TY - JOUR A1 - Villatoro, J. A1 - Zühlke, M. A1 - Riebe, D. A1 - Beitz, T. A1 - Weber, M. A1 - Riedel, Jens A1 - Löhmannsröben, H.-G. T1 - IR-MALDI ion mobility spectrometry: physical source characterization and application as HPLC detector N2 - Infraredmatrix-assisted laser dispersion and ionization(IR-MALDI) in combination with on mobility (IM) spectrometry enables the direct Analysis of biomolecules in aqueous solution. The release of ions directly from an aqueous solution is based on a phase explosion, induced by the Absorption of an IR laser pulse, which disperses the liquid as vapor, nano- and micro-droplets. The ionization process is characterized initially by a broad spatial distribution of the ions, which is a result of complex fluid dynamics and desolvation kinetics. These processes have a profound effect on the shape and width of the peaks in the IM spectra. In this work, the Transport of ions by the phase explosion-induced shockwave could be studied independently from the transport by the electric field. The shockwave-induced mean velocities of the ions at different time scales were determined through IM spectrometry and shadowgraphy. The results show a deceleration of the Ions from 118m∙s−1 at a distance of 400 μm from the liquid surface to 7.1 m∙s−1 at a distance of 10 mm, which is caused by a pileup effect. Furthermore, the desolvation kinetics were investigated and a first-order desolvation constant of 325 ± 50 s−1 was obtained. In the second part, the IR-MALDI-IM spectrometer is used as an HPLC detector for the twodimensional separation of a pesticide mixture. KW - Ion mobility spectrometry KW - IR-MALDI KW - Shadowgraphy KW - Laser PY - 2016 DO - https://doi.org/10.1007/s12127-016-0208-1 VL - 2016 IS - 4 SP - 197 EP - 207 PB - Springer-Verlag Berlin CY - Heidelberg AN - OPUS4-38467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Villatoro, J. A1 - Zühlke, M. A1 - Riebe, D. A1 - Riedel, Jens A1 - Beitz, T. A1 - Löhmannsröben, H.-G. T1 - IR-MALDI ion mobility spectrometry N2 - The novel combination of infrared matrix-assisted laser dispersion and inization (IR-MALDI) with ion mobility (IM) spectrometry makes it possible to investigate biomolecules in their natural environment, liquid water. As an alternative to an ESI source, the IR-MALDI source was implemented in an in-house-developed ion mobility (IM) spectrometer. The release of ions directly from an aqueous solution is based on a phase explosion, induced by the absorption of an IR laser pulse (λ = 2.94 μm, 6 ns pulse width), which disperses the liquid as nano- and micro-droplets. The prerequisites for the application of IR-MALDI-IM spectrometry as an analytical method are narrow analyte ion signal peaks for a high spectrometer resolution. This can only be achieved by improving the desolvation of ions. One way to full desolvation is to give the cluster ions sufficient time to desolvate. Two methods for achieving this are studied: the implementation of an additional drift tube, as in ESI-IM-spectrometry, and the delayed extraction of the ions. As a result of this optimization procedure, limits of detection between 5 nM and 2.5 μMas well as linear dynamic ranges of 2–3 orders of magnitude were obtained for a number of substances. The ability of this method to analyze simple mixtures is illustrated by the separation of two different surfactant mixtures. KW - Ion mobility KW - Spectrometry KW - IR-MALDI KW - Laser PY - 2016 DO - https://doi.org/10.1007/s00216-016-9739-x SN - 1618-2650 SN - 1618-2642 VL - 408 IS - 23 SP - 6259 EP - 6268 PB - Springer-Verlag CY - Heidelberg AN - OPUS4-37615 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kipphardt, Heinrich A1 - Matschat, Ralf A1 - Vogl, Jochen A1 - Gusarova, Tamara A1 - Czerwensky, Michael A1 - Heinrich, Hans-Joachim A1 - Hioki, A. A1 - Konopelko, L.A. A1 - Methven, B. A1 - Miura, T. A1 - Petersen, O. A1 - Riebe, Gundel A1 - Sturgeon, R. A1 - Turk, G.C. A1 - Yu, L. L. T1 - Purity determination as needed for the realisation of primary standards for elemental determination: status of international comparability N2 - Within the National Metrology Institutes (NMIs) and designated laboratories, an interlaboratory comparison, CCQM-P107, was conducted to verify the degree of international comparability concerning the results of purity analysis. The mass fractions of Ag, Bi, Cd, Cr, Ni, Tl at the lower mg/kg-level in a high purity zinc material were determined, but the real measurand in metrological sense was the sum of the six mass fractions. Homogeneity was investigated by glow discharge mass spectrometry, reference values were obtained using isotope dilution mass spectrometry. Six NMIs participated, contributing eight independent data sets. The agreement amongst the results of the participants, their median and the agreement with the reference values were usually excellent and in almost all cases below the target uncertainty of 30% relative. In this manner, the accuracy of results and the comparability between the participants was demonstrated to be established. KW - Interlaboratory comparison KW - Purity analysis KW - High purity metals KW - CCQM-P107 KW - Zinc PY - 2010 DO - https://doi.org/10.1007/s00769-009-0557-0 SN - 0949-1775 SN - 1432-0517 VL - 15 IS - 1 SP - 29 EP - 37 PB - Springer CY - Berlin AN - OPUS4-20767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Erler, A. A1 - Riebe, D. A1 - Beitz, T. A1 - Löhmannsröben, H.-G. A1 - Leenen, M. A1 - Pätzold, S. A1 - Ostermann, Markus A1 - Wójcik, M. T1 - Mobile Laser-Induced Breakdown Spectroscopy for Future Application in Precision Agriculture—A Case Study N2 - In precision agriculture, the estimation of soil parameters via sensors and the creation of nutrient maps are a prerequisite for farmers to take targeted measures such as spatially resolved fertilization. In this work, 68 soil samples uniformly distributed over a field near Bonn are investigated using laser-induced breakdown spectroscopy (LIBS). These investigations include the determination of the total contents of macro- and micronutrients as well as further soil parameters such as soil pH, soil organic matter (SOM) content, and soil texture. The applied LIBS instruments are a handheld and a platform spectrometer, which potentially allows for the single-point measurement and scanning of whole fields, respectively. Their results are compared with a high-resolution lab spectrometer. The prediction of soil parameters was based on multivariate methods. Different feature selection methods and regression methods like PLS, PCR, SVM, Lasso, and Gaussian processes were tested and compared. While good predictions were obtained for Ca, Mg, P, Mn, Cu, and silt content, excellent predictions were obtained for K, Fe, and clay content. The comparison of the three different spectrometers showed that although the lab spectrometer gives the best results, measurements with both field spectrometers also yield good results. This allows for a method transfer to the in-field measurements KW - LIBS KW - Precision agriculture KW - Soil KW - Multivariate methods KW - Feature selection PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580777 DO - https://doi.org/10.3390/s23167178 VL - 23 IS - 16 SP - 1 EP - 17 PB - MDPI AG CY - Basel, Schweiz AN - OPUS4-58077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -