Handheld X-ray Fluorescence Analyzer Research Articles

Effects of soil and phylogeny on sulfur and phosphorus concentrations in wild plants on volcanic and non-volcanic soils in Japan

ABSTRACT Andosols are soils characterized by relatively high sulfur concentrations, but also by their low phosphorus availability for crops and vegetables. We assessed the effect of soil type on the concentrations of sulfur and phosphorus in plants using handheld X-ray fluorescence (XRF) analysis on herbarium specimens collected from Andosols and non-volcanic soils in Japan. The sulfur concentrations in plants from Andosols were higher than plants from non-volcanic soils, but there was no significant difference between their foliar phosphorus concentrations. Only three specimens out of 1203 herbarium specimens were below the sulfur concentration (1000 mg kg−1) needed for adequate growth of crops, but about half of specimens were below that for phosphorus (2000 mg kg−1). The sulfur concentrations were high in herbaceous plants, especially in plants from the Brassicaceae and Liliaceae families. Overall, the results show that the sulfur concentrations in wild plants from Japan were higher in Andosols, with a low risk for sulfur deficiency. In contrast, the effect of soil type on the phosphorus concentrations in plants was small, and this may be explained because most wild plants grow under phosphorus-limiting conditions. Finally, the analysis reveals a strong correlation between sulfur and phosphorus concentrations in plants, suggesting the existence of a mechanism that controls the sulfur and phosphorus concentration ratios.

Radiation Techniques for Tracking the Progress of the Hydrometallurgical Leaching Process: A Case Study of Mn and Zn

With advancements in hardware and software, non-destructive radiometric analytical methods have become popular in a wide range of applications. A typical case is the study of the leaching process of metals from mineral ores and mine tailings. The objective of the current study was to develop a radiometric method based on neutron activation analysis (NAA), in particular, delayed gamma neutron activation analysis (DGNAA), to monitor the process of Mn and Zn leaching from Ti ore, Cu mine tailings, and Zn-Pb mine tailings. The DGNAA method was performed using a neutron source: a deuterium-tritium (D-T) neutron generator for Mn and a MARIA research nuclear reactor for Zn. Laboratory-scale Mn leaching from Ti ores, Cu tailings, and Zn-Pb tailings was investigated using delayed gamma-rays of 56Mn (half-life of 2.6 h). The dissolution efficiencies of Mn were found to increase with interaction time and HCl concentration (1 to 5 M) and to vary with the leaching temperature (22.5 to 110 °C). Such results were found to agree with those obtained by total reflection X-ray fluorescence (TXRF) spectrometry for the same samples. 65Zn (half-life of 244 days) was chosen to investigate real-time/online leaching of Zn in Ti ore, Cu tailings, and Zn-Pb tailings. During online monitoring, Zn recovery was also reported to increase with increased leaching time. After approximately 300 min of leaching, 80%, 79%, and 53% recovery of Zn in Zn-Pb tailings, Ti ore, and Cu tailings, respectively, were reported. Theoretically, developed mathematical prediction models for 65Zn radiotracer analysis showed that the spherical diffusion model requires much less time to attain saturation compared to the linear diffusion model. The results of NAA for Zn were compared with those obtained by handheld X-ray fluorescence (handheld-XRF) and TXRF analysis. The analyzed samples encompassed leached Ti ore, Cu tailings, and Zn-Pb tailings which were subjected to different conditions of leaching time, temperature, and HCl concentrations. The XRF analysis confirmed that the leaching efficiencies of Zn rise with the increase in leaching time and HCl concentration and fluctuate with leaching temperature. The developed approach is important and can be applied in laboratories and industrial setups for online monitoring of the recovery of any element whose isotopes can be activated using neutrons. The efficiency of the metal-recovery process has a direct impact on the normal operation and economic advantages of hydrometallurgy.

Elemental Analysis of Tetragonula laeviceps Propolis by X-Ray Fluorescence Spectroscopy

Propolis, a natural substance produced by stingless bees (Tetragonula laeviceps), consists of a blend of resins collected from plant exudates and other botanical sources. Bees utilize propolis for hive maintenance and protection against predators. Propolis is widely used in various therapeutic formulations, including treatments for upper respiratory tract infections, burns, acne, herpes, and neurodermatitis. The propolis samples were analyzed using Olympus DELTA Professional Handheld XRF Analyzer. This study employs X-Ray Fluorescence (XRF) analysis to investigate the elemental composition of propolis. Data results of XRF were presented in percentage with limit detection into ppm (%, ppm). The result showed that the three most dominant elements composition in propolis sample from FB 1 were Ca(77.12%) ; K(11.59%), and SO3(5.18%). Propolis Sample from KP 1 were Fe(31.73%);Ca (26.42%); and K(14.04%). Propolis Sample from KP 2 were K(28.32%); P2O5(24.35%); and Ca(18.82%). The conclusion was that the three propolis samples contained 2 constant elements, namely Calcium (Ca) and Potassium (K). Calcium and Potassium were found to be essential functions in all organisms.

Evaluating the Application of Portable Handheld X-ray Fluorescence (XRF) Scanner for Determining Seafood Provenance: A Case Study on Penaeus monodon.

Seafood elemental profiling (SEP) is the quantification of a range of elements in seafood products and may serve in addressing questions of seafood provenance and quality. Traditional methods for analyzing soft tissue present several limitations for the industry-level use of SEP. Portable handheld X-ray fluorescence (pXRF) analysis is a promising alternative to conventional methods; however, its application for biological analysis has not been fully established. Intact giant tiger prawn (Penaeus monodon) abdomens were analyzed with a Vanta M series XRF portable analyzer following a novel soft tissue protocol. Exploratory statistics (principal component analysis, nonmetric multidimensional scaling, and canonical discriminant analysis), as well as random forest models, have been implemented with pXRF profiles, yielding 81% accuracy when assigning the geographical origin of P. monodon. The results of this study highlight that SEP via pXRF is a viable industry-level analysis, and its application will depend on improved instrument calibration to account for fluctuating wetness factors that are influenced by cooking, storage, and other pre- and post-harvest treatments.

Improvement approach for determination of cadmium at trace levels in soils by handheld X-ray fluorescence analyzers

Determining trace levels of cadmium in soils by the handheld X-ray fluorescence analyzer is severely hampered by the spectrum baseline. To improve the peak-to-background ratio of the characteristic Cd-Kα X-ray, the filter structure, material, and thickness were optimized; to find the most informative variables for the PLS analysis of trace Cd, the related information enhancement competitive adaptive reweighted sampling (rieCARS) was proposed as a variable selection approach, which contains correlated spectral selection (CSS), double logarithmic processing(DLP), competitive adaptive reweighted sampling (CARS). To eliminate the interference of the K-series line of the Ag anode target on trace Cd, the X-ray tube was used with the Tungsten anode target. One combined filter containing a 0.4 mm thickness Cu and a 0.5 mm thickness Fe was selected, which was placed between the X-ray tube and the sample. The instrumental limit of detection for the Cd descended from 32 mg/kg to 0.02 mg/kg . Sixty-four soil samples were used to establish the model for the filtered signal. The model was compared with PLS, CARS+PLS, DLP + CARS+PLS, CSS + PLS, and CSS + CARS+PLS. The application of rieCARS improved the performance of the calibration model for trace Cd. The coefficient of determination R2 of the rieCARS+PLS model on the calibration set was 0.990; the RMSEP on the test set was 0.28 mg/kg; the average of the relative error in the Poyang Lake soil samples was 0.18; the relative standard deviation for the thirteen replicates of the GSD17 was 0.07. The developed analytical procedure will lay the foundation for the analysis of heavy metal pollution sources in soils and ecological sustainability assessment.

Non-destructive screening methodology based on handheld XRF for the classification of concrete: cement type-driven separation

The utilization of locally available concrete waste for producing recycled concrete aggregates is recognized as one of the most sustainable ways of satisfying the growing demand for concrete production. However, the quality of concrete waste depends on its origin and it may significantly differ from one concrete structure to another. Knowing the chemical composition of the parent concrete is crucial for determining or verifying the origin of the raw materials. For this reason, pre-demolition concrete waste streams need to be characterized and classified. Therefore, a new non-destructive method for determining the cement and aggregate type in hardened concrete using handheld X-ray fluorescence (hXRF) analyser is presented in this paper. The method was tested on different raw powders and on concretes containing different types of cements including CEM I 42.5 N (Portland cement), CEM II/B-V 42.5 N (Portland-fly ash cement), CEM III/B 42.5 N (GGBFS cement). Combined desktop XRF and Energy-dispersive X-ray Spectroscopy (EDS) measurements were used for the purpose of validation. The results revealed that the curing of concrete affects the results: a dried concrete surface condition was optimal for measurements since it limits the impact of the concrete surface moisture and efflorescence on characteristic element oxides, such as CaO. The effective measurement duration was 30 s. A CEM III/B 42.5 N (GGBFS)-based concrete surface was distinguished from other concretes using Al2O3, MgO and Fe2O3 as characteristic oxides. The inner layers of concrete were rich in SiO2, the oxide characteristic for the aggregate composition tested in this study. This shows that hXRF is suitable for use in concrete, provided that the concrete surface is dried and the characteristic elements are defined to ensure a distinction between different cement and aggregate types. Direct adoption of such characterization, however, requires field testing across a wide range of concrete compositions and in situ conditions.

Handheld X-ray fluorescence analysis of pottery unearthed from the site of Xinjie in Shaanxi Province of Northern China

Handheld X-ray fluorescence analysis of pottery unearthed from the site of Xinjie in Shaanxi Province of Northern China

Hand-held XRF sorting of spent refractory bricks to aid recycling

An improved methodology is presented for assessing the economic feasibility and effectiveness of recycling MgO-C and Al2CO3-MgO-C refractory bricks, which are widely used in the steelmaking industry. Since approximately 28 Mt of refractory bricks are discarded each year, it is logical to recycle them. When furnaces and ladles are relined, the spent refractory bricks become mixed up, and need to be sorted before recycling. This study examined the use of a hand-held X-ray fluorescence analyser (HH-XRF) to distinguish between spent oxide-based and oxide-carbon-based refractory materials, with special emphasis on spent MgO-C (MC) and Al2O3-MgO-C (AMC) bricks. HH-XRF analysis was conducted on 18 oxide-carbon refractory bricks as well as on MgO-chromite and bauxite-based refractories. X-ray diffraction, reflected light optical microscopy, and scanning electron microscopy with energy dispersive spectroscopy were used to characterize the MgO-C and Al2O3-MgO-C bricks to confirm the accuracy of the HH-XRF analyses. This study also underlined the importance of calibrating the HH-XRF analyser for the refractory bricks to be sorted. The HH-XRF was successful in distinguishing between the different oxide-carbon-based refractory bricks both before and after cleaning. This result is important as it proves that HH-XRF provides a method whereby spent MC and AMC bricks can be sorted quickly and reliably.

Use of a Portable X-Ray Fluorescence Analyzer for Rapid and Accurate Determination of Iron in Vitamins and Supplements

This study describes the development of an X-Ray Fluorescence (XRF) method to quantify iron in vitamins and supplements. Four different products and a NIST Standard Reference Material (SRM) were prepared by homogenizing 20 tablets in a mixer mill and diluting known masses of each sample into known masses of cellulose. Calibration standards were similarly prepared by diluting known masses of iron oxide into known masses of cellulose. Analyses were performed using a handheld XRF analyzer using one-minute analysis times. The method gave linear calibration curves with R2 values greater than 0.9995, and good accuracy as demonstrated by relative errors of 9% in the analysis of the NIST SRM. Experimentally determined concentrations of the samples were compared to the nominal concentration of the samples based on the mass of iron per tablet and the average tablet mass. XRF results gave relative differences of +4% and -4% for two iron supplements. XRF results gave a larger relative difference of -19% for the women’s vitamin product. Although the label on the men’s vitamin product stated it was iron-free, XRF and Microwave Plasma Atomic Emission Spectrometry (MP-AES) analyses showed it contained iron levels of 157 and 133 µg/g (ppm), respectively. This XRF method offers a simpler, faster, and less expensive alternative to conventional atomic spectrometry-based methods for this type of application.

Ceramic raptors unearthed at the site of Shimao (2300–1800 BCE) in northern China: Production and use

Ceramic raptors were unearthed at the site of Shimao (2300–1800 BCE), a 425-ha walled settlement on the Loess Plateau in northern Shaanxi, China. Bird-shaped figures of similar size and age are rare in prehistoric East Asia. For the first time, the present paper conducted a compositional study on the Shimao ceramic raptors using a non-invasive handheld X-ray fluorescence (hhXRF) analyzer. The hhXRF data were compared with those of Shimao utilitarian vessels and local clays to investigate the production of these artifacts. Multivariate statistical analyses of the compositional data suggest that the ceramic raptors are primarily similar to utilitarian pottery in chemical composition but the source(s) of the clay for making them do not match those of the sampled soils. Three subgroups of the ceramic raptors are recognizable by their body color and characteristics of the exterior surface, and they demonstrate compositional variability possibly suggesting different sources of the clay. In addition, calcium-rich whitish substances are inferred as residues of a white paint intentionally applied during the production or use of ceramic raptors. Based on a discussion of archaeometric and archaeological evidence, we propose that the Shimao ceramic raptors were manufactured by multiple production units and meant to mimic a specific, culturally significant bird species (eagles). We also speculate that they were displayed during special events at restricted locales and were intentionally (even ritually) discarded after use. It is possible that the ceramic raptors constituted a part of the political landscape shaped by the Shimao elites, who possessed authority and power on a regional scale.

Assessment of screening mineral wool waste from market by using handheld X‐ray fluorescence

AbstractStone wool from construction, renovation, demolition and horticultural applications is reclaimed for reuse and recycling. Variation of chemical composition of reclaimed material creates a challenge, especially with increasing quantities from construction and demolition sectors. Therefore, an assessment of handheld/portable X‐ray fluorescence (XRF) spectrometer was carried out with the objective to quickly discriminate various type of man‐made vitreous fibres (MMVF). The evaluation concerned mainly light element analysis. Therefore, the effect of disturbing factors, such as moisture, organic matter, surface roughness and sample density were evaluated. Direct measurement on mineral wool product or granulate gives a precision of ±1.5% for Al2O3 and ±2.1% for SiO2 after calibration. Precision is enhanced by preparing pressed pellets, resulting in precision down to ±0.9% for Al2O3 and ±1.5% for SiO2 after correction. Provided correctly calibrated, handheld XRF analysis gives a quick indication, though not necessarily conclusive, whether the reclaimed material applies to so called “old wool,” manufactured prior to the EU legislation requiring increased bio‐solubility. A quick indication is very relevant for the renovation and demolition sector and subsequent re‐use or recycling of mineral wool because it affects transport and handling requirements. In case the analysis is not obviously discriminative, desktop analysis is still required. Presence of moisture and organic matter influence the detection of lighter elements, which especially affects analysis of horticultural recycling substrate granulate.

Application of a handheld X-ray fluorescence analyzer for the quantification of air particulate matter on Teflon filters

Elemental characterization of air particulate matter samples through the application of X-ray fluorescence (XRF) spectrometry is a widespread analytical technique. This work presents the optimization and calibration methodology of a handheld XRF spectrometer and its subsequent application in elemental quantification of unknown particulate matter samples. The optimization of the handheld spectrometer was conducted through investigation of the elemental sensitivities and Limits of Detection (LoD) at variable excitation conditions (voltage, filter). Accordingly, five optimum operating conditions were obtained each one targeted in different elemental range: 1) Z = 11–12, 2) 12 < Z < 17, 3) 16 < Z < 23, 4) 22 < Z < 31 and 5) 30 < Z < 92. Subsequently, a number of reference (5 multi-element and 42 compound/single-element) materials were used to obtain calibration curves for 24 elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Pb). Weighted least-square regression analysis was implemented to best fit the experimentally measured intensities with mass loadings resulting for most of the elements to high correlations (Pearson r > 0.98) and low statistical error. In addition, intercomparison of the elemental concentrations from 28 unknown particulate matter samples between the handheld and a benchtop XRF spectrometer showed good agreement.

Characterization of inorganic elements in common consumer plastics using handheld X-ray fluorescence analyzer.

Plastics are increasingly being used in consumer products due to its versatility in many applications. However, these plastics may contain inorganic elements that may be harmful to humans. To determine any potential health risk of plastics, it was important to characterize elemental composition of plastics and assess usage patterns. To investigate plastic usage in a typical Jamaican household and to characterize the inorganic elements in consumer plastics using XRF analyzer. About 200 questionnaires were distributed to households to determine the types and quantity of plastics. A total of 130 plastic samples from 7 categories were collected and measured for inorganic elements using handheld XRF. Household plastics were mainly used for storage and personal hygiene products. On average, 10% of plastics were recycled, while 30% were burned. Inorganic elements present in plastic samples were Cl > Ti > Ba > Fe > Zn > Sb > Cr > Br > Cu > V > Pb > As. Elemental concentrations varied based on the category of plastics. Green plastics had the highest concentrations of each type of elements. This study provided useful information on characterizing the different types of elements present in common household plastics. Results from the survey were used to assess participants' attitude and behaviors towards plastics usage and disposal. It was important to obtain a profile of plastics waste from a typical household. This will allow for more targeted strategies to reduce plastics pollution.

Study of controlled migration of cadmium and lead into foods from plastic utensils for children.

Lead (Pb) is a highly neurotoxic chemical element known for reducing intelligence quotient (IQ) and promoting antisocial behavior in children and adolescents, while cadmium (Cd) is a carcinogenic bioaccumulative element. Both these metals are included in the priority pollutant list of the United States Environmental Protection Agency and in the WHO List of Chemicals of Major Public Health Concern, where contaminated foods and beverages are the most common pathways of exposure. The objective of this study was to determine total Cd and Pb levels in colored plastic utensils (cups, mugs, bowls, feeding bottles, and plates) for use by children and to measure the specific migration of these elements into beverages and foods. Total contaminant levels were determined using a handheld X-ray fluorescence analyzer. Specific migration tests were conducted using the simulant solutions acetic acid 3% (m/v) and water. Migration levels were determined by ICP-MS. Specific migration tests for Pb were also performed on commercially available samples (cola soft drink, orange juice, vinegar, and milk), with levels determined by graphite-furnace atomic absorption spectrometry (GF-AAS). A total of 674 utensils were analyzed in loco at major commercial centers in Greater São Paulo, of which 87 were purchased for containing Cd and Pb concentrations above permitted limits. Mean concentrations of the metals detected in the purchased utensils were 1110ppm for Pb and 338ppm for Cd. For specific migration assays, Pb levels were 187, 13, and 380 times above the permitted limit (0.01mg.kg -1) for acetic acid, water, and orange juice, respectively. Cd levels were 50 and 2.4 times above the maximum permitted limit (0.005mg.kg -1) for acetic acid and water, respectively. The districts where the utensils were purchased were grouped according to their social vulnerability index and compared using ANOVA. Pb levels were different between low and medium/high social vulnerability groups (p = 0.006). The findings corroborate the initial hypothesis that these utensils constitute a major source of exposure to PTEs such as Cd and Pb, pointing to the need for stricter regulation and inspection by the Brazilian regulatory agencies.

Recycling plastics containing decabromodiphenyl ether into new consumer products including children's toys purchased in Japan and seventeen other countries

Polybrominated diphenyl ethers (PBDEs) are flame retardants widely used to manufacture several commercial plastic products. The major homologue in commercial PBDE mixtures are listed in the Stockholm Convention on Persistent Organic Pollutants and are scheduled for global elimination. Hence, to understand more about unintentional contamination of plastic recycling stream by restricted PBDEs, we examined 540 small plastic consumer products (1139 components after dismantling), including children's toys, purchased in 18 countries (mainly Japan) between 2015 and 2019. Handheld X-ray fluorescence analysis revealed that 219 plastic components (19% of the total samples) contained bromine at a concentration of ≥30 mg kg−1. Chemical analysis of these bromine-positive components revealed that 109 pieces (9.6% of the total), mainly those made of black-colored plastic, contained PBDEs at concentrations ranging between 35 and 10,000 mg kg−1, with the maximum contribution from decabromodiphenyl ether (decaBDE). These PBDE concentrations were insufficient to impart flame retardancy, suggesting that the recycled plastic used to manufacture these consumer products probably originated from electronic waste, the manufacture of which was the primary use of commercial decaBDE mixtures. PBDEs were also found in secondary raw plastic materials and their final products obtained in India in 2019, demonstrating that plastics containing decaBDE end up in products where they serve no functional purpose. To contribute to the circular economy, the recycling of plastic waste in end-of-life products should be promoted. However, urgent action is needed to prevent plastic additives of concern, including PBDEs, from entering new products used in daily lives, particularly those used by children.

Economic rebound versus imperial monopoly: Metal provenance of Early Medieval coins (9th–11th centuries) from some Italian and French mints

This paper represents the first systematic Pb isotope investigation of Italian Medieval coins and aims to provide new parameters for a general historical interpretation of coin production and circulation in Medieval Europe. We collected more than one hundred specimens, minted in a period between 9th − 14th centuries AD and coming mostly from archaeological sites of Tuscany. Here we report the results on the oldest group of (44) coins, dated between the end of the 9th and 11th centuries. All coins where previously characterized with handheld X-ray fluorescence (pXRF) analysis and lead isotope composition (PbIC) was performed using an MC-ICP-Mass Spectrometer. The Carolingian coins have PbIC compatible with Melle silver district; the few Carolingian coins possibly minted in Italy (Venice and Milan) are also compatible with ore districts such as Melle and Harz Mountains. Coins in the names of Italian rulers (9th-10th century) from Lucca, Pavia and other uncertain mints show PbIC compatible with Melle, Black Forest and the Harz Mountains as well. A quite similar pattern applies to coins in the names of Otto I-III and Conrad II (10th-11th century) from Lucca and Pavia mints, although they show a better overlap with the Harz Mountains. The vast majority of early medieval coins issued by the Italian mints investigated in the present paper show isotope compositions that do not match with silver (lead-copper) mines from the Colline Metallifere district of southern Tuscany, notwithstanding their exploitation in the considered period is suggested by many settlements located near mining sites.

Screening for Heavy Metals in Tea Leaves from Bangladesh Using X-Ray Fluorescence

Trace metal contamination is a global health issue. This study evaluated boxed and loose-leaf tea from Bangladesh using a Handheld X-ray Fluorescence (XRF) analyzer for lead and other metals to rapidly screen tea as a potential hot spot of heavy metal exposure. Of the 33 elements measured, several priority pollutants were below the limit of detection (LOD) in all samples, including lead (LOD 2.17 mg/kg) and arsenic (LOD 1.68 mg/kg). Loose-leaf tea samples had higher copper (1.5-fold), zinc (1.3-fold), and manganese (1.8-fold) concentrations compared to boxed tea. Estimated daily intake (EDI) of lead from tea was calculated using three assumed extractability levels, 20%, 50%, and 100%, and assuming the lead concentration was at the LOD. The EDI for lead ranged from 0.008 µg/kg/bw day to 0.041 µg/kg/bw for adult males and 0.010 µg/kg/bw day to 0.049 µg/kg/bw day for adult females. Based on these tested samples, tea is not likely a primary source of lead exposure in the two sampled areas, Sirajdikhan and Pabna. Future research can evaluate potential processing steps for why some metals were higher in loose-leaf tea compared to boxed tea, including copper, zinc, and manganese. Other potential lead sources could be tested in the tea preparation process, including water sources and dishware used to prepare and consume the tea.

Non-destructive handheld XRF study of archaeological composite silver objects\u2014the case study of the late Roman Seuso Treasure

This study details the non-destructive chemical analysis of composite silver objects (ewers, situlas, amphora and casket) from one of the most significant late Roman finds, the Seuso Treasure. The Seuso Treasure consists of fourteen large silver vessels that were made in the fourth–early fifth centuries AD and used for dining during festive banquets and for washing and beautification. The measurements were systematically performed along a pre-designed grid at several points using handheld X-ray fluorescence analysis. The results demonstrate that all the objects were made from high-quality silver (above 90 wt% Ag), with the exception of the base of the Geometric Ewer B. Copper was added intentionally to improve the mechanical properties of soft silver. The gold and lead content of the objects shows constant values (less than 1 wt% Au and Pb). The chemical composition as well as the Bi/Pb ratio suggests that the parts of the composite objects were manufactured from different silver ingots. The ewers were constructed in two ways: (i) the base and the body were made separately, or (ii) the ewer was raised from a single silver sheet. The composite objects were assembled using three methods: (i) mechanical attachment; (ii) low-temperature, lead-tin soft solders; or (iii) high-temperature, copper-silver hard solders. Additionally, two types of gilding were revealed by the XRF analysis, one with remnants of mercury, i.e. fire-gilding, and another type without remnants of mercury, presumably diffusion bonding.

Use of a Handheld X-ray Fluorescence Analyser to Quantify Chloride Ions In Situ: A Case Study of Structural Repair

To ensure that a structure will last throughout its service life, repairing reinforced concrete entails, among others, correctly marking off the area affected by aggressive agents that may deteriorate both the concrete and the steel. Chloride, the most damaging source of reinforcement corrosion, may diffuse to a greater or lesser distance from the surface depending on the ease of penetration. In this study, we calibrated a handheld X-ray fluorescence analyser (hXRF) and used it to quantify the chloride concentration in cement-based materials. The findings were verified against a series of samples of known concentration to establish a suitable correction factor. Chloride ions were quantified precisely and accurately with the hXRF instrument, and we calculated a correction factor of 1.16. The instrument and the information recorded were used to quantify the chloride ion content in different parts of an existing structure. The analyser identified apparently healthy areas that could, nonetheless, pose oxidation problems in the near future due to significant chloride concentration. Chloride quantification data at different depths can be used to draw diffusion or penetration profiles and to determine whether ion concentration around the reinforcement is within the recommended limits. The method developed can be applied in situ to quickly locate the most critical areas.

Sensitivity Calibrations of K- and L-shell X-ray Lines for Elemental Analysis of Air Particulate Samples Using a Handheld XRF Spectrometer

The portability, ease of use, relative lower cost of procurement and simple maintenance of a handheld X-ray fluorescence analyzer makes it a potential alternative for air particulate analysis especially in highly polluted and economically disadvantaged regions of the world. Thus, this study assessed the performance of such analyzer in characterizing aerosol laden filters. Spectra of Certified Reference Materials (NIST 2783 CRM for aerosol filters) measured with a handheld X-ray fluorescence analyzer were calibrated and fitted using iterative nonlinear least-square fitting procedure provided by the International Atomic Energy Agency-Quantitative X-ray Analysis System. Elemental sensitivity calibration curves, method detection limits, uncertainty estimates of K- and L- X-ray lines in the elemental range 18 < Z < 39 and 47 < Z < 83 respectively were determined for four excitation conditions [High (Hi), Main (Ma), Light (Li) and Low (Lo)]. Signal counts for $$K_{\alpha {\text{and}} \beta }$$ (Ni, Zn, Se) and $$L_{\alpha {\text{and}} \beta }$$ (Pt, Te, Au) lines of the CRM’s were used to validate the analytical method. Concentrations values were evaluated for trueness and precision. Hi excitation condition has the least sensitivity (5 times less than Ma, 30–40 times less than Lo and more than 100 times lower than Li) within varying range of atomic number. However, Hi (R2 = 0.99) and Ma (R2 = 0.96) condition had the best overall trueness and precision score within an acceptable relative standard deviation ≤ 6% for the six CRM’s evaluated.