Search query: Fundamental parameter model for quantification of total reflection X-ray fluorescence analysis

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abstract: Abstract A new fundamental parameter model and calculation algorithm is presented for quantitative analysis for total reflection X ray fluorescence analytical technique. The model takes into consideration the geometrical parameters of the measuring set up, the energy distribution of the exciter X ray beam and its incidence angle to the surface of the sample holder. The numerical solution of this new model results the concentration of the sample elements. The system of equations of the fundamental parameter model involves the mathematical description of the excitation process in the sample layer and in the sample holder. The theoretical calibration for the quantitative determination of the sample elements is based on the numerical comparison of the measured and calculated X ray fluorescence signal of the pure silicon sample holder. For the numerical calculation computer code was created in order to solve numerically the model equations. The whole analytical procedure is a standard free method. The theoretical model and the complete numerical calculation was tested experimentally with standard solutions of K, Sc, V, Mn, Co, Ni and Cu elements, which were dripped onto high purity silicon wafer and dried before measurement. This standard free analytical procedure can be utilized in the semiconductor industry and in various total reflection X ray fluorescence analysis performed for investigations of environmental samples, natural waters, geological substances, foods and drinks.
author_names: Imre Szaloki

Gabor Radocz

Anita Gerenyi
title: Fundamental parameter model for quantification of total reflection X ray fluorescence analysis
venue: Spectrochimica Acta Part B: Atomic Spectroscopy
year: 2019

abstract: Abstract The performance has been compared of two different quantification methods namely, the commonly used empirical quantification procedure and a fundamental parameter approach for determination of the mass fractions of elements in particulate like sample residues on a quartz reflector measured in the total reflection geometry. In the empirical quantification procedure, the spectrometer system needs to be calibrated with the use of samples containing known concentrations of the elements. On the basis of intensities of the X ray peaks and the known concentration or mass fraction of an internal standard element, by using relative sensitivities of the spectrometer system the concentrations or mass fractions of the elements are calculated. The fundamental parameter approach does not require any calibration of the spectrometer system to be carried out. However, in order to account for an unknown mass per unit area of a sample and sample nonuniformity, an internal standard element is added. The concentrations/mass fractions of the elements to be determined are calculated during fitting a modelled X ray spectrum to the measured one. The two quantification methods were applied to determine the mass fractions of elements in the cross sections of a peat core, biological standard reference materials and to determine the concentrations of elements in samples prepared from an aqueous multi element standard solution.
author_names: Wawro Dariusz

Barbara Holynska

Beata Ostachowicz
title: A comparison of the performance of a fundamental parameter method for analysis of total reflection X ray fluorescence spectra and determination of trace elements, versus an empirical quantification procedure
year: 1998

abstract: Measurements of X ray fluorescence spectra versus grazing incident angles provide information on elemental composition as well as density and thickness of near surface layers. Calculations of fluorescence intensities are presented, which are used for the evaluation of data obtained by total reflection X ray fluorescence (TXRF) spectrometry. The calculation is based on a matrix formalism to account for standing wave phenomena due to transmission and reflection in layered material. For the determination of concentrations the model makes additional use of the fundamental parameter technique in order to include absorption and enhancement effects of the fluorescence radiation. On the basis of experimental data some capabilities of this nondestructive and contactless probing technique are presented.
author_names: U Weisbrod

R Gutschke

Joachim Knoth

Heinrich Schwenke
title: Total reflection X ray fluorescence spectrometry for quantitative surface and layer analysis
year: 1991

abstract: Total reflection X ray fluorescence analysis (TXRF) is a method for qualitative and quantitative analysis of trace elements. In general TXRF is known to allow for linear calibration typically using an internal standard for quantification. For small sample amounts (low ng region) the thin film approximation is valid neglecting absorption effects of the exciting and the detected radiation. However, for higher total amounts of samples deviations from the linear relation between fluorescence intensity and sample amount have been observed. The topic of the presented work is an investigation of the parameters influencing the absorption phenomenon. Samples with different total amounts of arsenic have been prepared to determine the upper limit of sample mass where the linear relation between fluorescence intensity and sample amount is no longer guaranteed. It was found that the relation between fluorescence intensity and sample amount is linear up to ~100 ng arsenic. A simulation model was developed to calculate the influence of the absorption effects. Even though the results of the simulations are not satisfying yet it could be shown that one of the key parameters for the absorption effect is the density of the investigated element in the dried residues.
author_names: C Horntrich

Florian Meirer

Christina Streli

Peter Kregsamer

Giancarlo Pepponi

Norbert Zoeger

Peter Wobrauschek
title: Influence of the sample morphology on total reflection X ray fluorescence analysis
venue: Powder Diffraction
year: 2009

abstract: Abstract A method for the determination of the concentrations of elements in particulate like samples measured in total reflection geometry is proposed. In the proposed method the fundamental parameters are utilized for calculating the sensitivities of elements and an internal standard is used to account for the unknown mass per unit area of a sample and geometrical constant of the spectrometer. The modification of the primary excitation spectrum on its way to a sample has been taken into consideration. The concentrations of the elements to be determined are calculated simultaneously with the spectra deconvolution procedure. In the process of quantitative analysis the intensities of all X ray peaks corresponding to K and L series lines present in the analyzed spectrum are taken into account. (c) 1997 Elsevier Science B.V.
author_names: Dariusz Wegrzynek

Barbara Holynska
title: Fundamental quantification procedure for total reflection X ray fluorescence spectra analysis and elements determination
year: 1997

abstract: Abstract Despite the fact that Total Reflection X ray Fluorescence (TXRF) is becoming more and more popular as a quantification technique in analytical chemistry due to its simplicity and robustness, there are still some key aspects related to the sample preparation that need to be improved. In this work, the effect of different parameters is investigated: measurement time, carrier position, sample volume and sample drying time. The measurement time and the sample volume on the carriers mainly affect the recovery rate and relative standard deviation of the quantified metal from aqueous solutions. The most important parameters that play a fundamental role in the calibration of a TXRF machine such as choice of the standard element and concentration ratio between the analyte and the standard are discussed. Practical and easy guidelines for the correct preparation of aqueous samples are presented. These can be used by both less and more experienced TXRF users, interested in measuring metal ion concentrations in aqueous samples.
author_names: Sofia Riano

Mercedes Regadio

Koen Binnemans

Tom Vander Hoogerstraete
title: Practical guidelines for best practice on Total Reflection X ray Fluorescence spectroscopy: Analysis of aqueous solutions
year: 2016

abstract: Abstract Secondary ion mass spectrometry (SIMS) has been the most widely used technique for the measurement of dopant distribution in Si because of its ability of determining profile shape, junction depth, and dose with adequate depth resolution and detection limits. In the case of ultrashallow implants though, SIMS is going towards its intrinsic limits; in fact, initial transient width and native oxide induced matrix effects affect the measurement in the first nanometres where a relevant part of the dopant is confined. Therefore, complementary techniques able to give information on the dose and on the distribution in the first nanometres are required. In this work, total reflection X ray fluorescence analysis (TXRF) resolved in angle has been evaluated as a candidate, given its high sensitivity in the near surface region, its ability of a quantitative analysis, its multielement capability, and its nondestructiveness. Three arsenic implanted Si samples have been analysed by SIMS and TXRF. The SIMS measurements have been carried out by a magnetic sector instrument of new generation with a Cs primary beam and by monitoring negative secondary ions. The TXRF measurements were performed at beamline 6 2 of the Stanford Synchrotron Radiation Laboratory. For the fluorescence measurements, an absolute quantification by fundamental parameters and comparison with the Si fluorescence signal has been adopted. The TXRF dose determination showed good agreement with other techniques. TXRF could also evaluate the accuracy of the SIMS profile in the first nanometres.
author_names: Giancarlo Pepponi

Christina Streli

Peter Wobrauschek

Norbert Zoeger

Katharina Luening

Piero A Pianetta

D Giubertoni

Mario Barozzi

Massimo Bersani
title: Nondestructive dose determination and depth profiling of arsenic ultrashallow junctions with total reflection X ray fluorescence analysis compared to dynamic secondary ion mass spectrometry
year: 2004

abstract: Abstract Polycapillary optics, consisting of bundles of narrow hollow glass channels, are regularly used in the field of (micro )X ray fluorescence (XRF) spectroscopy to focus X rays down to a microscopic spot while increasing the flux density of the beam on the sample. Polycapillaries guide X ray photons through multiple total reflection events, similar to how light is guided within optic fibers. Although the use of polycapillaries in XRF spectroscopy allows for fairly straightforward qualitative elemental analysis, fundamental parameter (FP) based quantification remains difficult due to the energy dependent photon transmission efficiency, focal size, acceptance, etc. of these optics. In order to predict the polycapillary and input beam parameter dependent beam forming properties, a multithreaded Monte Carlo based polycapillary X ray ray tracing code is presented. Apart from supporting photon ray tracing in 'ideal' straight, conical and ellipsoidal shaped polycapillary optics, it also allows for the simulation of photon propagation through arbitrarily shaped optics to account for small deviations from the ideal shape, as is often the case in real world examples. The current code allows for the simulation of so called 'leak events' where the probability of a photon traveling through a capillary wall is taken into account, and also includes support for photon beam polarization effects. The simulated results show good agreement with experimental results obtained at the BM26A beamline of the European Synchrotron Radiation Facility (ESRF, Grenoble, France) The (poly)capillary X ray ray tracing simulation code, called 'polycap' developed in the C language and with bindings for Python, is released under the GPLv3 license. The code is expected to assist in the quantification of (poly)capillary based X ray fluorescence spectroscopy and may yield additional insight into the manufacturing and development of polycapillary optics.
author_names: Pieter Tack

Tom Schoonjans

Stephen Bauters

Laszlo Vincze
title: An X ray ray tracing simulation code for mono and polycapillaries: Description, advances and application
year: 2020

abstract: This work illustrates the quantification of Fluorspar, it is commonly used during metallurgical operations as flux. In general practice it is quantified by conventional method for verification of mineralogy and grades by using 2 3 analysts and days respectively. By using conventional method analyst can estimate CaF2, CaO, SiO2, MgO and R2O3 (mixed oxides) except SrO, BaO, and P etc. due to trace low quantity. At present a new strategy opportunity has been developed for fast, less interfering and low cost for all type of CaF2 as pressed pellet by wavelength dispersive X ray fluorescence (WD XRF) For verification of such strategy, a series of calibration lines were established by certified reference materials (CRM's) and synthetic standards. Matrix effects were corrected by applied Fundamental Parameters (FP) model. In current methodology CaCO3 was calculated after analysis of total carbon (C) through Infra red combustion method. All estimations were done in dried samples after removal of moisture. CaF2 was calculated by applying mathematical formulation. The presence of CaCO3 instead of other carbonates like MgCO3, BaCO3, Na2CO3 and K2CO3 etc were confirmed by XRD, ATR FTIR, and Volatilization method as well as compared with conventional analysis results and results were validated by using ISO 17025 protocol. *Corresponding author: Naseem Akhter, People's Steel Mills Limited, Karachi, Sindh, Pakistan, Tel: 09202103362620599; E mail: naseemchemist@hotmail.com Received May 28, 2018; Accepted October 15, 2018; Published October 24, 2018 Citation: Akhter N, Mumtaz M, Hussain SS (2018) Quantification of Metallurgical Flux by Wavelength Dispersive X Ray Fluorescence. Chem Sci J 9: 195. doi: 10.4172/2150 3494.1000195 Copyright: (c) 2018 Akhter N, et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
author_names: Naseem Akhter

M Mumtaz

Syed Sajid Hussain
title: Quantification of Metallurgical Flux by Wavelength Dispersive X Ray Fluorescence
year: 2018

abstract: Bromine has been recognized as a valuable indicator for paleoclimatic studies. Wavelength dispersive X ray fluorescence (WDXRF) and total reflection X ray fluorescence (TXRF) methods were applied to study the bromine distributions in lake sediment cores. Conventional WDXRF technique usually requires relatively large mass of a sediment sample and a set of calibration samples. Some analytical approaches were developed to apply WDXRF to small sediment core samples in the absence of adequate calibration samples with a known Br content. The mass of a sample to be analyzed was reduced up to 200 300mg and the internal standard method with correction using fundamental parameters was developed for Br quantification. TXRF technique based on the direct analysis of a solid suspension using 20mg of sediment sample by internal standard method was additionally tested. The accuracy of the WDXRF and TXRF techniques was assessed by the comparative analysis of reference materials of sediments, soil and biological samples. In general, good agreement was achieved between the reference values and the measured values. The detection limits of Br were 1mg/kg and 0.4mg/kg for WDXRF and TXRF respectively. The results of the Br determination obtained with different XRF techniques were comparable to each other and used for paleoclimatic reconstructions.
author_names: Galina V Pashkova

T S Aisueva

Alexandr L Finkelshtein

Egor V Ivanov

Alexander A Shchetnikov
title: Analytical approaches for determination of bromine in sediment core samples by X ray fluorescence spectrometry.
venue: Talanta
year: 2016