scholarly journals Analysis of copper, selenium, and zinc in newborn dried bloodspots using total reflection X-ray fluorescence (TXRF) spectroscopy

2019 ◽  
Vol 1 ◽  
pp. e1 ◽  
Author(s):  
Jessica Pawly ◽  
Richard L. Neitzel ◽  
Niladri Basu
Keyword(s):  
Quality Control ◽  
Elemental Analysis ◽  
Analytical Method ◽  
Matrix Effects ◽  
Essential Elements ◽  
Standard Reference Materials ◽  
Sample Population ◽  
Robust Method ◽  
X Ray ◽  
Analytical Accuracy

Background There exists great interest in using dried bloodspots across the clinical, public health, and nutritional sciences to characterize circulating levels of essential elements yet current methods face several challenges related to instrumentation, quality control, and matrix effects. Elemental analysis via total X-ray fluorescence (TXRF) may help overcome these challenges. The objective of this study was to develop and apply a novel TXRF-based analytical method to quantify essential elements (copper, selenium, zinc) in dried bloodspots. Methods Analytical methods were developed with human whole blood standard reference materials from the Institut National de Santé Publique du Québec (INSPQ). The method was developed in careful consideration of several quality control parameters (e.g., analytical accuracy, precision, linearity, and assay range) which were iteratively investigated to help refine and realize a robust method. The developed method was then applied to a quantitative descriptive survey of punches (n = 675) taken from residual dried bloodspots from a newborn screening biobank program (Michigan BioTrust for Health). Results The analytical method developed to quantify the three target elements in dried bloodspots fared well against a priori quality control criteria (i.e., analytical accuracy, precision, linearity and range). In applying this new method, the average (±SD) blood copper, selenium, and zinc levels in the newborn samples were 1,117.0 ± 627.1 µg/L, 193.1 ± 49.1 µg/L, and 4,485 ± 2,275 µg/L respectively. All the elements were normally distributed in the sample population, and the measured concentrations fall within an expected range. Conclusions This study developed and applied a novel and robust method to simultaneously quantify three essential elements. The method helps overcome challenges in the field concerning elemental analysis in dried bloodspots and the findings help increase understanding of nutritional status in newborns.

scholarly journals Radionuclide x-ray fluorescence analysis of selected elements in agrimony tea samples with preconcentration

2013 ◽  
Vol 60 (2) ◽  
pp. 29-36
Author(s):  
Mikušová V. ◽  
Lukačovičová O. ◽  
Havránek E.
Keyword(s):  
Elemental Analysis ◽  
Analytical Method ◽  
Fluorescence Analysis ◽  
Low Energy ◽  
X Ray ◽  
Nitrocellulose Filter ◽  
Nuclear Analytical Method ◽  
Energy Gamma ◽  
Solid Form

Abstract The contents of selected elements (Mn, Fe, Co, Ni, Cu, Zn, Hg and Pb) in samples of loose tea of agrimony “Repikovy čaj” (Agrimonia eupatoria L.) were studied in this work. Identification and determination of the selected elements content were performed using X-ray fluorescence spectrometry - the nuclear analytical method based on the interaction between low-energy gamma and X radiation and analysed substance. Solid form samples were pressed in tablets and directly analysed. Prepared infusions were analysed after the preconcentration of the elements using precipitation with thioacetamide and ammonium diethyldithiocarbamate with subsequent filtration of created precipitates through a nitrocellulose filter. Detection limits obtained from both methods were compared and their suitability for elemental analysis of plant preparations was discussed.

Nondispersive X-Ray Fluorescent Spectrometer

1967 ◽  
Vol 11 ◽  
pp. 214-229
Author(s):  
W. Barclay Jones ◽  
Robert A. Carpenter
Keyword(s):  
Elemental Analysis ◽  
Matrix Effects ◽  
Excitation Source ◽  
X Rays ◽  
Particle Detector ◽  
Absorption Coefficients ◽  
X Ray ◽  
Electronic Circuitry ◽  
Sensitivity Curves ◽  
Inherent Stability

AbstractRecent advances in semiconductor particle detector resolutions along with new electronic circuitry associated with these detectors make possible their application in nondispersive elemental analysis. The use of radioactive sources for exciting the characteristic X-rays provides highly stable systems which can be used to accumulate data for prolonged periods. Due to the inherent stability of the detector and the excitation source, the only limitation in sensitivity is the ability to accumulate statistics above the background of scattered counts. Since this method of analysis is nondispersive, it has the capacity to determine many elements simultaneously. Solutions composed of mixtures of three or four elements were studied. The elements selected were bromine, rubidium, and strontium. These elements exhibit wide variations in mass absorption coefficients for the various characteristic X-rays emitted. The concentrations of the elements in solution varied from 10 ppm to 5% by weight. The relative intensities of the characteristic X-ray lines were compared with the concentration of the solutions to establish sensitivity curves and to study linearity of response as well. The interelemental interference was studied and the effect was evaluated for the particular elements under study. Means were developed for predicting and correcting for matrix effects.

Limits of Analytical Accuracy for Two Critical Semiconductors Systems: (Al, Ga)(As, P) and (In, Ga)(As, P)

1998 ◽  
Vol 4 (S2) ◽  
pp. 226-227
Author(s):  
John T. Armstrong
Keyword(s):  
Solid Solution ◽  
Quality Control ◽  
Quantum Wells ◽  
Semiconductor Materials ◽  
Multilayer Coatings ◽  
Bandgap Engineering ◽  
X Ray ◽  
Analytical Accuracy ◽  
Commercially Important

Among the more important semiconductor materials, with commercially important applications in microelectronics, photonics, and nanodevice development are alloys in the system GaP-GaAs-AlAs- InAs (e.g., 1). These components have extensive regions of solid solution. With the wide variety of phases that can be grown in this system, it is possible to “tailor” heterojunctions that have desired band offsets or quantum wells that have a given shape of confinement potential, which is the basis of “bandgap engineering” (e.g., 2-4). In order to characterize the properties of these phases and maintain quality control in the manufacturing of devices utilizing these phases, it is critical to be able to perform accurate determinations of their compositions. This can be especially difficult, since many of the applications utilizing these phases involve micro- or nano-devices or thin multilayer coatings. In terms of the spatial analysis requirements, electron microbeam x-ray microanalysis is ideally suited for characterization of such specimens.

Feasibility Study for On-Stream X-Ray Analysis of Barite

1981 ◽  
Vol 25 ◽  
pp. 139-144
Author(s):  
Yury M. Gurvich
Keyword(s):  
Process Control ◽  
Analytical Method ◽  
Analytical Methods ◽  
New Technology ◽  
Preliminary Investigation ◽  
X Ray ◽  
Solid Models ◽  
Accuracy And Precision ◽  
The World ◽  
Analytical Accuracy

Modern on-stream X-ray equipment for slurry analysis is now used in hundreds of mines throughout the world. This technique provides valuable information for process control which cannot be achieved by other analytical methods. One of the most recent successful examples is the Brenda Mines, in Canada, where the ARL Process Control X-ray Quantometer (PCXQ) is used for ten different streams in a Cu-Mo concentrator.The success of slurry analysis is highly dependent upon the analytical method selected, based on the following factors: (i) the features of the analyzed materials, (ii) the concentration ranges, (iii) percent of solids, and (iv) requirements of analytical accuracy and precision. A preliminary investigation of methods and of analytical conditions can be done on a laboratory X-ray spectrometer using solid models of slurry. Such preliminary work significantly simplifies the introduction of the new technology and helps in the preparation of proper specifications.

Quantitative Electron-Excited X-ray Microanalysis With Low-Energy L-shell X-ray Peaks Measured With Energy-Dispersive Spectrometry

2021 ◽  
pp. 1-34
Author(s):  
Dale E. Newbury ◽  
Nicholas W.M. Ritchie
Keyword(s):  
Intermetallic Compounds ◽  
Photon Energy ◽  
Matrix Effects ◽  
Energy Dispersive ◽  
Extensive Experience ◽  
X Ray ◽  
Rigorous Testing ◽  
Accuracy Of Measurements ◽  
Wide Range ◽  
Analytical Accuracy

Quantification of electron-exited X-ray spectra following the standards-based “k-ratio” (unknown/standard intensity) protocol with corrections for “matrix effects” (electron energy loss and backscattering, X-ray absorption, and secondary X-ray fluorescence) is a well-established method with a record of rigorous testing and extensive experience. Two recent studies by Gopon et al. working in the Fe–Si system and Llovet et al. working in the Ni–Si system have renewed interest in studying the accuracy of measurements made using L-shell X-ray peaks. Both have reported unexpectedly large deviations in analytical accuracy when analyzing intermetallic compounds when using the low photon energy Fe or Ni L-shell X-ray peaks with pure element standards and wavelength-dispersive X-ray spectrometry. This study confirms those observations on the Ni-based intermetallic compounds using energy-dispersive X-ray spectrometry and extends the study of analysis with low photon energy L-shell peaks to a wide range of elements, Ti to Se. Within this range of elements, anomalies in analytical accuracy have been found for Fe, Co, and Ge in addition to Ni. For these elements, the use of compound standards instead of pure elements usually resulted in significantly improved analytical accuracy. However, compound standards do not always provide satisfactory accuracy as is demonstrated for L-shell peak analysis in the Fe–S system: FeS and FeS2 unexpectedly do not provide good accuracy when used as mutual standards.

ELEMENTAL ANALYSIS OF ANCIENT CHINESE BRONZE ARTIFACTS WITH EXTERNAL-BEAM PIXE

1992 ◽  
Vol 02 (03) ◽  
pp. 269-284 ◽  
Author(s):  
E.K. Lin ◽  
Y.C. Yu ◽  
C.W. Wang ◽  
C.T. Shen ◽  
Y.M. Huang ◽  
...  
Keyword(s):  
Elemental Composition ◽  
Elemental Analysis ◽  
Analytical Method ◽  
Hpge Detector ◽  
External Beam ◽  
X Ray

External-beam PIXE has been applied for the determination of the elemental composition of ancient Chinese bronze artifacts. Characteristic x-ray spectra from the samples bombarded with protons of 3 MeV have been measured with a HPGe detector. At each sample three spots were irradiated per run. Results of measurements on three fragments of bronze drinking vessels and helmet of Chinese ancient Chou and Shang dynasties (17th-8th century B.C.) are presented. To check the analytical method, we have also made measurements on the elemental composition of some modern coins. The results are discussed.

Signal/Noise Ratio and Elemental Detectivity by Eels

1982 ◽  
Vol 40 ◽  
pp. 488-489
Author(s):  
R. F. Egerton
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Elemental Analysis ◽  
Electron Energy Loss Spectroscopy ◽  
Emission Spectroscopy ◽  
X Ray ◽  
Signal Noise ◽  
Characteristic Signal ◽  
Noise Ratio ◽  
Electron Energy Loss

An important parameter governing the sensitivity and accuracy of elemental analysis by electron energy-loss spectroscopy (EELS) or by X-ray emission spectroscopy is the signal/noise ratio of the characteristic signal.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

An improved interference correction for trace element analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1646-1647
Author(s):  
John J. Donovan ◽  
Donald A. Snyder ◽  
Mark L. Rivers
Keyword(s):  
Trace Element Analysis ◽  
Accurate Estimate ◽  
Simple Expression ◽  
Standard Reference Materials ◽  
Characteristic Line ◽  
Analytical Line ◽  
Element Analysis ◽  
Electron Probe Analysis ◽  
Calculated Concentration ◽  
X Ray

We present a simple expression for the quantitative treatment of interference corrections in x-ray analysis. WDS electron probe analysis of standard reference materials illustrate the success of the technique.For the analytical line of wavelength λ of any element A which lies near or on any characteristic line of another element B, the observed x-ray counts at We use to denote x-ray counts excited by element i in matrix j (u=unknown; s=analytical standard; ŝ=interference standard) at the wavelength of the analytical line of A, λA (Fig. 1). Quantitative analysis of A requires an accurate estimate of These counts can be estimated from the ZAF calculated concentration of B in the unknown C,Bu measured counts at λA in an interference standard of known concentration of B (and containing no A), and ZAF correction parameters for the matrices of both the unknown and the interference standard at It can be shown that:

Guideline for radioimmunotherapy of rituximab relapsed or refractory CD20+ follicular B-cell nonHodgkin´s lymphoma

2004 ◽  
Vol 43 (05) ◽  
pp. 171-176 ◽  
Author(s):  
T. Behr ◽  
F. Grünwald ◽  
W. H. Knapp ◽  
L. Trümper ◽  
C. von Schilling ◽  
...  
Keyword(s):  
Quality Control ◽  
Quality Management ◽  
Medical Physics ◽  
Essential Elements ◽  
Background Information ◽  
After Care ◽  
Complete Treatment ◽  
Close Cooperation ◽  
Work Up

Summary:This guideline is a prerequisite for the quality management in the treatment of non-Hodgkin-lymphomas using radioimmunotherapy. It is based on an interdisciplinary consensus and contains background information and definitions as well as specified indications and detailed contraindications of treatment. Essential topics are the requirements for institutions performing the therapy. For instance, presence of an expert for medical physics, intense cooperation with all colleagues committed to treatment of lymphomas, and a certificate of instruction in radiochemical labelling and quality control are required. Furthermore, it is specified which patient data have to be available prior to performance of therapy and how the treatment has to be carried out technically. Here, quality control and documentation of labelling are of greatest importance. After treatment, clinical quality control is mandatory (work-up of therapy data and follow-up of patients). Essential elements of follow-up are specified in detail. The complete treatment inclusive after-care has to be realised in close cooperation with those colleagues (haematology-oncology) who propose, in general, radioimmunotherapy under consideration of the development of the disease.

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