Development of a method for multielemental determination in water by EDXRF with radioisotopic source of 238Pu.

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Camilo Fuentes Serrano ◽  
Juan Reinaldo Estevez Alvares ◽  
Alfredo Montero Alvarez ◽  
Ivan Pupo Gonzales ◽  
Zahily Herrero Fernandez ◽  
...  
Keyword(s):  
Thin Layer ◽  
Expanded Uncertainty ◽  
Considerable Decrease ◽  
X Ray ◽  
Precipitation Efficiency ◽  
Method Of Determination ◽  
Sensitivity Curves ◽  
Order Of Magnitude ◽  
Metrological Parameters

A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of 238Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidinedithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of 238Pu instead of 109Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L).

scholarly journals Fluorescent Orthopalladated Complexes of 4-Aryliden-5(4H)-Oxazolones from the Kaede Protein: Synthesis and Characterization

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1238
Author(s):  
Eduardo Laga ◽  
David Dalmau ◽  
Sofía Arregui ◽  
Olga Crespo ◽  
Ana I. Jimenez ◽  
...  
Keyword(s):  
Intramolecular Interactions ◽  
Ortho Position ◽  
Fluorescent Properties ◽  
Ancillary Ligands ◽  
X Ray ◽  
Mononuclear Complexes ◽  
Fluorescence Measurements ◽  
Anionic Ligands ◽  
Order Of Magnitude

The goal of the work reported here was to amplify the fluorescent properties of 4-aryliden-5(4H)-oxazolones by suppression of the hula-twist non-radiative deactivation pathway. This aim was achieved by simultaneous bonding of a Pd center to the N atom of the heterocycle and the ortho carbon of the arylidene ring. Two different 4-((Z)-arylidene)-2-((E)-styryl)-5(4H)-oxazolones, the structures of which are closely related to the chromophore of the Kaede protein and substituted at the 2- and 4-positions of the arylidene ring (1a OMe; 1b F), were used as starting materials. Oxazolones 1a and 1b were reacted with Pd(OAc)2 to give the corresponding dinuclear orthometalated palladium derivates 2a and 2b by regioselective C–H activation of the ortho-position of the arylidene ring. Reaction of 2a (2b) with LiCl promoted the metathesis of the bridging carboxylate by chloride ligands to afford dinuclear 3a (3b). Mononuclear complexes containing the orthopalladated oxazolone and a variety of ancillary ligands (acetylacetonate (4a, 4b), hydroxyquinolinate (5a), aminoquinoline (6a), bipyridine (7a), phenanthroline (8a)) were prepared from 3a or 3b through metathesis of anionic ligands or substitution of neutral weakly bonded ligands. All species were fully characterized and the X-ray determination of the molecular structure of 7a was carried out. This structure has strongly distorted ligands due to intramolecular interactions. Fluorescence measurements showed an increase in the quantum yield (QY) by up to one order of magnitude on comparing the free oxazolone (QY < 1%) with the palladated oxazolone (QY = 12% for 6a). This fact shows that the coordination of the oxazolone to the palladium efficiently suppresses the hula-twist deactivation pathway.

Determination of traces of phosphate by thin layer x-ray fluorescence

1976 ◽  
Vol 48 (13) ◽  
pp. 1950-1953 ◽  
Author(s):  
Ghyslain. Dube ◽  
Gaston. Boulay ◽  
Frank M. Kimmerle
Keyword(s):  
Thin Layer ◽  
X Ray

scholarly journals Use of Spectroscopy and Computer Simulation to the Study of Surfaces Modified by Ionic Implantation

2021 ◽  
Vol 66 (6) ◽  
pp. 511
Author(s):  
D.Yu. Nikolaieva ◽  
V.V. Honcharov ◽  
D.Yu. Ivashin ◽  
V.O. Zazhigalov
Keyword(s):  
Computer Simulation ◽  
Photoelectron Spectroscopy ◽  
Curved Surfaces ◽  
X Ray ◽  
Method Of Determination ◽  
Energy Dispersion Spectrometry ◽  
Optimal Mode ◽  
Ionic Implantation ◽  
Phase And Elemental Compositions

Using X-ray Photoelectron Spectroscopy (XPS) and energy dispersion spectrometry, the phase and elemental compositions of the nanoscale surface layer of implants are studied. The method of determination of the optimal mode of nanoscale modification of the surfaces of metals and alloys by means of the ionic implantation is presented. The problem of processing the curved surfaces with mathematical calculations and a computer simulation is solved. The proposed technique is tested on synthesized implants. The sample hardness was taken as a criterion.

Determination of YBaCuO thin layer structural parameters by using high-resolution X-ray diffractometry

1995 ◽  
Vol 28 (4A) ◽  
pp. A212-A215 ◽  
Author(s):  
T S Argunova ◽  
R N Kyutt ◽  
M P Scheglov ◽  
N N Faleev
Keyword(s):  
High Resolution ◽  
Thin Layer ◽  
Structural Parameters ◽  
X Ray

Determination Of The Content Of Hf In Zirconium Alloys With Using A Wide Band X-Ray Emission Filter

2018 ◽  
pp. 153-159
Author(s):  
O.P. Omelnyk ◽  
V.V. Levenets ◽  
A.Yu. Lonin ◽  
I.V. Shevchenko ◽  
A.O. Shchur
Keyword(s):  
Pyrolytic Graphite ◽  
Zirconium Alloys ◽  
Analytical Signal ◽  
Wide Band ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
X Ray ◽  
Method Of Determination ◽  
Non Destructive

The possibilities of a non-destructive method of determination of the content of hafnium in zirconium alloys are studied. The method is based on excitation of the characteristic X-ray emission of the atoms of the object of interest, including the L-series of atom of Hf, by external beam of protons accelerated up to 2 MeV. The excited emission is modified by a wide band X-ray emission filter, which is made from pyrolytic graphite plates and measured by a Si-PIN detector. Optimal conditions for measurement of analytical signal were determined after experimental studying. It was shown that under the selected experimental conditions and the measurement time of 10 minutes, the detection limit of Hf in the zirconium matrix is equal 20 ppm. The ways for improving of the metrological characteristics of the technique in the presence of interfering elements are proposed. The content of hafnium and uniformity of its distribution in the cladding of nuclear fuel rod made from the alloy Zr1% Nb was determined.

scholarly journals Method of determination of palladium concentration for C-Pd nanostructural films as a function of film thickness, roughness and topography

2014 ◽  
Vol 32 (2) ◽  
pp. 228-235
Author(s):  
Joanna Rymarczyk ◽  
Mirosław Kozłowski
Keyword(s):  
Film Thickness ◽  
Structural Model ◽  
Quartz Substrate ◽  
X Ray ◽  
Qualitative And Quantitative ◽  
Method Of Determination ◽  
Palladium Concentration ◽  
Quantitative Analyses ◽  
Model Film

AbstractIn this paper a method of determination of Pd in a carbon-palladium film (C-Pd film) deposited on a quartz substrate is presented. This method is based on energy dispersive X-ray spectroscopy (EDX) and all experiments were performed using a scanning electron microscope (SEM) equipped with EDX system. Qualitative and quantitative analyses were carried out for C-Pd films prepared by PVD method in different technological conditions. It was shown that results of the experiments depended on the structural model, film thickness and electron beam energy used for Pd content calculation.This method enabled us to conclude on the homogeneity of palladium distribution in the whole volume of carbonaceous matrix, depending on the parameters of PVD process. Additionally, these studies showed that a different palladium concentration in C-Pd films had a significant impact on their topography and morphology.

Polytypism in GaAs nanowires: determination of the interplanar spacing of wurtzite GaAs by X-ray diffraction

2015 ◽  
Vol 22 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Martin Köhl ◽  
Philipp Schroth ◽  
Andrey A. Minkevich ◽  
Jean-Wolfgang Hornung ◽  
Emmanouil Dimakis ◽  
...  
Keyword(s):  
Interplanar Spacing ◽  
Stacking Sequence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zinc Blende ◽  
Gaas Nanowires ◽  
Mean Diameter ◽  
Order Of Magnitude ◽  
Focused Beam

In GaAs nanowires grown along the cubic [111]cdirection, zinc blende and wurtzite arrangements have been observed in their stacking sequence, since the energetic barriers for nucleation are typically of similar order of magnitude. It is known that the interplanar spacing of the (111)cGa (or As) planes in the zinc blende polytype varies slightly from the wurtzite polytype. However, different values have been reported in the literature. Here, the ratio of the interplanar spacing of these polytypes is extracted based on X-ray diffraction measurements for thin GaAs nanowires with a mean diameter of 18–25 nm. The measurements are performed with a nano-focused beam which facilitates the separation of the scattering of nanowires and of parasitic growth. The interplanar spacing of the (111)cGa (or As) planes in the wurtzite arrangement in GaAs nanowires is observed to be 0.66% ± 0.02% larger than in the zinc blende arrangement.

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