Portable XRF Device Research Articles

Elemental analysis using portable X-ray fluorescence: Guidelines for the study of dry human bone

ObjectiveX-ray fluorescence (XRF) is a non-destructive technique that measures the elemental concentration of different materials, including human bone. Recently, it began to be applied to paleopathological studies due to the development of portable devices and their relative ease of use. However, the lack of uniform procedures hampers comparability and reproducibility. This paper aims to provide guidelines for an efficient and standardized evaluation of bone elemental composition with a portable XRF (pXRF) device. MaterialsThis technical note is based on the application of the Thermo Scientific Niton XL3t 900 GOLDD+. MethodsThis work includes suggestions for the choice and preparation of human bone samples, both from archaeological context and documented collections, and methodological procedures in pXRF setup, such as choice of calibration, assessment of accuracy, and analysis run time. Additionally, recommendations for data validation and statistical analysis are also included. ConclusionsThis technique has great potential in paleopathology since bone chemical variations may be associated with different pathological conditions, environmental contamination (e.g., lead), and/or administered treatments, such as mercury. Following an expected increase in the number of studies, it is essential to establish good practices that allow results from different researchers to be comparable. SignificanceX-ray fluorescence is a non-destructive technique that measures small concentrations (ppm) of elements from magnesium (12Mg) through bismuth (83Bi). LimitationspXRF does not detect elements lighter than Mg, and its lower energy excitation penetrates less than other techniques. Suggestions for further researchOther research groups should test these guidelines and comment on their usefulness and replicability.

Quantification of Chlorides and Sulphates on Concrete Surfaces Using Portable X-ray Fluorescence. Optimization of the Measurement Method Using Monte Carlo Simulation.

A correct assessment of the pathologies that can affect a reinforced concrete structure is required in order to define the repair procedure. This work addresses the challenge of quantifying chlorides and sulphates directly on the surface of concrete. The quantification was carried out by means of X-ray fluorescence analysis on the surface of concrete specimens at different points with portable equipment. Concrete prisms were made with different amounts of NaCl and Na2SO4. To avoid the influence of coarse aggregate, a qualitative estimate of the amount of coarse aggregate analyzed has been made, although the results show that there is no significant influence. Monte Carlo simulations were carried out in order to establish the necessary number of random analyses of the mean value to be within an acceptable range of error. In the case of quantifying sulphates, it is necessary to carry out six random analyses on the surface, and eight measurements in the case of quantifying chlorides; in this way, it is ensured that errors are below 10% in 95% of the cases. The results of the study highlight that a portable XRF device can be used in situ to obtain concentrations of chlorides and sulphates of a concrete surface with good accuracy. There is no need to take samples and bring them to a laboratory, allowing lower overall costs in inspection and reparation works.

Evaluation of a portable XRF device for in vivo quantification of lead in bone among a US population

BackgroundLead (Pb) concentration in bone is a reliable biomarker for cumulative Pb exposure and studying associated health outcomes. However, the standard K-shell fluorescence (KXRF) bone Pb measurement technology has limitations in large-scale population studies. ObjectiveWe compared measurements from a portable XRF device and a KXRF device. MethodsWe measured bone Pb concentrations in vivo using portable XRF and KXRF, each measured at the mid-tibia bone in 71 people, 38–95 years of age (mean ± SD = 63 ± 11 years) living in or near three Indiana communities, US; 10 participants were occupationally exposed. We estimated the correlation between bone Pb concentrations measured by both devices. We also examined the extent to which the detection limit (DL) of the portable XRF was influenced by scan time and overlying soft tissue thickness. Finally, we quantified the associations of estimated bone Pb concentration with age and age with soft tissue thickness. ResultsThe mean bone Pb concentration measured via portable XRF was 12.3 ± 16.7 mg Pb/kg dry bone. The uncertainty of a 3-minute (N = 60) in vivo portable XRF measurement ranged from 1.8 to 6.3 mg/kg, in the context of soft tissue thickness ranging from 2 to 6 mm. This uncertainty was reduced by a factor of 1.4 with 5-minute measurements (N = 11). Bone Pb measurements via portable XRF and KXRF were significantly correlated: r = 0.48 for all participants, and r = 0.73 among participants with soft tissue thickness < 6 mm (72% of the sample). Bone Pb concentrations were higher among participants who were older or were occupationally exposed to Pb. Soft tissue thickness decreased with age. ConclusionWith its ease of use, portability, and comparable sensitivity with conventional KXRF systems, the portable XRF could be a valuable tool for non-invasive quantification of bone Pb in vivo, especially for people with thinner soft tissue.

Geochemical analyses result of prehistoric pottery from the site of Tol-e Kamin (Fars, Iran) by pXRF

ABSTRACT A series of pottery samples from the Iranian site Tol-e Kamin, ranging from pre-historical period to the New Elamite, were analyzed in order to study the geochemical variability of the pottery assemblage. A total amount of 168 measurements were obtained using a portable XRF device and were statistically handled. The results could successfully distinguish the geochemical composition of potteries from the chalcolithic to the New Elamite periods in the Kur River Basin. A major shift in the use of different clay sources could be detected since the Proto Elamite period and afterward, in which the carbonated and marl content clays represented by Ca, Ba and Sr shifted to clay sources with a tendency to non-carbonate silty clay Al, Ti, and Fe from a different geological background. The results stress the importance of further provenance studies to address issues of trade and exchange possibilities in southwestern Iran.

Specialized pottery production in Dalma tradition; a statistical approach in pottery analysis from Soha Chay Tepe, Zanjan, Iran

Soha Chay Tepe is located on the right bank of the Sojasrud River and lies within the province of Zanjan, in Western Iran. During excavation, one cultural period and two architectural phases have been distinguished, contemporary to the Middle Chalcolithic period (Dalma tradition). More complex activities in Chalcolithic period are well studied and accepted by researchers, however analyzing pottery according to stylistic attributes revealed more details about systematic pottery production of this period in the west of Iran. A total of 96 pottery samples was chemically analyzed with portable XRF device in order to detect clustering pattern. Results have revealed meaningful similarities concerning composition between the sampled groups in regards to their decoration style. It showed that the potters of Soha Chay Tepe might have made distinct operation decisions for their various pottery style productions. Portable XRF with relative internal calibration used in this study confirmed that it has high potential in compositional studies of ceramic regarding to more detailed questions.

A comparative study of PGAA and portable XRF used for non-destructive provenancing archaeological obsidian

Prompt Gamma Activation Analysis has successfully been applied to provenance research on Carpathian obsidians. The effectiveness of PGAA and a portable XRF device in discriminations of Carpathian, Lipari, Sardinia and Melos origin obsidians was compared on 75 representative geological samples obtained from the Lihotheca Collection of the Hungarian National Museum. Bivariate analyses and Principal Component Analysis have been made based on the individual PGAA and XRF data, as well as on the combination of both data types. Instrumental Neutron Activation Analysis was also applied on a group of 17 samples. The advantages and disadvantages of each method are discussed to determine the best possible way of investigations to fingerprint and characterize long-distance trade items with minimal damage to the samples.

Lead Determination and Heterogeneity Analysis in Soil from a Former Firing Range

Public places can have an unknown past of pollutants deposition. The exposition to such contaminants can create environmental and health issues. The characterization of a former firing range in Athens, Greece will allow its monitoring and encourage its remediation. This study is focused on Pb contamination in the site due to its presence in ammunition. A dense sampling design with 91 location (10 m apart) was used to determine the spatial distribution of the element in the surface soil of the study area. Duplicates samples were also collected one meter apart from 8 random locations to estimate the heterogeneity of the site. Elemental concentrations were measured using a portable XRF device after simple sample homogenization in the field. Robust Analysis of Variance showed that the contributions to the total variance were 11% from sampling, 1% analytical, and 88% geochemical; reflecting the suitability of the technique. Moreover, the extended random uncertainty relative to the mean concentration was 91.5%; confirming the high heterogeneity of the site. Statistical analysis defined a very high contamination in the area yielding to suggest the need for more in-depth analysis of other contaminants and possible health risks.

The use of various X-ray fluorescence analysis modalities for the investigation of historical paintings: The case study on the Late Gothic panel painting

The presence of heavy chemical elements in old pigments is possible to identify in historical paintings using X-ray fluorescence analysis (XRF). This is a non-destructive analytical method frequently used in examination of objects that require in situ analysis, where it is necessary to avoid damaging the object by taking samples. Different modalities are available, such as microanalysis, scanning selected areas, or depth profiling techniques. Surface scanning is particularly profitable since 2D element distribution maps are much more understandable than the results of individual analyses. Information on the layered structure of the painting can be also obtained by handheld portable systems. Results presented in our paper combine 2D element distribution maps obtained by scanning analysis, and depth profiling using conventional XRF. The latter is very suitable for objects of art, as it can be evaluated from data measured with portable XRF device. Depth profiling by conventional XRF is based on the differences in X-ray absorption in paint layers.The XRF technique was applied for analysis of panel paintings of the Master of the St George Altarpiece who was active in Prague in the 1470s and 1480s. The results were evaluated by taking micro-samples and performing a material analysis.