Trace element analysis of motor oil by reactor neutron activation analysis

Normal motor oil have been analyzed by RNAA using thermal neutrons and single comparator method. The samples were taken from the oil carter of an engine. The concentration of trace elements have been measured as a function of running kilometers by -ray spectrometry. The trace elements which have been detected are Na, Mg, Al, Cl, V, Mn, Cu, Cr, Fe, Co, Zn, Br, Sb and Cd.     

Trace element concentrations in human bone using instrumental neutron activation analysis

Instrumental neutron activation analysis has been applied to analyze 23 bone samples obtained from Libyan patient aged (3–80) years for the study of the concentration levels of trace elements Ba, Br, Ca, Fe, Sr and Zn and their concentration pattems regarding to the age and sex of the patients.     

Trace element concentration in human gallstones using instrumental neutron activation analysis

The concentrations of trace elements in two types of gallstones in 24 female patients in Tripoli aged 24–60 years have been determined using instrumental neutron activation analysis. These elements are Co, Fe, Mn, Se and Zn. The results are expressed in ppm and are in agreement with reported values. The data suggested that the concentrations of trace elements increase with age.Presented at the MTAA-8 Conference, September 16–20, 1991, Vienna, Austria.     

Trace element determination in rocks and sediments by neutron activation analysis

Neutron activation analysis (NAA) is one of the most used analytical techniques for trace element determination in rocks, because time consuming operations are avoided. We have analyzed different types of USGS reference materials (G-2, GSP-1, BHVO-1, STM-1, GXR-3, GXR-4, GXR-5), using both thermal (TNAA) and epithermal neutrons (ENAA). ENAA has been used to reduce interferences due to Sc-46 and to other high activities. The following elements have shown an improvement when analyzed by ENAA: Ba, Cs, Gd, Rb, Sb, Sr, Ta, Tb, Th, Tm, U, Yb, Zr; better results were found for Ce, Co, Cr, Eu, Fe, Hf, La, Lu, Na, Nd, Sc, Zn with TNAA. The accuracy of both methods has been tested comparing our results with some published values. The agreement is in general very good. The precision also is satisfactory, being for many elements better than 10%. After these tests, a study on some rock samples from the basaltic plateau of Kenya, east of Gregory Rift, has been performed by ENAA. Among the elements determined in this work, the rare earch elements (REE) can give significant petrogenetic information, by means of their distribution and fractionation in the rocks. The main parameters investigated are the degree of fractionation of light (La to Eu) relative to heavy (Gd to Lu) REE and the occurence of Eu anomalies, when the REE concentrations are compared to chondritic values. The evaluation of detection limits by TNAA has been performed for REE in sediment samples from Thyrrenian Sea (Central Italy).     

Trace element pharmacognostical study on diuretic drugs by neutron activation analysis

Some pharmacological properties and especially diuretic action of medicinal plants are attributed to their elemental content. The elements chlorine, manganese, potassium and sodium are determined by instrumental neutron activation analysis in the dry samples of the following drugs: stigmata of Zea mays, leaves of Uva ursi, rhizome of Cynodon dactylon, whole plant of Ceterach officinarum as well as in infusions, decoction of the same drugs and in the water used for these preparations. It has been found that manganese and potassium are transferred partially into prepared solutions. Sodium is not transferred into solutions from any of these drugs while only chlorine is transferred partially into infusion of Zea mays. From these results it is concluded that the diuretic action of the examined drugs should not be attributed exclusively to the presence of their potassium and chlorine content but also to other constituents.     

Trace element analysis of biological materials by thermal and epithermal neutron activation analysis

A scheme for instrumental neutron activation analysis of biological materials is proposed. The scheme is based on a combination of thermal and epithermal activation. The accuracy is evaluated by analyzing 4 standard reference materials. Results from the analysis of human blood serum and plasma are given.     

Trace element exposure in man by instrumental neutron activation analysis of hair

A nondestructive instrumental neutron activation technique was used to analyze human hair samples collected from people living in metropolitan and rural areas in Korea. Samples were also collected from factory workers and cancer patients. Hair from metropolitan area residents contain higher concentrations of Ca, Mg, Zn, Cu, Na, Br, Mn, I and S than rural area residents. Concentrations of I and S from cancer patients, Mg, Zn, Al, Na, Mn and As from glassware workers were relatively higher. The results show that the trace element concentrations of the hair are possibly related to the trace element concentrations in the body.     

Instrumental neutron activation analysis of blood serum

Instrumental neutron activation analysis has been used to determine 15 trace elements in twelve blood serum samples taken from healthy students at Bilkent University in Ankara. The method allowed the determination of Sc, Cr, Mn, Fe, Co, Zn, Se, Rb, Cs, Ce, Eu, Tb, Hf, Ta and Hg, which occur at the g.ml^–1 to ng.ml^–1 levels. There are no values reported for Tb, Hf, Ce, Eu and Ta before. The other results are compared with the values reported in the literature. Most are in the range of the reported values except for Fe, Zn, Se and Cs.     

Trace elements in human bone determined by neutron activation analysis

There is an evidence that some of the essential trace elements are crucial determinants of bone health. Excess or deficiency of these elements has a role in the development of bone diseases, therefore research on trace elements in bone is very important. Iliac crest bone biopsies were optioned from twelve persons undergoing orthopedic surgery due to any reason than osteoporosis. Cortical and trabecular parts were separated, and blood and fats were removed. Up to 30 minor and trace elements were determined in these samples by instrumental neutron activation analysis and other techniques and their relations were discussed.     

Variations in trace element concentrations in human blood serum in the normal state investigated by instrumental neutron activation analysis

Using instrumental neutron activation analysis, the variations in the serum levels of Br, Cs, Na, Rb, Se, and Zn were investigated in 18 persons in the normal state. By determining the element levels in relation to changes is the serum water content, information about the binding to the serum protein was obtained. The influence of physiological factors on the serum element levels was investigated. Changes in the concentrations due to variations in the protein/water ratio and in the zinc level as a result of different posture were observed. When standardized sampling procedures were used, the variations in the serum element concentrations during one hour and from day were found to be less than 10%.     

Trace element analyses of spectroscopically pure silicon dioxide by instrumental neutron activation analysis

Spectroscopically pure, 99.999% silicon dioxide (SiO₂) from five different companies was analysed for trace element impurities by instrumental neutron activation analysis using semiconductor detectors and gamma-ray spectrometry. If large amounts of these purified SiO₂ samples are added to, geological samples with low trace element contents e.g., mineral separates such as quartz, feldspar and olivine, the trace element contents of the SiO₂ are a significant contaminant.     

Trace element determination in aerosols from the Antarctic Peninsula by neutron activation analysis

The knowledge of the composition of atmospheric aerosols in remote areas, like the Antarctic Peninsula is of great importance for the study of long-range transport of atmospheric contaminants and also from the climatological point of view. Instrumental neutron activation analysis was applied in the present work to determine the elements Al, V, Mn, Na, Cl, Ca, Au, Br, Sb, Sc, Fe, Zn, K, Th and La in aerosol samples collected in the Brazilian Antarctic Station Comandante Ferraz (62° S, 58° W) located on King George Island in the Antarctic Peninsula. The sources of the aerosols were investigated by means of Enrichment Factors and Principal Factor Analysis. Both methods yielded similar results. Sea and soil were identified as the major sources of aerosols, in the samples collected at the Brazilian Station.     

Determination of vanadium in human serum by neutron activation analysis

Vanadium in serum has been investigated by the aid of neutron activation analysis (8 min irradiation at 8·10¹³ n·cm⁻²·s⁻¹ in the reactor FR-II of the Kernforschungszentrum in Karlsruhe). The lyophilized samples were dry-ashed before irradiation and the⁵²V activity extracted after irradiation. The values for V in the sera of 22 healthy males ranged from 0.029–0.939 ng V·ml⁻¹. There is a real assumption that some of the high figures are due to persons being contaminated with V. The 18 healthy females yielded a mean value of 0.033±0.012 ng V·ml⁻¹ for 17 of them and one additional value of 0.139 ng V·ml⁻¹. These V-data are the lowest ever reported in the literature. The analyses of two packed blood cell samples yielded 0.031 and 0.020 ng·g⁻¹, indicating that about 68% of the total V in blood is present in serum. There was no correlation between the V-content and age, nor between the V-content and the cholesterol, triglycerides or the lipoprotein fractions in serum.     

Trace element determinations in shale oil products by neutron activation

Neutron activation offers some important advantages for the determination of selected trace elements in shale oil products. This paper gives techniques and results of a study of crude shale oil and naphtha, heavy distillate, and wax products of shale oil. The elements determined were Al, As, Au, Br, Ce, Cl, Co, Cr, Fe, Hg, I, K, Mn. Mo, Na, S, Sb, Se, V, and Zn. Some elements (Mn, Na, As) tend to accumulate in heavier fractions, whereas chlorine and iodine are concentrated in the more volatile fractions. The volatility of sulphur compounds in the shale oil products appears to be essentially uniform, with some tendency toward accumulation in distillation residues. The tendency for the trace elements to accumulate in the waxes that precipitated from cooled heavy distillates was very low.     

The determination of strontium in human blood serum and packed blood cells by radiochemical neutron activation analysis

Strontium is a trace element whose distribution and metabolism are similar to those of calcium, its close chemical analogue. The element received scientific attention because of its potential beneficial effects in the treatment of osteoporosis andosteolytic metastatic bone lesions but also because of the possible problems associated with the retention of⁹⁰Sr from radioactive fall-out. In continuation of a series of experiments intended to establish reliable reference values for trace elements in human blood serum and packed blood cells, we set up a project to determine also strontium. The following values were obtained (mean±standard deviation): 22.2±4.8 ng/ml (serum) and 2.85±1.11 ng/g wet weight (packed blood cells).     

Trace element determination in high-purity scandium by neutron activation analysis and pre-irradiation matrix separation

A pre-irradiation separation procedure has been developed for the determination of trace elements in high-purity scandium by neutron activation analysis. The sample is dissolved in high-purity concentrated hydrochloric acid and scandium is extracted with the same volume of a solution of 50 vol.% bis(2-ethyl hexyl)-orthophosphoric acid (HDEHP) in toluene. The scandium matrix is removed from the most important trace impurities and the residual amount of Sc is in the range of 0.001%. The separation is carried out in the vial to be used in irradiation to prevent sample contamination. Detection limits in the ppb range were achieved with a sample of 10 mg, a thermal neutron flux of 2 · 10¹³ n · cm^–2 · s^–1 and an irradiation time of 48 hours. Most of the elements sought in two samples of high-purity scandium were below the detection limits.     

Rapid determination of selenium in human serum by neutron activation analysis

A simple and rapid method was developed for the determination of selenium in human serum using a pre-irradiation separation technique of ultrafiltration followed by neutron activation analysis via the short-lived activation product^77mSe. The method was validated using certified reference material.     

Trace characterisation of lithium niobate by neutron activation analysis

Summary Coprecipitation behaviour of As, Au, Co, Cr, Cu, Eu, Fe, Ir, La, Lu, Mn, Mo, Nb, Ni, Pd, Pt, Sb, Sc, Ta, W, Zn and Zr during precipitation of hydrous oxide of niobium from lithium niobate was investigated. The matrix was dissolved in HF-HNO₃, evaporated to dryness and niobium was precipitated from HNO₃-H₂O₂ medium. The recovery studies were made using radiotracers. A radiochemical separation scheme based on group precipitation has been developed for the determination of Au, Co, Cr, Cu, Fe, Mn, Ni, Pd, Pt, Zn, Zr and rare earth elements. The method was applied to the analysis of lithium niobate. This analysis has provided fruitful information for improving the quality of the crystal.     

Trace element levels of aerosols at an urban area of Korea by instrumental neutron activation analysis

Instrumental neutron activation analysis was used to measure the concentrations of about 27 elements associated with airborne PM 10 samples that were collected from a roadside sampling station at a moderately polluted urban area of Taejon city, Korea. The magnitude of their concentrations was clearly distinguished and spanned over four orders. If compared in terms of enrichment factors, it was found that certain elements (e.g., As, Br, Cl, Sb, Se, and Zn) are enriched in PM 10 samples of the study site. The factor analysis indicated three factors with statistical significance, which may exert dominant controls on regulating the metal concentration levels in the study area.     

Determination of certain elements in human serum albumin by neutron activation analysis

Instrumental activation analysis was used to determine the contents of certain elements in human serum albumin (HSA). Sample irradiation was performed with a thermal neutron flux of 1.5·10¹³ n·cm⁻²·sec⁻¹ in the RA nuclear reactor of the Boris Kidrič Institute, Vinča. Measurements were performed on a 4096-channel analyser with a high-resolution Ge(Li) detector. The Na, Cu, Br, Au, Hg, Cr, Fe, Ag, Sc, Ba and Co contents were determined in HSA produced by the Institute for Blood Transfusion, Belgrade.