Instrumental Neutron Activation Analysis Method Research Articles

The Relationship between Serum Selenium Levels and Lipid Profiles in Adult Women

Low selenium status draws much attention because of the possible involvement in the etiology of cardiovascular disease (CVD). Hyperlipidmia or dyslipidemia, a very important risk factor for CVD, occurs frequently in middle-aged Koreans. While selenium deficiency is supposed to aggravate blood lipid profiles, it has been shown that selenium status diminishes with advanced age. However, little is known about the selenium status of Koreans, its age-related change, and its relationship to blood lipid levels. In this study the serum selenium level of females according to age and its association with blood lipid profiles were examined. Serum selenium concentration was determined by the instrumental neutron activation analysis method (INAA) using the HANARO research reactor. The overall proportion of women having selenium deficiency, with less than 80.0 microg/L of the selenium concentrations in the serum, was 18.3%. The serum selenium levels in the young-adult. middle-aged and elderly groups were 120.6 microg/L, 97.2 microg/L, and 90.8 microg/L, respectively. Biochemical indices derived from serum selenium levels showed that subjects with the lowest tertile of selenium concentration had significantly higher atherogenic index and lower HDL-cholesterol levels compared to those with the highest tertile. However, only the serum HDL-cholesterol level showed the dependency on the selenium status as determined by step-wise analysis in the subjects below the age of 40. It was noted that in the subjects over the age of 40 (pooled middle-aged and elderly), any dependency of serum lipid profiles on the selenium status was not observed. The results of this study indicated that there is a decreasing tendency of selenium levels with age and that selenium status is associated with blood lipid levels only in young-adult females.

Impact of different pollutant sources on Shiraz air pollution using SPM elemental analysis

Weekly average suspended particulate matter (SPM) concentrations were measured in four locations in Shiraz, Iran. Sampling was carried out from July 1999 and continued until July 2000. Instrumental neutron activation analysis (INAA) and atomic absorption spectrometry (AAS) methods were employed to obtain the weekly concentrations of Pb, Br, V, Ca, Al, Fe, Cu, Cr, Mn, Sc and Zn. The mean annual concentrations (in μg/m 3) of 11 elements were found to be: Pb 0.545 (±33.8%), Br 0.413 (±34.1%), V 0.009 (±28.2%), Ca 13.36 (±24.5%), Al 2.56 (±46.3%), Fe 2.62 (±38.7%), Cu 0.122 (±41.4%), Cr 0.015 (±35.8%), Mn 0.053 (±35.5%), Sc 0.0008 (±37.5%) and Zn 0.085 (±25.2%). The results of the study show that vehicle (traffic) pollution in Shiraz is higher than WHO and EPA standards and natural and industrial pollution is exceeding international guidelines in some seasons. The findings of the study confirm that the nearby cement factory has a major pollution impact on Shiraz air.

中性子放射化分析法による鉱化および非鉱化の花こう岩中のタングステンの定量

Tungsten content in granitic rocks is precisely determined by an instrumental neutron activation analysis method (INAA) using several standard samples. Natural geostandard rocks are GSJ geostandard of JG-1, JG-1a, JG-2, JR-2 and JR-3, and artificial standard materials of JR-2 with added scheelite powder and tungsten-doped quartz sand were employed for the analysis. Each sample (100mg) was irradiated for short time (1min, 2min and 3min) at thermal neutron flux 2.8×1013n/cm2/s and for long time (60min) at thermal neutron flux 2.3×1013n/cm2/s. Gamma-ray spectrum of 187W at 685.72keV was used for the tungsten analysis in geostandards. The 187W gamma-ray spectrum was not recognized for Na-rich JG-1 (W concentration=1.5ppm), while the gamma spectrum of that was recognized for JR-2 (1.8ppm). S/N ratios of 187W for geostandards that irradiated for 3min and after cooling for 6 day were higher than those of another irradiation conditions. The analytical error of tungsten in geostandards with the confidential limit of 95% was ± 4.7ppm. This INAA with 3min irradiation is the most suitable method for the tungsten-bearing samples was successfully applied to wide range of tungsten (i. e. low W concentration of non-mineralized granites to high W concentration of mineralized granite and scheelite-bearing ore).

Comparative use of INAA and ICP-MS Methods for Environmental Studies

The advantages and drawbacks of using instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS) for soil, sediment, plant and water pollution studies are discussed. The experimental procedures used for each method and for each type of sample matrix are described. They were tested on several certified reference materials. The results obtained on these materials showed good agreement for many elements for which the two techniques are suited, and they were complementary for the other elements which are also of environmental interest. An element-by-element assessment is presented to indicate the precautions to be taken and the most convenient technique for each of them.

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.

Spatial distribution of extractable organohalogens in northern pink shrimp in the north Atlantic.

Extractable organohalogens (EOX) are organic compounds that contain chlorine, bromine and/or iodine, which can be separated from the matrix by liquid/liquid or liquid/solid extraction. A combination of instrumental neutron activation analysis (INAA) and solvent extraction methods has been developed for the determination of EOX from the shrimp Pandalus borealis. Levels of EOX were evaluated for spatial trends for shrimp caught in several areas off the Labrador coast, off the coast of Nova Scotia, and off the coast of Maine. Muscle contained 1.09-6.05 micrograms EOCl/g tissue and 105-498 micrograms extractable organochlorine (EOCl)/g lipid; 0.0607-0.288 microgram extractable organobromine (EOB)r/g tissue and 4.74-10.5 micrograms EOBr/g lipid; and 0.014-0.048 microgram extractable organoiodine (EOI)/g tissue and 1.03-1.76 micrograms EOI/g lipid, respectively. The levels of EOCl in roe were 1.60-12.34 micrograms/g tissue and 39.0-146 micrograms/g lipid. In roe, the EOBr levels were 0.707-1.03 micrograms/g tissue and 6.96-13.5 micrograms/g lipid; and EOI levels were 0.123-0.349 microgram/g tissue and 1.42-4.11 micrograms/g lipid. The EOCl, EOBr, and EOI levels in roe increased noticeably from north to south along the coast of Labrador. Samples taken from the coast of Maine and from Canso Hole were typically higher in EOCl levels than those taken from Labrador. The results for EOBr and EOI were in the same range as those from Labrador.

Several methods to determine heavy metals in the human brain

The determination of naturally occurring heavy metals in various parts of the human brain is discussed. The patients had no diseases in their central nervous systems (five individuals, mean age 70 years). Twenty brain parts were selected from both hemispheres. The analysis was carried out by graphite furnace atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry and instrumental neutron activation analysis methods. Accuracy and precision of the applied techniques were tested by using standard reference materials. Two digestion methods were used to dissolve the brain samples for ICP-AES and GF-AAS. One was performed in a Parr-bomb and the second in a microwave oven. The present results show a non-homogeneous distribution of the essential elements (Cu, Fe, Mn, Zn) in normal human brain. Corresponding regions in both hemispheres showed an almost identical concentration of these elements. In the case of toxic elements (Pb, Cd) an average value in different brain regions can not be established because of the high variability of individual data. This study indicates that beside differences in Pb and Cd intake with foods or cigarette smoke inhalation, the main factors of the high inter-individual variability of these element concentrations in human brain parts may be a marked difference in individual elimination or accumulation capabilities.

Neutron activation analysis of some building materials

Concentrations of As, Au, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mo, Na, Nd, Rb, Sb, Sc, Sr, Ta, Tb, Th, U. Yb, W and Zn in seven Romanian building materials were determined by the Instrumental Neutron Activation Analysis (INAA) method using the VVR-S Reactor of NIPNE- Bucharest. Raw matarials used in cement obtaining ≈ 75% of limestone and ≈ 25% of clay, cement samples from three different factories, furnace slag, phosphogypsum, and a type of brick have been analyzed. The brick was compacted from furnace slay, fly coal ash, phosphogypsum, lime and cement. The U, Th and K concentrations determined in the brick are in agreement with the natural radioactivity measurements of226Ra,232Th and40K. These specific activities were found about twice and 1.5 higher than the accepted levels in the case of226Ra and232Th, as well as40K, respectively. By consequence, the investigated brick is considered a radioactive waste. The rather high content of Co, Cr, K, Th, and Zh in the brick is especially due to the slag and fly ash, the main componets. The presence of U, Th and K in slag is mainly correlated with the limestone and dolomite as fluxes in matallurgy.

Slurry Sampling Electrothermal Atomic Absorption Spectrometry for the Analysis of Aluminum-Based Ceramic Powders

A slurry sampling electrothermal atomic absorption spectrometry method for the determination of Ca, Cr, Cu, K, Fe, Mg, Mn, Na, Ni, and Zn in aluminum oxide and aluminum nitride powders is described. For each analyte, the experimental conditions including atomization temperature, internal gas flow during atomization, and pyrolytic re-coating of the graphite tube were optimized with respect to the sensitivity and background absorption. Quantification was performed by means of calibration curves recorded with the use of aqueous standards. The achievable limits of detection are between 5 ng/g (K) and 130 ng/g (Fe). The accuracy was checked by comparison of the results with those obtained by instrumental and radiochemical neutron activation analysis and other methods.

Quality Control in Element Analysis of Plant Materials

A worldwide laboratory intercomparison was organized by the International Atomic Energy Agency's Analytical Quality Control Services (AQCS) involving the determination of elements in plant materials used for human consumption. The main purpose of this work was to evaluate the performance of our analytical methods including sample preparation and to obtain new reference materials that can be used in our further work. Both materials (spinach and cabbage) were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES) and instrumental neutron activation analysis (INAA). Six subsamples of each material were subjected to our digestion procedure and the solutions were measured by ICP-AES. The dried samples were analyzed using INAA. Up to 26 elements were determined in plant materials. For easy review of our data a score has been calculated based on the reference value for each measured element. According to our results the ICP-AES technique was useful for determination of the following elements: Ba, Ca, Cr, Fe, K, Mn, Mo, P, S, Sr, Ti. The INAA method was reliable for measurement of Ce, Co, Mn, Na, Rb, Th, and V.

Advantages of combined IENAA and K0-factor technique in the determination of U and Th concentrations in exploration rock samples

The improved accuracy and precision of instrumental epithermal neutron activation analysis (IENAA), using the K 0-factor technique over the conventional one-shot instrumental neutron activation analysis (INAA), in the measurement of uranium and thorium in geological samples is demonstrated. Using the geological reference material, GS-N, detection limits of 0.4 and 0.5 ppm were obtained for U and Th, respectively, by means of the INAA method, while superior 0.1 ppm and 0.25 ppm detection limits were obtained for these elements when the IENAA/ K 0-factor technique was employed. The concentrations of U in three samples of this reference material were measured as 8.05 ± 0.12, 8.12 ± 0.13 and 7.88 ± 0.19 ppm by the IENAA/ K 0-factor method showing an improved data disperson and accuracy over the values 6.17 ± 0.61, 6.39 ± 0.36 and 7.31 ± 0.39 ppm obtained by the INAA technique. These compare with the 8 ppm certified value for this element in this material. However, the improvement in precision and accuracy obtained for the thorium measurement is marginal. Analysis of a geological sample from Nigeria showed thorium to be more abundant than uranium in these rocks.

Non-destructive analysis of copper in human brain tissue by neutron activation analysis using coincidence and anti-coincidence techniques

Copper (Cu) is an essential element and is incorporated in many biomolecules that are involved in protecting the brain from oxidative damage. Many brain regions strongly affected by neurodegene rative diseases are small. A sensitive nondestructive procedure to determine Cu is desirable to preserve samples for additional studies. Copper is not easily determined by instrumental neutron activation analysis (INAA) due to high activity levels produced by major abundance elements such as sodium (Na) and chlorine (Cl), which produce a high Compton background. An INAA method involving a short epithermal neutron irradiation and counting with a Compton suppression system was developed to determine Cu in brain, via 5.1-min66Cu. These short irradiation results are compared to those based on coincidence spectrometry of annihilation photons from positron emitting 12.7-h64Cu after a long irradiation.

An evaluation of the environmental implications of petroleum refinery emissions by multielemental neutron activation analysis of rumen fluid ash of buffaloes.

In order to study environmental pollution in and around a petroleum refinery complex, a multielemental instrumental neutron activation analysis (INAA) method was used to assay concentrations of As, Ba, Br, Cl, Co, Cr, Cs, Cu, Fe, Hg, La, Mn, Mo, K, Na, P, Sc, Rb, Se, Sr, W and Zn in the rumen fluid ash samples of buffaloes from the vicinity of the refinery. Corresponding samples from a control area 300 km away from the refinery were analysed. Standard Reference Materials, Bovine liver (SRM 1577a), Oyster tissue (SRM 1566a) and Animal bone (CRM H-5) were also analysed for quality control. Samples were irradiated with thermal neutrons at 10(12)-10(13) n cm-2 s-1 and counted by high-resolution gamma spectrometry. Mean elemental concentrations of As, Ba, Br, Cr, Hg and Fe were found to be enhanced, whereas those of Na, K, Cl, Cu, Mn and P were depleted in samples from the vicinity of the refinery complex compared to controls. The environmental implications of anomalous elemental concentrations are discussed.

Determination of iodine in human nails via epithermal neutron activation analysis

An epithermal instrumental neutron activation analysis (EINAA) method, using a boron nitride irradiation capsule compatible with use in the University of Missouri Research Reactor pneumatic-tube irradiation facility, has been developed for the analysis of iodine in human nails. The principal objective was to determine if the nail could be used as a means of monitoring dietary intake of iodine. The EINAA method was used to analyze nails from subjects having iodine intakes that could be qualitatively differentiated. Iodine concentrations in nails from these subjects were positively correlated with apparent iodine intake.

Study of the correlation of trace elements in caprenters' toenails

Toenail samples were collected from 129 carpenters (average age 47). The bone and blood lead data for these carpenters have shown a broad range of lead-level exposure in this population. A total of 28 elements were measured in the sample set by a combination of instrumental neutron activation analysis (INAA) and graphite furnace atomic absorption spectrometry (GFAAS) methods. Of the elements measured, only Co, Cr, Fe, Na, Cd, Cu, F, and Ni were significantly correlated with lead. A statistical treatment of the overall data set, including principal component analysis, was further applied in an attempt to correlate the elements in the samples.

Determination of129I in low level radioactive waste by radiochemical instrumental neutron activation analysis

A program was initiated at Chalk River Laboratories (CRL) to determine the physical, chemical and radiological properties of wastes intended for disposal in IRUS (Intrusion Resistant Underground Structure), a below ground vault to be constructed at CRL. One of the most restrictive radionuclides for IRUS is129I, which has been assigned a maximum activity concentration in waste of 106 Bq/m3. The limit of detection for radionuclides in waste has been set at 1% of the approximate maximum activity concentration, or 104 Bq/m3 for129I. A radiochemical instrumental neutron activation analysis method has been developed to determine129I in two waste streams, incinerator ash and liquid feed to a bituminizer. Solid samples are spiked with125I tracer, fused at 960°C with Li2B4O7 in a platinum boat in a flowing oxygen stream inside a three zone tube furnace, and the volatilized I2 is trapped on in-line charcoal filters. The charcoal filters are irradiated together with a filter containing a spiked125I/129I standard, in the NRU reactor, and then subjected to post-irradiation chemistry to remove82Br interference. The129I concentration in the sample is determined by comparing the activity of the activated130I in the sample with that of the standard, and the chemical recovery for129I is determined from the activity of125I tracer. Limits of detection for129I in solids are typically 0.005 Bq/g, based on a 4 hour counting period on a 10% efficient HPGe gamma-spectrometer at a source to detector distance of approximately 12 cm. This paper presents a summary of the method and the results from analysis of two waste streams.

An environmental pollution study from multielemental analysis of pedestrian dust in Nagpur City, Central India

An instrumental neutron activation analysis (INAA) method has been used for the determination of 30 elements (Ag, As, Au, Ba, Br, Ce, Cr, Co, Cs, Cu, Eu, Fe, Ga, Hg, Hf, La, Lu, Mn, Na, P, Rb, Sb, Sc, Se, Sr, Ta, Tb, Th, Yb and Zn) in 16 pedestrian dust samples collected from various industrial, commercial-residential, transport areas and highways of Nagpur city. Elemental concentrations of As, Ba, Br, Cr, Cu, Hg, Sb, Se and Zn were found to vary significantly depending on the sampling location. Large variations have been also observed for concentrations of As, Ba, Br, Ce, Cr, Cu, Fe, Hg, Mn, P, Th, Sb and Zn in dust samples from similar type of areas. A comparison of the elemental contents with local garden soils shows elevated levels of pollutants (As, Ba, Br, Cu, Sb and Se) in the pedestrian dust. Environmental implications of the elemental contents have been explained in terms of the possible sources of origin.

Epithermal instrumental neutron activation analysis of biological reference materials for iodine

Epithermal instrumental neutron activation analysis (EINAA) methods have been optimized and applied to several biological reference materials and selected food items for the determination of iodine. The method involves irradiation of the samples for different periods in epi-cadmium and/or epi-boron flux of the Dalhousie University SLOWPOKE-2 reactor and direct counting without any pre-treatment on a 25-cm3 hyperpure Ge detector. The 443 keV photopeak of 128I is used for assaying the iodine content. Precision of measurements, expressed as the relative standard deviation, is 10–15% at 200–500 ppb and 3–12% at 500–6000 ppb levels of iodine. Accuracy of iodine measurements is within 5%. The detection limits for iodine in several biological materials with cadmium and boron, either alone or a combination of the two, as thermal neutron shields have been found to vary between 0.1 and 0.4 mg · kg−1 for different periods of irradiation, decay and counting. The results suggest that the EINAA methods can be successfully applied to biological materials for routine analysis of iodine at levels higher than 200 ppb.

Environmental pollution study by multielemental neutron activation analysis of garden soil samples from Nagpur City, India

A multielemental instrumental neutron activation analysis (INAA) method has been employed for the determination of 30 elements in seven garden soil samples from Nagpur City and two intercomparison soil standards from IAEA, Vienna and Institute of Radioecology and Applied Nuclear Techniques (IRANT), Slovak Republic. Environmental implications of elemental concentrations in different soils have been discussed.

Instrumental neutron activation analysis of sediment reference materials using the k0-standardization method

The k0-standardization method of INAA (instrumental neutron activation analysis) was applied to three reference materials: NIST (National Institute for Standards and Technology, Washington, D.C., USA) SRM (Standard Reference Material) 1646 Estuarine Sediment, NIST SRM 2704 Buffalo River Sediment and IAEA (International Atomic Energy Agency) CRM (Certified Reference Material) SL-1 Lake Sediment. Among the 50 elements sought yielding long-lived radioisotopes after (n, γ) activation, for 32 elements numerical values were obtained, and for the remaining 18, only detection limits were estimated. When comparing the results obtained in this work to certified, recommended or other literature values, good agreement was found, proving that the same analytical procedure can be applied with confidence for analysis of environmental sediment samples.