TY - GEN A1 - Abad Andrade, Carlos Enrique T1 - Molecular absorption spectrometry: a fast and accurate optical method for boron isotope analysis comparable to mass spectrometry N2 - Boron presents two stable isotopes, 10B and 11B and due to their relatively large mass difference (~ 10%) isotope fractionation leads to considerable isotope amount ratio variations n(10B)/n(11B) in natural occurrence. These have been used as a proof of provenance of mineral and biological samples, to estimate a contamination source and to the determination of geological processes by erosion or subduction. Additionally, boron is employed in the nuclear industry due to the capability of its isotope 10B to thermal-neutron capture and therefore 10B enriched boric acid solutions are used in the cooling system of thermonuclear facilities and in the alloying of steel and carbides for protective shielding. Usually, isotope ratio variations are determined by mass spectroscopic methods. Here an alternative faster and low cost method for isotope ratio determination is proposed: high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Boron isotope amount ratios have been determined by monitoring the absorption spectrum of boron monohydride (BH) in graphite furnace 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. 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, a precision and accuracy of the method of ± 0.5 ‰ for the evaluated spectral region around 437.1 nm is reported here. This accuracy and precision is comparable with those obtained by thermal ionization mass spectrometry (TIMS) and multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) for boron isotope ratio measurements. T2 - 30. Tag der Chemie CY - Berlin, Germany DA - 05.07.2017 KW - Boron isotopes KW - High-Resolution Continuum Source Molecular Absorption Spectrometry KW - HR-CS-MAS KW - Isotopic shift KW - Boron monohydride KW - Isotope ratio KW - Molecular absorption KW - Memory effect KW - Graphite furnace PY - 2017 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/41059 AN - OPUS4-41059 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany