X-ray Fluorescence Spectrometry Method Research Articles

MINERAL ELEMENTS OF RUBIA TINCTORUM L PLANT ROOT AND USE IN MEDICINE

In this article, the biological properties of the root of Rubia tinctorum plant and the amount of mineral elements in its chemical composition are determined using the X-ray fluorescence spectrometry method using the Spectro Xepos 111 (SSliA) device, and the information about the use of the root of the Rubia tinctorum plant in medicine is highlighted.

Evaluation of the surface water and sediment quality in the Duger basin (Burdur, Turkey) using multivariate statistical analyses and identification of heavy metals.

The study aims to determine the chemical contents of the surface water of the Duger Creek and the sediments of the Duger basin, which feeds the Burdur Lake, the correlation between these contents, the potential ecological risks of these contents, the toxic heavy metal contents, and their spatial distribution by using X-ray fluorescence (XRF) spectroscopy method. The Duger basin, which has been selected as the study area, is located on the streams feeding the Burdur Lake, which has been determined as the Ramsar area in Turkey. Burdur Lake has a key role in the ecological balance due to its biological diversity, characteristic animal/plant fauna since it provides a suitable area for seasonal migration of waterfowl. Considering all these functions, the surface water and sediment quality of the Duger basin, which is located in the streams feeding Burdur Lake, is critical. In this study, elemental compositions of 20 water and 20 sediment samples collected from the Duger basin were determined by using the XRF spectroscopy method. Many elements that may have toxicological characteristics in terms of human and environmental health have been detected in the surface water and sediment samples from the Duger basin. These elements were found to have the following average values: Al (60.09mg/L), Co (3.35mg/L), Zn (3.35mg/L), Cu (2.21mg/L), Cr (0.14mg/L). It is interpreted that they may be toxic because they exceed the limits specified in WHO 2004. In this context, the surface water in the Duger basin, which feeds the Burdur Lake, must be filtered before using it as drinking water or for agricultural and livestock purposes. New strategic planning is suggested to ensure the sustainability of the basin's surface water quality.

Structural study of Khosrow Parviz silver coins present in the museum of Bu Ali Sina tomb using X-ray fluorescence spectroscopy method

Structural study of Khosrow Parviz silver coins present in the museum of Bu Ali Sina tomb using X-ray fluorescence spectroscopy method

Heavy Metals Contamination and Water Quality Parameter Conditions in Jatiluhur Reservoir, West Java, Indonesia

Waste pollution into the Citarum River (main water source of Jatiluhur Reservoir) was dominated by the manufacturing industry sector (textile, chemical, metal, pharmaceutical). Industrial was the most common contributor to heavy metal waste. Heavy metal contamination into waters will cause any problems, one of which was the emergence of various diseases both short and long term. Based on the issues, the study of heavy metal contamination and also water quality parameter conditions in the Jatiluhur Reservoir was necessary. The heavy metals (Cu, Zn, Hg, Pb, Cd) contents were determined using the X-Ray Fluorescence (XRF) Spectrometry method (for sediment) and Atomic Absorption Spectrometry (AAS) method (for water). The other water quality parameters were analyzed using the methods from the Indonesian National Standard (SNI). Furthermore, the data were compared to the Canadian Sediment Quality Guidelines (for heavy metal in sediment) and water quality standards from Government Regulation of the Republic of Indonesia Number 82 of 2001 (Class 3) (for water quality parameters). Concerning the discussion, Jatiluhur Reservoir was divided into three zones i.e. the inlet area, main inundation area, and outlet area. Conditions in the sedimentary layer, mercury (Hg) have accumulated throughout the Jatiluhur Reservoir area with conditions exceeding the maximum limit, while Cu metal tends to accumulate in the inlet area with conditions exceeding the minimum limit. For other heavy metals, exceed the minimum limit at some locations, but more results were below that. Although all heavy metals have not been detected in water, this was a warning that the presence of heavy metals in sediments can potentially dissolve into the water, the most extreme thing that can happen was upwelling. If this happens, the heavy metals can be contained excessively in water, harmful to and possibly consumed by aquatic biota and human. Considering these conditions, the biota that was most likely to be exposed was benthic organisms. In general, the water quality parameters in Jatiluhur Reservoir meet the quality standards. Only ammonia that does not meet the quality standards for sensitive fish life, regarding the massively of aquaculture activity in this reservoir.

The Kaolinite Crystallinity and Influence Factors of Coal-Measure Kaolinite Rock from Datong Coalfield, China

In order to ascertain the kaolinite crystallinity of Carboniferous Permian coal-measure kaolinite rocks, seven groups of fresh samples were collected from below the ground in the Xiaoyu mine, Datong coalfield. Microscopy, X-ray diffraction (XRD), differential thermal analysis (DTA), infrared (IR) spectroscopy and X-ray fluorescence (XRF) spectrometry methods were applied to the samples. The petrographic analysis results show that the kaolinite rocks are characterized as compact, phaneritic, clastic, sand-bearing, sandy and silty types; the kaolinite content in the Shanxi formation and upper Taiyuan formations was more than 95%, while it was 60–90% in the middle and lower Taiyuan formations. Based on the Hinckley index and the features of XRD, DTA and IR of kaolinites, crystallinity was classified as having three grades: ordered, slightly disordered and disordered. The kaolinites’ SiO2/Al2O3 molar ratio was about 1.9–5.7, with a chemical index of alteration (CIA) of about 95.4–99.5. This research suggests that the kaolinite crystallinity correlates positively to its clay mineral content, purity and particle size, which are also related to the SiO2/Al2O3 molar ratio and CIA. The original sedimentary environment and weathering have a direct influence on kaolinite crystallinity, and the existence of organic matter is conducive to the stable existence of kaolinite. The study results have significance for the extraction and utilization of coal-measure kaolinite and the development of kaolinite crystallography and mineralogy.

The study of m-pentadecylphenol on the inhibition of mild steel corrosion in 1 M HCl solution

The acidic fluids used in the acidification of oil wells provoke corrosion of metallic materials unenviably. As a consequence, corrosion inhibitors are needed to mitigate or retard the corrosion process. Herein, we report m-pentadecylphenol as an eco-friendly corrosion inhibitor in acidic media developed from cashew nut shell liquid (CNSL), which is a low-cost and sustainable source. The inhibitor was evaluated as corrosion inhibitor for mild in 1 M HCl corrosive solution by potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), weight loss, Fourier transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM), and energy-dispersive X-ray fluorescence (EDX-RF) spectrometry methods. The results showed that the inhibition efficiency of m-pentadecylphenol was at least 95% at an optimal concentration (300 ppm). The inhibition efficiency was found to increase as the inhibitor concentration increments from 100 to 300 ppm. Further studies revealed the inhibition performance of m-pentadecylphenol to be marginally reliant on temperature as the temperature rises from 303 to 333 K. At 333 K, the inhibition performance of the inhibitor was still promising (about 85%) when the concentration was 300 ppm. The adsorption studies revealed the spontaneous aptitude of m-pentadecylphenol to inhibit corrosion by forming a non-conductive inhibitive layer on the mild steel surface mainly through the chemisorption mechanism. The chemisorption adsorption was satisfactorily described by the Langmuir adsorption isotherm model. Besides, the potentiodynamic polarization measurements revealed m-pentadecylphenol to act as an anodic inhibitor. The overall findings revealed that m-pentadecylphenol to be an effective corrosion inhibitor in harsh corrosive vicinities with the added advantages of being eco-friendly and relatively cheaper. Thus, it can replace the use of non-green and expensive corrosion inhibitors in the industry.

Resampling with in situ field portable X-ray fluorescence spectrometry (FPXRF) to reduce the uncertainty in delineating the remediation area of soil heavy metals.

There must be some uncertainty in the remediation areas delineated based on limited sample points, and resampling in the high-uncertainty areas is particularly necessary. In situ field portable X-ray fluorescence spectrometry (FPXRF), a rapid and cheap analysis method for soil heavy metals, is strongly affected by many spatially non-stationary soil factors. This study first delineated the high-uncertainty area (threshold-exceeding probabilities (PTE) between 30% and 70%) of soil Pb based on the 1000 realizations produced by sequential Gaussian simulation (SGS) with 93 ICP-MS Pb concentrations measured in a peri-urban agriculture area, China. Next, in situ FPXRF was used to increase sample density in this high-uncertainty area. Then, robust geographically weighted regression (RGWR) was used to correct the in situ FPXRF Pb, and the correction accuracies of RGWR, basic GWR, and traditionally-used ordinary least squares regression (OLSR) were compared. Finally, to explore the best way to combine these corrected in situ FPXRF concentrations in delineating the remediation area, we compared the following spatial simulation methods: basic SGS, sequential Gaussian co-simulation (CoSGS) with the RGWR-corrected in situ FPXRF Pb as auxiliary soft data (CoSGS-CorFPXRF), and SGS with the RGWR-corrected in situ FPXRF Pb as part of hard data (SGS-CorFPXRF). Results showed that (i) RGWR produced higher correction accuracy (RI=71.5%) than GWR (RI=59.68%) and OLSR (RI=25.58%) for the in situ FPXRF Pb; (ii) SGS-CorFPXRF produced less uncertainty (G=0.97) than CoSGS-CorFPXRF (G=0.95) and SGS (G=0.91) in the spatial simulation; (iii) High-uncertainty area (30%<PTE<70%) was reduced from 36.55% to 8.7% of the whole study area. It is concluded that the recommended methods are cost-effective to reduce the uncertainty in delineating the remediation areas of soil heavy metals.

Features of sample preparation techniques in the total-reflection X-ray fluorescence analysis of tea leaves

Tea is a popular drink around the world and contains essential minerals and trace elements for human health. In this study, the analytical capabilities of the total-reflection X-ray fluorescence method (TXRF) were considered for the analysis of tea. Different sample preparation techniques, e.g. suspension, open vessel acid digestion, and microwave acid digestion were examined. The influence of particle size was investigated in the analysis of the suspension of tea samples. Mass-absorption coefficients for the tea matrix and the critical surface density of the specimen were calculated. The data obtained explain the presence of absorption effects in the determination of P, S, Cl, and K in suspensions. The digestion procedure is chosen as an optimal sample preparation technique for the TXRF analysis of tea. Nineteen real tea samples were analyzed using TXRF. The advantages of TXRF have been presented through the comparison of results with the wavelength-dispersive X-ray fluorescence spectrometry method.

Unified method for the determination of chemical composition in different types of materials using Wavelength Dispersive X-ray Fluorescence Spectrometry

Abstract The aim of the article is to show that determination of the main chemical composition with Wavelength Dispersive X-ray Fluorescence Spectrometry method does not require the use of separate analytical applications and procedures for the tests of materials of different origin. This is however conditioned upon calcination of the tested initial sample at the temperature of 815 °C to remove organic matter and its preparation for X-ray measurements by fusing into a borate bead. Within the framework of the conducted research a special analytical application measuring 10 oxides: SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, SO3, TiO2 and P2O5 was developed. Standards and certified reference materials (CRMs) were applied for calibration. Synthetic standards with the use of oxides and salts of purity of 99.99% were also prepared to complete the measuring points on the calibration curves The curves determined based on the measuring points have high correlation coefficients and accuracy. The α empirical correction coefficients were applied to correct matrix effects. The range of the method was confirmed based on the measurements of 13 synthetic standards. The average values of the standard deviations in the lower range of the calibration curves were between 0.0008% for K2O and 0.0056% for Na2O and 0.0054% for MgO. The average values of the relative standard deviation were in the range between 1.81% for K2O and 13.92% for MgO and 11.21% for Na2O, respectively. In the upper range of the calibration curves, the average values of standard deviation were between 0.079% for TiO2 and 0.962% for P2O5, and the relative standard deviation was between 0.05% for SiO2 and 2.39% for P2O5. The accuracy of the developed WDXRF method was assessed based on the measurement of 10 certified reference materials representing all the tested materials (cement, coal ash, slag, fire clay, sediment and soil). Out of 98 conducted measurements (two CRMs did not contain the declared content of P2O5 and SO3 respectively), in 68 measurements, relative errors were below 5%, and, in next 27 measurements, they were between 5% and 10%. The errors were comparable for all the tested materials which confirms that in WDXRF analyses of borax beads the type, kind and origin of a sample do not affect accuracy of the obtained measurements.

Comparison of portable X-ray fluorescence spectrometry and laboratory-based methods to assess the soil elemental composition: Applications for wetland soils

Abstract The portable X-ray fluorescence spectrometry (pXRF) can be considered one of the most novelty for soil characterization. In tropical regions (e.g., Brazil), some studies have showed a consistent correlation between pXRF and laboratory-based methods. However, there is no any work dedicated exclusively for hydromorphic soils (gley or organic-rich soils). This study aims to assess the total elemental composition reported by portable X-ray fluorescence (pXRF) spectrometry and to compare it to laboratory-based wet digestion method and wavelength dispersive X-ray (WDXRF) spectrometry. A collection of 144 hydromorphic soil samples from six wetlands located in the Cerrado biome (Savannah), Brazil, was used for this investigation. Soil samples were disaggregated and passed through a 150- μ m nylon mesh and subjected to wet digestion (US EPA 3051a) followed by elemental determination via atomic absorption spectrometry (AAS). Subsamples of each ground soil were also directly analyzed via both pXRF and WDXRF. Linear regressions were performed to establish the relationship between methods. Several elements (Pb, Cu, Zn, Cr, Fe, Ti, Sr, and Y) determined via pXRF were successfully correlated to other methods (USEPA 3051a and WDXRF). Specially for Pb, a very strong correlation (R > 0.90) was observed between pXRF, WDXRF and US EPA 3051a methods. The pXRF revealed also to be a useful tool for characterization of hydromorphic soils and future studies can be conducted directly in the field to assess the elemental composition of Cerrado wetland soils.

Soil spatial patterns analysis at the ancient city of Ibida (Dobrogea, SE Romania), via portable X-ray fluorescence spectrometry and multivariate statistical methods

In this study we investigated the potential usefulness of multi-elemental soil analysis, obtained by a portable XRF spectrometer, to recognize ancient anthropogenic features, compared to the natural context on the territory of Roman-Byzantine Ibida city (Dobrogea, SE Romania). Soil samples were collected from 16 soil profiles and 2 archaeological excavations, from each soil horizon and cultural layer. Pearson correlation matrix of topsoil elements showed significant correlations among the various geogenic elements such as Ti, Fe, Mn, Zr, Ba and Cr. In the case of P, a strong correlation was found with Ca, a lower correlation with K, and no significant correlation with the other elements. Also, Cu and Zn behave differently, showing no significant correlation with any of the elements. Principal components analysis (PCA) and agglomerative hierarchical clustering (AHC) were carried out in order to identify groups of inter-correlated variables and assess the degree of association among soil profiles. The correlation between soil elements and the principal components suggest the presence of three groups which were defined as the geogenic, archaeo-anthropogenic and agro-anthropogenic component. Spatial distribution of topsoil elements was mapped by geostatistical methods in order to see if their spatial patterns reveal the influence of human activities. Although the results show that certain elements such as Ca, P and K present higher concentrations in the Ibida fortress area, we found that the interpretation of multi-elemental composition of the topsoil only is not sufficient for an accurate identification of the ancient characteristics which can be linked to the Roman-Byzantine period. Hence, we wanted to know if the presence of archaeological sites could be revealed by higher variation degree of soil elemental data along the profile depth. Therefore, we tested the utility of a synthetic statistical index, namely the variation coefficient, which was computed for each soil profile using all the available data. The results showed that if the index was standardized according to profile depth, then it became a useful indicator for the presence of ancient human activities.

The dry ashing - AAS method and the microwave digestion -ICP-MS method for determination of lead in plastic packaging bag

A pink plastic packaging bag sample from a enterprise was preliminarily screened via X-ray fluorescence spectroscopy method (XRF), it was found that the lead content exceeded the limit of relevant national standards. Subsequently, the total lead content in the packaging bag was determined via atomic absorption spectrophotometry pretreated by dry ashing method (DA-AAS) and inductively coupled plasma–mass spectrometry with microwave digestion method (MD-ICP-MS), respectively. The working curve equations were obtained by linear least squares method with the calculated linear correlation coefficients r above 0.9998 and the relative standard deviation (RSD) of the determination results from 1.0% to 6.2%, which was in good agreement with the result of XRF.

Use of the Optically Stimulated Luminescence Dating and X-Ray Fluorescence Spectrometry Methods as Tools in Paleoseismology

We have investigated the application of luminescence dating to sediment and pottery samples from a paleoseismological trench excavated in the Gyrtoni Fault, Tyrnavos Basin, Central Greece. The samples were dated following the optically stimulated luminescence (OSL) dating method, using the Riso TL/OSL DA-20 reader. The OSL ages were obtained from chemically purified quartz and a single-aliquot regenerative-dose (SAR) protocol was followed for the equivalent dose (De) determination. Additionally, samples were collected and analyzed with the method of X-ray Fluorescence (XRF) spectrometry, in order to assess their elemental composition. Radioisotope sources (109Cd and 241Am) were used for sample excitation, while X-ray spectra were acquired using a Si(Li) detector coupled with standard electronics. The XRF data were submitted to principal component analysis (PCA). This statistical handling aimed to distinguish from which part of the upthrown fault block scarp-derived colluvium and alluvial deposits, parts of the downthrown block were derived and thus estimate the displacement. The results indicated that both the OSL dating method and the XRF analysis combined with PCA can serve as useful tools for paleoseismological investigations.

Magmatism and Geothermal Potential in Pandan Volcano East Java Indonesia

Pandan volcano is a volcano formed on Tertiary sedimentary rocks from the Kendeng zone deposited in the basin of East Java. In addition to generating petroleum potentials, such as Cepu and Bojonegoro oil fields, this area also generates geothermal potential. As a source of heat from the geothermal system is igneous rock formed from the magmatism process. The type of rock formed by the process of magmatism in the Pandan geothermal system is basaltic-andesitic and hornblende andesite are medium-high K calk alkaline affinity located in the island arc. The interaction of hot rock from post magmatism process with hydrothermal fluid resulted in the manifestation of hot springs and calcite travertine in the study area. Prediction of the subsurface temperature of hot water from geothermometer silica analysis contained in Banyukuning and Jarikasinan show cristobalite Beta equilibrium (70oC) and quartz temperature (120oC). To study about magmatism and geothermal fluid using petrographic method and petrochemical analysis (X-ray fluorescence spectrometry method) to the sample of igneous rock. While to study the fluid type and geothermometer of geothermal fluid using data from previous researchers. This research study is expected to provide additional information on the field of geothermal and magmatism in this area.

Evaluation of analytical capabilities of total reflection X-ray fluorescence spectrometry for the analysis of drinks with sucrose matrix

Multielement analysis of food products, including drinks, is important for an assessment of the content of the useful and toxic elements for the human body. In this paper, the main problems and their solutions in the analysis of sugar-containing drinks by Total Reflection X-ray Fluorescence Spectrometry ( TXRF ) method have been considered. The organic sucrose matrix causes certain difficulties both in the preparation of the samples and in the processing of measurement data for TXRF. The following most common sample preparation procedures for TXRF were considered: direct, based on the analysis of initial sample, dilution with water and acid digestion. In order to assess the fulfillment of the thin layer criterion, the physical characteristics of dried samples on the carriers were determined after applying each of the above-mentioned preparation procedures, and the corresponding surface density values were established. The obtained values were compared with the theoretical ones. Based on the calculation of mass absorption coefficients for C 12 H 22 O 11 matrix, it was found that the method of acid digestion was suitable for the quantitative determination of light (14 < Z < 20) elements. When analyzing the sample without the preliminary preparation or after diluting the sample with water, the influence of absorption effects was noted due to the mismatch of the surface density with the thin layer criterion. This mismatch of the samples in the direct analysis was confirmed by the measurements using a method based on an angle incidence scanning of the primary radiation on the sample, establishing a violation of the conditions for the effect of total external reflection. The detection limits were calculated for the considered sample preparation procedures, and it was concluded that the quantitative identification of Fe, Ni, Cu, Zn, Rb, Sr, and Pb trace elements at the level of tens of μg/l was possible by the acid digestion procedure. The application of the addition method to assess the trueness of elemental determination led to the conclusion that it was possible to use the direct analysis of sugar-containing drinks for the elements with Z ≥ 24 in the concentration ranges of 0.5–10 mg/l. Key words : X-ray fluorescence, TXRF, soft drinks, matrix effects, absorption effects, sucrose, multielement analysis, addition method (Russian) DOI: http://dx.doi.org/10.15826/analitika.2019.23.4.009 A.S. Maltsev 1, 2 , A. von Bohlen 3 , R.A. Yusupov 2 , S.A. Bakhteev 2 1 Institute of the Earth’s Crust, SB RAS, Lermontov st., 128, Irkutsk, 664033, Russian Federation 2 Kazan National Research Technological University, Marksa st., 68, Kazan, 420012, Russian Federation 3 Leibniz-Institut fur Analytische Wissenschften ISAS, Bunsen-Kirchhoff-Str. 11, Dortmund, 44139, Germany

Multielement analysis of tea by X-ray fluorescence spectrometry with full external reflection

The main goal of this work was to assess the analytical capabilities of the full external reflection X-Ray Fluorescence Spectrometry method (TXRF) in the analysis of tea leaves and their infusions. As objects of the research, 19 samples of various sorts of Krasnodar tea were used. Two techniques of sample preparation were employed based on an open vessel acid digestion and a preparation of the suspension. The results of the certified standard tea sample analysis confirmed the possibility of the quantitative determination for the following elements: Mg, P, S, K, Ca, Fe, Ni, Cu, Zn, Br, Rb, Sr, Ba, and Pb. The best measurement results were achieved using the acid digestion technique. The analysis of the suspension could be carried out during the determination of elements such as Ca, Ni, Cu, Zn, Br, Rb, and Sr; for other elements, matrix effects were the interfering quantification factor. It was also found that the reliable determination of volatile elements, such as Cl and Br, was possible only when analyzing suspensions. The overall measurement uncertainty, including all stages of analysis, for most of the elements averaged to no more than 16%. The wavelength dispersive X-Ray Fluorescence method was used as a comparison method for the obtained measurement data of Krasnodar tea samples. The comparison was made using the Student's criterion and the convergence evaluation, based on which it was concluded that the data was in the good agreement for most of the elements. In addition, the analysis of tea infusions prepared according to the consumer procedure was carried out in order to study the solubility of the various elements and assess the quality and safety of tea. The results could be used in the laboratories for the quality control and for the assessment of the chemical composition of tea. Key words : X-ray fluorescence, TXRF, WDXRF, tea, infusion, multielement analysis DOI: http://dx.doi.org/10.15826/analitika.2019.23.2.009 (Russian) A.S. Maltsev 1, 2 , D.S. Sharykina 1 , E.V. Chuparina 3 , G.V. Pashkova 1 , A.G. Revenko 1 1 Institute of the Earth’s Crust, SB RAS, Lermontov st., 128, Irkutsk, 664033, Russian Federation 2 Kazan National Research Technological University, Marksa st., 68, Kazan, 420012, Russian Federation 3 Vinogradov Institute of Geochemistry, SB RAS, Favorsky st., 1A, Irkutsk , 664033, Russian Federation

Detection and Evaluation of metals in soil under influence of mining by Dispersive Energy X-ray Fluorescence Spectrometry (EDXRF), Lavras do Sul/RS

Rocks are the primary source of chemical elements found in the earth. Among them metallic elements, which are distributed in most natural environments and their distribution in soils is widespread. Knowledge of the soil chemical composition will provide subsidies for a prediction of phytotoxicity and possible groundwater contamination. Concentrations of metals, in the right quantities, are essential for maintaining life. Although, if in high quantities (toxicity), can cause damage to plants, animals, and humans. This work consists of a chemical analysis of soil samples in the region of Lavras do Sul / RS, where mineral deposits occur. Until the year 1981 mining activities occupied the area without municipality, resulting in ore and waste deposits at inappropriate places, generating environmental liabilities, contributing to soil chemistry, and consequently affecting public health. Through the energy dispersive X-ray fluorescence spectrometry (EDXRF) method, 20 soil samples were analyzed in two profiles surrounding the municipality. Among them, high concentrations of Zn, Cu, Ce and Cd were detected, possibly contributing to anthropic activities and seasonal fluctuations.

ICP-AES Analysis of Secondary Tungsten-Containing Raw Materials for Production of Hard Alloys

A method for ICP-AES determination of Ti, V, Cr, Fe, Co, Ni, Cu, Zn, and Ta in recycled cemented tungsten carbide is developed including preliminary microwave sample decomposition in a steam pressure vessel (autoclave). We have specified the composition of the reaction mixture for sample dissolution and optimized the parameters of microwave heating in the autoclave. Correctness of the results is proved by the method of sample weight variation and spike tests. The results of analysis are compared with the data obtained by standardless method of X-ray fluorescence spectrometry. The technique is characterized by good reproducibility and allows significant reduction of the analysis time owing to the combination of the multielement method of ICP-AES and microwave sample preparation.

Total risk of a false decision on conformity of an alloy due to measurement uncertainty and correlation of test results

Total risk (probability) of a false decision on conformity of an alloy due to measurement uncertainty and correlation of test results is quantified. As an example, a dataset of test results of a PtRh alloy is studied when contents of four components of the alloy composition are under control. There are specification limits for contents of 1) Pt and 2) Rh; 3) three precious impurities - Au, Ir and Pd, and 4) eight impurities, both precious Au, Ir, Pd, and non-precious Fe, Pb, Si, Sn, Zn. Test results of 100 batches of the alloy produced at the same plant, obtained by X-ray fluorescence and optical atomic emission spectrometry methods at the plant laboratory, were in the dataset. The Pt content was tested based on the mass balance. Measurement uncertainties of the test results are estimated summarizing data of validation reports of the measurement procedures for different elements/analytes. These test results are correlated because of the natural chemical origin of the raw materials used in the alloy production and mass balance constraints. Correlations between test results for two pairs of the components (Pt vs. Rh, and the three vs. the eight impurities) were strong. To assess the correlation effects on the total risk, the study was performed for two scenarios considering 1) correlated test results for all four components, and 2) practically uncorrelated test results for two components only - Rh and the eight impurities. A multiparameter Bayesian approach was applied for total risk evaluation, where the observed correlations are taken into account within the experimental correlation matrix. This matrix influenced all subsequent multivariate calculation results. It was shown that simplification of the testing by reducing the number of components under control leads to a significant increase of the probability of a false decision on conformity of an alloy batch randomly drawn from a statistical population of such batches. Core of the developed R code, used for the risk calculations, is presented.

Instrumental detection limit and sensitivity of K and L shell X-ray emission lines of 17 Cl, 37 Rb, and 38 Sr elements using PC-WDXRF spectrometer

This work was aimed to improve the instrumental detection limit and sensitivity of 17Cl, 37Rb, and 38Sr elements present in solid samples by using the advanced polychromatic wavelength dispersive X-ray fluorescence spectrometry method. Instrumental measuring parameters, as well as study of calibration curves of K and L shell spectral lines, were evaluated to select the best conditions for 17Cl, 37Rb, and 38Sr quantification. From the results, it was observed that the detection limits of the Rb Kα and Sr Kα spectral lines were lower than those of the Kβ1,3 and Lα spectral lines. From the calibration curves, it was concluded that Kα spectral lines are more suitable than Kβ1,3 and Lα lines to identify the traces of 17Cl, 37Rb, and 38Sr elements in different types of solid samples.