Search Results
Neutron activation analysis for environmental trace element research
Determination of aluminium in drinking water
Abstract
Instrumental neutron activation analysis (INAA) was applied to the rapid determination of aluminium in drinking water. Aluminium content was quantitatively determined by measuring the 
-ray photopeak at 1778 keV of the short-lived radionuclide28Al (half-life 2.25 min). The experimental procedure was aimed at reducing significantly all contributions to the background. The aluminium concentration in various sources of drinking water was found to range from 80 to 170 
g·1–1, well within the recommended European Standard of 200 g·1–1. The limit of detection (LOD), when assaying a sample of 10 ml under the specified experimental conditions, is 100 ng of Al.
This paper presents a nonstandard experimental procedure for detection of the presence of salts in building materials. The proposed tests helped modeling the deterioration of specific historical building materials caused by salts. The specimens were subject to visual survey and scanning electron microscope analyses, after submerging them in salt solutions. The results showed the damage of brick, cement based mortar and lime based mortar, caused by various concentrations of sulphate and chloride solutions. By this method various types of salt crystals could be identified. In cement and lime based mortars larger extents of salt deposits were found. A relevant difference between the control samples and the salt treated samples was observed.
Influence of the agricultural exploitation processes on the productivity capacity control of soils
Design of an experimental procedure
Summary Soil productivity and health were analyzed using an experimental procedure designed for this kind of studies. The continuous loss of fertile soil obliged the Food and Agriculture Organization (FAO) to declare soil as an item to be protected as a support of the world society welfare. The procedure here described is in accordance with the premises necessary for a rational and sustainable development of soil and the resources it contains and can be used to study any soil all over the world. The study was carried out using soil microbial population as a bioindicator of soil health. Microbial activity was followed using the microcalorimetric technique. The microcalorimetric study can be complemented through a deep analysis of soil physical, chemical and biological properties together with a study of the environmental properties that have a strong influence on the afore mentioned properties and, thus on the microbial activity in soil. The different properties follow different ASTM, ISS/FAO, USDA, etc. well defined standards. The experimental procedure reported in this work could be very helpful to create a data basis that could be useful to quantify and control soil potentiality or design soil decontamination and recovery systems.
Abstract
The paper presents evaluation of energy distribution of n-octane and pore-size distribution functions on the alumina oxide surface (e.g. total heterogeneity) of on the basis one experimental run. the Q-TG mass loss and derivative Q-DTG mass loss curves of n-octane thermodesorption from the alumina oxide sample were made using a hungarian derivatograph with an analyser equipped with an automatic ultraslow procedure and a special crucible of maintaining the quasi-isothermal heating procedure to increase the resolution of thermal analysis. a new theoretical and experimental procedure was developed for evaluation of distribution functions of liquid preadsorbed on the mesoporous surface from special thermogravimetry. An example of the approach to quantitative description of the energetic and structural heterogeneities of alumina oxide surface is given.
Abstract
We have studied the extraction of phosphovanadomolybdic acid labelled with32P. From the influence of the acidity on the distribution coefficient of phosphorus, we show that the phosphovanadomolybdic acid has four acidic groups. Under our experimental conditions, this compound is formed from condensed species of molybdenum and it is quantitatively formed in the acidity range 1N<[H+]<2N. The highest yield of extraction has been obtained with methyl isobutyl ketone. The best conditions for the extraction of phosphorus have been applied to the experimental procedure for the neutron activation analysis of phosphorus in steels. The results obtained for standard samples are good except for steel containing niobium which is an interfering element.
Abstract
The sediment samples have been collected from estuarine regions of Mindola and Purna of Gujarat State. These samples are found to contain less than 3% of organic matter which scavange and carry most of the activity of226Ra, etc., to the sediment floor. The activities of226Ra are found to vary from 0.1 to 0.5 pCi/g, while210Pb activities lie in the range of 3 to 8 pCi/g. These activities find their way into the organisms present in sea water and then into fish which is finally consumed by humans. This paper gives in detail the sampling techniques, experimental procedures and the distribution of the isotopes of226Ra and210Pb in the estuarine regions and the concentration factors of226Ra in the region.
Abstract
A gamma-spectrometric method independent of radon escape for the determination of U and Ra in rock samples based on the 63 keV and 1001 keV as well as 185 keV lines is described and discussed. A simple experimental procedure is given for the determination of the self-absorption factor. The method has been applied for the determination of uranium and radium in rock samples from Morocco containing uranium between 17.5 wt.% and 0.026 wt.%. The limits of determination, at 95% confidence level and 10% standard deviation, for the 63 keV and 1001 keV lines were found to be 0.075 wt.% and 0.62 wt.%, respectively, using samples of 6 g and chosing 1 h measuring time.
The γ-amino butyric acid (GABA) is the main inhibitory neurotransmitter system in the brain. Either imbalance in the extreme can result in several mental diseases like schizophrenia, cerebral stroke, temporal lobe epilepsy (TLE), Parkinson’s disease (PD), Huntington’s disease (HD), and anxiety disorders even death. Measurement of GABA in tissue will help to elucidate the metabolic role and diagnostic value. Various analytical techniques are employed to estimate GABA in biological samples but the experimental procedure and tedious techniques are required. The present study demonstrates a simple, feasible, and cost-effective high-performance thinlayer chromatography (HPTLC) method for estimation of GABA in mice brain tissue. The method was validated in terms of specificity, linearity, and detection limit. The precision was done for inter-day, intra-day, instrumental, and reproducibility. Accuracy was checked by recovery study. The results indicate that this method is fast, sensitive, and suitable for quantitative assessment.
Abstract
In this paper the performances and the limitations of three multi-elementary analysis techniques are compared applied to a study of air pollution biomonitoring in Morocco. These techniques are: (1) 14 MeV neutron activation analysis (14 MeV-NAA), (2) thermal neutron activation analysis using the k 0 quasi-absolute method (k 0-NAA) and (3) energy dispersive X-ray fluorescence analysis (ED-XRF). The experimental procedures and the control of the analytical results using certified reference materials are described and discussed. The three methods were confronted for the analysis of lichens, mosses and tree-barks. The complementarity of these methods enabled us to determine 43 elements in different samples. The most suitable method for each element was selected according to the sensitivity and selectivity necessitating the minimum corrections of the matrix effects and/or the interfering reactions.
Abstract
The concentrations of some essential micronutrient elements leadingto short-lived activation products in four Nigerian vegetable based oils (palmoil, palm kernel oil, sheabutter and groundnut oil) have been determined byneutron activation analysis using a small research reactor. One sample ofeach material was analysed and presented as an introduction for further investigations.Results indicate that the concentration range of the elements are 19.4–44.0µg/g for Al; 30.0–81.0 µg/g for Ca; 11.9–60.4 µg/gfor Cl; 1.43–5.96 µg/g for Cu; 7.3–28.1 µg/g for Mg;0.47–1.69 µg/g for Mn; 17.5–72.8 µg/g for Na and 0.04–0.07µg/g for V. The experimental procedure is suitable for routine determinationof micronutrient element in foods for control and monitoring purposes.
