scholarly journals Comparation of Pressed Powder Pellet and Fused Glass Bead Preparation Techniques for Mayor Elements Analysis of Rock Samples using X-Ray Fluorescence (XRF)

2020 ◽  
Vol 31 (2) ◽  
pp. 24-27
Author(s):  
Asep Rohiman ◽  
Agus Saiful Arifin
Keyword(s):  
Sample Preparation ◽  
Glass Bead ◽  
Chemical Elements ◽  
Preparation Technique ◽  
Standard Samples ◽  
X Ray ◽  
Rock Samples ◽  
Minor Elements ◽  
Rock Types ◽  
Analysis Process

The composition of chemical elements in rock samples can be used as a tool for classifying rock types, predicting the depositional environment, rock age, and the tectonic environment in which the rock is formed. X-Ray Fluorescence (XRF) is one of the instruments used to analyze rock samples. The advantage of using XRF analysis is that the analysis process can be done more quickly, easily, accurately, and does not damage the sample. However, before measurements are made using the XRF instrument it needs to be supported by an appropriate sample preparation process. In this study, optimal conditions in the standard (CRM) rock sample preparation of GBW 07105 and JR-1 have been studied. The parameters studied were variations in the composition ratio of Cellulose Mycro Crystalin (CMC) with standard (CRM) samples, namely 1: 4 and 1: 3. The technique of mixing the sample is done by using a mortar grinder and a shaker. Optimization of sample preparation was carried out using pressed powder pellet and fused glass bead techniques. Based on the data obtained from the analysis results the best ratio of binders to standard samples is 1: 3. The pressed powder pellet preparation technique is the best technique in analyzing samples using the X-Ray Fluorescence method. Further studies also need to be carried out to analyze minor elements and traces (REEs).

scholarly journals μXRF Mapping as a Powerful Technique for Investigating Metal Objects from the Archaeological Site of Ferento (Central Italy)

2020 ◽  
Vol 6 (7) ◽  
pp. 59
Author(s):  
Giuseppe Capobianco ◽  
Adriana Sferragatta ◽  
Luca Lanteri ◽  
Giorgia Agresti ◽  
Giuseppe Bonifazi ◽  
...  
Keyword(s):  
Chemical Elements ◽  
Central Italy ◽  
Principal Component ◽  
Archaeological Site ◽  
Point Of View ◽  
Multivariate Curve Resolution ◽  
Polycapillary Optics ◽  
X Ray ◽  
Minor Elements ◽  
Major Chemical

This research concerns the application of micro X-ray fluorescence (µXRF) mapping to the investigation of a group of selected metal objects from the archaeological site of Ferento, a Roman and then medieval town in Central Italy. Specifically, attention was focused on two test pits, named IV and V, in which metal objects were found, mainly pertaining to the medieval period and never investigated before the present work from a compositional point of view. The potentiality of µXRF mapping was tested through a Bruker Tornado M4 equipped with an Rh tube, operating at 50 kV, 500 μA, and spot 25 μm obtained with polycapillary optics. Principal component analysis (PCA) and multivariate curve resolution (MCR) were used for processing the X-ray fluorescence spectra. The results showed that the investigated items are characterized by different compositions in terms of chemical elements. Three little wheels are made of lead, while the fibulae are made of copper-based alloys with varying amounts of tin, zinc, and lead. Only one ring is iron-based, and the other objects, namely a spatula and an applique, are also made of copper-based alloys, but with different relative amounts of the main elements. In two objects, traces of gold were found, suggesting the precious character of these pieces. MCR analysis was demonstrated to be particularly useful to confirm the presence of trace elements, such as gold, as it could differentiate the signals related to minor elements from those due to major chemical elements.

scholarly journals Does bacterial weathering play a significant role in rock weathering?

2021 ◽  
Author(s):  
Adil Binal ◽  
Aylin Sel
Keyword(s):  
Significant Role ◽  
Chemical Elements ◽  
Bacterial Species ◽  
Building Stone ◽  
Rock Weathering ◽  
Experimental Conditions ◽  
Rock Samples ◽  
Rock Types ◽  
Stone Materials ◽  
Biological Weathering

Abstract Bacterial weathering plays a significant role in rock weathering, yet only a limited number of studies was conducted on this topic. The recent rapid developments in geomicrobiology are expected to increase the pace of research in this area. The extent and duration of the biological weathering processes on mineral and rock samples and minerals preferred by bacteria are still not fully understood due to the wide variety of both bacterial species and rock types. Biological weathering of rock types found in Turkey has also not been studied before. Here, we investigated the effects of two species of bacteria actively contributing to rock weathering on three rock types commonly used as building stone materials in Turkey. Granite, andesite, and limestone samples could interact with Bacillus species (B. subtilis and B. pumilus) in closed system reactors. Samples obtained from these reactors were analysed via Scanning Electron Microscopy (SEM) monitoring to identify morphological features and chemical composition changes. Chemical elements consumed most by bacteria were identified. Changes in the colour index were determined via RGB measurements. The effects of experimental conditions on bacterial growth were monitored via daily optical density measurements. The effects of bacteria on the physical properties of rock samples were also evaluated. B. subtilis and B. pumilus were found to be more aggressive on limestone/andesite and granite, respectively.

scholarly journals Tropical soils characterization at low cost and time using portable X-ray fluorescence spectrometer (pXRF): Effects of different sample preparation methods

2018 ◽  
Vol 42 (1) ◽  
pp. 80-92 ◽  
Author(s):  
Sérgio Henrique Godinho Silva ◽  
Elen Alvarenga Silva ◽  
Giovana Clarice Poggere ◽  
Luiz Roberto Guimarães Guilherme ◽  
Nilton Curi
Keyword(s):  
Sulfuric Acid ◽  
Sample Preparation ◽  
Chemical Elements ◽  
Total Content ◽  
Tropical Soils ◽  
Acid Digestion ◽  
Preparation Methods ◽  
X Ray ◽  
Fluorescence Spectrometer ◽  
Sample Preparation Methods

ABSTRACT Portable X-ray fluorescence spectrometer (pXRF) has been recently adopted by the Soil Science community for uses in both field and laboratory, obtaining the total content of several chemical elements in a few seconds. Sulfuric acid digestion is an expensive and time-consuming laboratory analysis that provides contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5, important for soil studies. Due to few pXRF studies in tropical soils, this work aimed to compare contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5 obtained by pXRF with sulfuric acid digestion results, and to evaluate the effects of varying forms of preparing soil samples and scanning with pXRF on the resulting values in Brazilian soils. Soils were scanned in five conditions in-field (in situ) and in laboratory, evaluating varying sample preparation methods, particle sizes and soil moisture. Four pXRF scanning operational modes were tested. Linear regressions were adjusted between results of pXRF and sulfuric acid digestion. Equations were validated with an independent set of samples. Statistical analyses compared the methods of preparing the samples. Adequate linear models reached R2 of 0.99 and 0.89 for Fe2O3 and TiO2, respectively. Validation promoted R2 greater than 0.97 and RMSE and ME close to zero for both oxides. Statistical differences of pXRF results were found among the methods of preparing samples. pXRF spectrometer has great potential to obtain Fe2O3 and TiO2 content rapidly and economically with high correspondence with laboratory results of sulfuric acid digestion analysis. Varying methods of preparing the samples promote differences in the results of pXRF.

Calculation of Theoretical Alpha Coefficients for XRF Analysis of Major and Minor Elements in Iron-rich Geological Samples

1995 ◽  
Vol 50 (9) ◽  
pp. 817-825 ◽  
Author(s):  
Younan Hua ◽  
C. T. Yap
Keyword(s):  
Fluorescence Analysis ◽  
Fundamental Parameter ◽  
Minor Components ◽  
Geological Samples ◽  
Standard Samples ◽  
X Ray ◽  
Xrf Analysis ◽  
Minor Elements ◽  
On Line ◽  
The Given

Abstract This paper introduces a method of calculating theorectical alpha coefficients for the X-ray fluorescence analysis of major and minor components in iron-rich samples. We choose a group of hypothetical standard samples whose average concentrations are those of the actual samples. The theoretical X-ray fluorescence relative intensities of the given components are calculated using the fundamental parameter NRLXRF program. We derived formulas from the Lachance-Traill equation and used these to calculate the basic, hybrid and modified alpha coefficients which are used respectively for the analysis of elements in compact specimens, oxides in compact specimens and oxides in diluted specimens. In order to use the theoretical alpha coefficients on-line, we also discuss the calculation of the alpha coefficients used in the D.J model.

EDXRF Determination of Major and Minor Elements in Compound Fertilizers

1984 ◽  
Vol 28 ◽  
pp. 215-220
Author(s):  
Leif Højslet Christensen ◽  
Leif Rasmussen
Keyword(s):  
Sample Preparation ◽  
Unique Solution ◽  
Fundamental Parameter ◽  
Fluorescence Technique ◽  
Matrix Correction ◽  
X Ray ◽  
Minor Elements ◽  
Elemental Analyses ◽  
Precision And Accuracy

AbstractThe combination of the energy-dispersive x-ray fluorescence technique and a backscatter/fundamental parameter-based matrix correction approach provides a new and unique solution to elemental analyses of fertilizers. This is demonstrated by means of results obtained for three reference materials and a range of in-house fertilizers. The results further demonstrate problems of sample preparation as well as the precision and accuracy of the method.

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