TY - JOUR A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - Heinrich, Hans-Joachim A1 - Recknagel, Sebastian A1 - Vogl, Jochen A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Determination of boron isotope ratios by high-resolution continuum source molecular absorption spectrometry using graphite furnace vaporizers JF - Spectrochimica Acta Part B: Atomic Spectroscopy N2 - Boron isotope amount ratios n(10B)/n(11B) have been determined by monitoring the absorption spectrum of boron monohydride (BH) in a graphite furnace using high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Bands (0→0) and (1→1) for the electronic transition X1Σ+ → A1Π were evaluated around wavelengths 433.1 nm and 437.1 nm respectively. Clean and free of memory effect molecular spectra of BH were recorded. In order to eliminate the memory effect of boron, a combination of 2% (v/v) hydrogen gas in argon and 1% trifluoromethane in argon, an acid solution of calcium chloride and mannitol as chemical modifiers was used. Partial least square regression (PLS) for analysis of samples and reference materials were applied. For this, a spectral library with different isotopes ratios for PLS regression was built. Results obtained around the 433.1 nm and 437.1 nm spectral regions are metrologically compatible with those reported by mass spectrometric methods. Moreover, for the evaluated region of 437 nm, an accuracy of 0.15‰ is obtained as the average deviation from the isotope reference materials. Expanded uncertainties with a coverage factor of k = 2 range between 0.15 and 0.44‰. This accuracy and precision are compatible with those obtained by mass spectrometry for boron isotope ratio measurements. KW - Boron isotopes KW - Isotope ratios KW - Boron monohydride KW - Molecular absorption KW - High-resolution continuum source absorption spectrometry KW - Graphite furnace KW - Memory effect KW - HR-CS-MAS PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S0584854717302537 DO - https://doi.org/10.1016/j.sab.2017.08.012 SN - 0584-8547 VL - 136 SP - 116 EP - 122 PB - Elsevier CY - Amsterdam, The Netherlands AN - OPUS4-42071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geilert, Sonja A1 - Vogl, Jochen A1 - Rosner, M. A1 - Voerkelius, S. A1 - Eichert, T. T1 - Boron isotope fractionation in bell pepper JF - Mass spectrometry: open access N2 - Various plant compartments of a single bell pepper plant were studied to verify the variability of boron isotope composition in plants and to identify possible intra-plant isotope fractionation. Boron mass fractions varied from 9.8 mg/kg in the fruits to 70.0 mg/kg in the leaves. Boron (B) isotope ratios reported as δ11B ranged from -11.0‰ to +16.0‰ (U ≤ 1.9‰, k=2) and showed a distinct trend to heavier δ11B values the higher the plant compartments were located in the plant. A fractionation of Δ11Bleaf-roots = 27‰ existed in the studied bell pepper plant, which represents about about 1/3 of the overall natural boron isotope variation (ca. 80‰). Two simultaneous operating processes are a possible explanation for the observed systematic intra-plant δ11B variation: 1) B is fixed in cell walls in its tetrahedral form (borate), which preferentially incorporates the light B isotope and the remaining xylem sap gets enriched in the heavy B isotope and 2) certain transporter preferentially transport the trigonal 11B-enriched boric acid molecule and thereby the heavy 11B towards young plant compartments which were situated distal of the roots and typically high in the plant. Consequently, an enrichment of the heavy 11B isotope in the upper young plant parts located at the top of the plant could explain the observed isotope systematic. The identification and understanding of the processes generating systematic intra-plant δ11B variations will potentially enable the use of B isotope for plant metabolism studies. KW - Boron isotopes KW - Bell pepper KW - Boron transport KW - Boron isotope fractionation KW - Intra-plant isotope variability KW - Plants KW - Bell KW - Pepper KW - Isotope fractionation PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-352289 DO - https://doi.org/10.4172/mso.1000101 VL - 1 IS - 1 SP - Article 1000101, 1 EP - 6 AN - OPUS4-35228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosner, Martin A1 - Wiedenbeck, M. A1 - Ludwig, T. T1 - Composition-induced variations in SIMS instrumental mass fractionation during boron isotope ratio measurements of silicate glasses JF - Geostandards and geoanalytical research N2 - An analytical artefact is reported here related to differences in instrumental mass fractionation between NIST SRM glasses and natural geological glasses during SIMS boron isotope determinations. The data presented demonstrated an average 3.4‰ difference between the NIST glasses and natural basaltic to rhyolitic glasses mainly in terms of their sputtering-induced fractionation of boron isotopes. As no matrix effect was found among basaltic to rhyolitic glasses, instrumental mass fractionation of most natural glass samples can be corrected by using appropriate glass reference materials. In order to confirm the existence of the compositionally induced variations in boron SIMS instrumental mass bias, the observed offset in SIMS instrumental mass bias has been independently reproduced in two laboratories and the phenomenon has been found to be stable over a period of more than one year. This study highlights the need for a close match between the chemical composition of the reference material and the samples being investigated. Nous montrons l'existence d'un artefact analytique reliéà différents fractionnements de masse instrumentaux, observés sur les verres NIST SRM et des verres naturels durant des mesures des isotopes de bore par SIMS. Les données montrent une différence d'environ 3.4‰ entre les verres NIST et les verres naturels, de composition variant de basaltique à rhyolitique, en termes de fractionnement des isotopes du bore principalement induit par le phénomène de dispersion. Comme aucun effet de matrice n'a été observé entre les verres basaltiques et les verres rhyolitiques, le fractionnement de masse instrumental de la plupart des verres naturels peut être corrigé en utilisant des verres de références appropriés. Dans le but de confirmer l'existence de biais de masse liéà la composition lors de mesure du bore par SIMS, nous avons reproduit indépendamment le décalage observé entre deux laboratoires et ce phénomène s'est révélé stable sur une période de plus d'un an. Cette étude met en lumière le besoin d'ajuster précisément les compositions chimiques des matériaux de référence et des échantillons à analyser. KW - Boron isotopes KW - SIMS KW - Matrix effect KW - Glass reference materials KW - Instrumental mass fractionation KW - Isotope du bore KW - Effet de matrice KW - Matériaux vitreux de référence KW - Fractionnement de masse instrumental PY - 2008 DO - https://doi.org/10.1111/j.1751-908X.2008.00875.x SN - 1639-4488 SN - 1751-908X VL - 32 IS - 1 SP - 27 EP - 38 PB - Blackwell CY - Oxford AN - OPUS4-17783 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -