A comparative study of trace elements in water from various sources in surrounding areas of Nagpur city (India) by instrumental neutron activation analysis

Instrumental neutron activation analysis (INAA) has been used for the determination of 27 elements (Ag, Au, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Ga, Hg, Hf, K, La, Mn, Na, Sb, Sc, Se Sr, Th, P, Ta, Tb, Zn and Zr) in 15 water samples collected from different sources (reservoirs, well, borewell, sewage tank, river, rain) in and around Nagpur city (central India) including doubly distilled and a sea water sample from Bombay. Sample residues after evaporation were irradiated at a thermal neutron flux of 10¹²–10¹³ n·cm^–2·s^–1 for 10 min, 1d and 1wk and counted using a HPGe detector and an 4k MCA at different intervals. Several environmental standards from NIST (USA), NIES (Japan) and USGS rock were also analysed for quality assurance. Wide variations in elemental concentrations have been observed in water samples from different sources. Most elemental concentrations in drinking water from various sources, are within ISI/WHO limits. Sea water showed very high concentrations of Ba, Cr, Co, Fe, Hg, Sb, Se and Zn. For doubly distilled and rain waters, however, very low elemental concentrations of Ba, Ce, Fe, Sc, Hg, Se, Sr and Th were observed.     

Nuclear quadrupole interaction at133Cs in some barium compounds

Nuclear quadrupole interaction frequencies at¹³³Cs following the electron-capture decay of¹³³Ba for BaSO₄, Ba/BrO₃/2 and Ba/NO₃/2 were obtained by measuring the perturbation of 356–81 keV cascade of¹³³Ba. Nuclear quadrupole interaction frequencies for BaSO₄ and Ba/BrO₃/2 are 17.2 Mrad sec^–1 and 14.6 Mrad sec^–1, respectively, while no perturbation of 356–81 keV cascade was observed in case of Ba/NO₃/2. Further the possibility of any after-effects of electron-capture decay is ruled out through the measurement of 276–161 keV gamma-gamma directional correlation.     

Separation of Ba and Pb from aqueous solutions of Sr with commercially available “precipitated active manganese dioxide”

Ba and Pb radionuclides can be removed from Sr in aqueous solution in both sodium acetate and acetic acid, containing 20 mg Sr carrier, by stirring with small (0.1–0.5 g) amounts of solid manganese dioxide. In tracer experiments⁸⁵Sr was separated with only small losses from¹³³Ba and²¹⁰Pb by separation factors of 87 and 135, respectively. The separation factor is defined here as the % of the initial⁸⁵Sr activity/ % of the initial¹³³Ba or²¹⁰Pb activity remaining in the aqueous phase after MnO₂ contact. The applicability of this technique for removing Ba and Pb radionuclides in the analysis of⁹⁰Sr in environmental samples (especially milk) is discussed.     

Organic acid solutions in the chromatography of inorganic ions. VII. Cation exchange of Mg(II), Ca(II), Sr(II), Ba(II), Mn(II), Cd(II), Co(II), Ni(II), Zn(II), Cu(II) and Fe(III) in succinate media

Summary The cation-exchange behaviour of Mg(II), Ca(II), Sr(II), Ba(II), Mn(II), Cd(II), Co(II), Ni(II), Zn(II), Cu(II) and Fe(III) in succinate media at various concentrations and pH, was studied with Dowex 50 WX8 resin (200–400 mesh) in the NH ₄ ⁺ form. As examples separations of Cd(II)/Co(II), Cd (II)/Ni(II), Fe(III)/Cu(II)/Ni(II) and Mg(II)/Ca(II)/Sr(II)/Ba(II) have been achieved.This work was supported by C.N.R. of Italy.     

The development of an automated HPLC system for the determination of trace-metals in concentrated brines and its application to process monitoring

Methodology based on high performance liquid chromatography (HPLC) has been developed for the determination of trace-metals in concentrated brines. Metal ions, (Al, Ba, Ca, Mg, Sr and Zn) were concentrated quantitatively and isolated from the sodium chloride matrix using a chelating ion-exchange column dynamically coated with the chelating dye xylenol orange. The pH dependence of the uptake of the metals was studied. Using the chelating ion-exchange preconcentration column followed by ion chromatography all the metals studied were determined at the low ng ml^–1 level in concentrated brines and linear/workable calibrations were obtained in the concentration range of interest (<100 ng ml^–1). The methodology developed was successfully transferred to an automated on-line monitoring system for the determination of Ba, Ca, Mg and Sr in concentrated feed brines used in the chlor-alkali industry.     

Assessment of the essential element and heavy metal content of edible fish muscle

The aim of this work was to determine the concentrations of some essential and toxic elements in the muscle of ten species of commercial fish consumed in Portugal. We combined two different techniques for determination of the elements—energy-dispersive X-ray fluorescence (EDXRF) was used to quantify K, Ca, Fe, Zn, Se, Rb, and Sr and flame atomic-absorption spectrometry for analysis of Cr, Ni, Cu, Cd, Hg, and Pb. The latter technique was used because of its higher sensitivity, because these elements were not detected by EDXRF. The results obtained show a similar pattern for the trace elements. K and Ca are present at the highest concentrations in all the samples studied, from 0.6–1.3% and from 0.04–0.08%, respectively, followed by Zn, Fe, Sr, Se, and Rb. Sr is present at higher concentrations than Rb in all the species studied except meagre. Concentrations of the elements in octopus do not follow this pattern—Fe is present at a higher concentration than Zn. Low concentrations of Cr (0.66–1.5 g g^–1), Ni (0.11–0.24 g g^–1), Cd (0.01–0.08 g g^–1), Hg (0.49–2.74 g g^–1), and Pb (0.02–0.06 g g^–1) were observed in all the samples analysed. The concentration of Hg was highest in Helicolenus dactylopterus—5.4 g g^–1 in one sample.     

Exchangeable fraction of elements in alluvial sediments under waste disposal site (Zagreb, Croatia)

Concentrations of Ag, Ba, Cd, Ce, Cs, Co, Cr, Eu, Fe, Rb, Sc, Sr, Th, and Zn exchangeable fractions were determined in alluvial sediments at waste disposal site area in the vicinity of water-well field. Samples have been leached with 0.5M NH₄Cl at a sample/solution ratio of 120 during 24 hours without shaking. INAA of dry NH₄Cl residues show that the concentrations of exchangeable elements determined in the most of the sediments below the wastes have natural levels. Ag, Ba and Sr are readily exchangeable; Rb, Cs and Zn have lower exchangeability, while Cd, Ce, Th, Sc, Eu, Cr, Fe and Co are rather immobile. Extremely high total and exchangeable silver concentration was found at 6.5–6.8 meters below waste in the aerated layer occasionally under the water table. Exchangeable concentrations in deeper water-bearing sediment layers are not elevated. Due to this, one can presume that the upper sediment layers act as chemical filter generally preventing the infiltration from overlying wastes into water-bearing layers.     

Nuclear data and measurements for the130Ba(n,γ)131Ba reaction

Although k₀-factors and related nuclear data for 122 radionuclides of interest in (n,) reactor neutron activation analysis have been tabulated, there are still some reactions attracting interest with respect to the accuracy of the literature data. The present paper deals with the reaction¹³⁰Ba(n,)¹³¹Ba, for which a more accurate half-life is proposed, together with re-evaluated Q₀ and k₀ factors. The new values are 11.53 days for T, 21.3 for Q₀, and for the k₀'s 3.90×10^–5, 2.75×10^–5, 1.92×10^–5 and 6.48×10^–5 for the -rays at 123.8 keV, 216.1 keV, 373.2 keV and 496.3 keV, respectively.     

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.     

Multielemental determination in water by 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 at 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 detected in the water sample are Ca, Cl, Na, Mg, and K present in levels 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 rare-earth elements, Ag, As, Ba, Cu, Cd, Fe, Sr, W, Zn, seem to be present in the water samples.     

Activity coefficients from the emf of liquid membrane cells V. alkaline earth hexacyanoferrates (III) in aqueous solutions at 25°C

The relative mean activity coefficients of the M₃[Fe(CN)₆]₂ salts, M=Mg, Ca, Sr, Ba, are measured down to about 5×10^–6 mol-kg^–1 using the liquid membrane cell method. In the dilute region these salts display negative instead of positive deviations from the limiting law, contrary to Debye-Hückel's theory predictions. An indirect method based on auxiliary emf measurements in MCl₂, K₃Fe(CN)₆ and KCl, rather than a theory-assisted direct extrapolation to zero of the relative activity coefficients, is used to identify the actual values of the activity coefficients. The data are compared with Mayer's theory, ion-pair theory and numerical integration of the Poisson-Boltzmann equation. Best-fit coefficients of Pitzer's equation which meet the activity coefficients of the M₃[Fe(CN)₆]₂ salts to be reproduced, are reported.     

Determination of Si,Al, Ti,Fe and Zr in glass sand samples by 14 MeV neutron activation analysis

Fast neutron activation analysis technique was applied for the determination of Si, Al, Ti, Fe and Zr in glass sand rock samples. The samples and standards were irradiated with a mono-energetic neutron flux of 10⁸n · cm^– · s^–1. Pneumatic facility was used. The gamma activities from samples and standards were counted using a 30 cm³ Ge(Li) detector, with FWHM of 2.9 keV at 1.332 MeV, coupled to an on-line computer facility.     

Trace element concentrations in human bone using instrumental neutron activation analysis

Instrumental neutron activation analysis has been applied to analyze 23 bone samples obtained from Libyan patient aged (3–80) years for the study of the concentration levels of trace elements Ba, Br, Ca, Fe, Sr and Zn and their concentration pattems regarding to the age and sex of the patients.     

Extraction-chromatographic system TBP-HBr in radiochemical neutron activation analysis of high-purity materials

The extraction and extraction-chromatographic behaviour of a variety of elements in the TBP-HBr system with concentrations from 0.1 to 7M HBr has been studied. The results allowed the development of simple procedures for radiochemical neutron activation determination of 22 impurity elements (Na, K, Sc, Cr, Mn, Fe, Co, Ni, Cu, Ga, As, Se, Rb, Sr, Zn, Mo, Ag, Sb, Te, Ba, La, Hf and W) in high-purity cadmium and indium samples with detection limits from 1 g g^–1 for Fe and Zr to 0.01 ng g^–1 for Na, Sc, Mn with relative standard deviations < 0.15. To increase the selectivity of the extraction-chromatographic separation, use was made of extraction suppression and co-extraction effects. The procedure for the extraction-chromatographic separation of scandium from a number of other elements is described as an example. The procedure can be used for simultaneous quantitative separation of impurity radionuclides from radiation produced long-life scandium radionuclides in the neutron activation analysis of titanium and vanadium.     

Simultaneous radiochemical determination of plutonium, strontium, uranium, and iron nuclides and application to atmospheric deposition and aerosol samples

Summary A procedure for the sequential radiochemical determination of plutonium, strontium, uranium and iron nuclides is described. The separation is carried out on a single anion exchange column. Pu(IV), U(VI) and Fe(III) are fixed on Bio Rad AG 1-X4 from 9 mol/l HCl, while the sample effluent is used for the determination of radio-strontium. Fe and U are eluted separately with 7 mol/l HNO₃, and Pu(III) is eluted with 1.2 mol/l HCl containing hydrogen peroxide. Subsequently, Pu and U are electrolysed and counted by alpha spectrometry. Radiostrontium is purified by the nitrate method and counted in a low level beta proportional counter. Fe is purified by extraction and cation exchange and ⁵⁵Fe is counted by X-ray spectrometry with a Si(Li) detector. The sample preparation and the application of the procedure to large samples, namely aerosols from 10⁵ m³ of air, and monthly deposition samples from 0.6 m² sampling area (10–100 l) are described. Chemical yields are for Pu 70±20, for Sr 80±15, for U 80–90, and for Fe 75±10%. As an example, the maximum airborne radionuclide concentrations determined with that procedure in fortnightly collected samples at Neuherberg after the Chernobyl accident were: ^239+240Pu, 2.58; ²³⁸Pu, 1.40; ²³⁸U, 0.65; ²³⁴U, 0.67; ⁹⁰Sr, 7600; and ⁵⁵Fe, 990 Bqm^–3.With appropriate changes in sample preparation, the procedure is applicable to other kinds of samples.     

In-situ spectrometry of137Cs in the soil by an unfolding method

The approach is based on in-situ measurements performed with a portable high-resolution germanium -spectrometer and on calculations of the depth distribution by an unfolding method. To unfold the depht distribution of¹³⁷Cs concentration in soil four detector responses and the iterative procedure SAND II were used. The detector responses consist of the responses to primary 662 keV photons and to photons scattered in soil with the rest energies of 620–655 keV. The detector is used with and without collimator. The method is sufficiently sensitive for measurements of¹³⁷Cs concentration in soil 10 years after the Chernobyl accident. The results are compared to laboratory analyses of collected soil samples and with a standard method of in-situ spectrometry.     

Apparent molar volumes of alkaline earth hexacyanocobaltates (III) in aqueous solution at 25°C

The apparent molar volumes of Mg, Ca, Sr, and Ba hexacyanocobaltates (III) have been determined from 1×10⁴ to 0.2M (mol-dm^–3), using both vibrating tube densimeter and dilatometric methods. The semiempirical Pitzer equation has been used to reproduce the experimental data. Positive deviations from the Debye-Hueckel limiting law (DHLL) have been observed at C<0.01M and are compared with the predictions of two other electrostatic approaches, the DHLL+B₂ approximation of the Mayer theory and the numerical integration of the exponential Poisson-Boltzmann equation. A least squares procedure has been used to obtain the best fit parameters, including the apparent molar volume at infinite dilution.     

Rapid multi-element analysis of groundwater by high-resolution inductively coupled plasma mass spectrometry

A rapid and sensitive method was developed to determine, with a single dilution, the concentration of 33 major and trace elements (Na, Mg, Si, K, Ca, Li, Al, P, S, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, In, Sn, Sb, Cs, Ba, Re, Hg, Pb, Bi, U) in groundwater. The method relies on high-resolution inductively coupled plasma mass spectrometry (HR ICP-MS) and works across nine orders of magnitude of concentrations. For most elements, detection limits for this method are considerably lower than methods based on quadrupole ICP-MS. Precision was within or close to ±3% (1) for all elements analyzed, with the exception of Se (±10%) and Al (±6%). The usefulness of the method is demonstrated with a set of 629 groundwater samples collected from tube wells in Bangladesh (Northeast Araiharzar). The results show that a majority of tube well samples in this area exceed the WHO guideline for As of 10 g L^–1, and that those As-safe wells frequently do not meet the guideline for Mn of 500 µg L^–1 and U of 2 µg L^–1.     

Multielement measurements in Mexican cigarette tobacco

The concentration of 21 elements in cigarette tobacco in nine different brands manufactured and commercially available in Mexico has been determined using neutron activation analysis. The concentration range of the measured elements (in g g^–1) were: As, (four brands) <0.55–3.24; Ba, 64–251; Br, (four brands) 49–136; Ce, <0.3–1.7; Co, 0.29–0.55; Cr, <0.8–2.4; Cs, 0.091–0.40; Eu, <0.03; Fe, 420–680; Hf, <0.03–0.13; K, (four brands) 18300–40300; La, (four brands) <0.2–0.66; Na, (four brands) 309–566; Rb, 19–50; Sb, <0.7; Sc, 0.13–0.22; Se, <0.7; Sm, (four brands) 0.07–0.14; Sr, 227–472; Th, <0.1–0.17 and Zn, 14–56. The results are compared with the literature values for the concentration of the above elements in cigarette tobacco from other countries.     

Separation of Cesium from Intermediate Level Waste Solutions Using Zirconyl Tungstate Ceramic-Supported Membranes

Zirconyl tungstate ceramic-supported membranes were developed and characterized. The transport process of Cs(I), Sr(II) and La(III) from the anode compartment to the cathode was investigated. The cationic fluxes for Cs(I), Sr(II) and La(III) were found to be 9·10^–10, 2.7·10^–9 and 2.4·10^–9 g·eq·cm^–2·s^–1, respectively. The transport numbers of these cations were found to be 0.12, 0.07 and 0.09, respectively. Separation of Cs(I), Sr(II) and La(III) was achieved using EDTA as a chelating agent in the anode compartment. Cs(I) was successfully separated with a decontamination factor of 97% from simulated intermediate level liquid waste (ILLW) containing Cs(I) and Sr(II).