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 - You, Yi T1 - Acoustic Ion Manipulation (AIM) N2 - The precise control of gaseous ions is a cornerstone in ion-based spectrometry and other disciplines such as materials processing. Traditional high-pressure ion optics rely on electrostatic and magnetic fields that often demand the use of intense electric fields, radio frequency activation, complex geometrical arrangements, or partially transmissive grids. Consequently, the efficiencies of such devices tend to be low or they require large footprints, as ion motions under ambient conditions are governed aerodynamically by collisions and fluid dynamics. However, from a different perspective and holistic reasoning, the limitations posed by collisions, aerodynamics, and other factors that hinder ion control in the open-air suggested an innovative direction for ion manipulation. Our study introduces a novel method that employs low-power standing acoustic waves to effectively manipulate ion beams. We observe that ions distinctively prefer traveling through areas of static pressure within the acoustic field, identified as "nodes." In contrast, neutral gases are unaffected by the acoustic field structure and continue to move along a straight trajectory. We have named this method Acoustic Ion Manipulation (AIM). Initial studies demonstrated selective and efficient manipulations of ion with AIM, including gating, redirection, regional dispersion, and focusing. This technique broadens the scope of ion manipulation strategies at high pressures while enriching our fundamental understanding of ion-acoustic kinetics. The potential applications of this method are vast, promising significant advancements in the fields of analytical chemistry, environmental science, and beyond. T2 - ANAKON 2025 CY - Leipzig, Germany DA - 10.03.2025 KW - Acoustic ion manipulation KW - Mass spectrometry PY - 2025 AN - OPUS4-64110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Saleh, Maysoon I. A1 - Rühle, Bastian A1 - Wang, Shu A1 - Radnik, Jörg A1 - You, Yi A1 - Resch-Genger, Ute T1 - Assessing the protective effects of different surface coatings on NaYF4:YB3+, Er3+, upconverting nanoparticles in buffer and DMEM N2 - We studied the dissolution behavior of β NaYF4:Yb(20%), Er(2%) UCNP of two different sizes in biologically relevant media i.e., water (neutral pH), phosphate buffered saline (PBS), and Dulbecco’s modified Eagle medium (DMEM) at different temperatures and particle concentrations. Special emphasis was dedicated to assess the influence of different surface functionalizations, particularly the potential of mesoporous and microporous silica shells of different thicknesses for UCNP stabilization and protection. Dissolution was quantified electrochemically using a fluoride ion selective electrode (ISE) and by inductively coupled plasma optical emission spectrometry (ICP OES). In addition, dissolution was monitored fluorometrically. These experiments revealed that a thick microporous silica shell drastically decreased dissolution. Our results also underline the critical influence of the chemical composition of the aqueous environment on UCNP dissolution. In DMEM, we observed the formation of a layer of adsorbed molecules on the UCNP surface that protected the UCNP from dissolution and enhanced their fluorescence. Examination of this layer by X ray photoelectron spectroscopy (XPS) and mass spectrometry (MS) suggested that mainly phenylalanine, lysine, and glucose are adsorbed from DMEM. These findings should be considered in the future for cellular toxicity studies with UCNP and other nanoparticles and the design of new biocompatible surface coatings. KW - Fluorescence KW - Lifetime KW - Method KW - Quantification KW - Stability KW - Coating KW - Surface chemistry KW - Lanthanide KW - Fluoride KW - Electrochemistry KW - ICP-OES KW - Upconversion KW - Nano KW - Particle KW - Aging KW - Quality assurance KW - Mass spectrometry KW - XPS PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515984 DO - https://doi.org/10.1038/s41598-020-76116-z SN - 2045-2322 VL - 10 IS - 1 SP - 19318-1 EP - 19318-11 PB - Springer Nature CY - London AN - OPUS4-51598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Yi T1 - Advanced Repetition-Rate Modulation and Computational Strategies for Background-Free LIBS Using Non-Gated Spectrometers N2 - Laser-induced breakdown spectroscopy (LIBS) is recognized for its rapid, direct elemental analysis capabilities. However, its general adoption is constrained by the reliance on expensive, high-power consumption, gated cameras such as intensified charge-coupled devices (CCDs). These devices, while sensitive, are expensive and possess low frame rates, limiting their efficacy in dynamic or challenging environments. Our study proposes an innovative approach that leverages non-gated spectrometers in conjunction with the framework of correlation spectroscopy to isolate analyte signals responsive to a specific repetition-rate modulation pattern, thereby yielding spectra with zero background. We utilized a diode-pumped solid-state laser, with repetition rates ranging from 10 Hz to 30 kHz, to induce plasma in aqueous solutions containing various alkaline and earth-alkaline metals. With a non-gated single-grating linear CCD spectrometer, we found that the continuum signal plateaued at approximately 7 kHz. In contrast, atomic emissions from the dissolved analytes showed continued increases. Notably, atomic emissions from the solvent (water) were observable only above 8.5 kHz, at a significant high rate of increase. Through computational synthesis of a modulation pattern, we determined an optimized scheme that effectively discriminates continuum and analyte signals; this pattern was optimized with a genetic algorithm. The spectral matrix correlating signal intensity with laser repetition rate and wavelength was used as the input of the model. Meanwhile, the fitness function that extracts the background-free spectra was built in-house and inspired by the Gardner transform, which exploits the power of Fourier transform, allowing for flagging and splitting analyte signal from other undesired features. This approach bypasses the limitations associated with gated cameras, while providing a cost-effective alternative for robust LIBS applications. This advancement is particularly relevant in field, portable and remote applications, aligning with the ongoing demand for accessible, high-performance analytical tools in diverse scientific fields. T2 - SCIX 2024 Conference CY - Raleigh, NC, USA DA - 20.10.2024 KW - LIBS KW - Data Processing KW - High Repetition Rate KW - Repetition Rate Modulation KW - Data-Oriented Experimental Design PY - 2024 AN - OPUS4-62137 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 - JOUR A1 - Song, L. A1 - You, Yi A1 - Perdomo, R. A1 - Evans-Nguyen, T. T1 - Inexpensive Ultrasonic Nebulization Coupled with Direct Current Corona Discharge Ionization Mass Spectrometry for Liquid Samples and Its Fundamental Investigations N2 - The concept of direct mass-spectrometric analysis, especially exploited by ambient desorption/ionization (ADI) methods, provides numerous means for convenient sample analysis. While many simple and versatile ionization sources have been developed, challenges lay in achieving efficient sample introduction. In previous work, a sample introduction method employing direct current corona discharge (CD) coupled to a surface acoustic wave nebulization (SAWN) device enhanced sampling performance for both polar and nonpolar analytes by up to 4 orders of magnitude. In fact, the SAWN-CD method generated a multiply charged peptide ion signal comparable to that of conventional ESI. Unfortunately, the high cost of the SAWN devices themselves limits their accessibility. Herein, we report on an analogous implementation of CD with an inexpensive ultrasonic nebulizer (USN) on the basis of a commercial room humidifier demonstrating equivalent exemplary performance. We subsequently compare the two methods of SAWN-CD and USN-CD in a screening application of milk for the detection of two antibiotic drugs, ciprofloxacin and ampicillin. Finally, we further investigate the relative softness of these CD-coupled acoustic nebulization methods in comparison to that of ESI using a survival yield study of the thermometer ion nitrobenzylpyridinium. KW - Rapid Analysis KW - Ultrasonic Nebulization KW - Corona Discharge PY - 2020 DO - https://doi.org/10.1021/acs.analchem.0c00524 VL - 92 IS - 16 SP - 11072 PB - ACS Publication AN - OPUS4-51225 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 -