scholarly journals Improvement and modification of energy-dispersive x-ray fluorescence method for determination of metal elements in cement leachates - chemometric approach

2020 ◽  
pp. 67-67
Author(s):  
Nevenka Mijatovic ◽  
Anja Terzic ◽  
Lato Pezo ◽  
Ljiljana Milicic ◽  
Dragana Zivojinovic
Keyword(s):  
Inductively Coupled Plasma ◽  
Chemical Elements ◽  
Certified Reference Materials ◽  
Optical Emission ◽  
Fluorescence Method ◽  
Energy Dispersive ◽  
Emission Spectrometry ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Optical Emission Spectrometry

A modification of analytical procedure for energy-dispersive X-ray fluorescence (EDXRF) quantification of ten chemical elements (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Zn) in the leachates obtained from cement binders was developed. Twenty-nine testing samples were used in the experiment. All samples were based on Portland cement. Fly ash of different origin, zeolite and bentonite were employed as mineral additives in the cement binders. Distilled water was used as leachate. Validation of the modified EDXRF procedure was conducted in terms of limits of detection and quantification, working range, linearity, selectivity, precision, trueness, and robustness. Traceability of the procedure was established using certified reference materials. Uncertainty of measurement was confirmed via ?in-house? laboratory validation approach. The expanded uncertainties for ten analysed elements were obtained for entire working range of EDXRF method. Robustness of the modified EDXRF procedure was assessed by means of chemometric in-house approach. The results obtained by modified X-ray fluorescence method were additionally correlated to those acquired by inductively coupled plasma optical emission spectrometry to confirm that EDXRF can be used as an effective and reliable alternative method for analysis of cement leachates.

scholarly journals Electrochemical Removal of Rare Earth Element in LiCl-KCl Molten Salt

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Gha-Young Kim ◽  
Junhyuk Jang ◽  
Seungwoo Paek ◽  
Sung-Jai Lee
Keyword(s):  
Rare Earth ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Alloy Formation ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Optical Emission Spectrometry ◽  
Re Elements ◽  
Electrochemical Removal

This study was carried out to examine the removal of rare earth (RE) elements by electrodeposition for the purification and reuse of LiCl-KCl salt after electrorefining and electrowinning. The electrochemical behavior of RE elements (Dy and Gd) in LiCl-KCl-DyCl3-GdCl3 at 500°C was investigated using the cyclic voltammetry (CV) technique using Mo and Mg electrodes. It was observed that the reduction potential of the RE elements shifted at the Mg electrode owing to the alloy formation with Mg (RE-Mg alloy). Subsequently, a series of potentiostatic electrolysis tests were conducted to remove the RE elements in the salt and check the formation of deposits at the Mg and Mo electrodes. The scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM/EDS) technique was used to confirm that the reduced RE metals were deposited on the surface of the Mg electrode. However, no significant deposit on the Mo electrode was observed, and a mud-like deposit was found on the bottom of the electrochemical cell. The salt analysis performed by employing the inductively coupled plasma-optical emission spectrometry (ICP-OES) indicated that the removal efficiency of Dy3+ and Gd3+ through electrodeposition was 83.5∼95.2 and 91.6∼95.2%, respectively.

Validation of an alkali reaction, borate fusion, X-ray fluorescence method for silicon metal

2007 ◽  
Vol 22 (2) ◽  
pp. 146-151 ◽  
Author(s):  
John R. Sieber ◽  
Elizabeth A. Mackey ◽  
Anthony F. Marlow ◽  
Rick Paul ◽  
Ryan Martin
Keyword(s):  
Inductively Coupled Plasma ◽  
Gamma Ray ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Lithium Silicate ◽  
Prompt Gamma ◽  
Linear Calibration ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Optical Emission Spectrometry

The value assignment of candidate Standard Reference Material (SRM®) 57b Silicon Metal provided an opportunity to develop an alkali reaction procedure as a precursor to borate fusion for the preparation of test specimens from the metal powder for X-ray fluorescence spectrometry (XRF). Suggested for this purpose by Blanchette in a 2002 Advances in X-ray Analysis article [45, 415–420 (2002)], the alkali reaction uses LiOH∙H2O to convert Si to Li2SiO3. Lithium silicate is fused with lithium borate flux without damage to platinum ware. Once specimens are fused and cast as beads, calibration standards are prepared to closely match the compositions of the specimens, allowing a linear calibration for each analyte. The XRF method yields results that are directly traceable to the mole through NIST SRM spectrometric solutions. The method was validated in two ways. First, the reaction was used on older SRMs for Si metal: SRM 57 and SRM 57a. Second, XRF results for candidate SRM 57b were compared to results obtained using prompt gamma-ray activation analysis (PGAA) and inductively coupled plasma optical emission spectrometry (ICPOES). Bias tests show the XRF results are accurate for the elements Al, S, Ca, Ti, Cr, Mn, Ni, Cu, and Zr. Levels of S, Ca, Cr, and Cu in candidate SRM 57b are near the limits of quantification of the borate fusion method. Iron results may be subject to a low bias. Phosphorus is not quantitatively retained during the alkali reaction and borate fusion. These elements, plus B, which cannot be determined after borate fusion, are listed in manufacturing specifications for Si metal.

Investigation and Electrodeposition Rate Optimization of Au–Cu Alloy Co-Deposition

2019 ◽  
Vol 16 (12) ◽  
pp. 5197-5204
Author(s):  
Hamid Babaei ◽  
Mohamad Reza Sovizi ◽  
Morteza Khosravi ◽  
Saeed Abedini Khorami
Keyword(s):  
Electrochemical Deposition ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Icp Oes ◽  
Characterization Methods ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Optical Emission Spectrometry ◽  
Rate Optimization

In the present study, influence of effective parameters on electrochemical deposition rate optimization of alloy Co-deposition. Main parameters in this method include current density direct, concentration of Au, Cu ions, solution pH, agitation, and effect of additive that are effectively optimized using “one-factor-at-a-time” method to achieve Au–Cu electrochemical alloy deposition with 18 carat (750 part in a hundred part Au in weight basis, according to the carats of formal national and international standards) and proper electrodeposition rates of 6 mA/cm2, 6 gr/lit, 55 gr/lit, 24 gr/lit, 66 °C, 12.3, 100 rpm and 1 gr/lit, respectively. Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), inductively coupled plasma-optical emission spectrometry (ICP-OES), and X-ray fluorescence (XRF) characterization methods were used in study of electrochemical deposition influence on cross sections of the deposited layers. In this method, results indicates that electrodeposition rate in optimum conditions and approximate karat of 750 K, with direct current (6 mA/cm2) in 4 hours is 0.841 μm/min. In this work, deposition rate has increased significantly compared to commercial methods 1 μm/3–7 min. Percentages of Au in deposited layers were compared through inductively coupled plasma-optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF) characterization methods, but ICP-OES is a more accurate method.

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