Nigerian coal analysis by PIXE and RBS techniques

PIXE and RBS techniques were employed for the measurement of the concentrations of the major, minor and trace elements in Nigerian coal samples from a major deposit. The samples were irradiated with 2.55 MeV protons from the 3 MeV tandem accelerator (NEC 3 UDH) in Lund. The PIXE results are reported and compared with an earlier work on Nigerian coal using FNAA and INAA analytical techniques while the RBS results are compared with ASTM previous results. The results show that Nigerian coals have a low (0.82–0.99)% sulfur content. This is quite important for pollution control reasons.     

PIXE and XRF elemental analysis of breakfast cereals consumed in Mexico

Elemental concentrations in breakfast cereals consumed in Mexico were measured using Particle induced X-ray emission with 1.7 MeV protons and X-ray fluorescence with a Rh X-ray tube operating at 35 kV. The specimens, obtained from packages purchased in markets, were freeze dried, ground and pelletized. Standardization was done with tomato, spinach, peach, and orchid leaves NIST standard reference materials, and analytical accuracy verified with NIST 3233 standard reference material (fortified cereal). The concentrations of nine elements did not agree with values quoted in the packages. Therefore, there may be inaccurate official estimations of Mexican population nutrient intakes.     

Characterization of colour pigments in pre-Columbian Chilean potteries by PIXE elemental analysis

Ancient ceremonial potteries belonging to pre-Columbian cultures in Chile, South America, are decorated with three different colours, red, white and black. Samples of these colours have been analyzed with induced X-ray fluorescence by a 6.6 MeV proton beam. The analyses show clearly distinct patterns for each pigment and also denote differences between the same colour in two cultures. Eight elements, from aluminium to copper were detected.Under partial support from the Departamento Técnico de Investigación de la Universidad de Chile, Grant 2438-8833.     

Studies on changes in trace elemental content of serum of uterine cervix cancer patients using PIXE

The objective of this study was to evaluate the levels of trace elements in blood sera of uterine cervix cancer patients, analyze their alteration with respect to healthy controls and identify the best predictors amongst these for disease occurrence and progression. Particle induced X-ray emission (PIXE) technique was used in this work to identify and quantify trace elements Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br in the blood sera of uterine cervix cancer subjects and healthy control subjects. The observed alterations are discussed with respect to the possible mechanisms by which these elements might influence the carcinogenic process.     

Evaluation of soil to tea plant elemental correlation using instrumental neutron activation analysis

Instrumental neutron activation analysis using relative and k ₀-based internal monostandard methods were employed for determination of concentrations of 12 elements in soil and tea plants collected from three different tea producing regions in India namely Assam, Darjeeling and Kangra. A total of 17 tea leaf samples along with corresponding soil samples were analyzed for elemental content. The obtained concentration data was used for the soil–plant elemental correlation studies. Positive correlation was observed between elemental concentrations of tea plants and the associated soil with Pearson correlation coefficient values in the range 0.6–0.9 for ten elements. Variations in transfer factor values were also observed according to the geo-chemical variation.     

PIXE analysis of blood serum of breast cancer patients undergoing successive chemotherapy

Journal of Radioanalytical and Nuclear Chemistry - Particle induced X-ray emission technique was used to obtain the serum elemental profile of healthy subjects and breast cancer patients (BCPs)...     

Problems associated with routine PIXE analysis in quantifying elemental concentrations of leukocytes from Coronary Artery Bypass Grafting (CABG) surgery patients

Whole blood from patients undergoing Coronary Artery Bypass Grafting (CABG) operations was separated into leukocyte subfractions of polymorphonuclearcytes (PMN) and peripheral blood mononuclear cells (PBMC). Blood samples were collected and analyzed at various timepoints to determine the elemental composition to provide a better understanding of recovery mechanisms and to indicate complications that may occur post-operatively. Proton induced X-ray emission (PIXE) analysis and Rutherford backscattering spectrometry (RBS) using the University of Surrey microprobe was employed to determine the concentrations of a range of elements. Accurate two-dimensional PIXE analysis however, requires knowledge of the sample matrix composition. These samples, on the other hand, showed varying thickness, lacked matrix homogeneity and displayed non-uniform trace element distribution. This paper discusses the results and problems associated with routine PIXE analysis and demonstrates the potential ability of ion beam analysis (IBA) depth profiling software, previously unused in PIXE analysis, to model a RBS spectrum of inhomogeneous, multi-layered samples prior to performing PIXE analysis.     

On the possibilities of elemental analysis of human serum by neutron activation analysis to short-lived radionuclides with previous removal of sodium and chlorine

Radiotracer experiments have been used to study the retention of Na from 14M HNO₃ mineralized serum samples by HAP in both batch and column processes. The specific capacity of HAP depends nonlinearly on the ratio initial Na-amount/amount of HAP. Pre-irradiation removal of Na by HAP-columns and of Cl by evaporation permits Cu, Mg an K in human serum to be determined by neutron activation analysis.     

XRF and PIXE analysis of metallic glasses

Radionuclide X-ray fluorescence (XRF) and particle induced X-ray emission (PIXE) methods have been used for a rapid and nondestructive analysis of metallic glasses. The methods are compared in accuracy and precision with the atomic absorption method. Some results of analyses of Fe_xNi₈₀-_xB₂₀ materials are briefly reviewed. The distribution of elements along the width as well as length and a qualitative analysis of the composition of material surfaces are considered.     

Applicability of PIXE to the analysis of biological reference materials

Summary Optimized PIXE procedures were applied to the analysis of up to 18 elements in certified biological reference materials. The exercise indicated that the total random error of the results from one single target analysis is in the range of 2–5% for elements heavier than K and for levels from 2 g/g on. The accuracy of the PIXE procedures is shown to be better than 5%.     

Recent PIXE analysis applied to bio-medical and environmental fields in Japan

The distribution of minor and trace elements in biological samples is very informative for bio-medical and environmental research. Particle induced X-ray emission (PIXE) analysis is a powerful tool for this subject since it can analyze many elements in samples non-destructively at high sensitivity and, with an advantage of micro-beam scanning capability. Recent studies in Japan on the application of PIXE analysis to these fields are introduced in this paper. This revised version was published online in July 2006 with corrections to the Cover Date.     

Blood serum DSC analysis of well-trained men response to CrossFit training and green tea extract supplementation

Differential scanning calorimetry (DSC) has been used for the detection of post-exercise changes in blood serum resulting from participation in the CrossFit (CF) training combined with green tea extract (GTE) supplementation. Blood samples from 20 well-trained men were collected at rest, immediately post-exercise and after 1 h of recovery in two trials: first before and second after CF training combined with GTE or placebo administration in the supplemented (S) and control (C) groups, respectively. Selected muscle damage biomarkers have been compared in different phases of the experiment. A significant increase in blood lactate content has been observed post-exercise in both trials in both participants’ groups. The opposite trends have been noted for the C and S groups in creatine kinase (CK) activity changes recorded during the first to the second trial: an increase in CK for the control and a decrease for the supplemented group in all phases of the experiment: pre-exercise, post-exercise and after recovery. In the second trial, all CK values for the S group have been found significantly lower than the corresponding values recorded in the C group. These results suggest a mitigate effect of GTE supplementation on post-training muscle damage. DSC results did not reveal clear effects of training nor GTE supplementation on serum denaturation transition. However, interesting dependences of thermodynamic parameters describing this transition have been observed in different phases of the experiment. Statistically significant negative correlations have been found between post-training VO_2max and post-exercise thermodynamic parameters associated with haptoglobin contribution to serum denaturation transition.     

PIXE analysis of human stones: Comparison with data from ICP-AES

25 human stone samples previously analyzed by inductively coupled plasma atomic emission spectroscopy /ICP-AES/ and the IAEA Animal Bone Standard Reference Material were used to evaluate trace element analysis by PIXE. Bombardment with 4 MeV protons was used for the determination of Mn, Fe, Cu, Pb, Br, Rb, Sr as well as Ca. PIXE and ICP-AES data gave correlation factors better than 0.97 for the elements Ca, Fe, Zn, Sr and Pb.     

Trace element analysis of placentas of alcoholics and controls with external beam PIXE

External beam PIXE analysis with a protonbeam of 2.4 MeV was used to study trace element concentrations in human placentas. The aim was to check the suitability of PIXE analysis regarding soft tissue samples. Sample preparation was kept as simple as possible to avoid contamination or losses due to volatilization. The element of interest /Fe, Cu, Zn, Se, Br, Rb, and Sr/ were easily detected. A comparison was made with placental samples of alcoholics and abstinent controls to determine whether trace element concentrations in the placenta play a role in the pathogenesis of fetal alcohol syndrome.     

Quantitative X-ray fluorescence analysis of an Egyptian faience pendant and comparison with PIXE

The X-ray fluorescence (XRF) technique is a common choice in the archaeometric field for in situ investigations with portable instruments. This work shows that XRF portable systems can be used for quantitative analyses using appropriate software, obtaining a similar accuracy to that provided with other techniques such as particle-induced X-ray emission (PIXE), as shown for an Egyptian faience pendant and for two glass standards.     

Total elemental analysis of lake sediments in palaeoecology: An investigation of sample preparation techniques for atomic absorption analysis

The results reported in this study suggest that care must be taken in choosing a sample digestion procedure for total elemental extraction using atomic absorption spectroscopy. This is particularly true when, for example, stratigraphic elemental studies are required involving down core phase changes. The problem is to separate real variations in metal concentration from spurious differences caused by the varying ability of extraction procedures to release elements from different phases.The variation is most problematic in relation to the major cations, in particular Na and K, which varied by up to 2000 and 700%, respectively. In this case and in the case of, for example, Ca and Mg, Cr and Co, methods 3 and 4 seem to be necessary if the findings are to be comparable. Methods 2–6 are suitable for phosphorus determination in the samples studied. The graphs presented as Figs. 1–3 suggest the likely effects of using less rigorous methods, for example, without using HF or HClO₄. Method 5 illustrates this point in that H₂SO₄ significantly increases the oxidizing ability of a H₂O₂-HNO₃ mixture (method 2) for K, Cu, Co, Mg in carbonate and clay phases. However, it presents considerable disadvantages in the determination of Ca in calcareous samples and should be avoided in such cases (12). In some cases it may be desirable to attempt the determination of elements which present greater extraction problems notably those associated with inorganic phases, for example, Al or Si. Here we suggest that methods such as acid-pressure decomposition using Teflon-lined bombs may be more appropriate (3, 9), but these will inevitably lead to an investment which smaller palaeoecological laboratories might be reluctant to enter into.     

Combination of neutron activation,atomic absorption spectroscopy and conventional methods in the elemental analysis of silicate rocks

Instrumental neutron activation, atomic absorption spectroscopy and conventional methods of analysis were used on eight different silicate rocks and two minerals. Trace elements and major constituents were determined. It was considered that the methods should be regarded as complementary analytical techniques.     

Thermal analysis of sulfurization of polyacrylonitrile with elemental sulfur

Thermal analysis of sulfurization of polyacrylonitrile (PAN) with elemental sulfur was investigated by thermogravimetry and differential thermal analysis of the mixture of polyacrylonitrile and elemental sulfur up to 600°C. Due to the volatilization of sulfur, the different heating rate (10 and 20 K min⁻¹) and different mixture proportion of polyacrylonitrile and elemental sulfur were adopted to run the analysis. The different heating rates make the DSC curves of sulfur different, but make the DSC curves of PAN similar. In the DSC curve of sulfur for the heating rate of 20 K min⁻¹ around 400°C, a small exothermic peak occurs at 400°C in the wide endothermic peak around 380∼420°C, indicative of that there is an exothermic reaction around 400°C. In the DSC curves of the mixture, the peaks around 320°C are exothermic as the content of sulfur is below 3.5:1 and endothermic as the content of sulfur is over 4:1, indicating that one of the reactions between PAN and sulfur takes place around 320°C. In the TG curves of the mixture, the mass losses begin at 220°C, and sharply drop down from 280°C. The curves for the low sulfur content obviously show two steps of mass loss, and curves for the high sulfur content show only one step of mass loss, indicative of more sulfur is benefit for the complete sulfurization of PAN. This study demonstrates that the TG/DSC analysis can give the parameter for the sulfurization, even if the starting mixture contains the volatile sulfur.     

Use of PIXE analysis to determine trace metals in drinking water in Jordan

The procedure for using proton induced X-ray emission (PIXE) in conjuction with the method of spotting for qualitative and quantitative multi-element analysis of drinking water in eight cities of Jordan is discussed in this article. It is likely that this method of preconcentration can be directly incorporated into field sampling procedures, thus eliminating the problems of sample contamination or trace element losses by absorption on container walls, the significance of some of the elements found in the samples is discussed.