Determination of trace elements in tissue of human uterine cancer by instrumental neutron activation analysis

In this article, the low-temperature freeze-drying pretreated technique and instrumental neutron activation analysis were used to determine 29 trace elements in samples of human uterine cancer tissue. The content of these trace elements in uterine cancer tissue was compared with that in cervicitis tissue and in healthy tissue, respectively. Preliminary results indicated that significant differences in contents of Au, I, and Se were observed in these tissues.     

Trace elements in the human central nervous system studied with neutron activation analysis

The central nervous system (CNS) should be especially sensitive to disturbances in trace element concentrations because of its high metabolic rate and low capacity for regeneration. Comparatively few studies have been made on trace elements in the CNS, which prompted us to begin a study of trace elements in four different brain lobes of the CNS, as well as in the spinal cord. Samples were obtained at autopsy and handled carefully in order to avoid contamination. They were freeze-dried and sealed in quartz tubes that were irradiated in a nuclear reactor. A simple chemical separation into six fractions was performed. The gamma spectra for these fractions was registered using a Ge(Li) detector and a computerized multichannel analyzer. Results for the following elements were obtained: Ca, Cd, Co, Cr, Cs, Cu, Fe, Rb, Se, and Zn, as well as for Na and K (not reported). Other elements were also detected in some samples. Using this technique, brain samples from ten patients with Alzheimer’s disease and ten control cases were examined.     

Instrumental neutron activation analysis of rib bone samples and of bone reference materials

The instrumental neutron activation analysis method was used for the determination of trace elements in rib bone samples taken from autopsies of accident victims. The elements Br, Ca, Cl, Cr, Fe, Mg, Mn, Na, P, Sr, Rb, and Zn were determined in cortical tissues by using short and long irradiations with thermal neutron flux of the IEA-R1m nuclear reactor. The reference materials NIST SRM 1400 Bone Ash and NIST SRM 1486 Bone Meal were also analyzed in order to evaluate the precision and the accuracy of the results. It was verified that lyophilization is the most convenient process for drying bone samples because it does not cause any element losses. Comparisons were made between the results obtained for rib samples and the literature values as well as between the results obtained for different ribs from a single individual and for bones from different individuals.     

Content of trace elements in the respirable fractions of the air particulate of urban and rural areas monitored by neutron activation analysis

The concentrations (ng/m³) of more than 30 trace elements have been determined in the total air particulate matter and in the sizesegregated fractions collected in urban, industrialized, and rural residential areas in northern Italy by means of a multistage inertial impactor with the PM10 inlet. All measurements have been carried out by instrumental neutron activation analysis, except for Pb and Cd, which have been determined by electrothermal atomic absorption spectroscopy. Analytical quality assurance procedures have been developed with special regard to blanks, reagents, and sampling. Total concentrations and the granulometric distribution found in the different locations are reported and compared.     

An elemental correlation study in cancerous breast tissue by total reflection x-ray fluorescence

The total reflection x-ray fluorescence method (TRXRF) has been employed to determine of P, S, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Se, Rb, Sr, and Pb concentration in the benign breast tumor tissue from 68 women and in the cancerous breast tissue from 26 women. Concentrations of most of elements show enhancement in cancerous breast tissue. Examined elements compete for binding sites in the cell, change its enzymatic activity, and exert direct or indirect action on the carcinogenic process accelerating the growth of rumors. Inhibition of enzymatic activity caused by variation in trace element concentrations results in immunological breakdown of the body system. An attempt has been made to correlate measured trace element concentrations with the clinical stage of cancer. Physical bases of used analytical method, experimental setup, and the procedure of sample preparation are described.     

Minor and trace elemental contents of cancerous breast tissue measured by instrumental and radiochemical neutron activation analysis

Many minor and trace elements influence the permeability of cell membranes by competing for binding sites, and exert direct or indirect action on the carcinogenic process. Instrumental and radiochemical neutron activation analysis has been employed for the determination of more than 20 elements in normal and cancerous breast tissues of 6 patients. Most trace elements, viz., Zn, Cu, Mn, Co, Se, Br, As, Sb and Cd, are elevated in cancerous tissue, whereas lower levels are observed for Fe, Cs, I, and Sr. Similarly, concentrations of minor constituents, such as Na, K, P, Cl, and Mg, are enhanced compared to normal tissue. Several elements incorporate into the normal cell, change its enzymatic activity, and accelerate the growth of tumor.

     

An environmental research on trace elements in freshwater fish by neutron activation analysis

For a case study of environmental contamination, radiochemical activation analysis has been applied to the crucians collected in the Han River. Sixteen trace elements (Hg, Cd, As, Br, Cu, Na, K, Se, Cr, Hf, Rb, Fe, Zn, Co, La, and Cs) were separated into three groups using distillation and diethyldithiocarbamate extraction methods, and their contents were determined by a single comparator method. Compared with the values 15 years ago, the values for mercury and cadmium have been drastically decreased at the middle and lower part of the river, but no typical change is found in other elements.     

Determination of trace elements in porcine brain by inductively coupled plasma-mass spectrometry,electrothermal atomic absorption spectrometry,and instrumental neutron activation analysis

Methods have been developed for the analyses of trace metals in various areas of porcine brains, (temporal, parietal, frontal cortex, both right and left hemispheres). Determinations were carried out using inductively coupled plasma-mass spectrometry (ICP-MS) and electrothermal atomic absorption spectrometry (ETAAS). The elements investigated were Li, Mn, Cu, Zn, Cd, Hg, and Pb by ICP-MS and Cu, Cd, and Mn by ETAAS. For determination by ICP-MS, a method of standard additions calibration coupled with internal standards was used, and for ETAAS, standard additions calibrations were prepared. The accuracy of all methods was determined using NIST and IAEA certified reference material. A small number of pig brains were analyzed by instrumental neutron activation analysis for Cr, Co, Cs, Fe, Rb, Se, Sc, Sb, and Zn using the comparator method of analysis. Four separate NIST standard reference materials have been used to examine the validity of the comparator method.     

Trace metals in oral mucosa in relation to the lichen ruber planus pathology. A preliminary study carried out by neutron activation analysis

Lichen ruber planus, contact allergy and hypersensitivity can be linked to oral exposure to metals released from metal alloys commonly used in dentistry. In this context neutron activation analysis was developed for the microdetermination of 36 elements in oral mucosa biopsies of two patients affected by lichen ruber planus and of five subjects as control group.In order to minimise metal contamination during sample collection, biopsies were taken by laser bistoury technique and then submitted to radiochemical neutron activation analysis (RNAA).Among the metals analysed, chromium showed obvious high concentration in gingival biopsies of the two pathological subjects compared to the corresponding tissues of control group. Cobalt and nickel were also determined in higher concentrations, but only in one of the oral mucosa of the two patients.The present findings way support the hypothesis concerning a potential link of lichen ruber planus condition with the exposure to Cr, Co and Ni as released into oral cavity from prosthodontic alloys.     

Environmental and biochemical trace-metal speciation studies by radiotracers and neutron activation analysis

Although knowledge of the total concentrations of trace metals in the environment and living organisms is still the essential starting point for any toxicological evaluation, it is, however, not sufficient to explain the mechanisms responsible for retention and toxic effect of trace metals. Differentiation between their chemical and biochemical forms is necessary. The need to resolve the total concentration of trace metals into single chemical species poses great experimental difficulties and imposes the use of very sensitive analytical techniques for trace metal determinations after specific preseparation procedures of the different chemical species. Thus, once the chemical or biochemical metal species have been selectively isolated, the speciation becomes merely an analytical problem, which requires high sensitivity and accuracy, as well as the evaluation of matrix effects, blanks, contamination, loss, and sampling. This paper describes the use of nuclear and radiochemical techniques related to chemical and biochemical speciation problems at the Joint Research Centre, Ispra, with carrier-free radiotracers and radiochemical neutron activation analysis.     

Applications of neutron activation analysis to the study of age-related neurological diseases

Although the etiology and pathogenesis of Alzheimer’s disease, Pick’s disease, and amyotrophic lateral sclerosis are still unknown, it has been suggested that perturbations in element metabolism may play a role. Even if not causative factors, these imbalances may prove to be markers that could aid in diagnosis. We have employed a sequential neutron activation analysis (NAA) procedure to determine elemental concentrations in brain, hair, fingernails, blood, and cerebrospinal fluid (CSF) of these patients and age-matched controls. Samples are first irradiated with accelerator-produced 14-MeV neutrons for determination of nitrogen and phosphorus, then with reactor thermal neutrons for the instrumental determination of 16–18 minor and trace elements, and, finally, reactor-irradiated again, followed by a rapid radiochemical separation procedure (RNAA) to determine four additional elements. Major advantages of NAA are: (1) its simultaneous multielement capability; (2) the relative freedom from reagent and laboratory contamination; (3) the absence of major matrix effects; and (4) an adequate sensitivity for most elements of interest. Ranges of concentrations by INAA and RNAA in selected control tissues and interelement correlations in control brain are presented to illustrate results obtained by the procedure. Longitudinal studies of tissues from Alzheimer’s disease (AD) and amyotrophic lateral sclerosis (ALS) patients are still in progress.     

Multielement compositions of marine phytoplankton samples from coastal areas of japan by instrumental neutron activation analysis

Phytoplankton samples were collected during spring bloom of diatoms from three coastal areas of Japan using a NORPAC P-25 net (25-Μm opening) with a NGG52 prenet (335-Μm opening), and 25 major and trace elements have been analyzed by INAA. Concentration ranges of analyzed phytoplankton samples are much wider than the concentration ranges compiled by Bowen (1979) except for As, and data of marine phytoplankton samples for Br, Sb, Hf, Sc, La, Ce, Sm, and Eu were not included in the compilation. The 25 analyzed elements have been categorized into three groups: elements showing positive correlation with Br, positive correlation with Al, and no positive correlation with Br or Al. The marine phytoplankton samples have been plotted on a Masuzawa-Koyama-Terazaki (MKT) plot and it proved that the MKT plot is applicable to marine phytoplankton samples.     

Chromium,nickel, and arsenic determinations in human samples by thermal and epithermal neutron activation analyses

Both thermal and epithermal neutron activation analyses have been employed to determine chromium and nickel in lung tissue and arsenic in urine. Based on accuracy, precision, and detection limits, these techniques have been successfully used to analyze lung tissue from a deceased welder, who died, from cancer, and to paratake in an interlaboratory toxicological urine program.     

Determination of selenium in canadian food items by cyclic instrumental neutron activation analysis

Instrumental neutron activation analysis (INAA) and pseudocyclic INAA (PCINAA) have been used to determine the selenium content of a variety of Canadian food items. Use of the 162-keV gamma ray of short-lived^77mSe in INAA allowed relatively simple and rapid determinations and was suitable for many of the foods. PCINAA was found to give lower detection limits and was used for the low-selenium food samples. Both internal and external quality assessments were used to evaluate and assure the accuracy and precision of the methods developed.     

Air quality status in Kinshasa as determined by instrumental neutron activation analysis,atomic absorption spectrometry,and ion-exchange chromatography

Three independent analytical techniques: instrumental neutron activation analysis, atomic absorption spectrometry, and ion-exchange chromatography were applied to airborne particulates collected on filters, and to atmospheric acid gases collected in carbonate buffer solutions. Twenty trace elements and seven acid gases and acid aerosols were determined. Results were compared with those observed elsewhere and showed that air pollution is low in Kinshasa and should not cause anxiety. The main known sources of pollutants are vehile exhaust and aeolian processes on stripped soils.     

A survey of trace elements in fresh-water fish and rice along the Han River by neutron activation analysis

For a case study of environmental pollution, radiochemical neutron activation analysis (RNAA) was applied to the crucian and rice collected along the Han River. The crucian was analyzed for three times in 1973, 1987, and 1990. Sixteen trace elements (Hg, Cd, As, Br, Cu, Na, K, Se, Cr, Hf, Rb, Fe, Zn, Co, La, and Cs) were determined by RNAA using distillation and diethyldithiocarbamate extraction methods. Contents of Na, K, Se, Hf, Fe, Zn, and Co were almost constant regardless of the sampling place and year. The contents of the other elements showed increasing trends down river, especially in the first investigation. At the lower part of the river, the contents showed decreasing trends with the time of sampling, especially during the first two investigations. These trends were typical for Hg and Cd. Rice was analyzed by the same method for 12 elements, and the results showed no regional trends, but have decreased after 1973.     

Trace element correlations in the blood of indian women with breast cancer

Fourteen minor (Na, K, P, Fe) and trace (Br, Co, Cr, Cs, Hg, Rb, Sb, Se, Sr, Zn) elements have been determined in pre and postoperative blood samples of 10 breast-cancer-affected. Indian women and compared with controls. The study showed elevation of Cr, Hg, Fe, Rb, Sb, and Zn and lowering of Se, K, P, and Sr contents in the blood of cancer patients. Most elemental contents in pre and postoperative stages remain unaltered except Br, Co, and Sb. Statistical significance of Fe, Se, Zn, and Hg levels has been tested by box plots. Lowering of Se in blood (-54.4%) is correlated with its enhancement in cancerous breast tissue (94.7%) of various clinical stages. Se/Zn and Se/Fe ratios are lowered in the blood of cancer patients, whereas Na/K ratio is only marginally enhanced. An attempt has been made to correlate Se levels with the dietary intake and breast cancer risk vis-a-vis American and Japanese women.     

Comparison of SR-excited X-ray fluorescence analysis with neutron activation analysis for hair and fiber

Human scalp hair and some kinds of vegetable and animal fibers were analyzed by means of the SR excited X-ray fluorescence method (SRXFA) and the neutron activation method (NAA). Human hair samples collected from five males and five females were washed by the IAEA method prior to analysis. In the SRXFA analysis, samples were excited by monochromated X-rays. Fluorescence X-rays were measured by an Si(Li) detector. The elements detected in all hair samples were S, Ca, Cu, Fe, Zn, Br, and Sr. The elements K, Ti, Cr, Mn, Ni, Se, Hg, and Pb were also detected in several samples. After SRXFA analysis these same samples were analyzed by the NAA method. Elements such as Cu, Zn, and Br were detected by both methods, and their relative concentrations show a good agreement of variation between individuals. However, Pb was only detected by SRXFA, and Na, Au, and Sb were only detected by NAA. Therefore, these two methods are complementary to each other for trace element analysis.     

Investigation of selenium distribution in subcellular fractions of human liver by neutron activation analysis

Selenium is an important and essential trace element to living systems. In the article, two methods of instrumental neutron activation analysis and hydride generation-atomic fluorescence spectrometry were applied to determine Se in biological samples and the accuracy was evaluated by several reference materials. The subcellular distribution of selenium in human liver samples, which were obtained from normal subjects who had an accidental death, was investigated by differential centrifugation combined with INAA. Selenium was mainly enriched in mitochondria, nuclei, and cytosol. Almost half of the total Se content existed in nuclei as a result of the large amount in liver and the high Se concentration. Generally, the highest Se concentration in the mitochondrial fractions of each liver sample suggested that Se had important functions in this liver component.     

Study of physiopathological phenomena in dental enamel by neutron activation analysis

An epithermal neutron activation method is used to determine the concentration of mineral elements in human dental enamel. A large number (252) of samples from ancient and modern origins are analyzed. The analytical results are mathematically processed using a statistical multivariant method. This allows to differentiate deciduous from permanent teeth and decayed from sound enamel. It is also possible to distinguish the teeth coming from two different necropoles. The origin and the localization of determined elements in the mineralized part, or in the aqueous-organic part, of enamel is suggested. Their role, as witnessed in the physiopathological phenomena of dental enamel, is discussed.