Direct multielement determination of trace elements in boron carbide powders by slurry sampling ETV-ICP-OES

Abstract

The use of slurry sampling electrothermal evaporation inductively coupled plasma optical emission spectrometry (SlS-ETV-ICP-OES) for the direct determination of trace elements in boron carbide powders with different particle size distributions was investigated. It was found that the addition of 6 mL min À1 of Freon R12 (Cl 2 F 2 C) to the 500 mL min À1 Ar carrier gas flow as a thermochemical reagent resulted in an increase of the net line intensity for Ti by a factor of 25 in SlS-ETV-ICP-OES, when analyzing 20 mL of a slurry containing 1% of the boron carbide powder BC-1. After heating the dry residue of 20 mL of a slurry of 1% of boron carbide for 12 s to 2600 C on a L'vov platform the residues on the platforms were analyzed by total reflection X-ray fluorescence spectrometry (TXRF). The evaporation efficiency for Ti was found to have increased from 12 to 97% by the addition of 6 mL min À1 of R12 as compared to evaporation in Ar only. When heating dry residues of boron carbide slurries on L'vov platforms to temperatures ranging from 2000 to 2600 C without adding R12 to the Ar, it could be observed visually that only a small fraction of the boron carbide matrix is evaporated. However, when heating at 2600 C under the addition of R12 almost no residues were found on the platform after the evaporation step. For the analysis of boron carbide powders with SlS-ETV-ICP-OES the limits of detection were found to be between 0.002 and 2 mg g À1 for the elements Al, Ca, Co, Cr, Cu, Fe, Mg, Mn, Na, Ni and Ti. For Fe a wide variety of samples could be analyzed by SlS-ETV-ICP-OES with one calibration under the use of R12. This was shown for different samples, namely three boron carbide powders, three boron nitride powders, an aluminium oxide powder (NIST 699), silicon carbide powder (BAM S-003), powdered apple leaves (NIST 1515), a reference sample for trace elements in natural water (NIST 1643d) and an aqueous standard solution. When plotting the net line intensities versus the accepted concentrations a coefficient of determination of 0.990 is obtained. By SlS-ETV-ICP-OES under the addition of R12 the values obtained were found to be between 78 to 128% of the mean of the results of slurry sampling-TXRF and of ICP-OES subsequent to wet chemical digestion. 11 trace elements with concentrations ranging from 0.7 to 370 mg g À1 for Co and Fe, respectively, could be determined in two boron carbide powders with particle size distributions of d 90 ¼ 3.5 mm and d 90 ¼ 9.2 mm, respectively.

Synthesis, characterization and investigation of thermal, mechanical and antibacterial properties of boric acid-incorporated polyurethane foams

“…The ICP-OES analyses of these nine samples were found to be 5% BA. A low variance among the results highlighted that BA is homogenously dispersed in the PU foam [29]. BA release studies of four different samples obtained by immersing in distilled water were confirmed by ICP-OES measurements.…”

Oxidative pyrolysis combined with the microwave-assisted extraction method for the multi-elemental analysis of boron carbide powders by inductively coupled plasma optical emission spectrometry (ICP-OES)

“…To the best of our knowledge, this is the rst time that the oxidative pyrolysis procedure has been applied in combination with the MAE method for the multi-elemental analysis of boron carbide samples. Amberger and Broekaert 10,11 and Wang 12,13 have reported the analysis by slurry based sampling methods, wherein the particle size of the sample, the addition of reagents (such as Triton X-100Ò, citric acid, polyacrylamide or polyethylene imine (PEI)), the concentration of the slurry, and its pH assume importance for maintaining the stability of the slurry and analysis. The proposed OP-MAE method is simpler in comparison and does not require the addition of organic reagents resulting in reduced blank contributions.…”

“…Furthermore, boron is a strong neutron absorber with high neutron absorption cross-sections, especially 10 B for thermal neutrons. The absorption cross-sections of 10 B and 11 B for thermal neutrons are 3837 b and 5 mb, respectively, while those for the fast neutrons ($100 keV) are very much lower, 2.7 b for 10 B and 9.7 Â 10 À5 b for 11 B respectively. 6 The ability of boron carbide to absorb neutrons without forming long-lived radionuclides makes it attractive as an absorbent for neutron radiation arising in nuclear power plants.…”

“…9 Amberger and Broekaert have reported various slurry based sampling methods for the determination of trace elements in boron carbide powders by total reection X-ray uorescence spectrometry and ETV-ICP-OES techniques. 10,11 Wang et al 12,13 described a method for the determination of various metallic impurities in boron carbide by slurry introduction with an axially viewed ICP-OES. The stability of the slurry as well as its homogeneity, particle size and sedimentation are some of the limitations of slurry sampling introduction methods.…”

AMS measurements of trace levels of boron in graphite

“…The best detection limit reached to date is in the range of tens of ng g À1 . 7,8 This paper presents the measurement of low boron concentrations in nuclear graphite by Accelerator Mass Spectrometry (AMS) that pushes the detection limit to much lower values than those obtained by previously reported methods.…”