Use of Multiple Irradiations and Reference Materials as Comparators in Quality Control of Neutron Activation Analysis Data of Biological Samples.

We propose that several different reactor irradiation times followed by assaying of activity for differential counting periods may be employed for quality control (QC) of neutron activation analysis (NAA) data of biological samples. It is also recommended that three to four reference materials (RMs) of similar matrix but from different agencies such as National Institute of Standards and Technology (NIST, USA), International Atomic Energy Agency (IAEA, Vienna), Institute of Nuclear Chemistry and Technology (INCT, Poland), and National Institute of Environmental Studies (NIES, Japan) including a synthetic multielemental primary standard should always be analyzed simultaneously along with the samples. Finally, the mean ± σ values so obtained may be considered as more reliable after statistical analysis. Our analytical data for Na and K in three RMs (SRM 1572, CRM H-9, and Bowen's Kale) using different irradiation periods of 15 m, 2 h, 6 h, and 1 day were comparable with the certified values within error range of + 0.2 to - 2.7%. We report our data for 20 elements in two candidate RMs corn flour (INCT-CF-3) and soya bean flour (INCT-SBF-4) from the INCT, Poland, where Z-score values for most elements are in reasonable range of certified values.

Preliminary study on forgery identification of Hetian Jade with Instrumental Neutron Activation Analysis.

In this study, Instrumental Neutron Activation Analysis (INAA) was applied to study the elemental information of geological samples with the assistance of chemometric techniques. Samples of genuine Hetian Jade from Xijiang Province of China, counterfeit jade samples purchased at the neighborhood market, and granitoid samples from the same geographic location of genuine Hetian Jade were analyzed using INAA. The preliminary study indicates that INAA, with the help of principal component analysis (PCA), can be applied to obtain the multi-elemental concentrations of geological samples with high sensitivity, thereby effectively differentiating genuine Hetian Jade from counterfeit ones.

Feasibility study on rare earth ion exchange resin saturation analysis based on PGNAA technique.

In this work, prompt gamma ray neutron activation analysis technique was used to monitor the REEs saturation in resin. A facility consisted of a D-T neutron generator, a BGO detector and a 3He detector was established and applied to analyze REEs (Gd and Sm) samples. Neutron self-shielding effect was also corrected. The enriched Gd and Sm in resin were close to saturation at about 400 min. The results showed a satisfactory agreement with the XRF tests, which demonstrated that PGNAA was sufficient for monitoring REEs saturation in resin.

Measurements of epithermal neutron properties of ITU Triga Mark II research reactor.

The k0 standardization method is one of the most commonly used neutron activation analyses to determine the concentrations of elements in the sample. To perform this method, it is required to know the neutron spectrum parameters such as epithermal neutron flux shape factor (α) and thermal to epithermal neutron flux ratio (f). In this study, the α and f parameters were determined using the Cd-ratio dual monitor method and bare triple monitor method. In both methods, irradiation studies were performed in the central thimble at the ITU Triga Mark II research reactor. A gamma-ray counting system (HpGe detector) was used for measuring foil activation values. The selected monitors were 197Au and 94Zr for the Cd-ratio dual monitor method and 197Au/94Zr/96Zr for the bare triple monitor method. The α and f parameters were -0.221 ± 0.018 and 41.826 ± 4.701 for 197Au/94Zr (724 keV) monitors, -0.231 ± 0.019 and 42.626 ± 4.791 for 197Au/94Zr (756 keV) monitors, 0.228 ± 0.025 and 43.917 ± 3.596 for 197Au/94Zr/96Zr monitors, respectively.

Discovery of neutron activation analysis.

It is well known that George Hevesy and Hilde Levi were the original discoverers of neutron activation analysis. However, there were many other researchers in Europe that firstly unknowingly and knowingly discovered the neutron, and others who experimented in neutron induced radioactivity. A historical timeline of the several parallel experiments in a very short period is given in this synopsis. It eventually was Hevesy and Hilde to first use the powerful technique of neutron activation analysis for analytical chemistry.

Comparison between NIS and TNC channels for the detection of nickel in soil samples.

The prompt gamma-ray neutron activation analysis (PGNAA) is a significant technique for determining the quantities of a variety of elements in natural materials, whether online or in situ, regardless of their chemical compounds. This study focused on evaluating the performance of a portable PGNAA setup based on a Genie 16 DD neutron generator to determine the minimum detectable concentration (MDC) of nickel in soil samples. Two separate reaction mechanisms were used to activate the samples. A CeBr3 detector was used to detect nickel gamma rays at 1331 and 1454 keV caused by neutron inelastic scattering, as well as those at 8553 and 8998 keV emitted following thermal neutron capture activations. The obtained MDC values for both reaction channels have improved as a result of the research.

A pilot study on the use of neutron activation analysis and multivariate statistics for the provenance of Jamaican Cannabis sativa L (Marijuana).

The aim of this study was to use instrumental neutron activation analysis and multivariate analysis to determine the provenance of Jamaican Cannabis sativa L. Sixty-three samples were collected from various areas in Jamaica, with no other data but their known or self-reported growing regions. The samples were analysed for Al, As, Br, Ca, Cd, Co, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc, Sm, Sr, V, and Zn. The resulting elemental data were statistically evaluated using agglomerative hierarchical cluster analysis and principal component analysis. Cluster analysis was able to group the samples into their known or reported growing regions with a high degree of accuracy. Principal component analysis was also able to elucidate some of the underlying geochemical factors that could explain the clustering. These included the underlying bauxitic geochemistry and the influence of fertilizer inputs. Of the analysed elements, Al, As, Cd, Co, Fe, K, La, Mg, Mn, Sc, Sm, V, and Zn appear to be most significant in identifying the growing regions of the cannabis samples. Results indicate the promise of this methodology with an increased dataset and potentially further refinement of the identifying elements.

Fast and non-destructive neutron activation analysis for simultaneous determination of TiO2 and SiO2 in sunscreens with attention to regulatory and research issues.

A new instrumental neutron activation analysis (INAA) for the simultaneous determination of titanium (TiO2) and silica (SiO2) dioxide as UV-filters in sunscreens is described. Samples are encapsulated, neutron irradiated (30 s) and after a suitable decay (3 min), the induced 51Ti (T1/2 = 5.76 min) and 29Al (T1/2 = 6.56 min) radionuclides are measured for the emitted γ-ray fingerprint. Three applications were carried out: (i) screening study (analysis of commercial sunscreens in combination with single particle inductively coupled plasma mass spectrometry (sp-ICP-MS); (ii) research study (development of innovative UV-filters such as titanium dioxide or bismuth titanate loaded inorganic mesoporous silica nanoparticles, MSN); (iii) validation study (intercalibration of a spectrochemical method - inductively coupled plasma optical emission spectrometry, ICP-OES). Collectively, the nuclear method appears a powerful tool adequate for quantifying TiO2 and SiO2 in the above studies. The limited accessibility at the nuclear reactor for neutron activation is probably one of the reasons why the excellent characteristics of the nuclear technique are not always fully known and exploited in the industrial and research chemical world.

Utilization of accelerator and reactor based nuclear analytical techniques for chemical characterization of automobile windshield glass samples and potential of statistical analyses using trace elements towards glass forensics.

Glass forensics is an important area in forensic crime investigations, wherein glass origin or source finding is necessary mainly through chemical composition. In the present work, Nuclear Analytical Techniques namely external (in air) Particle Induced Gamma-ray Emission (PIGE) and Instrumental Neutron Activation Analysis (INAA) were utilized for complete chemical characterization of twenty-five "as received" windshield glass samples of six car manufactures. Concentrations of four major elements (Si, Na, Mg and Al) by PIGE using proton beam and nineteen elements including sixteen trace elements by INAA using research reactor neutrons were determined. Both the methods were validated by analysing matrix matched glass certified (standard) reference materials. Trace elemental concentrations including rare earth elements (REEs) and ternary plot using concentrations of major, transition elements and REEs were utilized to obtain preliminary grouping of the analyzed glass samples. Statistical tools namely K-mean, Cluster Analysis and Principal Component Analysis (PCA) using trace elemental concentrations were utilized for grouping studies, important for forensic applications. Among these statistical analysis techniques, PCA results confirmed that windshield glasses from six manufactures clearly belong to six different groups.

Performance of various mathematical functions for the in-situ relative detector efficiency towards its applicability for k0 IM-NAA.

The in-situ relative detection efficiency strongly influences the characteristics of the k0-based internal monostandard neutron activation analysis (IM-NAA). In the present work, various mathematical functions were explored for the establishment of in-situ relative detector efficiency calibration and compared their performance based on the reduced chi-square (χ2) values. Among the various mathematical functions, the polynomial logarithm with 6th order was found to be associated with the minimum mean standard deviation for the experimental data and the lowest value of reduced χ2 after carrying out multiple iterations using Nelder-Mead algorithm. Quality assurance of the function was tested by carrying out elemental quantification of the NIST SRM 1633b coal fly ash. Gamma energies of the activation products, 152mEu, 59Fe, 140La, 24Na and 46Sc of the irradiated NIST standard were used for the in-situ relative full energy peak efficiency calibration of 30% HPGe detector. The sample was counted for different time intervals for the complete profiling of the elements present in the NIST SRM. The deviations for most of the elements were found to be within ±5% with respect to the certified values and ξ-score values were within ±2, demonstrating its better accuracy. This method was also applied satisfactorily to profile the elemental concentrations of alloy materials used in a thermal sensor guide tube of the steam generator in a test reactor.

Late Pleistocene pottery production and exchange: Provenance studies of hunter-gatherer wares from southern Kyushu, Japan by neutron activation analysis.

Late Pleistocene hunter-gatherers in East Asia adopted pottery, yet the ability to reconstruct circulation, mobility, and exchange has been hampered, in part, due to problematic regional geochronology. The driving forces behind pottery adoption is unclear. The purpose of this study is to test our results of the first systematic petrographic pottery sourcing from the pre-Younger Dryas by utilizing neutron activation analysis. We examine samples from the Sankauyama I site on Tanegashima Island, southern Japan, dating to the Incipient Jomon, ca. 14,000/13,500-12,800 cal BP, with a well-defined geochronology. Our NAA results corroborate with the petrographic study suggesting that pottery was mainly produced in-situ, but some vessels were transported long distances from another island. Changing from high mobility, sedentary Incipient Jomon foragers made pottery, occasionally investing in long-distance ceramic vessel transportation and exchange likely involving ocean crossing. This may be associated with a risk-buffering strategy in the context of rising sea levels and isolation of Tanegashima.

GAMMA SPECTROMETRY AND NEUTRON ACTIVATION ANALYSIS OF TOOT OILFIELD WELLS OF DATTA FORMATION, UPPER INDUS BASIN, DISTRICT ATTOCK, PUNJAB, PAKISTAN.

Present study was aimed to investigate trace elemental composition and possible elemental correlation with depth of some Pakistani wells. Exploratory oil wells of Toot oilfield from Potwar region of upper Indus basin were selected for this purpose. Samples of well cuttings and soil sections were collected with the assistance of Oil and Gas Development Company Limited. Elemental analyses were performed using instrumental neutron activation analysis. This study is the first of its kind to report detailed elemental profile of Toot oilfield, Attock, Punjab, Pakistan, via instrumental neutron activation analysis (INAA). Source formation of Toot oilfield is characterized by Jurassic Datta formation. Around 19-26 elements were identified by INAA. Major, minor and trace elemental concentrations varied with depths along the sampling lines. Data analysis was performed by the application of principal component analysis (PCA). PCA was useful in differentiating between surface and depth samples. Elemental volumes of different wells were established through bi-plots. In extension, naturally occurring radioactive materials and technologically enhanced naturally occurring radioactive materials were also determined for the wells of Toot oilfield. Annual dose rates and activity levels were calculated in oil well formations. Measurements of annual dose rates fall within safe limits, indicating anodyne atmosphere. Contamination indices, such as enrichment factor with respect to Al, geo accumulation index (Igeo), pollution index and integrated pollution index, were also determined. Cr and Zn were found to cross the safe limits, which may be due to the local industrial and anthropogenic activities.

Determination of Some Chemical Elements of Common Spices Used by Algerians and Possible Health Risk Assessment.

Spices in general owned a very important reputation in the herbal plantae Kingdom; they have been used for food flavoring, preservation, aroma, and coloring for more than 2000 years. Moreover, spices are classified as all natural, and for this reason, they attracted a large scale of consumers worldwide; however, since most of spices are consumed in their natural form (without grounded them), it is necessary to monitor their consumed quantities. Hence, the aim of this work was to quantify major and trace elements contained in some Algerian kitchen frequently used spices (Piper nigrum L., Nigella sativa L., and Pimpinella anisum L.). Spice materials were washed well then pass through an instrumental neutron activation analysis (INAA). Results revealed the existence of twenty-six elements among them: K, Ca, Fe, and Na which showed significant concentrations, consecutively, while Ce, Eu, Lu, Sm, and Tb were presented at low concentrations. Furthermore, these spices consumption assessment results were found to be well below the tolerance limits compared with the recommended values (RDA) suggested by the FAO association.

Determination of Multi Elements in Tobacco Plant of Northeast India by Neutron Activation Analysis and Atomic Absorption Spectrometry.

Even when cultivated in uncontaminated soils, tobacco plant has higher propensity to extract and accumulate trace elements. The concentrations (mass fractions) of essential elements (K, Ca, Mg, Na, Cl, Mn, Fe, Cu, and Zn) and 28 non-essential elements in tobacco plant (leaves, stem, and root) of Northeast India and their respective soils were quantitatively measured. Hg mass fraction in all samples analyzed were found to be < 10 mg/kg. The heavy element mass fractions of tobacco are weakly correlated to different soil parameters. The bioconcentration factor values indicated that Cd (7) is selectively absorbed and translocated in the tobacco leaves compared to Zn (1.7), Cu (1.5), Ni (0.12), and Pb (0.1). Under acidic soil conditions, tobacco plant efficiently absorbed and translocated Cl- ion with great ease, whereas it may be a very low accumulator of rare-earth elements. The mass fractions of Mn, Cu, Sb, Cs, Rb, and Pb are very similar to the "reference plant," whereas significantly higher mass fractions of Al, Sc, Ti, Zr, Hf, Ta, Th, and U are present in the roots of tobacco plant relative to the "reference plant." Principal component analysis has revealed that Northeast Indian tobacco can be clearly differentiated from other varieties of tobaccos used in different countries because of their element profiles.

Measurement of talc in flour by the prompt-gamma ray neutron activation analysis method.

Prompt gamma-ray neutron activation analysis method (PGNAA) was used to measure the talc content in flour. Neutron activation prompt gamma spectrum measured by NaI(Tl) detector has complex components, poor energy resolution, and high Compton plateau, how to obtain accurate element content from the prompt γ spectrum is one of the core problems of PGNAA. To reduce the systematic uncertainty caused by the variation of the neutron energy spectrum and γ self-absorption in different samples, the spectral decomposition method based on library least-squares was improved. As a result, the average relative deviation between the calculated values from measured spectra and the theoretical values based on the known composition was reduced from 6.1% to 0.3%. The relative uncertainty of 30 measurements on the same sample was reduced from 4.8% to 3.0%. The detection time can be reduced to 1 min, which meets the requirement of on-line measurement for talc in flour.

A full spectral analysis method for the gamma spectrum: weighted library least squares.

The traditional library least squares approach (LLS) is affected by the inconsistency of the statistical uncertainties of different channels in a gamma spectrum, which leads to large fluctuations in the analysis results. This work proposes a weighted library least squares approach (WLLS) that uses the square root of the count to weight the regression objective function and has implemented a verification experiment based on Prompt Gamma Neutron Activation Analysis (PGNAA). The results showed that, after weighing using the square root of the count, the fluctuation level of statistical uncertainty in the spectrum was reduced from 44.34 to 2.25. After the analysis of the WLLS approach, the average standard deviation of the results was reduced to at least 0.37 times that of the LLS approach.

Future technological developments in proton therapy - A predicted technological breakthrough.

In the current spectrum of cancer treatments, despite high costs, a lack of robust evidence based on clinical outcomes or technical and radiobiological uncertainties, particle therapy and in particular proton therapy (PT) is rapidly growing. Despite proton therapy being more than fifty years old (first proposed by Wilson in 1946) and more than 220,000 patients having been treated with in 2020, many technological challenges remain and numerous new technical developments that must be integrated into existing systems. This article presents an overview of on-going technical developments and innovations that we felt were most important today, as well as those that have the potential to significantly shape the future of proton therapy. Indeed, efforts have been done continuously to improve the efficiency of a PT system, in terms of cost, technology and delivery technics, and a number of different developments pursued in the accelerator field will first be presented. Significant developments are also underway in terms of transport and spatial resolution achievable with pencil beam scanning, or conformation of the dose to the target: we will therefore discuss beam focusing and collimation issues which are important parameters for the development of these techniques, as well as proton arc therapy. State of the art and alternative approaches to adaptive PT and the future of adaptive PT will finally be reviewed. Through these overviews, we will finally see how advances in these different areas will allow the potential for robust dose shaping in proton therapy to be maximised, probably foreshadowing a future era of maturity for the PT technique.

Biomonitoring Assessment of Toxic and Trace Elements in Sterechinus neumayeri Sea Urchins from the Comandante Ferraz Station in Antarctica.

In the present study, sea urchin Sterechinus neumayeri tissues were used for the passive biomonitoring of toxic and trace elements at the Comandante Ferraz Station, Antarctica and compared to a pristine region (Botany). As, Ba, Br, Ca, Co, Cr, Fe, K, Na, Rb, Sc, Se and Zn concentrations were determined by instrumental neutron activation analysis (INAA), while toxic metals (Cd, Hg, Ni and Pb), and Cu were determined by atomic absorption spectrometry (GF-AAS). The findings were compared to other organisms commonly applied for biomonitoring purposes and to the sediment concentrations of each sampling region. Urchins from the Ferraz Station area presented higher Br, Co, Cr, Cs, K, Se and Zn levels than the pristine location. The results obtained herein suggest S. neumayeri can be applied to the biomonitoring of Cr and Zn. The present study also contributes to knowledge of the mineral composition of the sea urchin S. neumayeri.

Simulation of the cement measurement based on the pulse DT neutron generator: A Monte Carlo study.

The PGNAA system for the cement measurement was simulated based on Monte Carlo method. The sizes of the moderator and reflector for the 14 MeV DT neutron generator were optimized for fast and thermal neutron outputs. The DT neutron generator was simulated at the pulse mode, and the gamma-ray detector was set as LaBr3(Ce) scintillator. The characteristic peaks of the major elements (Ca, Si, Al, Fe) can be identified from the gamma-ray spectra which induced at the different time intervals of the neutron radiation. For the different thicknesses of the cement sample the ratios of the gamma-ray peaks were observed, and the result showed that when the thickness was between 20 to 30 cm, the ratios became stable. With the ratios, we can calculate the iron modulus, silica modulus and lime saturation factor.

Analysis of the soil to food crops transfer factor and risk assessment of multi-elements at the suburban area of Ho Chi Minh city, Vietnam using instrumental neutron activation analysis (INAA).

The contamination of heavy metals in agricultural ecosystem is one of the most important problems in developing countries as Vietnam. In this study, we investigated the multi-element concentrations in soil, vegetables, soil-to-plant transfer factors and target hazard quotient (THQ) due to the consumption of heavy metals in Ho Chi Minh City, Vietnam. In general, the element concentrations in soil and plants were similar to different studies in the world and in the range of allowable values provided by WHO and the Ministry of Health of Vietnam. The transfer factors indicated the influence of element characteristics and plant genotypes on the accumulation and translocation of elements from soil to plants. It is found that I. batatas, B. alba, A, tricolor, O. basilicum, and B. juncea could be potential candidates for phytoremediation in soil contaminated of heavy metals. The results of individual and total THQ were below unity for Cr, Mn, Fe, Co, Zn, As, and Sb. The total THQ is in the range from 0.11 for R. sativus to 0.84 for B. alba with the average value of 0.43, in which Mn and As are the major contributions to the total THQ with the average values of 75% and 18%, respectively. The safety assessment based on national regulations and THQ indicated that the consumption of investigated vegetables poses no risk to the consumers.