The uptake of radioisotopes onto clays and other natural materials

The ability of natural and simulated soils to take up radioisotopes of cesium, strontium and ruthenium was examined. Uptakes were assessed by distribution coefficients measured in the presence of different concentrations of Na, Ca, Mg and HN₄ cations, and from synthetic groundwaters. Peat was included in similar studies for comparison purposes. Conclusions were drawn as to the effect of soil and ground water compositions on isotope uptake taking into account the results described in Part 1 of this series¹ which estimated the distribution coefficients for¹³⁷Cs,⁸⁹Sr and¹⁰⁶Ru (as chloride or nitrosyl) shown by illite and montmorillonite clays. These, or similar, clays were soil components in this study.     

Characterization of silicate monomer with sodium,calcium and strontium but not with lithium and magnesium ions by fast atom bombardment mass spectrometry

Fast atom bombardment mass spectrometry (FABMS) was applied to the direct detection of silica species dissolved in LiCl, NaCl, MgCl(2), CaCl(2) and SrCl(2) solutions in order to investigate its dissolution process in solution. Several species of dissolved silicate complexes in the solution were directly detected by FABMS. The peak intensities of [SiO(2)(OH)(2)Na](-), [SiO(3)(OH)Ca](-) and [SiO(3)(OH)Sr](-) increased with increasing concentrations of NaCl, CaCl(2) and SrCl(2), whereas the peak intensities of [SiO(2)(OH)(2)Li](-) and [SiO(3)(OH)Mg](-) did not increase with increasing concentrations of LiCl and MgCl(2). These results indicte that silicate and cation bind in the solution not after but before ionization. The isotope pattern of Sr(2+) confirmed the existence of the silicate-Sr complex not only with increase of the concentration of silica but also the mass numbers of Sr. The silicate complexes formed with Na(+), Ca(2+) and Sr(2+) showed high stability in chloride solution. This is in good accordance with the fact that Na(+), Ca(2+) and Sr(2+) accelerate the dissolution of silica to form complexes during solution equilibrium. Considering that the stability constant was examined and reported in other papers, this new findings that Mg(2+) does not form a complex with silicic acid (Si(OH)(4)) is very important.     

Excretion of biotrace elements using the multitracer technique in mice

A radioactive multitracer solution obtained from the nuclear reaction of selenium with 25 MeV/nucleon⁴⁰Ar ions was applied to the investigation of the trace elements behavior in feces and urine of mouse. The excretion rates of 23 elements, Na, K, Rb, Mg, Ca, Sr, Ga, As, Sc, V, Cr, Mn, Co, Fe, Zn, Y, Zr, Mo, Nb, Tc, Ru, Ag and In were simultaneously detected under strictly identical experimental conditions, in order to clarify the excretion behavior of the elements in mice. Fecal and urinary excretion rates of the elements in mice reached the highest value separately at 48 and 24 hours. The total excretion of Mo, Tc and Co within 96 hours were all larger, more than 60%. Accumulative excretion rates of Ca, Nb, Mg, Sr, V, Sc, Na, Cr, Fe, Ag, Mn and Zr were 60-30%. The total rates of Ru, K, As, Zn, Rb, Y, Ga and In were less than 30%, and low excretion. The main excretion pathway of Mo, Co, Mg, Fe and Ag was through urine, and Na, K, As and Rb were eliminated from the body also in urine. But fecal excretion of Tc, Nb, Sr, Y, Ru, and In were larger than urinary excretion, and Ca, Sc, Mn, Zr, Zn were eliminated from the body in feces.     

白族长寿地区硬果仁中19种元素的测定分析

用电感耦合等离子体发射光谱法（ICP－AES）,对云南省白族长寿区的葵花子仁、麻子仁和核桃仁中的Ca、Mg、P、S、Na、AI、B、Fe、Zn、Cu、Mo、Sr、Mn、Cr、Se、Ge、Cd、Pb、As等19种元素进行了测定分析。结果表明,3种硬果仁中含有丰富的人体必需的Ca、Mg、P、S、Na、Fe、Zn、Mn、Se、Cu、Cr、Sr、Mo等有益元素,且P、Mg、S、Ca、Na、Zn、Mn、Fe、Se的含量较高。这些生命元素在3种硬果仁中的含量存在差异。有害元素Cd、Pb均未检出,核桃仁中As含量较高。硬果仁中富含这些生命元素是该地区老人健康长寿的一个重要原因。     

Effect of exchangeable cation on the swelling property of 2:1 dioctahedral smectite--a periodic first principle study

We used both localized and periodic calculations on a series of monovalent (Li+, Na+, K+, Rb+, Cs+) and divalent (Mg2+, Ca2+, Sr2+, Ba2+) cations to monitor their effect on the swelling of clays. The activity order obtained for the exchangeable cations among all the monovalent and divalent series studied: Ca2+ > Sr2+ > Mg2+ > Rb+ > Ba2+ > Na+ > Li+ > Cs+ > K+. We have shown that, in case of dioctahedral smectite, the hydroxyl groups play a major role in their interaction with water and other polar molecules in the presence of an interlayer cation. We studied both type of clays, with a different surface structure and with/without water using a periodic calculation. Interlayer cations and charged 2:1 clay surfaces interact strongly with polar solvents; when it is in an aqueous medium, clay expands and the phenomenon is known as crystalline swelling. The extent of swelling is controlled by a balance between relatively strong swelling forces and electrostatic forces of attraction between the negatively charged phyllosilicate layer and the positively charged interlayer cation. We have calculated the solvation energy at the first hydration shell of an exchangeable cation, but the results do not correspond directly to the experimental d-spacing values. A novel quantitative scale is proposed with the numbers generated by the relative nucleophilicity of the active cation sites in their hydrated state through Fukui functions within the helm of the hard soft acid base principle. The solvation effect thus measured show a perfect match with experiment, which proposes that the reactivity index calculation with a first hydration shell could rationalize the swelling mechanism for exchangeable cations. The conformers after electron donation or acceptance propose the swelling mechanism for monovalent and divalent cations.     

Determination of trace elements in bone crusts of rabbit during healing after fracture by INAA

The radius of rabbits were fractured by operation and the contents of Ca, Na, Mg, Zn, Mn and Sr in bone crusts during the period between the first to seventh week after fracture were determined by INAA. The tests show that all the contents of 6 elements in bone crusts are higher than those in contrast lateral in the same rabbit. The elemental metabolism curves in both laterals are roughly parallel. The content of Ca in the fractured position is almost constant during healing, those of Mn, Mg and Zn change apparently, and that of Sr changes in different way with the other elements.     

INAA of cortical and trabecular bone samples from animals

Instrumental neutron activation analysis (INAA) was applied to determine Ba, Br, Ca, Cl, Fe, K, Mg, Mn, Na, P, Sr and Zn in bovine and porcine rib bones. Precise results were obtained in analyses of freeze-dried cortical and trabecular bones separately, and also of whole bone ashes. Cortical tissues presented higher concentrations of Ba, Ca, Mg, Mn, Na, P, Sr and Zn than those obtained in trabecular ones. Comparisons were also made between the results obtained for bovine and porcine rib bones. This revised version was published online in August 2006 with corrections to the Cover Date.     

A novel sample introduction system for microwave-induced plasma optical emission spectrometry

A newly developed micro-sampling technique using a discrete sample introduction system (DSIS) has been demonstrated for simultaneous multi-element analysis by microwave-induced plasma optical emission spectrometry (MIP-OES). A microliter volume of sample solution (20 μl) is manually inserted into a Teflon microsampling device and subsequently pumped at low solution uptake rates of <100 μl min⁻¹ to a Meinhard-type concentric nebulizer and then into a 250-W helium plasma. The performance of DSIS-MIP-OES was demonstrated by the determination of major (Na, K, Ca, Mg), minor (Cu, Fe, Zn) and trace (Sr) elements in two clinical standard certified reference materials (serum, hair). Standard microaddition procedures were used to minimize possible matrix interference. The detection limit (3σ) obtained was 10, 30, 50, 100, 10, 5, 20 and 40 ng ml⁻¹ for Ca, Cu, Fe, K, Mg, Na, Sr and Zn, respectively. The method offers relatively good precision (RSD ranged from 5 to 14%) and microsampling capability. Agreement between analytical results and certified values for the test elements was good. The method could be useful as a routine clinical laboratory procedure.     

原子吸收光谱法测定野生及养殖灵芝中10种元素含量

采用火焰原子吸收光谱法测定了养殖及野生灵芝中的铜、钠、铁、钾、镁、钙、锰、锌、锶、铅元素含量。结果表明,野生灵芝和养殖灵芝中均含有较高的钾,其中野生灵芝中铜、钙、锶、锌含量较高,养殖灵芝中钠、铁、镁、锰含量较高。可为探讨野生灵芝与养殖灵芝中含量及其疗效的关联性等提供科学依据。     

Chromatographische trennung von metallionen durch elution mit ammoniumsulfat: Bestimmung von magnesium,calcium und strontium in salzreichen wässern

The chromatographic separation of Mg, Ca, Sr, Ba, Fe(II, III) and Mn(II) by elution with ammonium sulphate solution from Dowex 50–X₁₀ was studied. The optimum conditions for the separation of the alkaline earths from each other were established. The method was applied for the separation of Mg, Ca and Sr in salt waters; Mg and Ca were determined by EDTA titration and Sr spectrographically, the coefficient of variation being 1.9% for Mg and 1.4% for Ca.     

Evaluation of strontium isotope abundance ratios in combination with multi-elemental analysis as a possible tool to study the geographical origin of ciders

In order to evaluate alternative analytical methodologies to study the geographical origin of ciders, both multi-elemental analysis and Sr isotope abundance ratios in combination with multivariate statistical analysis were estimated in 67 samples from England, Switzerland, France and two Spanish regions (Asturias and the Basque Country). A methodology for the precise and accurate determination of the ⁸⁷Sr/⁸⁶Sr isotope abundance ratio in ciders by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) was developed. Major elements (Na, K, Ca and Mg) were measured by ICP-AES and minor and trace elements (Li, Be, B, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Mo, Cd, Sn, Sb, Cs, Ba, La, Ce, W, Tl, Pb, Bi, Th and U) were measured by ICP-MS using a collision cell instrument operated in multitune mode. An analysis of variance (ANOVA test) indicated that group means for B, Cr, Fe, Ni, Cu, Se, Cd, Cs, Ce, W, Pb, Bi and U did not show any significant differences at the 95% confidence level, so these elements were rejected for further statistical analysis. Another group of elements (Li, Be, Sc, Co, Ga, Y, Sn, Sb, La, Tl, Th) was removed from the data set because concentrations were close to the limits of detection for many samples. Therefore, the remaining elements (Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba) together with ⁸⁷Sr/⁸⁶Sr isotope abundance ratio were considered for principal component analysis (PCA) and linear discriminant analysis (LDA). Finally, LDA was able to classify correctly 100% of cider samples coming from different Spanish regions, France, England and Switzerland when considering Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba and ⁸⁷Sr/⁸⁶Sr isotope abundance ratio as original variables.     

Temperature dependency of element incorporation into European eel (Anguilla anguilla) otoliths

The present study experimentally tested the influence of water temperature on the inclusion of 15 elements into juvenile European eel (Anguilla anguilla) otoliths in freshwater. It should be investigated (1) if temperature effects on otolith Sr/Ca might impair the interpretation of migration studies and (2) if the elemental composition of otoliths can be used to reconstruct experienced temperature histories of eels. Therefore, eels were kept under full experimental conditions at three different water temperatures (14 °C, 19 °C and 24 °C) for 105 days. Thereafter, laser ablation inductively coupled mass spectrometry (LA-ICPMS) was conducted on the outer edge of their otoliths. Our analyses revealed significant temperature effects on otolith Na/Ca, Sr/Ca, Mg/Ca, Mn/Ca, Ba/Ca, Zr/Ca and Y/Ca ratios. Variations of Sr/Ca caused by temperature were far below those used to detect eel movements between waters of different salinities and will therefore not affect the interpretation of migration studies. Elemental fingerprints of Sr/Ca, Mg/Ca, Mn/Ca and Ba/Ca ratios resulted in clearly separated groups according to temperature treatments, indicating that changes in water temperature might lead to characteristic changes in otolith element composition. However, the successful application of elemental fingerprints to reconstruct moderate changes of water temperature seems doubtful because the influence of somatic growth on otolith microchemistry still remains unclear, and temperature-induced variations could be overlaid by changes of water element concentrations during growth periods. Nevertheless, our results contribute to the completion of knowledge about factors influencing element incorporation and help to explain variations in element composition of fish otoliths.     

Ultrafine Na-4-mica: uptake of alkali and alkaline earth metal cations by ion exchange

The cation exchange properties of alkali and alkaline earth metal cations at room temperature were investigated on an ultrafine, highly charged Na-4-mica (with the ideal mica composition Na4Mg6Al4Si4O20F4.xH2O). Ultrafine mica crystallites of 200 nm in size led to faster Sr2+ uptake kinetics in comparison to larger mica crystallites. The alkali metal ion (K+, Cs+, and Li+) exchange uptake was rapid, and complete exchange occurred within 30 min. For the alkaline earth metal ions Ba2+, Ca2+, and Mg2+, however, the exchange uptake required lengthy periods from 3 days to 4 weeks to be completed, similar to its Sr uptake, as previously reported. Kinetic models of the modified Freundlich and parabolic diffusion were examined for the experimental data on the Ba2+, Ca2+, and Mg2+ uptakes. The modified Freundlich model described well the Ba2+ ion uptake kinetics as well as that for the Sr2+ ion, while for the Ca2+ and Mg2+ ions the parabolic diffusion model showed better fitting. The alkali and alkaline earth ion exchange isotherms were also determined in comparison to the Sr2+ exchange isotherm. The thermodynamic equilibria for these cations were compared by using Kielland plots evaluated from the isotherms.     

Viscometric Study of Fixation of Cations in Aqueous Solutions of Polyelectrolytes Based on Salts of 2-Acrylamido-2-Methylpropanesulfonic Acid

An experimental study is made of the effect of the solution ionic strength and the nature of a cation (Li, Na, K, Mg, Ca, Sr, and Ba) on fixation of counterions on polysulfonate anions in aqueous solutions of poly-2-acrylamido-2-methylpropanesulfonic acid and copolymers of acrylamide and N-vinylpirrolidone with 2-acrylamido-2-methylpropanesulfonic acid.     

INAA of Ca, Cl, K, Mg, Mn, Na, P, and Sr contents in the human cortical and trabecular bone

Summary Concentration of Ca, Cl, K, Mg, Mn, Na, P, and Sr were determined by instrumental neutron activation analysis using short-lived radionuclides in intact cortical and trabecular bone of femoral neck and iliac crest of 81 relatively healthy 15-55 years old women (n = 36) and men (n = 45). In cortical bone the Ca, P, and Mg mass fractions in the femoral neck were statistically significantly higher, and Cl, K, and Na lower, than the values for the iliac crest. In trabecular bone the Cl, K, and Na mass fractions in the iliac crest were significantly higher, and Ca, P also higher, than the values for the femoral neck.     

The analysis of archaeological glass by inductively coupled plasma optical emission spectroscopy

Summary An analytical procedure is described for the analysis of archaeological glass by inductively coupled plasma optical emission spectroscopy (ICP-OES). Glass samples were analysed in solution after fusion with lithium metaborate at 1100°C. The analyses were performed in the sequential multielemental mode of operation, with the determination of 15 elements in four analytical runs; only elements with not too large concentration difference were analysed in a single run. The following elements were accounted for: Si, Na, Ca, Al, Fe, Mg, Mn, Ti, Sr, Ba, Cr, Ni, Cu, Co, Pb.     

Decationization and dealumination of clinoptilolite tuff and ammonium exchange on acid-modified tuff

The paper presents results of investigation of exchange of the clinoptilolite tuff cations with hydrogen ions from HCl solution of concentration 0.1 mmol cm(-3) and ammonium ions solutions of concentrations 0.0071 to 2.6 mmol cm(-3). Molal concentrations, x (mmol g(-1)) of cations exchanged in acid solution and in ammonium ions solutions were compared with molal concentrations of cations obtained by determination of the cation-exchange capacity of clinoptilolite tuff. The obtained results show that at ammonium ion concentrations lower than 0.1 mmol cm(-3), with regard to exchange capacity for particular ions, best exchanged are Na+ ions, followed by Mg2+ and Ca2+ ions, while exchange of K+ ions is the poorest (Na+ > Mg2+ > Ca2+ > K+). At ammonium concentrations from 0.2 to 1 mmol cm(-3) the order is Na+ > Ca2+ > Mg2+ > K+. At concentrations higher than 1 mmol cm(-3) the order is Na+ > Ca2+ > K+ > Mg2+. The results are a consequence of the uptake of hydrogen ions by zeolite samples in ammonium ions solutions at concentrations lower than 1 mmol cm(-3) and indicate the importance of Mg2+ (besides Na+ ions) for the exchange between clinoptilolite cations and H+ ions, in contrast to K+ ions, whose participation in the reaction with H+ ions is the lowest. During decationization of the clinoptilolite in acid solution, best exchanged are Na+, Mg2+, and Ca2+ ions, while exchange of K+ ions is the poorest. Due to poor exchange of K+ and H+ ions and good exchange of Na+, Mg2+, and Ca2+ ions, it is to be assumed that preservation of stability of the clinoptilolite structure is caused by K+ ions present in the channel C. Clinoptilolite is dissolved in the clinoptilolite A and B channels where Na+, Mg2+, and Ca2+ ions are present. On the acid-modified clinoptilolite samples, exchange of ammonium ions is poorer than on natural zeolite. The longer the contact time of the zeolite and acid solution, the worse ammonium ions exchange. It can be assumed that H+ ions exchanged with zeolite cations are consumed for solution of aluminum in the clinoptilolite structure; therefore the concentration of H+ ions as exchangeable cations decreases. In the ammonium ion solution at a concentration of 0.0065 mmol cm(-3), from the acid-modified zeolite samples, Al3+ ions are exchanged best, followed by Na+, Mg2+, Ca2+, and K+ ions. Further to the results, it is to be assumed that exchangeable Al3+ ions available from clinoptilolite dissolution are best exchanged with H+ ions in acid solution.     

Multivariate classification of cigarettes according to their elemental content determined by inductively coupled plasma optical emission spectrometry.

In this paper we describe our study on the characterization of cigarette samples according to their mineral content. Acid digestion assisted by microwaves was employed, and inductively coupled plasma optical emission spectrometry was the analytical technique used for the determination of Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, P and Sr in conventional, light, and flavorized cigarettes. Multivariate techniques, such as hierarchical clusters analysis (HCA) and principal-component analysis (PCA), were applied to discriminate among different types of cigarettes. Cluster analysis and principal-component analysis showed differences in cigarettes according to the type and mineral composition. The cigarette samples were divided within the 3 groups according to their mineral composition. Ca, Sr, Cu, K and Na were the most important elements for cigarette classification, and only these 5 variables were sufficient for the classification and discrimination of the evaluated types of cigarettes.     

Preparation of alkaline earth phosphates with sol containing sodium alginate and sodium diphosphate

Magnesium hydrogen phosphate, calcium hydroxyapatite, and strontium hydroxyapatite were successfully prepared from sol consisting of sodium alginate and Na4P2O7 with Mg2+, Ca2+, and Sr2+ in the corresponding nitrates, respectively. It is revealed that the order of the addition of those substrates and the role of sodium alginate are important factors for the preparation of desired phosphate compounds. According to the previous paper on the preparation of calcium hydroxyapatite, sodium alginate was mixed with aqueous Na4P2O7, followed by the addition of the aqueous divalent cations, resulting in the poor formation of the target phosphates. However, as a revised sol-gel technique, sodium alginate was added to the mixture of Na4P2O7 and aqueous Mg2+ and Sr2+, resulting in a rather favorable formation of MgHPO4 and strontium hydroxyapatite, respectively, while the sol thus obtained was stable within a few days. However for aqueous Ca2+, calcium hydroxyapatite could not be obtained through the revised sol-gel technique. In the preparation of magnesium hydrogen phosphate, sodium alginate contributes mainly to the sol formation of the precursor. The ion exchange between Na+ in sodium alginate and aqueous Ca2+ was important for the preparation of calcium hydroxyapatite. In contrast, the reaction of sodium alginate with the mixture of Na4P2O7 and aqueous Sr2+ afforded strontium hydroxyapatite at the specific ratio of those three substrates. The structure of calcium and strontium phosphates prepared from the revised sol-gel process evidently depended on the amount of sodium alginate introduced into the mixture of Na4P2O7 and the corresponding divalent cations.     

The preparation of high-purity magnesium oxide

Investigations on the separation of trace amounts of Ba, Mn, Fe, Sr+Y, Co, Ca, Zn, Ag and Na from macro-amounts of Mg are described.