TY - JOUR A1 - You, Yi A1 - Xue, Boyang A1 - Riedel, Jens T1 - Enhancement of LIBS plasma in air with organic solvent vapors N2 - Laser-induced breakdown spectroscopy (LIBS) offers versatile, field-deployable elemental analysis; however, compact, high-repetition-rate nanosecond laser systems typically face constraints in power consumption and size, often compromising emission intensity and thus analytical performance. We demonstrate a significant improvement in LIBS signals through the controlled introduction of common organic solvent vapors into a sheath gas, with a diode-pumped solid-state laser (1064 nm, 2–28 kHz repetition rate, 450–600-μJ pulse energy). Optical and acoustic diagnostics reveal up to ca. 40-fold enhancement of the N II emission line at 567 nm when ambient air serves as the analyte. Maximal enhancement occurs at intermediate repetition rates of ca. 15 kHz, particularly at pulse energies approaching the optical breakdown threshold; this observation suggests a viable strategy for operating LIBS at lower pulse energies and higher repetition rates. Enhancement effects scale jointly with both vapor pressure and ionization energy of the organic species, with acetone and toluene markedly outperforming methanol and isopropanol. These findings provide a rational foundation for significantly improving the analytical performance of portable LIBS instruments without exceeding platform-specific constraints. KW - LIBS PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653758 DO - https://doi.org/10.1016/j.sab.2025.107309 SN - 0584-8547 VL - 236 SP - 1 EP - 6 PB - Elsevier B.V. AN - OPUS4-65375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stindt, Arne A1 - Buurman, Merwe A1 - Panne, Ulrich A1 - Riedel, Jens T1 - CO2 laser ionization of acoustically levitated droplets N2 - For many analytical purposes, direct laser ionization of liquids is desirable. Several studies on supported droplets, free liquid jets, and ballistically dispensed microdroplets have been conducted, yet detailed knowledge of the underlying mechanistics in ion formation is still missing. This contribution introduces a simple combination of IR-MALDI mass spectrometry and an acoustical levitation device for contactless confinement of the liquid sample. The homebuilt ultrasonic levitator supports droplets of several millimeters in diameter. These droplets are vaporized by a carbon dioxide laser in the vicinity of the atmospheric pressure interface of a time of flight mass spectrometer. The evaporation process is studied by high repetition rate shadowgraphy experiments elucidating the ballistic evaporation of the sample and revealing strong confinement of the vapor by the ultrasonic field of the trap. Finally, typical mass spectra for pure glycerol/water matrix and lysine as an analyte are presented with and without the addition of trifluoracetic acid, and the ionization mechanism is briefly discussed. The technique is a promising candidate for a reproducible mass spectrometric detection scheme for the field of microfluidics. KW - Ambient mass spectrometry KW - Levitated droplets KW - IR-MALDI PY - 2013 DO - https://doi.org/10.1007/s00216-012-6500-y SN - 1618-2642 SN - 1618-2650 N1 - Geburtsname von Buurman, Merwe: Albrecht, M. - Birth name of Buurman, Merwe: Albrecht, M. VL - 405 SP - 7005 EP - 7010 PB - Springer CY - Berlin AN - OPUS4-27429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Andrade, M. A. B. A1 - Stindt, Arne A1 - Panne, Ulrich A1 - Riedel, Jens A1 - Adamowski, J. C. T1 - Numerical and experimental determination of the sound pressure distribution in single-axis acoustic levitators N2 - This paper presents a numerical and an experimental procedure to obtain the pressure field in single-axis acoustic levitators. Numerically, the pressure field is determined by a matrix method based on the Rayleigh integral that take into account the multiple wave reflections that occur between the transducer and the reflector. The numerical pressure field is compared with the acoustic pressure measured by an earplug microphone, that is connected to a hollow needle. The tip of the needle is moved by a µm translation stage through the field and the signal is recorded using a lock-in amplifier locked to the levitator frequency. The pressure field obtained numerically show good agreement with that obtained experimentally. T2 - 2012 IEEE International Ultrasonics Symposium (IUS) CY - Dresden, Germany DA - 07.10.2012 KW - Acoustic levitation KW - Matrix method KW - Pressure field PY - 2012 SN - 978-1-4673-4562-0 DO - https://doi.org/10.1109/ULTSYM.2012.0690 SP - 2754 EP - 2757 PB - Institute of Electrical and Electronics Engineers (IEEE) CY - Piscataway, NJ AN - OPUS4-32587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Michalik-Onichimowska, Aleksandra A1 - Beitz, T. A1 - Panne, Ulrich A1 - Löhmannsröben, H.-G. A1 - Riedel, Jens T1 - Laser ionization ion mobility spectrometric interrogation of acoustically levitated droplets N2 - Acoustically levitated droplets have been suggested as compartmentalized, yet wall-less microreactors for high-throughput reaction optimization purposes. The absence of walls is envisioned to simplify up-scaling of the optimized reaction conditions found in the microliter volumes. A consequent pursuance of high-throughput chemistry calls for a fast, robust and sensitive analysis suited for online interrogation. For reaction optimization, targeted Analysis with relatively low sensitivity suffices, while a fast, robust and automated sampling is paramount. To follow this approach, in this contribution, a direct coupling of levitated droplets to a homebuilt ion mobility spectrometer (IMS) is presented. The sampling, Transfer to the gas phase, as well as the ionization are all performed by a single exposure of the sampling volume to the resonant output of a mid-IR laser. Once formed, the nascent spatially and temporally evolving analyte ion cloud needs to be guided out of the acoustically confined trap into the inlet of the ion mobility spectrometer. Since the IMS is operated at ambient pressure, no fluid dynamic along a pressure Gradient can be employed. Instead, the transfer is achieved by the electrostatic potential gradient inside a dual ring electrode ion optics, guiding the analyte ion cloud into the first stage of the IMS linear drift tube accelerator. The design of the appropriate atmospheric pressure ion optics is based on the original vacuum ion optics design of Wiley and McLaren. The obtained experimental results nicely coincide with ion trajectory calculations based on a collisional model. KW - Ambient pressure laser ionization KW - Ionmobility spectrometry KW - Acoustic levitation KW - ion optics PY - 2019 DO - https://doi.org/10.1007/s00216-019-02167-5 VL - 411 IS - 30 SP - 8053 EP - 8061 PB - Springer CY - Heidelberg AN - OPUS4-50132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ickert, Stefanie A1 - Schwaar, Timm A1 - Springer, A. A1 - Grabarics, M. A1 - Riedel, Jens A1 - Beck, S. A1 - Pagel, K. A1 - Linscheid, M. W. T1 - Comparison of the fragmentation behavior of DNA and LNA single strands and duplexes N2 - DNA and locked nucleic acid (LNA) were characterized as single strands, as well as double stranded DNA-DNA duplexes and DNA-LNA hybrids using tandem mass spectrometry with collision-induced dissociation. Additionally, ion mobility spectrometry was carried out on selected species. Oligonucleotide duplexes of different sequences – bearing mismatch positions and abasic sites of complementary DNA 15-mers – were investigated to unravel general trends in their stability in the gas phase. Single stranded LNA oligonucleotides were also investigated with respect to their gas phase behavior and fragmentation upon collision-induced dissociation. In contrast to the collision-induced dissociation of DNA, almost no base loss was observed for LNAs. Here, backbone cleavages were the dominant dissociation pathways. This finding was further underlined by the need for higher activation energies. Base losses from the LNA strand were also absent in fragmentation experiments of the investigated DNA-LNA hybrid duplexes. While DNA-DNA duplexes dissociated easily into single stranded fragments, the high stability of DNA-LNA hybrids resulted in predominant fragmentation of the DNA part rather than the LNA, while base losses were only observed from the DNA single strand of the hybrid. KW - Oligonucleotide fragmentation KW - Locked nucleic acids KW - Collision induced dissociation (CID) KW - Double strands KW - Ion mobility spectrometry PY - 2019 DO - https://doi.org/10.1002/jms.4344 VL - 54 IS - 5 SP - 402 EP - 411 PB - Wiley AN - OPUS4-47485 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ickert, Stefanie A1 - Beck, S. A1 - Linscheid, M. A1 - Riedel, Jens T1 - VUV Photodissociation Induced by a Deuterium Lamp in an Ion Trap N2 - Tandem mass spectrometry represents an important analytical tool to unravel molecular structures and to study the gas-phase behavior of organic molecules. Besides commonly used methods like collision-induced dissociation and electron capture or transfer dissociation, new ultraviolet light–based techniques have the potential to synergistically add to the activation methods. Here, we present a new simple, yet robust, experimental design for polychromatic activation of trapped ions using the 115–160 nm output of a commercially available deuterium lamp. The resulting continuous dissociative excitation with photons of a wide energy range from 7.7 to 10.8 eV is studied for a comprehensive set of analyte classes in both positive and negative ion modes. While being simple, affordable, compact, and of low maintenance, the new setup initiates fragmentation of most precursor ions via their known dissociation pathways. Additionally, some new fragmentation patterns were discovered. Especially, electron loss and electron capture reactions with subsequent fragmentations were observed. For oligonucleotides, peptides, carbohydrates, and organic dyes, in comparison to collision-induced dissociation, a significantly wider fragment distribution was obtained, resulting in an information increase. Since the individual photons carry enough energy to post-ionize the nascent fragments, a permanent vacuum ultraviolet light exposure inside the ion trap potentially goes along with a general increase in detection capability. KW - Fragmentation activation KW - Vacuum ultraviolet (VUV) light KW - Mass spectrometry KW - Tandem MS PY - 2019 DO - https://doi.org/10.1007/s13361-019-02282-8 SN - 1044-0305 VL - 30 IS - 10 SP - 2114 EP - 2122 PB - Springer Nature CY - Heidelberg AN - OPUS4-48756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bayerlein, Bernd A1 - Hanke, T. A1 - Muth, Thilo A1 - Riedel, Jens A1 - Schilling, Markus A1 - Schweizer, C. A1 - Skrotzki, Birgit A1 - Todor, A. A1 - Moreno Torres, Benjami A1 - Unger, Jörg F. A1 - Völker, Christoph A1 - Olbricht, Jürgen T1 - A Perspective on Digital Knowledge Representation in Materials Science and Engineering N2 - The amount of data generated worldwide is constantly increasing. These data come from a wide variety of sources and systems, are processed differently, have a multitude of formats, and are stored in an untraceable and unstructured manner, predominantly in natural language in data silos. This problem can be equally applied to the heterogeneous research data from materials science and engineering. In this domain, ways and solutions are increasingly being generated to smartly link material data together with their contextual information in a uniform and well-structured manner on platforms, thus making them discoverable, retrievable, and reusable for research and industry. Ontologies play a key role in this context. They enable the sustainable representation of expert knowledge and the semantically structured filling of databases with computer-processable data triples. In this perspective article, we present the project initiative Materials-open-Laboratory (Mat-o-Lab) that aims to provide a collaborative environment for domain experts to digitize their research results and processes and make them fit for data-driven materials research and development. The overarching challenge is to generate connection points to further link data from other domains to harness the promised potential of big materials data and harvest new knowledge. KW - Data infrastructures KW - Digital representations KW - Digital workflows KW - Knowledge graphs KW - Materials informatics KW - Ontologies KW - Vocabulary providers PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546729 DO - https://doi.org/10.1002/adem.202101176 SN - 1438-1656 SP - 1 EP - 14 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-54672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Li, Xunyu A1 - Riedel, Jens A1 - You, Yi T1 - Determination of broadband-light atomic absorption through interferometric spectrometry with a spatial heterodyne spectrometer N2 - A spatial heterodyne spectrometer (SHS) was combined with a flame atomic absorption (FAA) setup to reveal the analytical potential of SHS to be used as a tool for high-resolution atomic absorption studies. Exploiting the advances in modern computational power, the spectral information encoded in the interferograms was extracted and separated. Consequently, unseeable interferometric ingredients corresponding to narrow-band absorption lines could be recognized. Namely, a single SHS absorption interferogram simultaneously contains both illumination background and absorption information, which can be distinguished through a series of computational steps. In the examples given by this work, we demonstrate the construction of Na absorbance spectra from a single image. The described single-image approach can be used to investigate highly dynamic systems, whereby background collections can be obviated. KW - Optical Spectrometry KW - Spatial Heterodyne Spectrometry KW - Atomic Absorption PY - 2023 DO - https://doi.org/10.1039/D2JA00367H VL - 38 IS - 5 SP - 1088 EP - 1096 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58332 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Riedel, Jens T1 - Acoustic Ion Manipulation: Electric-field-free Approach to Gate, Focus, and Separate Ions at Atmospheric Pressure N2 - Approaches to control the motion and direction of ionized particles and mole-cules are an essential aspect of ion-based spectrometries, such as mass spec-trometry (MS) and ion mobility spectrometry (IMS). A wide variety of ion optics exist to reflect, focus, separate, gate, and filter ions based on physical proper-ties. Notably all rely on electric and magnetic fields to alter the trajectory of ionized atoms and molecules. While these optics are quite efficient at low pressures due to the large mean free path, diffusion and electrostatic repulsion between ions dominate at higher pressures. Conventional ion optics, that use electric or magnetic fields, can guide ions at atmospheric pressure (AP), but require high field strengths to overcome the dominating aerodynamic effects. Here, we describe a remarkable phenomenon whereby low-power acoustic fields are used to move, shape, gate, and separate beams of gaseous ions at atmospheric pressure. We refer to this approach as Acoustic Ion Manipulation (AIM). Gaseous ions at AP are directed towards and separated by the presence of the acoustic field. To better understand the phenomenon, an ion-detector array provided a measure of bulk ion movement, while mass spectrometry (MS) offered chemical-specific information. As one example of an AIM setup, a standing acoustic wave was formed with two ultrasonic speakers and placed between an ionization source and ion detector. Ion beams preferentially travel through regions of stable pressure gradients (i.e. nodes) and deflect from un-stable regions (i.e. antinodes). Shadowgraphy revealed that the ions are sepa-rated from a neutral gas stream. Specific examples of ion focusing, gating, and separation (based on ion size) will be shown. In addition, experimental findings will be used to postulate a theory to develop a better understand of the behav-ior of gas-phase ions in acoustic fields. This discovery could have profound im-pacts in IMS/MS instrumentation as well as materials processing and charac-terization. T2 - 56. Jahrestagung der DGMS CY - Göttingen, Germany DA - 04.03.2025 KW - Acoustic Ion Manipulation KW - Mass spectrometry KW - Ultrasound PY - 2025 AN - OPUS4-64208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Danischewski, Julia L. A1 - You, Yi A1 - Bauer, Lauren A1 - Riedel, Jens A1 - Shelley, Jacob T. T1 - Use of Resonant Acoustic Fields as Atmospheric-Pressure Ion Gates N2 - Ion optics are crucial for spectrometric methods such as mass spectrometry (MS) and ion mobility spectrometry (IMS). Among the wide selection of ion optics, temporal ion gates are of particular importance for time-of-flight MS (TOF-MS) and drift-tube IMS. Commonly implemented as electrostatic ion gates, these optics offer a rapid, efficient means to block ion beams and form discrete ion packets for subsequent analysis. Unfortunately, these devices rely on pulsed high voltage sources and are not fully transparent, even in their open state, which can lead to ion losses and contamination. Here, a novel atmospheric-pressure ion gate based on a resonant acoustic field structure is described. This effect was accomplished through the formation of a resonant, standing acoustic wave of alternating nodes and antinodes. Alignment of an atmospheric-pressure gaseous ion beam with an antinode, i.e. a region of transient pressure, of the acoustic structure acted as a gate and blocked ions from impinging on ion-selective detectors, such as a mass spectrometer and a Faraday plate. The velocity of the ion stream and acoustic power were found to be critical parameters for gating efficiency. In the presence of an acoustic field (i.e., a closed gate), ion signals decreased by as much as 99.8% with a response time faster than the readout of the ion-measurement devices used here (ca. 75 ms). This work demonstrates the basis for a low-cost, acoustic ion gate, which is optically transparent and easily constructed with low-power, off-the-shelf components, that could potentially be used with MS and IMS instrumentation. KW - Acoustic Ion Manipulation PY - 2025 DO - https://doi.org/10.1021/acs.analchem.4c05493 SN - 1520-6882 VL - 97 IS - 5 SP - 2890 EP - 2898 PB - American Chemical Society AN - OPUS4-62648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Riedel, Jens T1 - Airborne Laser-Induced Plasma as an Ambient Desorption/Ionization Source for Mass Spectrometry and its Characterization N2 - Laser-induced plasma (LIP) has drawn significant amount of attentions in the past decades, particular in elemental analyses for solid or liquid samples. Through proper focusing of the highly energetic laser beam, the plasma can also be ignited in the ambient air, where airborne analytes can be ionized. Such an effect enabled the use of airborne LIP as an ambient ionization source for mass spectrometric analyses. In contrast to other ambient desorption/ionization sources, airborne LIP does not require a specific discharge medium or expensive gas stream. Meanwhile, the airborne LIP produces reagent ion species for both proton-transfer and charge-transfer reactions in addition to the vacuum ultraviolent photons that are capable of promoting single photon ionization, which can be utilized to ionize polar and non-polar analytes. In order to gauge the analytical performance of airborne LIP, it is critical to understand the undergoing chemistry and physics during and after the plasma formation. Due to the ambient nature of airborne LIP, the variations of air composition and flow strongly affect the plasma behaviors. Preliminary result suggested the addition of a laminar flow of nitrogen gas favored the formation of protonated species (MH+) against the molecular ones (M+). Although the gas addition approach cannot fully tune the ionization process towards the specific production of pseudo-molecular species versus molecular ones, the alternation of molecular ion formation can be used for analyte recognitions through post processing of the ion patterns. The pulsed character of the used lasers makes the reagent ion equilibrium both transient- and highly fluid-dynamically controlled. The acoustic shock-waves induced by the airborne LIP get affected by an applied gas streams towards the plasma center, influencing the molecular-ion and ion-ion interactions in the near proximity of the plasma. To understand the airborne LIP formation, the temporally and spatially resolved optical emission spectra were recorded. The results will be correlated to time-resolved mass-spectrometric investigations of the ion profile during different stages of the plasma formation. As one example, the formation of pyrylium ion originating from aromatic compounds will be highlighted. T2 - SciX 2018 CY - Atlanta, GA, USA DA - 21.10.2018 KW - Laser-Induced Plasma KW - Ambient Desorption/Ionization KW - Mass Spectrometry KW - Characterization PY - 2018 AN - OPUS4-46376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bierstedt, Andreas A1 - You, Yi A1 - van Wasen, Sebastian A1 - Bosc-Bierne, Gaby A1 - Weller, Michael G. A1 - Riedel, Jens T1 - Laser-Induced Microplasma as an Ambient Ionization Approach for the Mass-Spectrometric Analysis of Liquid Samples N2 - An airborne high repetition rate laser-induced plasma was applied as a versatile ambient ionization source for mass-spectrometric determinations of polar and nonpolar analytes in solution. The laser plasma was sustained between a home-built pneumatic nebulizer and the inlet capillary of an Orbitrap mass spectrometer. To maintain stable conditions in the droplet-rich spray environment, the plasma was directly fed by the fundamental output (λ = 1064 nm) of a current state-of-the-art diode-pumped solid-state laser. Ionization by the laser-driven plasma resulted in signals of intact analyte ions of several chemical categories. The analyte ions were found to be fully desolvated since no further increase in ion signal was observed upon heating of the inlet capillary. Due to the electroneutrality of the plasma, both positive and negative analyte ions could be formed simultaneously without altering the operational parameters of the ion source. While, typically, polar analytes with pronounced gas phase basicities worked best, nonpolar and amphoteric compounds were also detected. The latter were detected with lower ion signals and were prone to a certain degree of fragmentation induced during the ionization process. All the described attests the laser-induced microplasma by a good performance in terms of stability, robustness, sensitivity, and general applicability as a self-contained ion source for the liquid sample introduction. KW - Laser KW - Laser-induced plasma KW - Ambient ionization KW - Mass Spectrometry PY - 2019 DO - https://doi.org/10.1021/acs.analchem.9b00329 SN - 0003-2700 VL - 91 IS - 9 SP - 5922 EP - 5928 PB - American Chemical Society CY - Washington, DC, USA AN - OPUS4-47939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -