Comparison of Fused Glass Beads and Pressed Powder Pellets for the Quantitative Measurement of Al, Fe, Si and Ti in Bauxite by Laser‐Induced Breakdown Spectroscopy

Abstract

Due to matrix interference and sample particle size effects, some of the most important and difficult issues in laser‐induced breakdown spectroscopy (LIBS) analysis are the calibration and quantitative measurement of a complex matrix. This study proposes the use of borate fusion as an alternative sample preparation procedure for the quantitative measurement of Al, Fe, Si and Ti in bauxite by LIBS. Analytical calibration curves were made using bauxite certified reference materials (CRM), and the precision and accuracy of the methods were evaluated by analysing an additional bauxite CRM, using two different approaches: pressed powder pellets and fused glass beads. The borate fusion method was the most suitable sample preparation technique, since particle size effects and matrix interference could be minimised, obtaining better linearity on the analytical calibration curves (r2), and more accurate and more precise results for bauxite analysis.

Development of two novel natural calcite reference materials for enhanced in situ elemental and Sr isotopic analysis

“…Existing powdered carbonate pellet reference materials (e.g., MACS-1, MACS-3, MACS-3NP, JCP-1, and JCt-1) are deemed unsuitable for long-term preservation and use due to their poor physical characteristics, leading to the physical matrix difference compared to natural calcite. 47,48 Conversely, natural calcite crystal reference materials offer a better match in terms of matrixes with real natural samples and exhibit enhanced stability. In in situ Sr isotope analysis, MNP, TLM, and LSJ07 are recently developed reference materials, 37 with 87 Sr/ 86 Sr ratios of 0.70617 ± 0.00005 (2SD), 0.70969 ± 0.00023 (2SD), and 0.71006 ± 0.00015 (2SD) respectively (Table 3), while MPN calcite with Sr content up to 10 000 mg g −1 may not be well-matched with low-Sr mass-fraction samples.…”

Feasibility of laser-induced breakdown spectroscopy for determination of neodymium in magnet alloys

“…Both approaches depend on proper matrix-matching, which was achieved by sample fusion. 18 SRC stands out as the best calibration strategy because only one calibration standard is needed and more accurate results are achieved. 28,30…”

“…When there is a lack of proper calibration standards, synthetic standards may be prepared by spiking increasing amounts of the analytes onto a diluent such as cellulose powder 14 or filter paper 15 in the analysis of plant materials and alginin in the analysis of human nails. 11 In order to compensate for instrumental drifts and instabilities, and sometimes also matrix effects on the plasma, the internal standard (IS) calibration method has been useful, 16 as demonstrated for geological 17,18 and biological 19 samples. The standard addition method (SAM) is not practical for solid sample analysis because of the difficulties in adding proper analyte amounts to the sample and errors may be caused by the heterogeneous distribution of the spiked analytes.…”

Desulphurisation of dibenzothiophene and 4,6–dimethyl dibenzothiophene via enhanced hydrogenation reaction route using RePd–TiO2/SiO2 aerogel catalysts: kinetic parameters estimation and modelling

“…Deep HDS requires supports with high surface areas, enhanced pore sizes, higher fraction of mesopores and small macropores, larger pore volumes allowing increased exposure of active sites and better dispersion of active components and their availability to large sulphur molecules. Due to these reasons, the conventionally used γ-alumina (γ-Al2O3) support is a far less efficient option compared to other supports like highly porous silicas, which are increasingly attractive [5][6][7][8][9][10]. Their main advantages for use as catalyst supports are: high surface areas of about 600-1300 m 2 /g and huge pore volumes; uniform topology providing high dispersion of metal nanoparticles and easy access of the reactants to the active sites; excellent mechanical properties and hydrothermal stability for demanding reaction conditions.…”