is a computationally efficient and potentially superior strategy for conformational analysis of natural products to interpret gas-phase CCS data. PMID:25360896

  12. Flow-background subtraction in the charge-separation measurements in heavy-ion collisions

    Science.gov (United States)

    Wen, Fufang

    2016-09-01

    Recent azimuthal-angle correlation measurements in high-energy heavy-ion collisions have observed charge-separation signals perpendicular to the reaction plane, and the observations have been related to the chiral magnetic effect (CME). However, the correlation signal is contaminated with the background contributions due to the collective motion (flow) of the collision system, and it remains elusive to effectively remove the background from the correlation. In this poster, we present a method study with a simple Monte Carlo simulation and the AMPT model. We develop a scheme to reveal the true CME signal via the event-shape engineering with the magnitude of the flow vector, Q: the flow-background is removed at Q = 0. Artificial signal/background effects will also be discussed.

  13. CALCULATIONS OF ION TRAJECTORIES AT MAGNETOPLASMA SEPARATION AND EXPERIMENTS WITH POLYATOMIC GASES

    Directory of Open Access Journals (Sweden)

    Vladimir Yuferov

    2017-02-01

    Full Text Available Calculated trajectories of ions with different masses, indicating the possibility of a mixture separation, are obtained. Comparative experiments for plasma of monatomic and polyatomic gases (Ar, N2, CO2, upon combination of pulsed discharge with a stationary one with incandescent cathode, are carried out. The oscillograms of discharge current and voltage at low emission currents and a constant energy input show that energy is spent on other processes different from ionization. With an increase of emission current, the nonlinear character of the discharge current and voltage, which may be indicative of the role of dissociation and vibrational levels in energy consumption, is observed. In addition, there is connection between the number of atoms in molecule and the values of maximum discharge current and the pressure of injected gas.

  14. Standard practice for The separation of americium from plutonium by ion exchange

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This practice describes the use of an ion exchange technique to separate plutonium from solutions containing low concentrations of americium prior to measurement of the 241Am by gamma counting. 1.2 This practice covers the removal of plutonium, but not all the other radioactive isotopes that may interfere in the determination of 241Am. 1.3 This practice can be used when 241Am is to be determined in samples in which the plutonium is in the form of metal, oxide, or other solid provided that the solid is appropriately sampled and dissolved (See Test Methods C758, C759, and C1168). 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  15. Retention behavior of phenols, anilines, and alkylbenzenes in liquid chromatographic separations using subcritical water as the mobile phase.

    Science.gov (United States)

    Yang, Y; Jones, A D; Eaton, C D

    1999-09-01

    The unique characteristic of subcritical water is its widely tunable physical properties. For example, the polarity (measured by dielectric constant) of water is significantly decreased by raising water temperature. At temperatures of 200-250 °C (under moderate pressure to keep water in the liquid state), the polarity of pure water is similar to that of pure methanol or acetonitrile at ambient conditions. Therefore, pure subcritical water may be able to serve as the mobile phase for reversed-phase separations. To investigate the retention behavior in subcritical water separation, the retention factors of BTEX (benzene, toluene, ethylbenzene, and m-xylene), phenol, aniline, and their derivatives have been determined using subcritical water, methanol/water, and acetonitrile/water systems. Subcritical water separations were also performed using alumina, silica-bonded C18, and poly(styrene-divinylbenzene) columns to study the influence of the stationary phase on analyte retention under subcritical water conditions.

  16. Sandwich-like heat-resistance composite separators with tunable pore structure for high power high safety lithium ion batteries

    Science.gov (United States)

    Shi, Junli; Shen, Tao; Hu, Huasheng; Xia, Yonggao; Liu, Zhaoping

    2014-12-01

    We demonstrate a new kind of composite separators. A unique feature of the separators is the three-tier structure, i.e. the crosslinked polyethylene glycol (PEG) skin layer being formed on both sides of the nonwoven separators by in-situ polymerization and the large pores in the interior of the nonwoven separators being remained. The surface pore structure and the thickness of the skin layer could be adjusted by controlling the concentration of the coating solution. The skin layer is proved to be able to provide internal short circuit protection, to contribute a more stable interfacial resistance and to alleviate liquid electrolyte leakage effectively, yielding an excellent cyclability. The remained large pores in the interior of the composite separators could provide an access for the fast transportation of lithium ions, giving rise to a very high ion conductivity. The polyimide (PI) nonwoven is employed to ensure enhanced thermal stability of the composite separators. More notably, the composite separators fabricated from the coating solution with a composition ratio of 20 wt% provide superior cell performances owing to the well-tailored microporous structure, comparing with the commercialized polypropylene (PP) separator, which show great promise for the application in the high power lithium ion batteries.

  17. Sustainable, heat-resistant and flame-retardant cellulose-based composite separator for high-performance lithium ion battery

    Science.gov (United States)

    Zhang, Jianjun; Yue, Liping; Kong, Qingshan; Liu, Zhihong; Zhou, Xinhong; Zhang, Chuanjian; Xu, Quan; Zhang, Bo; Ding, Guoliang; Qin, Bingsheng; Duan, Yulong; Wang, Qingfu; Yao, Jianhua; Cui, Guanglei; Chen, Liquan

    2014-02-01

    A sustainable, heat-resistant and flame-retardant cellulose-based composite nonwoven has been successfully fabricated and explored its potential application for promising separator of high-performance lithium ion battery. It was demonstrated that this flame-retardant cellulose-based composite separator possessed good flame retardancy, superior heat tolerance and proper mechanical strength. As compared to the commercialized polypropylene (PP) separator, such composite separator presented improved electrolyte uptake, better interface stability and enhanced ionic conductivity. In addition, the lithium cobalt oxide (LiCoO2)/graphite cell using this composite separator exhibited better rate capability and cycling retention than that for PP separator owing to its facile ion transport and excellent interfacial compatibility. Furthermore, the lithium iron phosphate (LiFePO4)/lithium cell with such composite separator delivered stable cycling performance and thermal dimensional stability even at an elevated temperature of 120°C. All these fascinating characteristics would boost the application of this composite separator for high-performance lithium ion battery.

  18. Electronic tongue system for remote multi-ion sensing using blind source separation and wireless sensor network

    Science.gov (United States)

    Chung, Wen-Yan; Cruz, Febus Reidj G.; Szu, Harold; Pijanowska, Dorota G.; Dawgul, Marek; Torbicz, Wladyslaw; Grabiec, Piotr B.; Jarosewicz, Bohdan; Chiang, Jung-Lung; Cheng, Cheanyeh; Chang, Kuo-Chung; Truc, Le Thanh; Lin, Wei-Chiang

    2010-04-01

    This paper presents an electronic tongue system with blind source separation (BSS) and wireless sensor network (WSN) for remote multi-ion sensing applications. Electrochemical sensors, such as ion-sensitive field-effect transistor (ISFET) and extended-gate field-effect transistor (EGFET), only provide the combined concentrations of all ions in aqueous solutions. Mixed hydrogen and sodium ions in chemical solutions are observed by means of H+ ISFET and H+ EGFET sensor array. The BSS extracts the concentration of individual ions using independent component analysis (ICA). The parameters of ISFET and EGFET sensors serve as a priori knowledge that helps solve the BSS problem. Using wireless transceivers, the ISFET/EGFET modules are realized as wireless sensor nodes. The integration of WSN technology into our electronic tongue system with BSS capability makes distant multi-ion measurement viable for environment and water quality monitoring.

  19. Comparing Ion Exchange Adsorbents for Nitrogen Recovery from Source-Separated Urine.

    Science.gov (United States)

    Tarpeh, William A; Udert, Kai M; Nelson, Kara L

    2017-02-21

    Separate collection of urine, which is only 1% of wastewater volume but contains the majority of nitrogen humans excrete, can potentially reduce the costs and energy input of wastewater treatment and facilitate recovery of nitrogen for beneficial use. Ion exchange was investigated for recovery of nitrogen as ammonium from urine for use as a fertilizer or disinfectant. Cation adsorption curves for four adsorbents (clinoptilolite, biochar, Dowex 50, and Dowex Mac 3) were compared in pure salt solutions, synthetic urine, and real stored urine. Competition from sodium and potassium present in synthetic and real urine did not significantly decrease ammonium adsorption for any of the adsorbents. Dowex 50 and Dowex Mac 3 showed nearly 100% regeneration efficiencies. Estimated ion exchange reactor volumes to capture the nitrogen for 1 week from a four-person household were lowest for Dowex Mac 3 (5 L) and highest for biochar (19 L). Although Dowex Mac 3 had the highest adsorption capacity, material costs ($/g N removed) were lower for clinoptilolite and biochar because of their substantially lower unit cost.

  20. Recycling metals from lithium ion battery by mechanical separation and vacuum metallurgy.

    Science.gov (United States)

    Xiao, Jiefeng; Li, Jia; Xu, Zhengming

    2017-09-15

    The large-batch application of lithium ion batteries leads to the mass production of spent batteries. So the enhancement of disposal ability of spent lithium ion batteries is becoming very urgent. This study proposes an integrated process to handle bulk spent lithium manganese (LiMn2O4) batteries to in situ recycle high value-added products without any additives. By mechanical separation, the mixed electrode materials mainly including binder, graphite and LiMn2O4 are firstly obtained from spent batteries. Then, the reaction characteristics for the oxygen-free roasting of mixed electrode materials are analyzed. And the results show that mixed electrode materials can be in situ converted into manganese oxide (MnO) and lithium carbonate (Li2CO3) at 1073K for 45min. In this process, the binder is evaporated and decomposed into gaseous products which can be collected to avoid disposal cost. Finally, 91.30% of Li resource as Li2CO3 is leached from roasted powders by water and then high value-added Li2CO3 crystals are further gained by evaporating the filter liquid. The filter residues are burned in air to remove the graphite and the final residues as manganous-manganic oxide (Mn3O4) is obtained. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Multidimensional separations of ubiquitin conformers in the gas phase: relating ion cross sections to H/D exchange measurements.

    Science.gov (United States)

    Robinson, Errol W; Williams, Evan R

    2005-09-01

    Investigating gas-phase structures of protein ions can lead to an improved understanding of intramolecular forces that play an important role in protein folding. Both hydrogen/deuterium (H/D) exchange and ion mobility spectrometry provide insight into the structures and stabilities of different gas-phase conformers, but how best to relate the results from these two methods has been hotly debated. Here, high-field asymmetric waveform ion mobility spectrometry (FAIMS) is combined with Fourier-transform ion cyclotron resonance mass spectrometry (FT/ICR MS) and is used to directly relate ubiquitin ion cross sections and H/D exchange extents. Multiple conformers can be identified using both methods. For the 9+ charge state of ubiquitin, two conformers (or unresolved populations of conformers) that have cross sections differing by 10% are resolved by FAIMS, but only one conformer is apparent using H/D exchange at short times. For the 12+ charge state, two conformers (or conformer populations) have cross sections differing by ion collisional cross sections and H/D exchange distributions are not strongly correlated and that factors other than surface accessibility appear to play a significant role in determining rates and extents of H/D exchange. Conformers that are not resolved by one method could be resolved by the other, indicating that these two methods are highly complementary and that more conformations can be resolved with this combination of methods than by either method alone.

  2. Ion Mobility Measurements of Nondenatured 12-150 kDa Proteins and Protein Multimers by Tandem Differential Mobility Analysis-Mass Spectrometry (DMA-MS)

    Science.gov (United States)

    Hogan, Christopher J.; de la Mora, Juan Fernández

    2011-01-01

    The mobilities of electrosprayed proteins and protein multimers with molecular weights ranging from 12.4 kDa (cytochrome C monomers) to 154 kDa (nonspecific concanavalin A hexamers) were measured in dry air by a planar differential mobility analyzer (DMA) coupled to a time-of-flight mass spectrometer (TOF-MS). The DMA determines true mobility at atmospheric pressure, without perturbing ion structure from that delivered by the electrospray. A nondenaturing aqueous 20 mM triethylammonium formate buffer yields compact ions with low charge states, moderating polarization effects on ion mobility. Conversion of mobilities into cross-sections involves a reduction factor ξ for the actual mobility relative to that associated with elastic specular collisions with smooth surfaces. ξ is known to be 1.36 in air from Millikan's oil drop experiments. A similar enhancement effect ascribed to atomic-scale surface roughness has been found in numerical simulations. Adopting Millikan's value ξ = 1.36 and assuming a spherical geometry yields a gas-phase protein density ρ p = 0.949 ± 0.053 g cm-3 for all our protein data. This is substantially higher than the 0.67 g cm-3 found in recent low-resolution DMA measurements of singly charged proteins. DMA-MS can distinguish nonspecific protein aggregates formed during the electrospray process from those formed preferentially in solution. The observed charge versus diameter relation is compatible with a protein charge reduction mechanism based on the evaporation of triethylammonium ions from electrosprayed drops.

  3. Bioleaching of valuable metals from spent lithium-ion mobile phone batteries using Aspergillus niger

    Science.gov (United States)

    Horeh, N. Bahaloo; Mousavi, S. M.; Shojaosadati, S. A.

    2016-07-01

    In this paper, a bio-hydrometallurgical route based on fungal activity of Aspergillus niger was evaluated for the detoxification and recovery of Cu, Li, Mn, Al, Co and Ni metals from spent lithium-ion phone mobile batteries under various conditions (one-step, two-step and spent medium bioleaching). The maximum recovery efficiency of 100% for Cu, 95% for Li, 70% for Mn, 65% for Al, 45% for Co, and 38% for Ni was obtained at a pulp density of 1% in spent medium bioleaching. The HPLC results indicated that citric acid in comparison with other detected organic acids (gluconic, oxalic and malic acid) had an important role in the effectiveness of bioleaching using A. niger. The results of FTIR, XRD and FE-SEM analysis of battery powder before and after bioleaching process confirmed that the fungal activities were quite effective. In addition, bioleaching achieved higher removal efficiency for heavy metals than the chemical leaching. This research demonstrated the great potential of bio-hydrometallurgical route to recover heavy metals from spent lithium-ion mobile phone batteries.

  4. Lithium-ion battery electrolyte mobility at nano-confined graphene interfaces

    Science.gov (United States)

    Moeremans, Boaz; Cheng, Hsiu-Wei; Hu, Qingyun; Garces, Hector F.; Padture, Nitin P.; Renner, Frank Uwe; Valtiner, Markus

    2016-01-01

    Interfaces are essential in electrochemical processes, providing a critical nanoscopic design feature for composite electrodes used in Li-ion batteries. Understanding the structure, wetting and mobility at nano-confined interfaces is important for improving the efficiency and lifetime of electrochemical devices. Here we use a Surface Forces Apparatus to quantify the initial wetting of nanometre-confined graphene, gold and mica surfaces by Li-ion battery electrolytes. Our results indicate preferential wetting of confined graphene in comparison with gold or mica surfaces because of specific interactions of the electrolyte with the graphene surface. In addition, wetting of a confined pore proceeds via a profoundly different mechanism compared with wetting of a macroscopic surface. We further reveal the existence of molecularly layered structures of the confined electrolyte. Nanoscopic confinement of less than 4–5 nm and the presence of water decrease the mobility of the electrolyte. These results suggest a lower limit for the pore diameter in nanostructured electrodes. PMID:27562148

  5. An Effective Approach for Coupling Direct Analysis in Real Time with Atmospheric Pressure Drift Tube Ion Mobility Spectrometry

    Science.gov (United States)

    Keelor, Joel D.; Dwivedi, Prabha; Fernández, Facundo M.

    2014-09-01

    Drift tube ion mobility spectrometry (DTIMS) has evolved as a robust analytical platform routinely used for screening small molecules across a broad suite of chemistries ranging from food and pharmaceuticals to explosives and environmental toxins. Most modern atmospheric pressure IM detectors employ corona discharge, photoionization, radioactive, or electrospray ion sources for efficient ion production. Coupling standalone DTIMS with ambient plasma-based techniques, however, has proven to be an exceptional challenge. Device sensitivity with near-ground ambient plasma sources is hindered by poor ion transmission at the source-instrument interface, where ion repulsion is caused by the strong electric field barrier of the high potential ion mobility spectrometry (IMS) inlet. To overcome this shortfall, we introduce a new ion source design incorporating a repeller point electrode used to shape the electric field profile and enable ion transmission from a direct analysis in real time (DART) plasma ion source. Parameter space characterization studies of the DART DTIMS setup were performed to ascertain the optimal configuration for the source assembly favoring ion transport. Preliminary system capabilities for the direct screening of solid pharmaceuticals are briefly demonstrated.

  6. Hydrodynamics with chiral anomaly and charge separation in relativistic heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Yi, E-mail: yyin@bnl.gov [Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Liao, Jinfeng, E-mail: liaoji@indiana.edu [Physics Department and Center for Exploration of Energy and Matter, Indiana University, 2401 N Milo B. Sampson Lane, Bloomington, IN 47408 (United States); RIKEN BNL Research Center, Bldg. 510A, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2016-05-10

    Matter with chiral fermions is microscopically described by theory with quantum anomaly and macroscopically described (at low energy) by anomalous hydrodynamics. For such systems in the presence of external magnetic field and chirality imbalance, a charge current is generated along the magnetic field direction — a phenomenon known as the Chiral Magnetic Effect (CME). The quark–gluon plasma created in relativistic heavy ion collisions provides an (approximate) example, for which the CME predicts a charge separation perpendicular to the collisional reaction plane. Charge correlation measurements designed for the search of such signal have been done at RHIC and the LHC for which the interpretations, however, remain unclear due to contamination by background effects that are collective flow driven, theoretically poorly constrained, and experimentally hard to separate. Using anomalous (and viscous) hydrodynamic simulations, we make a first attempt at quantifying contributions to observed charge correlations from both CME and background effects in one and same framework. The implications for the search of CME are discussed.

  7. Plasma processes in the preparation of lithium-ion battery electrodes and separators

    Science.gov (United States)

    Nava-Avendaño, J.; Veilleux, J.

    2017-04-01

    Lithium-ion batteries (LIBs) are the energy storage devices that dominate the portable electronic market. They are now also considered and used for electric vehicles and are foreseen to enable the smart grid. Preparing batteries with high energy and power densities, elevated cycleability and improved safety could be achieved by controlling the microstructure of the electrode materials and the interaction they have with the electrolyte over the working potential window. Selecting appropriate precursors, reducing the preparation steps and selecting more efficient synthesis methods could also significantly reduce the costs of LIB components. Implementing plasma technologies can represent a high capital investment, but the versatility of the technologies allows the preparation of powdered nanoparticles with different morphologies, as well as with carbon and metal oxide coatings. Plasma technologies can also enable the preparation of binder-free thin films and coatings for LIB electrodes, and the treatment of polymeric membranes to be used as separators. This review paper aims at highlighting the different thermal and non-thermal plasma technologies recently used to synthesize coated and non-coated active materials for LIB cathodes and anodes, and to modify the surface of separators.

  8. Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation of Sodium Salts

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A.; Bonnesen, Peter V.; Custelcean, Radu; Delmau, Laetitia H.; Engle, Nancy L.; Kang, Hyun-Ah; Keever, Tamara J.; Marchand, Alan P.; Gadthula, Srinivas; Gore, Vinayak K.; Huang, Zilin; Sivappa, Rasapalli; Tirunahari, Pavan K.; Levitskaia, Tatiana G.; Lumetta, Gregg J.

    2005-09-26

    The purpose of this research involving collaboration between Oak Ridge National Laboratory (ORNL) and Pacific Northwest National Laboratory (PNNL) is to explore new approaches to the separation of sodium hydroxide, sodium nitrate, and other sodium salts from high-level alkaline tank waste. The principal potential benefit is a major reduction in disposed waste volume, obviating the building of expensive new waste tanks and reducing the costs of vitrification. Principles of ion recognition are being researched toward discovery of liquid-liquid extraction systems that selectively separate sodium hydroxide and sodium nitrate from other waste components. The successful concept of pseudo hydroxide extraction using fluorinated alcohols and phenols is being developed at ORNL and PNNL toward a greater understanding of the controlling equilibria, role of solvation, and of synergistic effects involving crown ethers. Synthesis efforts are being directed toward enhanced sodium binding by crown ethers, both neutral and proton-ionizable. Studies with real tank waste at PNNL will provide feedback toward solvent compositions that have promising properties.

  9. Separation of uremic toxins from urine with resorcinarene-based ion chromatography columns.

    Science.gov (United States)

    Panahi, Tayyebeh; Weaver, Douglas J; Lamb, John D; Harrison, Roger G

    2015-01-01

    People with chronic kidney disease suffer from uremic toxins which accumulate in their bodies. Detection and quantification of uremic toxins help diagnose kidney problems and start patient care. The aim of this research was to seek a new method to assist this diagnosis by trace level detection and separation of guanidine containing uremic toxins in water and urine. To detect and quantify the uremic toxins, new stationary phases for ion chromatography (IC) columns based on glutamic acid functionalized resorcinarenes bound to divinylbenzene macroporous resin were prepared. The new column packing material afforded separation of the five compounds: guanidinoacetic acid, guanidine, methylguanidine, creatinine, and guanidinobenzoic acid in 30min. Peak resolutions ranged from 7.6 to 1.3. Gradient elutions at ambient temperature with methanesulfonic acid (MSA) solution as eluent resulted in detection levels in water from 10 to 47ppb and in synthetic urine from 28 to 180ppb. Limits of quantification for the analytes using pulsed amperometric detection were 30-160ppb in water and 93-590ppb in urine. Trace levels of creatinine (1ppm) were detected in the urine of a healthy individual using the columns.

  10. Method for selective detection of explosives in mass spectrometer or ion mobility spectrometer at parts-per-quadrillion level

    Science.gov (United States)

    Ewing, Robert G.; Atkinson, David A.; Clowers, Brian H.

    2015-09-01

    A method for selective detection of volatile and non-volatile explosives in a mass spectrometer or ion mobility spectrometer at a parts-per-quadrillion level without preconcentration is disclosed. The method comprises the steps of ionizing a carrier gas with an ionization source to form reactant ions or reactant adduct ions comprising nitrate ions (NO.sub.3.sup.-); selectively reacting the reactant ions or reactant adduct ions with at least one volatile or non-volatile explosive analyte at a carrier gas pressure of at least about 100 Ton in a reaction region disposed between the ionization source and an ion detector, the reaction region having a length which provides a residence time (tr) for reactant ions therein of at least about 0.10 seconds, wherein the selective reaction yields product ions comprising reactant ions or reactant adduct ions that are selectively bound to the at least one explosive analyte when present therein; and detecting product ions with the ion detector to determine presence or absence of the at least one explosive analyte.

  11. Comparison of the performance of three ion mobility spectrometers for measurement of biogenic amines

    Energy Technology Data Exchange (ETDEWEB)

    Karpas, Zeev, E-mail: karpas4@netvision.net.il [3QBD, Arad (Israel); Chemistry Department, Nuclear Research Center, Negev, Beer-Sheva 84190 (Israel); Guaman, Ana V., E-mail: aguaman@ibecbarcelona.eu [Departament d' Electronica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Artificial Olfaction Lab, Institute for Bioengineering of Catalonia, Baldiri i Rexach, 4-8, 08028 Barcelona (Spain); Pardo, Antonio, E-mail: apardo@el.ub.edu [Departament d' Electronica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Marco, Santiago, E-mail: smarco@ibecbarcelona.eu [Departament d' Electronica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Artificial Olfaction Lab, Institute for Bioengineering of Catalonia, Baldiri i Rexach, 4-8, 08028 Barcelona (Spain)

    2013-01-03

    Graphical abstract: The response to different amounts of TMA (in {mu}g) that were placed in a headspace vial as a function of time for the VG-Test (top) and the GDA (bottom). Note that the ratio [TMA/(TMA + TEP)] (top) and [TMA/(TMA + RIP)] (bottom) and the clearance time increase with the amount of TMA deposited in the vial. Highlights: Black-Right-Pointing-Pointer First comparison of performance of IMS devices. Black-Right-Pointing-Pointer Gas-phase ion chemistry affected by operational parameters. Black-Right-Pointing-Pointer Limits of detection quite similar despite differences in devices. Black-Right-Pointing-Pointer LODs determined in controlled continuous flow and in headspace vapor. Black-Right-Pointing-Pointer Exponential dilution of headspace studies. - Abstract: The performance of three different types of ion mobility spectrometer (IMS) devices: GDA2 with a radioactive ion source (Airsense, Germany), UV-IMS with a photo-ionization source (G.A.S. Germany) and VG-Test with a corona discharge source (3QBD, Israel) was studied. The gas-phase ion chemistry in the IMS devices affected the species formed and their measured reduced mobility values. The sensitivity and limit of detection for trimethylamine (TMA), putrescine and cadaverine were compared by continuous monitoring of a stream of air with a given concentration of the analyte and by measurement of headspace vapors of TMA in a sealed vial. Preprocessing of the mobility spectra and the effectiveness of multivariate curve resolution techniques (MCR-LASSO) improved the accuracy of the measurements by correcting baseline effects and adjusting for variations in drift time as well as enhancing the signal to noise ratio and deconvolution of the complex data matrix to their pure components. The limit of detection for measurement of the biogenic amines by the three IMS devices was between 0.1 and 1.2 ppm (for TMA with the VG-Test and GDA, respectively) and between 0.2 and 0.7 ppm for putrescine and cadaverine

  12. Applications of ion cyclotron-resonance to stable isotope separation; Les applications de la resonance cyclotron ionique a la separation des isotopes stables

    Energy Technology Data Exchange (ETDEWEB)

    Louvet, P.; Metayer, L. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Procedes d`Enrichissement

    1994-12-31

    The principles and the technological basic concepts of the ion cyclotron-resonance process applied to the separation of metallic isotopes which mass ranges from 40 to 200 for medical and nuclear applications, are reviewed. The CEA (France) has developed a prototype plant, ERIC; first results showing high separation factors allow to consider higher production in the future. A modular code has been developed (RICAN) in order to assess the technic-economical feasibility of the process for various isotopes; examples of calculated results (costs and production) for calcium 48 and gadolinium 157 production are presented. 4 figs., 1 tab., 4 refs.

  13. Evaluation of the thermal effect on separation selectivity in anion-exchange processes using superheated water ion-exchange chromatography.

    Science.gov (United States)

    Shibukawa, Masami; Taguchi, Akihiko; Suzuki, Yusuke; Saitoh, Kazunori; Hiaki, Toshihiko; Yarita, Takashi

    2012-07-07

    The thermal effect on retention and separation selectivity of inorganic anions and aromatic sulfonate ions in anion-exchange chromatography is studied on a quaternized styrene-divinylbenzene copolymer anion-exchange column in the temperature range of 40-120 °C using superheated water chromatography. The selectivity coefficient for a pair of identically charged anions approaches unity as temperature increases provided the ions have the same effective size, such that the retention of an analyte ion decreases with an increase in temperature when the analyte ion has stronger affinity for the ion-exchanger than that of the eluent counterion, whereas it increases when it has weaker affinity. The change in anion-exchange selectivity with temperature observed with superheated water chromatography has been discussed on the basis of the effect of temperature on hydration of the ions. At elevated temperatures, especially in superheated water, the electrostatic interaction or association of the ions with the fixed ion in the resin phase becomes a predominant factor resulting in a different separation selectivity from that obtained at ambient temperature.

  14. Enhanced extraction yields and mobile phase separations by solvent mixtures for the analysis of metabolites in Annona muricata L. leaves.

    Science.gov (United States)

    Ribeiro de Souza, Eloana Benassi; da Silva, Renata Reis; Afonso, Sabrina; Scarminio, Ieda Spacino

    2009-12-01

    The effects of five extraction solvents and their mixtures on the yield of metabolites in crude and fractionated extracts of Annona muricata L. leaves were investigated by direct comparison. Extraction media were prepared using simplex centroid mixtures of ethanol, ethyl acetate, dichloromethane, acetone, and chloroform. The effects of the mobile phase solvent strength and the analysis wavelength on the chromatographic separation were also investigated. Solvent mixtures rather than pure solvents were found to be the most efficient extractors for the different fractions. The results indicated that the mobile phase composed of methanol/acetonitrile/water (26:27:47 v/v/v) was most suitable for the basic fraction analysis at 254 nm, whereas the mobile phase composed of methanol/acetonitrile/water (35:35:30 v/v/v) was the most adequate for the organic fraction analysis at 254 nm. The results indicated that the chromatographic profiles and number of peaks were affected by the mobile phase strength and analysis wavelength.

  15. Simultaneous spectrophotometric determination of phosphate and silicate ions in river water by using ion-exclusion chromatographic separation and post-column derivatization.

    Science.gov (United States)

    Nakatani, Nobutake; Kozaki, Daisuke; Masuda, Wakako; Nakagoshi, Nobukazu; Hasebe, Kiyoshi; Mori, Masanobu; Tanaka, Kazuhiko

    2008-06-30

    The simultaneous spectrophotometric determination of phosphate and silicate ions in river water was examined by using ion-exclusion chromatography and post-column derivatization. Phosphate and silicate ions were separated by the ion-exclusion column packed with a polymethacrylate-based weakly acidic cation-exchange resin in the H(+)-form (TSKgel Super IC-A/C) by using ultra pure water as an eluent. After the post-column derivatization with molybdate and ascorbic acid, so-called molybdenum-blue, both ions were determined simultaneously by spectrophotometry. The effects of sulfuric acid, sodium molybdate and ascorbic acid concentrations and reaction coil length, which have relation to form the reduced complexes of molybdate and ions, on the detector response for phosphate and silicate ions were investigated. Under the optimized conditions (color-forming reactant, 50 mM sulfuric acid-10 mM sodium molybdate; reducing agent, 50 mM ascorbic acid; reaction coil length, 6 m), the calibration curves of phosphate and silicate ions were linear in the range of 50-2000 microg L(-1) as P and 250-10,000 microg L(-1) as Si. This method was successfully applied to water quality monitoring of Kurose-river watershed and it suggested that the effluent from a biological sewage treatment plant was significant source of phosphate ion in Kurose-river water.

  16. Preconceptual design for separation of plutonium and gallium by ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    DeMuth, S.F.

    1997-09-30

    The disposition of plutonium from decommissioned nuclear weapons, by incorporation into commercial UO{sub 2}-based nuclear reactor fuel, is a viable means to reduce the potential for theft of excess plutonium. This fuel, which would be a combination of plutonium oxide and uranium oxide, is referred to as a mixed oxide (MOX). Following power generation in commercial reactors with this fuel, the remaining plutonium would become mixed with highly radioactive fission products in a spent fuel assembly. The radioactivity, complex chemical composition, and large size of this spent fuel assembly, would make theft difficult with elaborate chemical processing required for plutonium recovery. In fabricating the MOX fuel, it is important to maintain current commercial fuel purity specifications. While impurities from the weapons plutonium may or may not have a detrimental affect on the fuel fabrication or fuel/cladding performance, certifying the effect as insignificant could be more costly than purification. Two primary concerns have been raised with regard to the gallium impurity: (1) gallium vaporization during fuel sintering may adversely affect the MOX fuel fabrication process, and (2) gallium vaporization during reactor operation may adversely affect the fuel cladding performance. Consequently, processes for the separation of plutonium from gallium are currently being developed and/or designed. In particular, two separation processes are being considered: (1) a developmental, potentially lower cost and lower waste, thermal vaporization process following PuO{sub 2} powder preparation, and (2) an off-the-shelf, potentially higher cost and higher waste, aqueous-based ion exchange (IX) process. While it is planned to use the thermal vaporization process should its development prove successful, IX has been recommended as a backup process. This report presents a preconceptual design with material balances for separation of plutonium from gallium by IX.

  17. High performance liquid chromatography/ion-trap mass spectrometry for separation and simultaneous determination of ethynylestradiol, gestodene, levonorgestrel, cyproterone acetate and desogestrel.

    Science.gov (United States)

    Matejícek, David; Kubán, Vlastimil

    2007-04-11

    A fast and highly sensitive high performance liquid chromatographic/ion-trap mass spectrometric method (LC/MS) has been developed for simultaneous determination of ethynylestradiol (EE2), gestodene (GES), levonorgestrel (LNG), cyproterone acetate (CPA) and desogestrel (DES). Among three types of sorbents tested (C8, C18 and phenyl) from two suppliers, the best separation was achieved on reverse phase Zorbax SB-Phenyl column using aqueous methanol as a mobile phase. A linear gradient profile from 70 up to 100% (v/v) in 7th min, kept constant at 100% up to 10th min and followed by a negative gradient to 70% of methanol up to 12th min was used for elution. Applicability of electrospray ionization (ESI) an