A fusion method for preparing glass samples of peridotitic and picritic rock compositions for bulk analysis

1995 ◽  
Vol 59 (395) ◽  
pp. 267-271 ◽  
Author(s):  
N. W. A. Odling
Keyword(s):  
Bulk Composition ◽  
Fluorescence Analysis ◽  
Significant Loss ◽  
Glass Beads ◽  
Crystalline Material ◽  
Time Analysis ◽  
Bulk Analysis ◽  
X Ray ◽  
Natural Rock ◽  
Microscope Stage

AbstractA design for a micro furnace and a fusion technique are described by which silicate materials (in particular picritic and peridotitic rock compositions) may be fused and quenched to a homogeneous glass without significant loss of components, for the purposes of bulk analysis. The furnace consists of a Pt wire electrical resistance heater mounted in a furnace assembly which is fitted to a microscope stage. Microscopic examination of the sample during the fusion process allows the sample to be quenched as soon as all crystalline material has been fused and thus minimizes the loss of iron and alkalis due either to over-heating or prolonged fusion time. Analysis of glass beads of a model peridotite composition (analysed independently by X-ray fluorescence analysis) shows that for typical fusion times (5–10 seconds) the bulk composition is preserved at distances of > 25 µm from the margins of the glass beads. Analysis of natural rock powders of known composition shows that the method can be used to analyse whole rock compositions. The furnace is simple to construct and cheap to run and provides a simple and rapid method of producing glass samples for bulk analysis.

scholarly journals X-Ray Fluorescence Analysis of a Gold Ibex and other Artifacts from Akrotiri

2019 ◽  
Vol 11 ◽  
Author(s):  
A. G. Karydas ◽  
T. Pantazis ◽  
C. Doumas ◽  
A. Vlachopoulos ◽  
P. Nomikos ◽  
...  
Keyword(s):  
Bulk Composition ◽  
Fluorescence Analysis ◽  
Wall Painting ◽  
Inorganic Elements ◽  
X Ray ◽  
Wide Range ◽  
Soldering Technology ◽  
Excavation Area

In-situ X-ray fluorescence analysis (XRF) of ancient artifacts from the excavation area was performed using a novel X-ray instrumentation, composed of a portable silicon PIN thermoelectrically cooled X-ray detector, a miniature X-ray source, and portable data acquisition devices. The main objective of the analyses in Akrotiri was to explore the potential of the technique to provide answers to a wide range of archaeometric questions regarding the bulk composition of metal alloys, especially of gold, the characterization of corrosion products in bronze artifacts, identification of inorganic elements which are fingerprints of the minerals used in wall-painting pigments, and of the painting materials and techniques used for the decoration of clay vase surfaces. Among the analysed artifacts are a unique gold ibex, a bronze dagger and blade, various pigments from the wall paintings of room 3 in Xeste 3, decoration pigments from rosettes of faience, a bichrome jug, and other clay vases. The results of the in-situ XRF survey, primarily those of the bulk composition and soldering technology of the gold ibex, are discussed and compared with literature.

scholarly journals Comparative analysis of X-ray fluorescence methods for elemental composition determination of the archaeological ceramics from low sample quantity

2021 ◽  
Vol 25 (1) ◽  
pp. 20-33
Author(s):  
G. V. Pashkova ◽  
◽  
M. M. Mukhamedova ◽  
V. M. Chubarov ◽  
A. S. Maltsev ◽  
...  
Keyword(s):  
Elemental Composition ◽  
Inductively Coupled Plasma ◽  
Bulk Composition ◽  
Fluorescence Analysis ◽  
Total Reflection ◽  
Late Neolithic ◽  
Burial Site ◽  
Archaeological Ceramics ◽  
X Ray

Wavelength-dispersive X-ray fluorescence analysis (WDXRF) and total-reflection X-ray fluorescence (TXRF) analysis were applied to study the elemental composition of the Late Neolithic ancient ceramics collected at the Popovsky Lug burial site (Kachug, Upper Lena river, Russia). Semi-quantitative non-destructive analysis of ceramic pieces showed that measurements of the upper and lower sides of the ceramic are less informative than the measurement of its cut. Various sample preparation techniques for the low quantity of crushed ceramics such as fusion, pressing and preparation of suspensions were compared to preserve the material. Samples were prepared as 150 mg fused beads and 250 mg pressed pellets for WDXRF, and as suspensions of 20 mg sample based on the aqueous solution of the Triton X-100 surfactant for TXRF. Certified methods were used to validate the obtained contents of rock-forming oxides and inductively coupled plasma mass spectrometry was used to confirm the results of trace elements determination. Based on the carried-out studies, a combination of the wavelength-dispersive X-ray fluorescence analysis (glass) and total-reflection X-ray fluorescence analysis (suspension) methods was chosen to obtain the data on the elemental bulk composition of archaeological ceramics. The proposed combination allowed the quantitative determination of Na, Mg, Al, Si, P, K, Ca, Ti, Mn, Fe, V, Cr, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Pb, and Ba from the sample of crushed ceramics weighing only about 170 mg.

Bulk Composition from Electron Beam Excited X-RAY Analysis?

1992 ◽  
Vol 50 (2) ◽  
pp. 1662-1663
Author(s):  
Charles R. Herrington ◽  
Joseph D. Geller
Keyword(s):  
Electron Beam ◽  
Inductively Coupled Plasma ◽  
Bulk Composition ◽  
Optical Emission ◽  
X Rays ◽  
Bulk Analysis ◽  
X Ray ◽  
Inductively Coupled ◽  
Electron Beam Excitation ◽  
Excitation Volume

Bulk analysis is often accomplished using techniques such as classical wet chemistry, atomic absorption, x-ray fluorescence, inductively coupled plasma, combustion procedures, and optical emission spectroscopy. To use "ZAF" or other programs (which are for electron beam excited x-ray spectra) to convert "k" or intensity ratios to concentration it is required that the electron beam excitation volume be homogeneous. The correction programs calculate atomic number, absorption, and fluorescence factors from the detected x-ray intensity fractions assuming the x-rays are coming from this homogeneous volume. If the specimen is not homogeneous within the excitation volume the program will miscalculate the factors. Often used (but incorrectly applied) methods for analyzing large areas on bulk materials are defocusing of the electron beam and rastering a focussed beam over areas to cover the phases present. The purpose of this study is to demonstrate the dangers of improperly applying these corrections and to demonstrate the alternate technique of using phase area analysis combined with the chemistry and density of each phase to arrive at bulk composition.

Quantitative verification of 1 : 100 diluted fused glass beads for X-ray fluorescence analysis of geological specimens

2020 ◽  
Vol 35 (12) ◽  
pp. 2826-2833
Author(s):  
Ding-Shuai Xue ◽  
Ben-Xun Su ◽  
Dan-Ping Zhang ◽  
Yan-Hong Liu ◽  
Ju-Jie Guo ◽  
...  
Keyword(s):  
Preparation Method ◽  
Fluorescence Analysis ◽  
Small Sample ◽  
Glass Beads ◽  
New Method ◽  
Icp Oes ◽  
Acid Attack ◽  
X Ray ◽  
Accuracy And Precision ◽  
Quantitative Verification

This paper proposed a semi-automated small sample (30 mg) preparation method. The accuracy and precision of this new method were verified by measuring two CRMs among XRF, ICP-OES (fusion), and ICP-OES (acid attack) tools.

REE redistributions during granite weathering: Implications for Ce anomaly as a proxy for paleoredox states

2020 ◽  
Vol 105 (6) ◽  
pp. 848-859 ◽  
Author(s):  
Koji Ichimura ◽  
Kenzo Sanematsu ◽  
Yoshiaki Kon ◽  
Tetsuichi Takagi ◽  
Takashi Murakami
Keyword(s):  
Field Emission ◽  
Inductively Coupled Plasma ◽  
Atmospheric Oxygen ◽  
Fluorescence Analysis ◽  
Significant Loss ◽  
Formation Mechanisms ◽  
Weathering Profile ◽  
X Ray ◽  
Ce Anomaly ◽  
Topmost Layer

Abstract Different responses of Ce to the redox state from those of the other light rare earth elements (LREEs) can be used to understand paleoredox states. To establish the possibility of using the Ce anomaly as a proxy for paleo-environments, we examined the mineralogical and chemical characteristics of bulk samples and REE-bearing minerals of a modern weathering profile developed on granite, by X-ray fluorescence analysis, laser-ablation inductively coupled plasma mass spectrometry, field emission electron microprobe analysis, field emission scanning electron microscopy, and X-ray diffractometry. Bulk samples showed no significant Ce-anomalies except for the topmost layer that had a positive Ce-anomaly reflecting significant loss of LREEs except for Ce. Allanite-(Ce), primary REE-bearing mineral, contributed to ~100% of La, Ce, Pr, and Nd in the parent rock, and gradually decreased in amount toward the topmost layer. Secondary cerianite-(Ce) [Ce(IV)O2] was observed in the weathering profile, especially at shallower depths. Secondary rhabdophane-(La), -(Ce), -(Nd), and -(Y) were also observed in the weathering profile but in less amounts in the topmost layer. The occurrences of rhabdophane-(La) and -(Nd) in contact with halloysite, a secondary clay mineral, suggest probable adsorption of REEs onto halloysite prior to their formation. Similar formation mechanisms are likely for rhabdophane-(Ce) that commonly occurred in grain boundaries and was usually formed in contact with halloysite. Rhabdophane-(Y) occurred in association with fluorapatite. The ratios of La, Pr, and Nd of rhabdophane-(La), -(Ce), and -(Nd) were similar to that of allanite-(Ce), suggesting that these LREEs are inherited from allanite-(Ce) and behave similarly before the formation of rhabdophane. Different negative Ce-anomaly values of rhabdophane [i.e., ~0.03–0.34 for rhabdophane-(La), -(Nd), and -(Y), and ~0.6 for rhabdophane-(Ce)] can result from a difference in intensity of the formation of cerianite-(Ce) prior to the precipitation of rhabdophane. We have classified LREE redistributions in both secondary minerals and bulk weathered samples during oxic weathering and suggested that Ce anomaly can provide useful information on anoxic weathering and thus atmospheric oxygen evolution in the Precambrian if Ce anomalies of both bulk samples and secondary REE-bearing minerals are determined.

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