Characterization of Phoenician pottery from Mothia by neutron activation analysis

The concentration of 7 elements (Na, Al, Mg, Ti, Ca, V, Mn) was determined by Neutron Activation Analysis in 35 samples of pottery and 14 samples of clay. The samples were collected in Mothia (a Phoenician stronghold in Sicily during 5^th–4^th century B. C.) and in its neighbourhoods. Cluster analysis of the data showed that most of the samples are homogeneous and confirmed the archaeological evidence that they are mostly local ware. The detailed results of the analyses are reported and the technique used for cluster analysis is described.     

Rapid sample digestion by fusion and chemical separation of Hf for isotopic analysis by MC-ICPMS

A new method for rapid sample digestion and efficient chemical separation of Hf and REE from rock samples for precise isotopic analysis is presented. Samples are digested by fusion in the presence of a lithium borate flux at 1100 °C and dissolved whilst molten in dilute nitric or hydrochloric acid. Prior to chemical separation using ion exchange techniques, Li and B from the flux material and Si from the sample are separated from the remaining major elements, REE and high field strength elements (HFSE) in the sample by Fe-hydroxide co-precipitation. The chemical separation of Hf is a two-stage procedure designed to first remove the remaining matrix elements (e.g. Fe, Ba) in the sample using standard cation exchange techniques, followed by separation of Hf from the REE and HFSE on TEVA extraction chromatographic resin. Hf yields are >90% and total procedural blanks are ca. 50 pg. Hf isotope ratios of a synthetic standard solution and replicate digestions of international rock standards BHVO-1 and BCR-1 measured on multi-collector inductively coupled plasma mass spectrometer (MC-ICPMS) reproduce similarly to ≤50 ppm (2 S.D.). The following elemental ratios are routinely obtained for elements, which interfere isobarically or may affect the ionisation and/or fractionation behaviour of Hf during analysis: ¹⁷⁶Yb/¹⁷⁶Hf<0.0001; ¹⁷⁶Lu/¹⁷⁶Hf<0.00001; Ti/Hf<0.05. This technique also provides a means of separating Nd from the REE fraction for isotopic analysis and, potentially, may be adapted for measurement of Lu/Hf ratios by isotope dilution techniques.     

Ion chromatographic separation for analysis of radiostrontium in nuclear reprocessing solutions of high ionic strength

Determination of⁹⁰Sr in nuclear fuel reprocessing solutions can be facilitated by a preparatory separation using analytical ion chromatography (IC). Furthermore, a novel acid suppression system is described which permits IC separation even in the presence of very strong (0.33M) acid. Following acid suppression (where needed), Sr²⁺ is concentrated and separated from most other solution components by selective adsorption on cation concentrator columns. Cation species retained on the concentrator columns with strontium are subsequently separated on a cation IC column. The Sr²⁺ peak aliquot is collected for subsequent radiostrontium analysis by liquid scintillation counting of the beta activity. Results have shown quantitative separation and recovery of strontium. The entire separation system is automated under computer control and is able to handle samples of large (500 ml) and small (l) sizes.     

Serial separation of cations and anions by ion chromatography using the peak parking technique and sulfosalicylic acid as the eluent

An improvement of the peak parking technique is described for the serial determination of cations (Na⁺, , K⁺, Mg²⁺, and Ca²⁺) and anions (Cl⁻, , and ) using a single pump, a single eluent and a single detector. The present system used commercially-available unmodified cation exchange and anion exchange columns, which were attached to each switching valve. When 1.75 mM 5-sulfosalicylic acid was used as the eluent, serial separation of the above cations and anions was achieved in less than 20 min. The proposed ion chromatographic method was successfully applied to the serial determination of cations and anions in tap water and river water samples. The limits of detection at S/N=3 for an injection of 20 μl were 16–68 ppb (μg/l) for cations and 15–28 ppb for anions.     

Separation of metallic impurities from uranium by anion exchange on Dowex 1×8 resin

The separation of metallic impurities from uranium by anion exchange with a Dowex 1×8 resin has been investigated. The following elements can be quantitatively separated from 400 mg uranium using a 1 cm diameter 15 or 30 cm long column. The elements Ag, Al, Ba, Ca, Cr, Cs, K, Mg, Mn, Na, Ni, Rb, REE, Sc, Th, Ti and Y can be separated by eluting the elements with conc. HCl. Uranium is retained by the resin. Al, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, REE and V can be separated by eluting with 0.01 N H₂SO₄. Uranium is retained by the resin. Cd and Zn can be separated by first eluting uranium with 0.5 N HCl and then eluting Cd and Zn with 1 N NH₃. Hf, Zr and V can be separated by eluting with 5 N HCl but some uranium contamination is unavoidable.     

An application of the pixe method: Analysis of trace elements after wet digestion of uterine tissue

The authors present an application of the PIXE (Particle Induced X-ray Emission) method: determination of trace element concentrations in uterine tissue after wet digestion by HNO₃. A method for calibration of the system is described. Results of the analysis of a NBS reference material (National Bureau of Standards), SRM 1577 bovine liver, are given and possible sources of error are discussed. In the authors’ experience, the combination of wet digestion and PIXE provides a tool for reliable analysis of trace element concentrations in tissues.     

Determination of rare earth elements in Indian kimberlite using inductively coupled plasma mass spectrometer (ICP-MS)

A method has been developed for the analysis of rare earth elements (REEs) in kimberlite samples using inductively coupled plasma mass spectrometer (ICP-MS). The samples were dissolved using sodium peroxide fusion and after appropriate dilutions the solutions were analyzed using ICP-MS. The paper presents the concentration of rare-earth elements as determined by ICP-MS in eight kimberlite samples from Central India. The method was validated using certified reference materials STSD-1 and STSD-2 from Canadian Certified Reference Material Project. The method detection limit of various REEs varies from 0.12 to 1.54?mg?kg^?1. The total REE concentrations range from 418 to 726?mg?kg^?1 and fall within the interval of those reported in the literature for kimberlites. Despite the marked difference in the REE contents, all the analyzed samples show similar REE patterns that resemble those for kimberlites. In order to compare ICP-MS results, the samples were analyzed using instrumental neutron activation analysis which is a reference method for determination of REEs in geological samples.     

Separation of methyltin species from inorganic tin,and their interactions with humates in natural waters

Tin(II) and tin(IV) are absorbed from aqueous solutions by Sephadex G-25 gel, from which they can be eluted by humates or fulvates, with which they interact more strongly. Methyltin species are not absorbed by Sephadex G-25, and so can be separated from inorganic tin. Both inorganic tin and methyltin species in natural waters at pH 7.4 can be quantitatively retained by passing through small columns of Chelex-100 resin: the methyltin species can then be washed off the resin with 4M nitric acid. Trimethyltin chloride¹¹³Sn in water scarcely interacts with fulvates, humates, kaolinite or montmorillonite but is absorbed bySphagnum peat. Dimethyltin dichloride-¹¹³Sn reacts significantly with all the above materials after 2 hours equilibration. Methyltin trichloride-¹¹³Sn interacts weakly in alkaline solutions.     

Fast atom bombardment combined with mass spectrometry for characterization of polycyclic aromatic hydrocarbons

A new approach using fast atom bombardment combined with mass spectrometry to characterize polycyclic aromatic hydrocarbons (PAHs) in the range of 128-252 u molecular weight is described. Sulfolane was employed as a liquid matrix for these π-conjugated hydrocarbons. Bombardment of sulfolane solution of certain PAHs with an atom beam produces both radical cation (M^+.) and protonated molecule [(M + H)⁺], with no evidence of fragmentation. Collisional activation of the fast atom bombardment-desorbed M^+. ions, however, results in several structure-specific fragment ions. Structural differences in a few isomeric hydrocarbons can be detected using the [(M + H)⁺]/[M^+.] abundance ratio and in the pyrene-fluoranthene pair by the B/E linked-field-collision-activated dissociation data. The [(M + H)⁺]/[M^+.] was found to be compound-specific and correlated well with certain properties (resonance energy, proton affinity, and ionizing energy) of PAHs.     

Chemical separation of molybdenum from uranium and fission product nuclides

A very rapid method for the separation of molybdenum(VI) from neutron irradiated uranium and its fission products is described. The procedure is based on the selective extraction of molybdenum(VI) by a 0.1M solution of 2-hexylpyridine in benzene from 4M HCl+0.04M KSCN. Decontamination factors were estimated to be >10⁴ for the radionuclides of niobium, zirconium, ruthenium, lanthanum, cerium, promethium, yttrium, strontium and barium.     

A direct hydrogen-1 and phosphorus-31 nuclear magnetic resonance cation solvation study of Al(ClO4)3, Ga(ClO4)3, In(ClO4)3, UO2(ClO4)2, and UO2(NO3)2 in water-acetone-dimethylsulfoxide and water-acetone-hexamethylphosphoramide mixtures

A competitive solvation study of Al(ClO₄)₃, Ga(ClO₄)₃, In(ClO₄)₃, UO₂(ClO₄)₂, and UO₂(NO₃)₂ in water-acetone-dimethylsulfoxide (DMSO) and water-acetone-hexamethylphosphoramide (HMPT) mixtures has been carried out by direct H¹ and P³¹ nuclear magnetic resonance (NMR) techniques. At low temperature, proton and ligand exchange are slow enough in these systems to permit the observation of signals for bulk and coordinated molecules of water and the organic bases (DMSO and HMPT). Both DMSO and HMPT compete effectively with water for coordination sites in the Al³⁺, Ga³⁺, and In³⁺ systems, with steric effects dominating the HMPT results. Both Al³⁺ and In³⁺ are able to bind a maximum of two to three HMPT molecules, for example. In contrast, UO²⁺ is solvated selectively by the organic molecules to the allowed maximum of 4 molecules per cation. H¹ and P³¹ NMR spectral results support the formation of only the mono-, tri-, and tetra-HMPT solvation complexes.     

Final purification and concentration of americium/curium separated from high-level reprocessing waste

A cation-exchange cycle has been developed for the recovery and concentration of the Am/Cm product from a DTPA/lactic acid solution used in an extraction process for the isolation and separation of the actinides from lanthanide fission products. The optimum pH region for the sorption of Am³⁺ from 0.05M DTPA/1M lactic acid solutions by strongly acidic cation-exchange resins is pH 0.9–1.0. Maximum usable capacities, heights of the exchange zone, and concentration factors for different resins, cross-linkages and temperatures have been determined. Decontamination factors are given for some fission products, as well as U, Np and Pu.     

Multielemental NAA of geological micro-grain samples for origin identification

Thirty two elements were determined in five pieces of presumed cosmic dust samples with the weights of 5 to 25 g by neutron activation analysis (NAA). All the interferences from fission, threshold reactions and -spectra were corrected for and different counting geometries normalized. Enrichment factors with reference to C1-chondrite are about 200 and 100 for lithophile refractory elements (e.g., V, Th, Hf and W) and rare earth elements (REE), respectively. Deficiencies were observed for Co, Cr, Mg and Na, etc. The C1-chondrite normalized REE patterns are close to those of extraterrestrial materials, with no anomaly of Eu, indicating an extraterrestrial origin of the grain samples analyzed.     

Search for optimal conditions for the extraction of thiosulfate complexes of Cu(II) by 4-(5-nonyl)pyridine from aqueous mineral acid solutions

Solvent extraction of Cu(II) by 4-(5-nonyl)pyridine (NPy) in benzene from mineral acid solutions containing thiosulfate ions has been studied at room temperature (23±2°C). Mineral acid solutions alone constitute an aqueous phase from which Cu(II) is not extracted. Addition of small amounts of thiosulfate ions augments the extraction to an extent that quantitative recovery is possible. Stoichiometric studies reveal the involvement of ion-pair type complexes (NPy·H)₂·Cu(S₂O₃)₂ which are responsible for extraction. Stability constants lg K_ex for this complex are 7.2±0.2; 9.1±0.2 and 9.5±0.2 for HCl, HNO₃ and H₂SO₄, respectively. The presence of 0.01 mol/l of some complexing ions like ascorbate, acetate, citrate, oxalate, tartrate or iodide does not affect the extraction, thus allowing the recovery of the metal from diverse matrices. Under optimal conditions (0.1M NPy in benzene-0.1M HNO₃ or H₂SO₄+0.01M S₂O ₃ ^?2 or 0.5M HCl+0.05 M S₂O ₃ ^?2 ) a clean separation from some elements, e.g. Cs(I). Co(II), Fe(III), Eu(III), Ce(III), Se(IV) and Cr(VI) can be achieved.     

Studies on the selectivity of Na+ separation on specially prepared hydrated antimony pentoxide

The selectivity of Na⁺ separation on especially prepared hydrated antimony pentoxide (HAP) was studied with respect to trace elements. For this purpose NaCl samples, doped with 0.5 μg each of altogether 21 selected elements in form of suitable neutron activated compounds, were in relation to practice subjected to column experiments. In some cases trace elements were used in different oxidation states. Considered were elements which are of particular interest for neutron activation analysis. With simultaneous retention of Na⁺ (DK≥10⁸) Cs, Ba, Sc, La, Ce, Eu, Cr, Mo, Mn, Co, Cu, Ag, Au, Zn, Cd, Hg, and Sb are completely eluted from the HAP column, using 7.5N HCl, whereby Cs and to some extent Ba and Sc in comparison to the elements mentioned above required a higher elution volume. Rb, Se and As on the contrary were almost quantitatively retained on HAP column, W partly as WO ₄ ^2? . The scope of validity of the results will be discussed.     

Isolation and alpha-particle spectrometric determination of238Pu and239,240Pu in sediments

A simple method is described for the isolation and determination of plutonium isotopes in sediments. The method involves leaching of sample with nitric acid and subsequent separation of plutonium on an anion-exchange column. Major matrix elements and several potential radiochemical interferences are removed during 8M HNO₃ sample loading on the column. Thorium is removed by thorough washing with 10M HCl. Plutonium (IV) is eluted with 4M HCl. Source for alpha-particle spectrometry is prepared by LaF₃ coprecipitation technique at which stage a complete separation from uranium(VI) is also achieved. The entire analytical procedure is completed in about two days.     

Separation of tin from some metals by extraction chromatography

Much attention has been devoted to Sn (IV) strongly retained on the TBP-Daiflon column from 2M HCl in extraction chromatography. The separations of Sn?Cu, Zn, As, Cd, Sb, Pb,¹¹³Sn-¹²⁵Sb,¹¹³Sn-^113mIn (^113mIn milking) and Sn?Hg?Fe were successfully achieved without any contamination. In the separations, except for the last, only tin was retained separately on the column upon passing the mixed solution. The daughter indium was eluted with 0.5M HCl. In the last separation, iron was eluted with 0.5 M HCl, tin with 0.1M HCl and mercury with 2M HNO₃, for these metals retained on the column. Radioactive tracers for tin, iron, mercury and antimony were used.     

Flow procedure for ion-exchange preconcentration and on-line spectrophotometric determination of iron(III) as its thiocyanate complex

On-line ion-exchange preconcentration of iron(III) on a conventional cation exchange resin with spectrophotometric detection based on thiocyanate complexation is described. The calibration graph is linear over the range 0.01–0.2 g ml^–1 and the detection limit (3 ) is 6 ng ml^–1 for a 6-ml sample. No interference effects were detected. The recovery of iron from the resin is 95%. 12 samples h^–1 can be analysed.     

The determination of rare earth alloying additives in special steels by neutron activation analysis

A procedure for neutron-activation analysis of cerium, lanthanum, praseodymium and neodymium, tested on more than thirty samples of steels, is described. After irradiation for 20 hrs with a neutron flux of 1.2·10¹³ n·cm⁻²·sec⁻¹ the steel samples were dissolved in aqua regia and extraction separation of iron from 6N HCl by ether was employed. The REE were separated as a group by precipitation as fluorides and hydroxydes. The individual rare-earth elements were separated from each other using a KU-2 cation exchange resin and a solution of ammonium α-hydroxyisobutirate as eluant. The separated samples were counted on a NaI(T1) γ-spectrometer.     

Ultrasound-promoted Friedel-Crafts acylation of arenes and cyclic anhydrides catalyzed by ionic liquid of [bmim]Br/AlCl3

A simple and efficient method of Friedel-Crafts acylation of arenes with succinic anhydride, phthalic anhydride and glutaric anhydride under the action of 1-butyl-3-ethylimidazolium ([bmim]Br/AlCl₃ ([bmim]⁺) cation (ionic liquid) and ultrasound irradiation is presented. Thy purity of products was tested by GC-MS and their structures evaluated by IR and ¹H NMR spectroscopy.