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At least 19 recordsLinked to original sources
PubMed1991

The determination of platinum in biological tissue by instrumental neutron activation analysis.

Neutron activation analysis was used to determine platinum in the tissues of rats that had received doses of the tumor chemotherapy agent cis-Pt. Two elements causing spectral interference were identified as 47Sc from 46Ca, a natural component of tissue, and tin (117mSn), an element introduced inadvertently during necropsy and sample work-up. A protocol was devised to correct for interference, using emission lines from 47Ca and 113Sn, respectively, with appropriate consideration for relative detector efficiencies, decay times and half-lives.

Animals↗
PubMed1979

Cadmium analysis by radiochemical neutron activation analysis.

Radiochemical neutron activation analysis (RNAA) has been routinely used at the National Bureau of Standards to analyze Cd in a variety of environmentally important matrices. The method used to separate Cd from other neutron-activated products is solvent extraction. Zinc diethyldithiocarbamate [Zn(DDC)2] in chloroform will quantitatively extract Cd from an aqueous solution over a pH range from 1 to 12. In addition to the extraction of Cd, Zn(DDC)2 will also extract Cu, which can interfere with the Cd analysis by producing a high background level of radiation. This can be avoided by first extracting with Bi(DDC)3 in chloroform which removes Cu, but not Cd. Copper concentrations can, therefore, be determined in addition to Cd. This two extraction radiochemical separation procedure is very versatile and is often used as part of a larger multi-element analysis scheme. One such scheme involves the use of an inorganic-ion exchanger, Hydrated Manganese Dioxide (HMD), to retain As, Sb, Se, and Cr prior to extraction. The eluted fraction is then extracted with Bi(DDC)3 to remove Cu, and then with Zn(DDC)2 to remove Cd.

Activation Analysis↗
PubMedDate not supplied

Determination of inorganic components in Brazilian medicinal plants by neutron activation analysis.

Instrumental neutron activation analysis (INAA) has been applied to multielemental determinations of medicinal extracts obtained from the plants. Cordia Verbenacea DC, Folidago Microglossa DC, and Petiveria Alliacea. Concentrations of the elements Al, Br, Ca, Cl, Co, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, and Zn have been determined in dried extracts of these herbs by short and long irradiations under a thermal neutron flux of 10(11)-10(13) n/cm2s in the IEA-R1 nuclear reactor. The NBS Tea Leaves (1572) and NIES Pepperbush (1) reference materials were analyzed simultaneously with the plant extracts. The results obtained in these analyses have shown a good accuracy and reproducibility of the method. The relative errors and the relative standard deviations were less than 10% for most of the elements analyzed.

Brazil↗
PubMed1978

Measurement of chromium VI and chromium III in stainless steel welding fumes with electrom spectroscopy for chemical analysis and neutron activation analysis.

Electron Spectroscopy for Chemical Analysis (ESCA) was explored as a means of studying the oxidation state of chromium in SMAC (coated electrode) stainless steel welding fume collected on Nucleopore filters in the laboratory. Chromuim VI and III (as a percent of the total chromium) obtained from ESCA analysis was applied to results from Neutron Activation Analysis (NAA) to yield an average of 69 microgram chromium VI per sample. Diphenylcarbazide/atomic absorption (DPC/AA) results are reported for samples submitted to an industrial laboratory. Possible chemical species and solubility of chromium VI in stainless steel fumes is discussed in light of analogy between the SMAC process and the manufacturing process for chromates.

Air Pollutants↗
PubMed1978

Determination of certain selected bulk and trace elements in the bovine liver matrix using neutron activation analysis.

Effective utilisation of neutron activation analysis (NAA) for the elemental analysis of biomedical samples with or without a radiochemical separation, especially when optimal Ge(Li) well type detectors are employed for the acquisition of complex spectra, is demonstrated by determining normal values for 25 elements in bovine liver. Optimal conditions for the determination of Ag, Br, Cl, Co, Cs, Fe, I, K, Mn, Na, P, Rb, Sb, Sc, Se and Zn with the aid of instrumental thermal neutron activation analysis (INAA) by varying the irradiation and decay time are presented. Where INAA was inadequate, simple post irradiation separation based on ion-exchange has been used to determine such elements as Au, Ca, Cd, Ce, Cr, Cu, La, Mo and W. Results from the IAEA intercomparison run for animal muscle (H-4) are also given. The influence of sample size with respect to within-tissue variation of the bulk and trace elements in liver and the contamination of liver samples from the interfering components such as residual blood are also discussed.

Activation Analysis↗
PubMedDate not supplied

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.

Bone Density↗
PubMed1987

Multielement determination of metals in biological specimens of hard metal workers: a study carried out by neutron activation analysis.

Multielemental analysis, using neutron activation, was carried out on the urine, whole blood, pubic hair and toenails of thirty subjects occupationally exposed to hard metal dusts. A high concentration of Co, W and Cr was observed in all samples analysed. The concentrations determined, when subjected to statistical analysis using pattern recognition techniques (e.g. cluster analysis), indicated a positive correlation, at p = 0.001, for the pair (Co, W) in urine and blood, as well as a possible influence of Cr on this pair.

Adolescent↗
PubMed1988

[Evaluation of intraocular metallic foreign bodies by multi-element neutron activation analysis].

Multi-element neutron activation analysis method was applied to the determination of metallic foreign bodies which penetrated into the eyes of workers while engaged in grinding and cutting work. A total of 23 small pieces ranging in size from 1 to 10(2) mg were surgically obtained and then analyzed non-destructively with only simple washing treatment. The components of 21 samples were mainly iron and the others were hard pieces of wolfram compound. Elements determined in samples over one weight percent were iron, manganese, chromium, wolfram, and cobalt. All the samples were divided into five classes according to their own elemental composition. It was considered that foreign bodies were composed of carbon steel, steel alloy, and tungsten carbide. These results are regarded to be useful in studying the mechanism of accidents and their effects on eyes.

Eye Foreign Bodies↗
PubMedDate not supplied

Nondestructive determination of arsenic in urine by epithermal neutron activation analysis and Compton suppression.

Epithermal neutron activation analysis, in conjunction with Compton suppression, has been employed to determine arsenic levels in artificially doped urine samples. Typical detection limits were of the order of 10 ng/g. Replicate determinations gave precision values between 2 and 12%, whereas accuracy measurements were between +/- 1 and +/- 20%. Biological and geological reference materials from the National Institute of Standards and Technology (NIST) were also analyzed for arsenic content. Typically, the precision achieved again was between 2 and 12%, whereas the accuracy measurements were in excellent agreement with the certified values.

Arsenic↗
PubMed1975

[Investigations of contact tissues of Blount vitallium staples using the instrumental neutron activation analysis (author's transl)].

Instrumental neutron activation analysis with Gamma-spectroscopy is a very sensitive method for testing trace elements. Specimens of contact tissue around 5 Blount's vitallium clamps were, after preparation at the Nuclear Research Institute Jülich irradiated with thermic neutrons and their element-specific gamma spectra were measured after 33 and 125 days. In contact tissue a significant rise in concentration of the alloy-specific elements cobalt and chromium was found. The unspecific elements silver, caesium, iron, rubidium, antimon, scandium and zink were either within or very close to the normal. The metallosis of contact tissue is due to corrosion of the surfaces of cobalt-chromium implants.

Activation Analysis↗
PubMed1990

Neutron activation analysis of manganese contents in ordinary hospital meals.

Neutron activation analysis (NAA) was applied to measurement of manganese (Mn) content in food as an example of ordinary hospital meals. The results showed that: 1. NAA permits measurement of Mn with a simple pretreatment procedure in comparison with AAS (atomic absorption analysis). 2. Daily Mn intake was estimated to be about 3 mg from food, and about 4 mg from green tea. Neutron activation analysis (NAA) has been used for measuring various elements under the conditions appropriate for the irradiated or radioactivated subject of analysis. We presently applied NAA to measurement of manganese (Mn) contents in food as an example of ordinary hospital meals with an estimation of daily Mn intake.

Food Analysis↗
PubMed1978

[Studies on the presence of metal traces in tissue surrounding A.O. angle plates, based on neutron activation analysis (author's transl)].

Using instrumental neutron activation analysis, 11 samples of tissue in contact with A.O. angle plates and 8 samples of fascial tissue were examined for their content of trace elements, half a year to 5 1/2 years after hip joint intertrochanteric osteotomies. Significant increases in the concentrations of the elements Cr, Fe, Co, Ni and Mo, all of which are contained in the A. O. steel plates (V4A steel), were found both in the contact tissue and in the tissue of the fascia lata femoris about 4--8 cm away from the angle plates, whereas the levels of concentration of elements not specific for the alloy in question, namely, Zn, Se, Rb and Cs, were normal or just subnormal. It was possible to prove by means of element correlations that the elements Cr, Co, Ni and Mo are present in constant ratios in those tissue samples which are loaded with traces of metals foreign to the body. However, only the Mo:Cr ratio corresponds to that of the angle plates. The authors considered Ni to be a useful indicator for the degree of metal loading of a tissue, since Ni will normally occur in human tissue in very low concentrations (less than or equal to 10(-6) g/g dry substance) and was identified by the authors--contrary to previous studies--even in the fascial tissue located up to 8 cm away from the contact tissue. Non-linear correlations were found between iron and the other components of the steel, reflecting the complicated regulatory mechanisms governing the presence of iron in the organism. The results of the analysis are discussed in respect of possible long-term action of the implantate components liberated by corrosion, which, in case of long-term implantates might place an overall burden of foreign ions on the body.

Chromium↗
PubMed1979

Neutron activation analysis of selenium and 17 elements in sediment.

Instrumental neutron activation analysis was performed to determine Na, Mg, Al, Cl, Sc, V, Cr, Mn, Fe, Co, Ni, Rb, Sb, Cs, Ba, Ce and Eu in the Pacific core sediment. Selenium was also determined by neutron activation analysis, by applying a solvent extraction method with 2,3-diaminonaphthalene (DAN) as a post-irradiation procedure, after the wet-ashing of the sediment. Homogeneity of trace constituents in the sediment and neutron flux corrections for accurate determination were also investigated.

Activation Analysis↗
PubMed1978

A two-way scanning method for total body in vivo neutron activation analysis.

When determining the total body content of many elements by neutron activation analysis, irradiation and whole body counting by scanning along the length of the body has significant advantages. A neutron source of lower output and a whole body counter using smaller detectors and shielding (than otherwise needed) can provide a high, uniform response for many elements throughout the body. This was previously achieved by making the speed and direction of scanning identical in irradiation and counting (one-way scanning). A simple theoretical model for scanned irradiation and counting is described. The model is used to show that a scanning regime in which both scanning directions are used (two-way scanning) can provide acceptably uniform response for elements having induced activities of a wide range of half-life. This is supported by measurements made using an existing scanning facility for total body in vivo neutron activation analysis. The two-way scanning regime offers the advantages of increased patient comfort, simpler operation and more efficient use of the time available for counting induced activity.

Activation Analysis↗
PubMed1977

Determination of gold in plasma and plasma fractions by atomic absorption spectrometry and by neutron activation analysis.

Three techniques of gold analysis, flame and electrothermal atomic absorption spectrometry and neutron activation analysis, have been compared, using plasma and plasma fractions (derived by gel chromatography) from rheumatoid patients receiving aurothiomalate therapy and from plasma samples incubated with aurothiomalate in vitro. The three methods correlated well in the analysis of gold in whole plasma, but only neutron activation analysis was suitable for the assay of all the plasma fractions. The susceptibility of the two atomic absorption methods to interference by sodium chloride was investigated.

Gold↗
PubMed1989

Energy dispersive X-ray microanalysis, neutron activation analysis and atomic absorption spectrometry--comparison using biological specimens.

X-ray microanalysis, neutron activation analysis and atomic absorption spectrometry were performed on normal and injured skeletal muscle. X-ray microanalysis of tenotomized rat soleus muscle showed significantly elevated levels of sodium and chlorine and lower potassium compared with normal muscle. Similar ion shifts could be demonstrated by neutron activation analysis and atomic absorption spectrometry. The concentrations of sodium and chlorine obtained by these techniques were somewhat higher and that of potassium lower than the values obtained by X-ray microanalysis. This can probably be attributed to the fact that in atomic absorption spectrometry and in neutron activation analysis the entire muscle biopsy contents are measured while in X-ray microanalysis only the content of muscle cells unaffected by extracellular, non-muscular components are determined. It can be concluded that X-ray microanalysis is a reliable technique to study the elemental content of biological tissue, especially tissue undergoing pathological changes affecting the extracellular spaces. Other types of analysis should be used when elements not detectable by X-ray microanalysis are of interest.

Activation Analysis↗