Multielemental determination in some water samples by neutron activation method

A method was developed for the determination of element concentrations in structured water samples (water with high oligoelements content). Sixteen elements (As, Br, Ca, Ce, Co, Cr, Eu, Fe, K, La, Lu, Na, Sb, Sc, Sm, Zn) were determined in 4 structured water samples and one taken from the water tap. The samples were preconcentrated evaporating 1 1 at atmospheric pressure and obtaining 100–500 mg of dry residue. Measurement accuracy by -spectroscopy was 3–30% and it can be improved by increasing the measurement time. The method allows simultaneous multielement analysis of various water sources and may successfully be used in environmental pollution control.     

Multielemental determination in platinum rocks by nondestructive neutron activation analysis

Na, Zn, Re, Sc, Ir, Ru, Pt, Fe and Co have been determined in Pt-rock samples from different parts of the state by thermal neutron-activation analysis followed by nondestructive analysis on a MCA. The accuracy and precision of the method have been determined.     

Multielemental analysis of soils by instrumental neutron activation analysis

The results of an instrumental neutron activation analysis of some elemental concentrations in different soil samples near the industrial areas at Tirupati, India, are reported. Altogether 14 elements, Sm, La, Cr, Co, Zn, Cs, Ce, Th, Rb, Na, K, Sr, Fe and Eu were determined. The samples were irradiated with neutrons at the 100 kW Triga - Mainz research reactor and the induced activities were measured by gamma-ray spectrometry using an efficiency calibrated high resolution high purity germanium (HPGe) detector in connection with a multichannel analyzer. The results are discussed.     

Multielemental analysis of metallurgical samples by thermal neutron activation

Instrumental neutron activation analysis (INAA) was applied to investigated a total of 16 samples of raw materials, intermediate and final products involved in metallurgical processes in Romanian Iron and Stell works Sidex Galatzy: iron ores and pellets from different regions of the world, cast iron, slag and steels. A series of chemical elements was determined in the analyzed samples: Al, As, Ce, Co, Cr, Fe, La, Mn, Na, Sc, Sm, V, W. A qualitative discussion regarding the passing of from elements with different chemical affinity for oxygen compared to that of iron, from the raw materials to slag or to finite products is presented.     

Multielement determination in water by instrumental neutron activation analysis

Instrumental neutron activation analysis /INAA/ technique has been applied to a water sample to determine the elemental concentrations. The sample was irradiated with a neutron flux of 1.2×10¹² n cm^–2 s^–1 for two different periods followed by counting at three different decay times, using two coaxial type high-resolution Ge/Li/ detectors. The dominant elements determined in the water sample are Ca, Cl, Na, Mg, and K present in ppm-level while Co, I, Mn, Sm, and Sb are present in smaller amounts, approximately on the average 0.01 ppm. Only traces of other elements such as the rare-earth elements, Ag, As, Ba, Cu, Cd, Fe, Sr, W, Zn, seem to be present in the water sample.     

Multielement determination in river water by neutron activation analysis

Concentrations of Al, Br, Ca, Ce, Co, Cr, Eu, Fe, Hf, La, Lu, Mg, Mn, Na, Rb, Sc, Sm, Sr, Tb, Th, Ti, V, Yb, Zn, and Zr have been measured in Tigris and Euphrates river water, using neutron activation analysis in combination with preconcentration technique. River water samples were preconcentrated by evaporation at 70°C under atmospheric pressure. The samples with standard reference materials were irradiated with a neutron flux of 2.3·10¹³ n·cm^–2·s^–1.     

Multielemental analysis of Brazilian milk powder and bread samples by neutron activation

The concentrations of Na, Cl, Mn, Br, Fe, Zn, Rb, Sb, Sc, Cr, Al and Mg were determined in some types of bread and in some brands of milk powder consumed in the city of São Paulo (SP—Brasil), by instrumental neutron activation analysis. Radiochemical separations were carried out by means of retention of²⁴Na on hydrated antimony pentoxide (HAP) from a 8N HCl solution, after digestion of the organic matter. It was possible in this way to determine the radioisotopes⁶⁴Cu,^69mZn and¹⁴⁰La in the effluent solution. The detection limits of the trace elements analyzed in bread and milk powder samples were determined using the Currie and Girardi criterions.From a dissertation submitted by V. A. MAIHARA to the University of São Paulo in partial fullfillment of the requirements for a Master of Science Degree in Nuclear Technology.     

The determination of iodide in sea water by neutron activation analysis

A simple and sensitive method for the determination of iodide in sea water by neutron activation analysis has been developed. Iodide is separated from most other anions by passing sea water through a strongly basic anion-exchange column, recovered by elution with 2 M sodium nitrate, and concentrated from the eluate by precipitation as palladium(II) iodide in the presence of excess of palladium(II) with elemental palladium as carrier; elemental palladium is generated by reduction of some of the palladium(II) with thiosulfate. The precipitate is separated from the supernatant liquid by filtration. Checks on the efficiency of separation by means of added ¹²⁵I showed recoveries of 100 ± 3 %. The filter paper containing the precipitate is pressed into a pellet for neutron activation analysis by irradiation for 5 min at a flux of 4 ·10¹² n cm^?2 s^?1 and counting the ¹²⁸I 442.7-keV photopeak.     

Multielemental analysis of vegetarian human diets and dietary components by neutron activation

Two vegetarian diet samples representative of the Indian sub-continent were prepared (in raw form) by the proportionate blending method for adolescent and adult age groups. These along with its components, viz. wheat, rice flours and pulses, were analyzed for 12 minor and trace elements by instrumental neutron activation analysis (INAA) and high resolution -ray spectrometry. Bowen's kale was also analyzed to check the accuracy of the method. The concentrations of Br, Co, Cu, Fe, K, Mn and P are comparable to the non-vegetarian American and European diets. Zinc concentrations are however lower than the recommended dietary allowances (RDA) and the western non-vegetarian diets.     

Multielemental hair composition of Brazilian Indian populational groups by instrumental neutron activation analysis

In the present paper, for the first time the multielemental compositionof hair samples of Indian populations living in the Xingu Park Reservation,in the Brazilian Amazonic region has been determined, by INAA. Irradiationswere carried out at the Interfaculty Reactor Institute (Delft, The Netherlands)and, using a combination of different irradiation and decay times, about 40elements could be determined in the hair. Previous analysis made at the RadiochemistryDivision of IPEN/CNEN-SP (Brazilian Nuclear Energy Commission) of hair samplesof a Brazilian control population allowed the determination of 20 elements,also by INAA. Comparison of the data obtained for the Indian populations andthe controls showed very significant differences in elemental compositionsfor some elements, like Hg, Mn and Al while for others, like Cu and Zn, theconcentrations were similar. A discussion of the differences found for otherelements also is made in the present paper.     

The determination of inorganic arsenic in water by thermal neutron activation analysis

A simple method is presented for the determination of inorganic arsenic in water samples. The lower limit of determination is 0.01 μg·1⁻¹. Penta-and trivalent arsenic ions as well as arsenic acid substituted with aromatic ligands are collected by coprecipitation with Fe(OH)₃. After irradiation the arsenic is separated from the iron by adsorption to Al₂O₃. The overall efficiency is (97∓1)%. The procedure takes one day per ∼20 samples. It has been checked by standard addition. Data for sea- and surface-water are given. As the concentration of aromatic arsenic-compounds is very small in comparison to that of the inorganic species, it does not affect the result of the determination.     

Substoichiometric determination of chromium by neutron activation analysis

A method of radioactivation analysis has been developed for the determination of chromium. It is based on the substoichiometric extraction of chromium diethyldithio-carbamate into methyl-isobutyl-ketone from acetate buffer solution in the presence of EDTA and potassium cyanide. The method has been applied for the determination of chromium in high-purity calcium carbonate and NBS glasses as standard reference materials.     

Substoichiometric determination of palladium by neutron activation analysis

A method is described for the substoichiometric determination of traces of palladium by neutron activation analysis involving the extraction of palladium with isonitrosoacetophenone. The sensitivity of the method is 0.005 μg of Pd. With 200 mg of silver alloy containing 0.0005% palladium, the average of three determinations of Pd is 0.98 μg, which varies between 1.07 μg and 0.91 μg at 95% confidence limit. The time required for radiochemical purification and counting of the sample does not exceed 12 minutes. Part of this work was presented at the International Conference on Modern Trends Activation Analysis, held in Gaithersburg, Maryland, USA, October 7–11, 1968.     

Substoichiometric determination of mercury by neutron activation analysis

A method has been developed for the substoichiometric determination of mercury by thermal neutron activation analysis, based on the selective extraction of the Hg(II)—Bindschedler's Green complex into 1,2-dichloroethane. The method has been applied for the determination of trace amounts of mercury in geological standards such as W-1, GR, Sye-1, and T-1, meteorite Allende de Publito, and biological materials such as kale, IR1 standard tobacco, and human blood serum.     

Substoichiometric determination of gold by neutron activation analysis

A rapid method has been developed for the determination of gold in catalyst samples by thermal neutron-activation analysis incorporating substoichiometric solvent extraction of Au/III/ with 1,2,3-benzotriazole /1,2,3-BT/ into n-butanol. The time required for radiochemical purification and counting of two samples and a standard was 1 h.     

Substoichiometric determination of Cd by neutron activation analysis

A rapid method has been developed for the determination of cadmium in environmental samples by thermal neutron activation analysis involving substoichiometric extraction with 1,2,3-benzotriazole /1,2,3-BT/. Cd was radiochemically separated as CdS using 1-amidino-2-thiourea. The time required for radiochemical purification containing two samples and a standard was about 2 h. 4.63 g of Cd can be determined with an accuracy of 6.69% and precision of 6.25%. Mash potatoes, animal bones, raw sludge and cattle manure have been analyzed by this method.     

Multielemental neutron activation analysis of fugitive dust particulates from cement factories in Central India

Knowledge of occurrence and concentration of trace elements in dust particulates from and around industrial establishments is essential to know the source of pollutants and atmosphere quality. Dust particulates from two cement factories in the central part of India were analyzed for 5 minor (Cl, Fe, K, Mg, Na) and 23 trace elements (Ag, As, Ba, Br, Cd, Co, Cr, Cs, Dy, Eu, Ga, Hf, Hg, La, Mn, Sb, Sc, Se, Sm, Sr, Th, W and Zn) by INAA and RNAA techniques. Significant differences have been observed for some toxic trace elements at different locations. Mn content is particularly high in all the dust particulates. Urban particulate (SRM 1648) and Coal fly ash (SRM 1633a) from NIST and Pond sediment (CRM No. 2) from NIES were also analyzed. The data have been analyzed and interpreted in terms of air quality at different locations inside the plant and two factories.     

Substoichiometric determination of tungsten by neutron activation analysis

A method for the substoichiometric determination of tungsten by thermal neutron activation analysis has been developed based on the selective extraction of the tungsten dithiol complex into amyl acetate. The method is simple, rapid and accurate. It has been used in the determination of tungsten in alloy steel, meteorites and biological standard kale.     

Multielemental analysis of soil samples by fast-neutron activation

Neutron activation analysis (NAA) have been used for the determination of major, minor, and trace elements in 20 soil samples from 5 crop fields of the Crop Research Centre, Pantnagar, India. Fast neutron activation analysis (FNAA) and cyclic neutron activation analysis (CNAA) have been used to determine the concentrations of various elements. The results for minor and trace elements are compared with the level of abundances of world soils. The present study provides the basic data of elemental concentrations in soil samples of 5 major crop fields located in one of the leading agricultural universities of India for future measurements with the objectives of efficient use of fertilizers and pesticides in accordance with the high yield.