TY - CONF A1 - Warschat, Carsten T1 - Field-induced droplet ionization assisted by ultra sound N2 - Charge separation in liquid droplets within a strong electric field leads to opposite directed progeny droplet jets. That phenomenon is called field induced droplet ionization (FIDI). The jets contain charged molecules, which enables a mass spectrometric analysis. Acoustic levitation of droplets has matured to a powerful tool for containerless sample handling in micro fluidic systems in order to suppress agglomeration and classic contamination pathways. Herein we present the combination of both: FIDI assisted By Ultra-Sound (FIDIBUS). Compared to FIDI, it felicitates a steady observation of a single droplet during its jet formation. Furthermore, it allows for using different shaped electrodes and a multiple droplet interrogation. T2 - 49. Jahrestagung der Deutschen Gesellschaft für Massenspektrometrie CY - Hamburg, Germany DA - 28.02.2016 KW - Massenspektrometrie KW - Mass Spectrometry KW - Akustische Levitation KW - Acoustic Levitation KW - Feld-induzierte Tropfenionisation KW - Field-Induced Droplet Ionization PY - 2016 AN - OPUS4-35462 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Riedel, Jens A1 - Warschat, Carsten T1 - Studying the field induced breakup of acoustically levitated drops N2 - Coulomb fission of charged droplets (The terms drop and droplet are often used synonymous. Throughout this manuscript, to avoid confusion, the terms drop and droplet will be used for liquid spheres with radii in the millimeter range and the micrometer range, respectively. In our experiments, the first correspond to the parent drop while the latter describes the ejected progeny droplets.) is a wellstudied natural phenomenon. Controlled droplet fission is already successfully employed in several technological applications. Still, since the occurring surface rupture relies on the exact understanding and description of the liquid gas boundary, some details are still under debate. Most empirical systematic studies observe falling micrometer droplets passing through the electric field inside a plate capacitor. This approach, although easily applicable and reliable, limits the experimental degrees of freedom regarding the observable time and the maximum size of the drops and can only be performed in consecutive individual observations of different subsequent drops. Here we present a novel setup to study the field induced breakup of acoustically levitated drops. The design does not bear any restrictions towards the temporal window of observation, and allows handling of drops of a tunable radius ranging from 10 µm to several millimeters and a real-time monitoring of one single drop. Our comprehensive study includes a time resolved visual inspection, laser shadowgraphy, laser induced fluorescence imaging, and ambient mass spectrometric interrogation of the nascent Taylor cone. The results shown for a millimeter sized drop, previously inaccessible for Coulomb fission experiments, are mostly comparable with previous results for smaller drops. The major difference is the time scale and the threshold potential of the drop rupture. Both values, however, resemble theoretically extrapolations to the larger radius. The technique allows for a systematic study of breakup behavior of drops of different charge, material, and size. KW - Droplet fission KW - Levitated droplets KW - Taylor limit KW - Spray PY - 2017 DO - https://doi.org/10.1063/1.5004046 SN - 0034-6748 SN - 1089-7623 VL - 88 IS - 10 SP - 105108-1 EP - 105108-6 PB - AIP publishing AN - OPUS4-42940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Warschat, Carsten T1 - Charakterisierung einer Sonic Spray Ionisationsquelle mittels Laserinduzierter Fluoreszenz T2 - DGMS 2014 CY - Frankfurt am Main, Germany DA - 2014-03-02 PY - 2014 AN - OPUS4-30346 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Warschat, Carsten T1 - Spray-Ionisation mit einer handelsüblichen Airbrushpistole T2 - DGMS 2013 CY - Berlin, Germany DA - 2013-03-10 PY - 2013 AN - OPUS4-30345 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stindt, Arne A1 - Warschat, Carsten A1 - Bierstedt, Andreas A1 - Panne, Ulrich A1 - Riedel, Jens T1 - Characterisation of an inexpensive sonic spray ionisation source using laser induced fluorescence imaging and mass spectrometry N2 - A commercially available airbrush gun as a new source for spray ionization is presented. It is best operated employing moderate stagnation pressures, resulting in a sonic gas flow. A mass spectrometric investigation on the amino acid lysine and several peptides reveals that this inexpensive approach results in reproducible mass spectra. The ion patterns strongly resemble the results from other studies obtained with custom made sonic spray vaporizers. The patterns as well resemble the mass spectra recorded with electrospray devices. For a better understanding of the vaporization process, the mass spectrometry experiments are accompanied by laser induced fluorescence experiments. Inverse Abel transform of the obtained fluorescence maps allows the determination of the full 3D distribution of the spray cone. Furthermore, via exploitation of the solvatochromism of the used dye the solvation state distribution can be visualized. In addition, expansion parameters like droplet size and velocity are obtained by laser stroboscopy. The experiments demonstrate that the analyte is hardly desolvated throughout the expansion. This indicates a subsequent vaporization of the residual solvent in the intermediate pressure region of the mass spectrometer. KW - Sonic spray ionization KW - Mass spectrometry KW - Solvatochromism KW - Inverse Abel Transform KW - Sonic spray KW - Airbrush KW - Laser induced fluorescence PY - 2014 DO - https://doi.org/10.1255/ejms.1242 SN - 1469-0667 SN - 1356-1049 SN - 1365-0718 VL - 20 IS - 1 SP - 21 EP - 29 PB - IM Publications CY - Chichester AN - OPUS4-30403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Warschat, Carsten T1 - Improving the performance of an ultrasonic levitator coupled to API-TOF MS T2 - International Mass Spectrometry Conference 2014 CY - Geneva, Schweiz DA - 2014-08-24 PY - 2014 AN - OPUS4-31848 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Warschat, Carsten A1 - Stindt, Arne A1 - Panne, Ulrich A1 - Riedel, Jens T1 - Mass spectrometry of levitated droplets by thermally unconfined infrared-laser desorption N2 - An ionization scheme for fast online mass spectrometric interrogation of levitated droplets is presented. That renewed method comprises the output of an a Er:YAG laser at λ = 2.94 µm which is in resonance with the OH stretch vibration band of solvents like water and alcohols. A temporal pulse width larger than the time needed for pressure redistribution and also above the temperature redistribution time constant was found to lead to soft evaporation/ionization. Despite these mild desorption conditions, no additional postionization is found to be needed. Accordingly, the ionization is found to be very soft resulting in entirely intact analyte ions and concentration dependent cluster ions. Resulting mass spectra of small amino acids and large antibiotics are presented showing the versatility of the introduced technique. Above a critical mass of m ≈ 1 kDa, the formed ions carry multiple charges as it is typical for thermospray or electrospray ionization. The detection technique enables fast contactless analysis of the chemical composition of levitated microreactors and, thus, paves the way for future contactless reaction monitoring. KW - Laser desorption ionization KW - Levitated droplets KW - Ambient mass spectrometry PY - 2015 DO - https://doi.org/10.1021/acs.analchem.5b01495 SN - 0003-2700 SN - 1520-6882 VL - 87 IS - 16 SP - 8323 EP - 8327 PB - American Chemical Society CY - Washington, DC AN - OPUS4-35134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Warschat, Carsten T1 - Excitation of whispering gallery modes in acoustically levitated droplets T2 - 114th Gneral assembly of the German Bunsen Society for Physical Chemistry CY - Bochum, Germany DA - 2015-05-14 PY - 2015 AN - OPUS4-33544 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Warschat, Carsten T1 - Near-IR laser induced desorption sampling of acoustically levitated liquids T2 - DGMS 2015 CY - Wuppertal, Deutschland DA - 2015-03-01 PY - 2015 AN - OPUS4-33640 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Warschat, Carsten T1 - Near-IR laser induced desorption sampling of acoustically levitated liquids T2 - Berliner Chemie Symposium 2015 CY - Berlin, Germany DA - 2015-04-09 PY - 2015 AN - OPUS4-33637 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Warschat, Carsten T1 - Whispering Gallery Modes in Acoustically Levitated Droplets T2 - Anakon 2015 CY - Graz, Österreich DA - 2015-03-23 PY - 2015 AN - OPUS4-33636 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -