INAA of IAEA-331 (spinach), SRM,for 40 elements

Forty elements in IAEA-331 (Spinach), an intercomparison material, have been determined using NAA. Among them, 30 elements, Ag, Al, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, K, La, Mg, Mn, Na, Ni, Rb, Re, Sc, Se, Sr, Ta, Tb, Th, V, Zn and Zr were determined by INAA. A series of simple and quantitative radiochemical separation procedures were established for the determination of ten additional elements. Cd, Lu, Mo, Sb, Sm, Yb, U were determined by removing the major interfering nuclide⁸²Br. Cu was determined by 0.048M NaDDTC/CHCl₃ extraction from 1M HCl medium. As and P were determined using an inorganic exchange column of acid aluminium oxide (AAO). Integral counts from 80 keV to 130 keV contributed by Bremsstrahlung from³²P -were used to evaluate the content of phosphorus.     

Determination of Cd, Co, Cr, Cu, Fe, Mn, Ni and Pb in natural waters, alkali and alkaline earth salts by electrothermal atomic absorption spectrometry after preconcentration by column solid phase extraction

Methods are described for the determination of trace and ultra trace amounts of Cd, Co, Cr, Cu, Fe, Mn, Ni and Pb in natural waters, alkali and alkaline earth salts. Separation and preconcentration of trace metals is achieved by a column solid phase extraction procedure using silica gel modified with derivatives of dithiocarbamates — Na-DDTC (sodium diethyldithio-carbamate and HMDTC (ammonium hexamethylene-dithiocarbamate) as column packing material. The influence of the sorbent preparation procedure on the degree of sorption of the trace analytes is examined for different pH values of the sample solution. Isobutylmethyl ketone (IBMK) is proposed as an effective eluent for quantitative elution of retained metal ions. Optimal instrumental parameters for ETAAS determination of preconcentrated elements in organic eluate are presented. Practical application of sorbents in analysis of natural waters and alkali and alkaline earth salts is demonstrated. Proposed preconcentration procedure combined with ETAAS determination of trace analytes allows the determination of 0.04 g l^–1 Cd, 0.1 g l^–1 Cr, Cu, and Mn and 0.3 g l^–1 Co, Fe, Ni and Pb in natural waters and 1.10^–7% Cd, 3.10^–7% Cr and Mn, 7.10^–7% Co, Ni and Pb and 2.10^–6% Cu and Fe in alkali and alkaline earth salts.     

Determination of Cd,Mo, Cr and Co in biological materials by RNAA

A method for the determination of trace amounts of Mo, Cd, Co and Cr in biological materials by neutron activation analysis with radiochemical separation is presented. The method is based on the ion-exchange scheme developed by SAMSAHL, where Co and Cr are trapped on BioRad Chelex-100 and Cd and Mo on BioRad AG2X8. The elements Mo, Cd and Co can be determined without systematic errors. For the element chromium the situation is less clear, partially due to lack of sufficient certified reference materials for Cr. The method has been used in the characterization of candidate reference materials. Detection limits in these materials range from 1.5 g/kg for Co to 10 g/kg for Cr. Actual levels as low as 8 g/kg for Cd and 7 g/kg for Co were measured.     

Simultaneous Production of 57Co and 109Cd in Cyclotron

⁵⁷Co and ¹⁰⁹Cd simultaneous production was studied, using composite targets of ^natNi and ^natAg. The targets were irradiated at the CV-28 Cyclotron, with proton beams of 24 MeV. The average production yields of ⁵⁷Co and ¹⁰⁹Cd were 1179.93 kBq/A·h, produced by direct and indirect reactions (11.31 days after the EOB) and 71.41 kBq/A·h (EOB), respectively. The chemical separation procedure was developed in order to obtain a mixed calibration source of ⁵⁷Co and ¹⁰⁹Cd, with a separation yield higher than 80%. The gamma spectroscopy technique was used for the radioactive analysis, using a HPGe detector. The stable elements were identified by atomic absorption spectrophotometry.     

137Cs,trace and toxic elements distribution in Austrian mushrooms

Various mushroom species have been analyzed for their elemental composition (i.e., Al, B, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Sr and Zn) by means of ICP-AES. The accuracy of the measurements was confirmed by analyzing a series of the same samples by short time activation analysis. The data were evaluated statistically including the values of¹³⁷Cs. The results denote that the distribution of these elements and their correlation of these elements and their correlation coefficients are highly distinctive for each mushroom species. K, Na and P were found to correlate negatively with¹³⁷Cs in most species. Suillus grevillei and Cantharellus cibarius show high Be values (0.27 and 0.30 g g^–1, respectively), while Pb was high in Suillus grevillei (16.3 g g^–1) and Amanita rubescens (9.3 g g^–1). Higher levels of Cd were found in Rozites caperata and Russula vesca with a mean of 9.2 and 16.1 g g^–1, respectively. Cluster analysis was applied to classify these samples according to their botanical species using their elemental composition. The concentrations of Al, Cr, Mn, Na and¹³⁷Cs have no influence on the classification of these samples.     

Radiochemical neutron activation analysis for arsenic,cadmium, copper and molybdenum in biological matrices

A simple two step radiochemical separation scheme has been developed which permits the RNAA determination of As, Cd, Cu and Mo in biological matrices. The RNAA separation is applied following the INAA determination of at least 17 other elements in the same samples. Under our experimental conditions which included a four day decay period for handling and shipping from a remote reactor site, detection limits for As, Cd, Cu and Mo are 0.24, 6.6, 45 and 3.4 ng, respectively, in NBS biological standard reference materials SRM 1571 and 1567. Decontamination factors for the major spectral interferences,⁸²Br,⁴²K,²⁴Na³²P and¹²²Sb have been determined and found to be sufficiently high for measurement of the elements of interest in most biological matrices. The overall INNA/RNAA procedure takes full advantage of high resolution Ge(Li) gamma-ray spectroscopy and involves minimal chemical processing.     

Determination of lead,cadmium and thallium by neutron activation analysis in environmental samples

A radiochemical procedure for simultaneous determination of lead (²⁰³Pb), thallium (²⁰²TI) and cadmium (¹¹⁵Cd^115mIn) after fast neutron activation, based on ion-exchange separation from bromide medium and additional purification steps for Pb and Tl is described. Radioactive tracers²¹⁰Pb and¹⁰⁹Cd were used for determination of the chemical yields of Pb and Cd; for Tl it was determined gravimetrically. Two standard reference materials, BCR CRM No. 146 Sewage Sludge and NIST SRM 1633a Coal Fly Ash were analyzed and satisfactory agreement with certified values was obtained.     

Dispersive liquid-liquid microextraction for simultaneous determination of cadmium, cobalt, lead and nickel in water samples by inductively coupled plasma optical emission spectrometry

We report on a new method for the dispersive liquid-liquid microextraction of Cd(II), Co(II), Pb(II) and Ni (II) from water samples prior to their simultaneous determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The procedure is based on the injection of a ternary solvent system composed of appropriate quantities of extraction solvent (trichloroethylene), dispersive solvent (ethanol), and the chelating reagent 2-(2′-benzothiazolylazo)-p-cresol into the sample solution. The solution turns turbid immediately after injection, and the analytes are extracted into the droplets of the organic phase which was dried and dissolved in a mixture of Triton X-114, nitric acid, and ethanol. The metal ions in this mixture were quantified by ICP-OES. The detection limits under optimized conditions are 0.2, 0.3, 0.2 and 0.7?μg?L^?1 for Cd(II), Co(II), Pb(II) and Ni(II), respectively. The enrichment factors were also calculated for Cd (13), Co (11), Pb (11) and Ni (8). The procedure was applied to the determination of cadmium, cobalt, lead and nickel in certified reference material (waterway sediment) and water samples.

Polarography of hexavalent molybdenum in hypophosphorous acid solutions

The polarographic behaviour and determination of Mo(VI) in hypophosphorous acid solutions of concentrations varying from 0.1 to 5.0 mol l^?1 andT=25±0.1 °C have been investigated. It was shown that reduction of MoO ₄ ^2? takes place along a single or two waves depending upon the acid concentration. Microcoulometric experiments have been performed at the limiting region of the different waves obtained at different acid concentrations. A scheme for the mechanism of reduction occuring at theDME has been deduced. A method for analytical determination of Mo(VI) on both the micro- and macro-scales in hypophosphorous acid solutions has been reported. Analysis of a binary mixture Mo(VI)/Cd(II) and a tertiary mixture Mo(VI)/Cd(II)/Zn(II) in mol l^?1 hypophosphorous acid has been investigated.     

LLX separation of carrier-free,94,95,97,103Ru,93,94,95,96,99mTc and95,96Nb produced in alpha-particle activated molybdenum by TOA

A radiochemical charged particle activation procedure for the simultaneous production of carrier-free radioisotopes of more than one element in a single target and their subsequent separation through LLX has been demonstrated. The carrier free isotopes,^95,96Nb,^{93,94,95,96,99m}Tc and^94,95,97,103Ru formed through Mo(,pxn), Mo(,pxn) and Mo(,xn) nuclear reactions with 40 MeV -particle as detected by nondestructive -ray spectroscopy, have been effectively separated through LLX using TOA as an anionic extractant. Separation of the bulk matrix of molybdenum from the carrier free products has been monitored radiometrically using isotopic^93,99mMo formed through the Mo(,xn) reaction, as radioindicators for the target element. Purity of the separated carrier free radionuclide has been verified by -ray spectrometry.     

Determination of As,Cd, Cu,Hg, Mo,Sb, and Se in biological reference materials by radiochemical neutron activation analysis

The elements As, Cd, Cu, Hg, Mo, Sb, and Se were determined in the biological reference materials (RMs) Bowen's Kale, NIST SRM-1577 Bovine Liver, NIST SRM-1549 Milk Powder, and Versieck's 2nd Generation Biological RM Human Serum using two newly developed radiochemical neutron activation analysis (RNAA) procedures. The first is based on sample decomposition in a mixutre of H₂SO₄+HNO₃+H₂O₂ and simultaneous extraction of the elements As, Cd–In, Cu, Mo, and Sb by 0.025M Zn(DDC)₂ in chloroform from 2–4M H₂SO₄ in the presence of 0.01M KI. The second consists of sample decomposition in HNO₃ in teflon bombs heated at 150°C, Hg extraction by 0.01M Ni(DDC)₂ in chloroform from about 1M HNO₃, and Se precipitation by ascorbic acid from about 1M HClO₄. The RNAA procedures were also used for intercomparison analyses of A and P NIST Leaf Materials (NIST candidate SRM-1515 Apple Leaves and NIST SRM-1547 Peach Leaves, respectively), and CZIM Bovine Liver 12-02-01 RM. Very good agreement of results with certified and/or literature values proved the high accuracy of these determinations by the proposed RNAA procedures, even at the sub-ng/g levels.     

Element Fractionation in Suspended Matter in Landfill Leachate Using Single Extractions

This study presents the determination of the pseudo-total and available element contents in suspended matter in leachate using stripping voltammetry (DPASV) on a hanging mercury drop electrode and an inductively coupled plasma mass spectrometer (ICP-MS). The following elements were studied: Zn, Pb, As, Sb, Co, Cu, Ni, Cr, Sn, Mo and Cd. To determine the pseudo-total metal contents, we applied microwave digestion using a mixture of HNO₃ and HClO₄ with a small quantity of HF. To assess the metal availability from suspended matter in leachate, the single extraction procedure with 0.1mol·L^–1 acetic acid and 0.01mol·L^–1 ammonium acetate was applied. Metal bioavailability based on single extraction with 15% H₂O₂ was determined. We also estimated the association with particular phases of suspended matter in leachate.     

Trace element determination in seawater by ICP-SFMS coupled with a microflow nebulization/desolvation system

Direct and simultaneous determination of Al, Ag, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Pb, Sb, U, V and Zn in diluted (1:10 v:v) seawater from the Antarctic Ocean and the Venice Lagoon at the ng mL^–1 and pg mL^–1 level has been performed by using an inductively coupled plasma sector field mass spectrometer (ICP-SFMS). Samples were analysed by using a PFA microflow nebulizer coupled with a desolvation system or a PFA microflow nebulizer coupled with a Teflon spray chamber, respectively. Measurements were carried out at low (LR, m/m=300), medium (MR, m/m=3,000) and high (HR, m/m=7,500) resolutions depending on the studied isotope. To avoid contamination, sample pre-treatment was carried out in a clean laboratory equipped with a Class 100 vertical laminar flow hood. Concentration ranges (minimum–maximum in ng mL^–1) found in the Antarctic seawater samples (in depth profiles) were: Ag 0.0004–0.0018, As 0.69–1.32, Cd 0.031–0.096, Co 0.018–0.065, Cr 0.18–0.46, Cu 0.04–1.58, Fe 0.13–1.63, Mn 0.02–0.12, Mo 5.97–12.46, Pb 0.007–0.074, Sb 0.033–0.088, U 0.5–1.9, V 0.6–2.5 and Zn 0.16–0.80. Concentration ranges (min–max in ng mL^–1) found in the Venice Lagoon water samples (temporal profile from a benthic chamber experiment) were: Al 0.24–0.61, Ag 0.007–0.031, As 1.42–2.27, Cd 0.050–0.182, Co 0.440–1.461, Cr 0.15–0.34, Cu 0.81–2.46, Fe 0.25–1.66, Mn 11.6–31.7, Mo 6.50–10.6, Pb 0.047–0.225, Sb 0.240–0.492, U 1.7–3.3, V 1.3–2.8 and Zn 5.20–21.5. The detection limits range between 0.06 pg mL^–1 for Ag and U to 15 pg mL^–1 for Fe. In order to check the accuracy of the analytical procedure, measurements of the trace elements in a certified reference material (coastal Atlantic seawater, CASS-4-NRCC) were compared with the certified values. In addition, the results from the Antarctic and Venice Lagoon samples were compared with those obtained by using different analytical techniques.     

Optimierung der l?sungsspektrographischen Methode mit Capillarelektroden

Zusammenfassung Bei der Lösungsspektrographie mit Capillarelektroden wurde der Wechselstromabreißbogen untersucht und dessen Vorteile gezeigt. Mit Hilfe von statistischen Methoden für die Planung extremer Versuche wurden die Arbeitsbedingungen in bezug auf Nachweisvermögen optimiert. Der Einfluß der Probenzusammensetzung wurde durch eine Matrix 2⁴ überprüft. Bei Elementen wie Cd, As, B wurde die Notwendigkeit der Korrelationsspektralanalyse bewiesen (Anwendung einer einfachen Korrektur von Y _Me/Co je nach Anregungsbedingungen).Aufgrund der Untersuchungen wurde eine in bezug auf Nachweisvermögen und Zuverlässigkeit optimierte spektrographische Methode zur Analyse von Al, As, B, Ca, Cd, Cu, Fe, Mg, Mn, Mo, Si, Sr in verschiedenartigen Lösungen ausgearbeitet.

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Optimization of the spectrographic method with capillary electrodes in solution analysis

Summary The possibilities of the interrupted a.c. arc in spectral solution analysis with capillary electrodes are investigated and its advantages are pointed out. With the help of statistic methods for planning of extreme experiments the working conditions are optimized with respect to the detection limit. The influence of the sample content is examined by the matrix 2⁴. With the elements Cd, As and B the necessity of correlation spectral analysis is proved, i. e. by simple correction of Y _Me/Co according to the excitation conditions.On the basis of these investigations a spectrographic method has been developed and optimized with respect to the detection limit and reliability, for the analysis of Al, As, B, Ca, Cd, Cu, Fe, Mg, Mn, Mo, Si, Sr in various solutions.

     

Schwingungsspektren und Normalkoordinatenanalysen der 92Mo-, 100Mo-, 35Cl- und 37Cl-Isotopomeren der Clusteranionen [(Mo6X)Y]2−; Xi = Cl,Br; Ya = F,Cl, Br,I

Vibrational Spectra and Normal Coordinate Analysis of ⁹²Mo, ¹⁰⁰Mo, ³⁵Cl, and ³⁷Cl Isotopomers of the Cluster Anions [(Mo₆X )Y ]^2?; Xⁱ = Cl, Br; Y^a = F, Cl, Br, I The tetrabutylammonium (TBA) salts of the octa-μ₃-halogeno-hexahalogeno-octahedro-hexamolybdate(2 –) anions [(Mo₆X)Y]^2?; Xⁱ = Cl, Br; Y^a = F, Cl, Br, I; have been synthesized using ⁹²Mo, ¹⁰⁰Mo, ³⁵Cl, and ³⁷Cl. The 10 K IR and Raman spectra reveal significant frequency shifts due to the isotopic labelling of the Mo₆ cage, the inner sphere halides X₈ⁱ or the outer sphere ligands Y, respectively. The normal coordinate analysis yields (Mo? Mo) valence force constants of about 1.3 to 1.5 mdyn/Å. For the μ₃-bonded halogenes Clⁱ and Brⁱ valence force constants of 1.1 resp. 1.0 mdyn/Å are calculated. The values for (Mo? Y^a) bonds are found in the usual halide range. The observed isotopic shifts are verified very well by the calculations, allowing detailed assignment of the IR and Raman spectra of these compounds for the first time.     

Amberlite XAD-2 functionalized with 2-aminothiophenol as a new sorbent for on-line preconcentration of cadmium and copper

A new functionalized resin has been applied in an on-line preconcentration system for copper and cadmium determination. Amberlite XAD-2 was functionalized by coupling it to 2-aminothiophenol (AT-XAD) by means of an NN spacer. This resin was packed in a minicolumn and used as sorbent in the on-line system. Metal ions were sorbed in the minicolumn, from which it could be eluted directly to the nebulizer-burner system of the flame atomic absorption spectrometer (FAAS). Elution of Cd(II) and Cu(II) from minicolumn can be made with 0.50 mol l⁻¹ HCl or HNO₃. The enrichment factors obtained were 28 (Cd) and 14 (Cu), for 60 s preconcentration time, and 74 (Cd) and 35 (Cu), if used 180 s preconcentration time. The proposed procedure allowed the determination of cadmium and copper with detection limits of 0.14 and 0.54 μg l⁻¹, respectively, when used preconcentration periods of 180 s. The effects of foreign ions on the adsorption of these metal ions are reported. The validation of the procedure was carried out by analysis of certified reference material. This procedure was applied to cadmium and copper determination in natural, drink and tap water samples.     

Neutron activation analysis techniques for identifying elemental status in Alzheimer's disease

Brain tissue (hippocampus and cerebral cortex) from Alzheimer's disease and control individuals sampled from Eastern Canada and the United Kingdom were analyzed for Ag, Al, As, B, Br, Ca, Cd, Co, Cr, Cs, Cu, Fe, Hg, I, K, La, Mg, Mn, Mo, Ni, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Ti, V and Zn. Neutron activation analysis (thermal and prompt gamma-ray) methods were used. Highly significant differences (probability less than 0.005) for both study areas were shown between Alzheimer's diesease (AD) and control (C) individuals: AD>C for Al, Br, Ca and S, and AD<C for Se, V and Zn. Aluminium content of brain tissue ranged from 3.605 to 21.738 g/g d.w. (AD) and 0.379 to 4.768, g/g d.w. (C). No statistical evidence of aluminium accumulation with age was noted. Possible zinc deficiency (specially for hippocampol tissue), was observed with zinc ranges of 31.42 to 57.91 g/g d.w. (AD) and 37.31 to 87.10 g/g d.w. (C), for Alzheimer's disease patients.     

A kinetic determination of ultramicro quantities of manganese(II), molybdenum(VI) and tungsten(VI) on the basis of their catalytic action on the oxidation of Azorubin S by hydrogen peroxide

Summary A study has been made of the kinetics of catalytic oxidation of Azorubin S by hydrogen peroxide in the presence of Mn(II), Mo(VI) and W(VI) in order to find optimal conditions for the kinetic catalytic determination of these elements. Manganese(II), molybdenum(VI) and tungsten(VI) were determined in the concentration ranges 5.5–33.0×10^–3, 1.3–8.1 and 5.9–44.1g/ml, respectively. Standard deviations were less than 11%. The effect of some foreign ions on these determinations was also investigated.

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Zusammenfassung Die Kinetik der katalytischen Oxydation von Azorubin S mit Wasserstoffperoxid in Anwesenheit von Mn(II), Mo(VI) und W(VI) wurde untersucht, um die optimalen Bedingungen für deren kinetisch-katalytische Bestimmung zu finden. Mn(II) wurde im Konzentrationsbereich von 5,5–33,0×10^–3, Mo(VI) von 1,3–8,1 und W(VI) von 5,9–44,1g/ml mit Standardabweichungen <11% bestimmt. Außerdem wurden einige der möglichen Störungen untersucht.

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This work was presented in part at the 20th Annual Meeting of the Serbian Chemical Society, Belgrade, January 17, 1977.     

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.     

Elemental analysis of selected Indian monazite ores by energy dispersive X-ray fluorescence /EDXRF/ spectroscopy

Analysis by Energy Dispersive X-ray Fluorescence spectroscopy of monazite ores from Kerala /Chavara and Manavalakurichi/, Orissa /Chattrapur/ and Tamil Nadu /Tirunelveli/ has been carried out for the determination of their elemental composition using¹⁰⁹Cd /annular/ and²⁴¹Am /disc/ radioisotope sources. The elements Y, Zr, Mo, Pb, Th and U were analyzed using a¹⁰⁹Cd source, and the elements La, Ce, Pr, Nd, Sm, Gd and Dy were analyzed using the²⁴¹Am source in side source geometry. Quntitative results on these 13 elements present in these ores were obtained by the EDXRF technique. It was seen that despite the diverse geological settings, there is remarkable similarity in the elemental composition of these ores, although some trace elements do show certain variations from sample to sample. These results are presented and discussed in this paper.