In vivo activation analysis of organ cadmium using the Tsing Hua Mobile Educational Reactor

This work describes a nuclear facility forin vivo prompt gamma activation analysis (IVPGAA) using a moderated neutron beam from a 0.1 W Tsing-Hua Mobile Educational Reactor (THMER). The IVPGAA measurement is a new technique for toxic cadmium determination in organs, which can efficiently be used in clinical diagnosis. The low-power nuclear reactor provides a total neutron flux of 3.3·10⁴ n·cm^–2·s^–1 on the surface of the central vertical neutron beam tube to which a liquid phantom is positioned. The capability of such partial-body irradiation facility is demonstrated. The detection limit of cadmium in the left kidney for a skin dose equivalent of 1.66 mSv (166 mrem) was 1.34 mg in a 500-s irradiation/counting period, and the sensitivity in the left kidney was 103 counts mg^–1·mSv^–1. The performance of IVPGAA system using the THMER nuclear facility therefore has the advantages of mobility and feasibility with high sensitivity under low neutron and gamma doses.     

Spectrophotometric determination of trace amounts of cadmium using Cd(II)-KI-Crystal violet system in the presence of triton X-100 and PVA

A new highly sensitive spectrophotometric method for determination traces of cadmium using Cd-(II)-KI-Crystal Violet system in the presence of Triton X-100-poly(vinyl) alcohol (PVA) mixture has been developed. The apparent molar absorptivity of the system is 1.77 × 10⁵ 1-mol^–1 cm^–1 and its Sandell's sensitivity is 6.35 × 10^–4 g·Cd·cm^2–. Beer's law is obeyed up to 0.32 g·Cd(II)·ml^–1. The method has been applied to determine Cd(II) in waste water, rice and pork meat samples with satisfactory results.     

Spectrophotometric extractive determination of Ti in mineral samples and aluminium alloys as a mixed-ligand Ti(IV)-salicylhydroxamic acid-thiocyanate complex

A sensitive method for the determination of titanium, based on the formation of a mixed-ligand Ti (IV)-salicylhydroxamic acid-thiocyanate complex and extraction of this into a liquid ion-exchanger phase has been developed. The extract has maximum absorbance at 400–460 nm and the apparent molar absorptivity is 1.8 × 10⁴l · mole^–1 · cm^–1 at 420 nm. The system obeys Beer's law at 420 nm in the range 0.16–3.20 mg/1 Ti, the detection limit being 0.1 mg/1. The method is found suitable for determination of titanium in aluminium alloys and silicate rocks.     

Amperometrische Untersuchungen von Cadmiumpolyvanadaten und polarographische Bestimmung ihrer Löslichkeiten

Zusammenfassung Die Bildung und Zusammensetzung von Cadmiumvanadaten, die man durch Wechselwirkung von Cadmiumsulfat mit verschiedenen Alkalivanadaten (ortho-, pyro-, meta- und poly-) erhält, wurde durch amperometrische Titration der Reaktanten bei verschiedenen Konzentrationen untersucht. Die gut definierten Knicke der Titrationskurven liefern eindeutige Beweise für die Bildung von Cadmiumorthovanadat (3 CdO·V₂O₅) und Cadmiumpyrovanadat (2 CdO·V₂O₅) in den pH-Bereichen 7,5–8,5 bzw. 6,5–7,5. Es zeigte sich, daß die Fällung von Cadmium-orthovanadat fast quantitativ, und die amperometrische Titration eine einfache und rasche Methode zur Bestimmung von Vanadium(V) in Lösungen geeigneter Konzentration ist. Die Löslichkeiten von Cadmium-orthovanadat und-pyrovanadat wurden polarographisch bei 37°C zu 1,90·10^–2 g/l bzw. 4,10·10^–2 g/l bestimmt.

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Amperometric investigations of Cd polyvanadates; polarographic determination of their solubilities

The formation and composition of cadmium vanadates obtained by the interaction of cadmium sulphate and different alkali vanadates (ortho-, pyro-, meta- and poly-) have been investigated by means of amperometric titrations of the reactants at several concentrations. The well defined breaks in the titration curves provide cogent evidence for the formation of cadmium orthovanadate (3 CdO·V₂O₅) and cadmium pyrovanadate (2 CdO·V₂O₅) in the pH ranges 7.5–8.5 and 6.5–7.5 respectively. The precipitation of cadmium orthovanadate has been found to be almost quantitative and the amperometric titration offer a simple and rapid method for the determination of vanadium(V) in solution at suitable concentrations. The solubilities of cadmium orthovanadate and cadmium pyrovanadate have been determined polarographically at 37°C and are found to be 1.90·10^–2 g/l and 4.10·10^–2 g/l resp.

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Mit 1 Abbildung     

Solubility of particulate cadmium sulfide at pH=1–14: A radiotracer study

Cadmium sulfide particles were prepared by precipitation from acid solution. A radiotracer technique with¹⁰⁹Cd was applied to measure the solubility of cadmium sulfide at various pH's. Filtration, centrifugation, ultracentrifugation, and dialysis were used to separate the particles from the solution. Only the last two techniques proved to be successful. The solubility of cadmium sulfide in water (pH=7) is found to be: 7.9·10^–5 mol·l^–1 in contrast with the literature value of 9.0·10^–6 mol·l^–1. At low pH (1–4), the solubility agrees fairly well with the solubility calculated on the basis of generally accepted values for the solubility product and for the various complex formation constants, while at high pH (4–14) the solubility is higher than expected.     

Characterization of an epithermal irradiation facility

An epithermal energy neutron irradiation facility has been used to perform instrumental activation analysis for iodine, silicon, nickel, zirconium, uranium and thorium. The facility, which is adjacent to the fuel of the University of Virginia 2.0 MW pool reactor, consists of a dry sample region surrounded by a fixed cadmium shield. A boron nitride capsule can be used to hold the sample in the cadmium facility to further enhance the reduction of thermal neutron activation. The neutron fluence rate is 2.2×10¹⁶ n·m^–2·s^–1 for fission spectrum energy neutrons (measured with Ni(n,p)Co) and 8.2·10¹⁵ n·m^–2·s^–1 for resonance energy neutrons (measured with gold).Iodine has been measured at concentrations as low as 0.1 mg/kg with 3% counting statistics in powdered infant formula and 0.15 mg/kg with 5% statistics in liquid infant formula. Silicon has been measured at concentrations of 0.2% in biological samples with counting statistics between 5 and 10% and in coal and soil at concentrations greater than 4% with better than 1% statistics. Nickel has been measured in coal and soil at the 20 mg/kg level and higher with 6% statistics. Zirconium has been determined at 600 mg/kg and greater in ceramics with counting errors less than 3%. Uranium and thorium have been measured at the 10 mg/kg level with 3% counting statistics.     

Spectrophotometric determination of cadmium with 1-[(5-chloro-2-pyridyl)azo]-2-naphthol

Summary Cadmium(II) reacts with l-[(5-chloro-2-pyridyl)azo]-2-naphthol (5-C1--PAN) in aqueous solution; the complex can be extracted with chloroform at pH 9–11 to give a red solution with an absorption peak at 566 nm. The colour in chloroform is stable and the system conforms to Beer's law; optimal range in the chloroform layer for measurement at 1.00-cm cells is 0.1–1 ppm cadmium. Common cations and anions do not interfere. Large amounts of some cations can be masked by potassium cyanide, the cadmium cyanide complex being demasked by formaldehyde. The proposed method is one of the most sensitive procedure for the determination of cadmium. The molar absorptivity in the chloroform extract is 6.6· 10⁴ 1 mole^–1 cm^–2 at 566 nm.

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Zusammenfassung Cadmium reagiert mit 1-(5-Chlor-2-pyridyl) azo-2-naphthol, 5-C1--PAN, in wäßriger Lösung; der rote Komplex kann bei pH 9–11 mit Chloroform extrahiert werden und hat ein Absorptionsmaximum bei 566 nm. Die chloroformische Lösung ist stabil und entspricht dem Beerschen Gesetz; für die Messung in l-cm-Küvetten eignen sich am besten 0,1–1 ppm Cd. Übliche Ionen stören nicht. Große Mengen einiger Kationen können mit KCN maskiert werden, wahrend [Cd(CN)₄]^2– von Formaldehyd gespalten wird. Die vorgeschlagene Methode ist eine der empfindlichsten für die Bestimmung von Cd. Die molare Extinktion des chloroformischen Extraktes betragt bei 566 nm 6,6 · 10⁴ 1 · mol^–1 · cm^–2.

     

A simplified polarographic determination of dissolved Cd(II) at the 10?10 M level

Summary To simplify the determination of dissolved Cd(II) in water and sea water-like solutions at the 10^–10–10^–9 M level an automated concentration step was developed consisting of percolating about 21 of sample over a column with an immobilized reagent (ED₃A) and dissolving the trapped cadmium in 0.1 M nitric acid. A concentration factor of 50 or more is easily obtained. Recoveries are about 90%. With anodic stripping differential pulse polarography as a final determination technique overall standard deviations are in the range of 0.1–0.4·10^–10 Mol of Cd.On leave from Lisbon University, Portugal     

Low level measurements of thorium and neptunium in environmental samples using the (γ, f) reaction

A new highly sensitive track method for the determination of thorium (²³²Th) and neptunium (²³⁷Np) has been developed. The technique includes the radiochemical separation procedure of the isotopes followed by the irradiation of the resultant samples on the MT-25 microtron. The detection limit is équivalent up to 3·10^–13 g of²³²Th and 7·10^–14 of²³⁷Np. The method was used to determine²³²Th and²³⁷Np isotopes in water samples.     

Determination of thorium by adsorptive type chemically modified electrode with a polycomplex system

A preconcentration and determination method for thorium in aqueous solution with a tri-n-octylphosphine oxide modified glassy carbon electrode is proposed. In the presence of 2-thenoyltrifluoroacetone, thorium in NaAc-HAc supporting electrolyte is preconcentrated on a modified rotating disk electrode, and a highly sensitive reduction peak is obtained by cathodic stripping voltammetry at –1.10 V versus Ag/AgCl. A linear response of reduction peak height and concentration is observed for 1.15×10^–9–1.44×10^–8 mol·1^–1 of thorium and the detection limit is 1.0×10^–9mol·1^–1. It is very selective and sensitive, with a standard deviation of 3.4% and a recovery of 90–110%.     

Extraction-spectrophotometric determination of uranium(VI) with PAR and N-octylacetamide

A new and simple method for selective spectrophotometric determination of uranium(VI) with 4-(2-pyridylazo)resorcinol (PAR) and N-octylacetamide into benzene over pH 7.0–9.0 is described. The molar absorptivity of the complex with 9 different amides is in the range of (0.40–3.2)·10⁴ 1·mol^–1·cm^–1 at the absorption maximum. Out of these, the most sensitive compound N-octylacetamide (OAA) was chosen for detailed studies in the present investigation. The detection limit of the method is 0.008 g U·ml^–1. The system obeys Beer's law in the range of 0–5 g U·ml^–1. The method is free from interferences of most of the common metal ions except vanadium(V) and copper(II), which are masked by proper masking agents. The composition of the complex is determined by curve-fitting method. The method has been applied for the recovery of the metal from rock samples and synthetic mixtures.     

137Cs in Biota and Sediment Samples from Turkish Coast of the Black Sea, 1997–1998

During the periods of 1997–1998, macroalgae, sea snail, mussel, fish and sediment samples were collected from different stations at Turkish Black Sea coast in order to determine activity levels of ¹³⁷Cs radionuclide. ¹³⁷Cs activity in the tested algae species and in soft parts of mussel and sea snail, were found to be below the lower limit of detection. On the other hand, the ¹³⁷Cs concentration in muscle tissue of the sea snail samples were found from 6±2 to 19±7 Bq·kg^–1 dry weight. The range of the ¹³⁷Cs concentration in anchovy fish muscles were found between 4±2 – 10±5 Bq·kg^–1 dry weight. The ¹³⁷Cs concentration in the whiting fish muscle was found below the lower limit of detection. However, this activity found in shad fish muscle to be 25±10 Bq·kg^–1 dry weight. The concentrationsof the ¹³⁷Cs activity in the sediment samples proved that the eastern region of the Black Sea was affected by Chernobyl at a very high degree compared with the western part. The measured ²³⁸U, ²³²Th and ⁴⁰K concentrations in sediment samples are within the range of the cited values in the previous works at the Turkish Black Sea coast.     

Measurement of Phosphorus in Metals by RNAA

An RNAA procedure has been developed for measurement of low-level phosphorus in metals. Samples are irradiated at a neutron flux of 2.7·10¹³ n·cm^–2·s^–1 then mixed with carrier and dissolved in acid. After chemical separation and purification of the phosphorus and gravimetric determination of carrier yield, ³²P is determined using a beta proportional counter. The detection limit for a 0.1 g sample irradiated for 30 minutes is 5 g/kg. The method has been used to determine 6.4±0.6 mg/kg phosphorus in SRM 2175 refractory alloy.     

The preparation and characterization of mono- and bis-chelated cadmium(II) complexes of the di-2-pyridylketone Schiff base of S-methyldithiocarbazate (Hdpksme) and the X-ray crystal structure of the [Cd(dpksme)2] · 0.5 MeOH complex

New cadmium(II) complexes of empirical formulae, [Cd(dpksme)X] (dpksme = anionic form of the Schiff base; X = NCS^–, Cl^–, I^–) and [Cd(dpksme)₂] · 0.5MeOH, respectively have been prepared and characterized. The mono-ligated cadmium(II) complexes, [Cd(dpksme)X] are four-coordinate and tetrahedral but the bis-ligand complex, [Cd(dpksme)₂] · 0.5MeOH is six-coordinate and octahedral. The crystal and molecular structure of [Cd(dpksme)₂] · 0.5MeOH has been determined by X-ray diffraction. The complex has a distorted mer-octahedral structure in which the ligands are coordinated as uninegatively charged tridentate chelating agents via the pyridine nitrogen atoms, the azomethine nitrogen atoms and the thiolate sulfur atoms. The distortion from regular octahedral geometry is ascribed to the restricted bite angles of the ligands. The Schiff base and its cadmium(II) complexes exhibit mild antibacterial activities against Shigella dysenteriae, Bacillus cereus, Staphylococcus aureus and Escherichia coli. They are also mildly fungitoxic against the phytopathogenic fungi, Alternaria alternata and Macrophomina phaseolina.     

A kinetic method of determination of cobalt in zinc and cadmium selenide

Summary A kinetic method of cobalt determination has been applied for the determination of this element in zinc and cadmium selenides. The method is based on the catalytic effect of cobalt on the oxidation of Direct Blue 6B (C. I. 24410) by hydrogen peroxide at pH=10.8 and in the presence of tiron as an activator. The trace amounts of cobalt have been separated from the bulk zink and cadmium by means of the ion exchanger Lewatit 5080. In samples of 20–100 mg cobalt can be determined in the range of 7.1·10^–5%–2.4·10^–4%.

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Eine kinetische Methode zur Bestimmung von Kobalt in Zink- und Cadmiumselenid

Zusammenfassung Das Verfahren beruht auf dem katalytischen Effekt von Kobalt bei der Oxydation von Direkt Blau 6B (C. I. 24410) durch Wasserstoffperoxid bei pH 10,8 in Gegenwart von Tiron als Aktivator. Die Kobaltspuren wurden von der Hauptmenge Zink und Cadmium mit Hilfe des Ionenaustauschers Lewatit 5080 abgetrennt. In 20–100 mg Probe kann Kobalt in Mengen von 7,1·10^-5 bis 2,4·10^–4% bestimmt werden.

     

Determination of boron in high-purity silicon and trichlorosilane indirectly by measurement of cadmium in tris (1,10-phenanthroline) cadmium tetrafluoroborate

Summary An indirect method has been developed for the determination of boron in high-purity silicon materials, based on the reaction of tetrafluoroborate ion (BF ₄ ^– ) with tris(1,10-phenanthroline)cadmium reagent (Cd(Ph) ₃ ²⁺ ) to form the tris(1,10-phenanthroline)cadmium tetrafluoroborate (Cd(Ph)₃ · 2BF₄) ion-association complex, followed by spectroscopic or radiometric determination of the cadmium in the product complex. The optimal conditions for the separation of B from the silicon matrix, the transformation of B to BF ₄ ^– , the reaction of Cd(Ph) ₃ ²⁺ and BF₄ to Cd(Ph)₃ · 2BF₄, the separation of the complex from unreacted Cd(Ph) ₃ ²⁺ by solvent extraction have all been investigated in detail. Two methods, radio-reagent and GFAAS, have been used for the indirect determination of B in the complex. When the B content is plotted against the radioactivity of ¹¹⁵Cd(Ph)₃ · 2BF₄ in the organic phase, a linear relationship persists down to 20 ng; whereas the application of GFAAS to the determination of Cd in the complex, results in a determination limit of 5 ng for B. The limit of detection of this method is obviously decided by the blank value introduced by the contaminants from the reagents, container surfaces, etc. and, more seriously, by the incomplete separation of unreacted reagent Cd(Ph) ₃ ²⁺ from the complex. The method developed has been applied to the determination of B in various silicons.

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Indirekte Borbestimmung in hochreinem Silicium und Trichlorsilan durch Bestimmung des Cadmiums in Tris (1,10-phenanthrolin)-cadmiumtetrafluoroborat

Zusammenfassung Die empfohlene indirekte Borbestimmung beruht auf der Reaktion von Tetrafluoroboration (BF ₄ ^– ) mit Tris(1, 10-phenanthrolin)-cadmium-Reagens (Cd(Ph) ₃ ²⁺ ) zum Ionenassoziationskomplex Cd(Ph₃) · 2BF₄ und nachfolgender Bestimmung des Cadmiums (spektrometrisch oder radiometrisch) in diesem Komplex. Die optimalen Bedingungen zur Abtrennung des Bors von der Siliciummatrix, zur Umsetzung von B zu BF ₄ ^– , für die Reaktion zum Komplex sowie die Abtrennung des Komplexes von nicht umgesetztem Cd(Ph) ₃ ²⁺ durch Flüssigextraktion wurden im einzelnen untersucht. Radiometrie und Graphitofen-AAS wurden zur Bestimmung eingesetzt. Eine lineare Abhängigkeit des B-Gehaltes von der Radioaktivität des ¹¹⁵Cd(Ph)₃ · 2BF₄ wurde bis herab zu 20 ng festgestellt. bei Anwendung der Graphitofen-AAS ergab sich eine Nachweisgrenze von 5 ng B. Die Nachweisgrenze wird entscheidend beeinflußt durch eingeschleppte Verunreinigungen aus den Reagentien, Gefäßwänden usw., mehr noch durch die unvollständige Abtrennung nicht umgesetzten Reagenses vom Komplex. Das ausgearbeitete Verfahren wurde für die Borbestimmung in verschiedenen Si-Proben angewendet.

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Presented at the 9th International Symposium on Microchemical Techniques, Amsterdam, August 28–September 2, 1983     

Spectrophotometric and first-derivative spectrophotometric determination of cadmium witho-hydroxybenzenediazoaminoazobenzene (HDAA)

The synthesis ofo-hydroxybenzenediazoaminoazobenzene (HDAA) is described. Cadmium forms with HDAA in the presence of Triton X-100 a 13 complex, which gives a maximum absorption at 520nm with an apparent molar absorptivity of 1.97 × 10⁵1 · mol^–1 · cm^–1 in pH 10 borax buffer solution and 1.52 × 10⁵1 · mol^–1 · cm^–1 in ammoniacal medium. In both media, Beer's law is followed in the range of 0 –10 g of cadmium in 25ml of solution and the coefficients of variation do not exceed 1.5%. A derivative method has been employed to determine cadmium in certain waste water samples without separation.     

A Catalytic Method for Determining Cadmium(II), Nickel(II), and Zinc(II) Inhibitor Metals

The inhibitory effect of Cd(II), Ni(II), and Zn(II) on the oxidation of 3,3′,5,5′ -tetramethylbenzidine with periodate was detected. The optimum reaction conditions were found, and the procedures were developed for determining 1 × 10⁻² to 10 μg/mL Cd(II), Ni(II), and Zn(II) in solution. The indicator reaction was performed on a number of supports. The maximum inhibitory effect was observed on silica gel-based plates for TLC. Procedures for determining 6 × 10⁻³ to 0.4 μg of these metals were developed. Silica gel plates with the immobilized reagent for cadmium (bromobenzothiazo) were used to preconcentrate cadmium. A selective test procedure was developed for determining 1 × 10⁻⁴ −3 × 10⁻³ μg/mL cadmium with the visual detection of the process rate. Upon the introduction of dimethylglyoxime into the indicator reaction, the inhibitory effect of nickel changed to its promoting effect and the detection limit for nickel was lowered. A procedure was developed for determining 3 × 10⁻⁴ −3 × 10⁻³ μg/mL nickel in solution and 7 × 10⁻³−4 × 10⁻¹ μg nickel on the surface of Sorbfil plates. An assumption was made about the reasons for the inhibitory effect of metal ions on the oxidation of aryl diamines with periodate.__________Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 6, 2005, pp. 662–669.Original Russian Text Copyright © 2005 by Beklemishev, Kiryushchenkov, Stoyan, Dolmanova.     

Inverse Pulspolarographie am h?ngenden Quecksilbertropfen

Zusammenfassung Die inverse Voltammetrie am hängenden Quecksilbertropfen mit pulspolarographischer Aufzeichnung der anodischen Auflösungsströme wird auf ihre Leistungsfähigkeit untersucht. 10^–9 M Lösungen von Cu, Pb, Cd, Zn können im Routinebetrieb analysiert werden. In Alkalisalzmatrices sind Direktbestimmungen der Schwermetalle im 10^–7 bis 10^–8%-Bereich möglich. Die Nachweisgrenze für Cd beträgt 5 · 10^–11 Mol/l. Die Empfindlichkeit der Methode wird mit derjenigen verwandter voltammetrischer Verfahren verglichen.

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Anodic stripping pulse polarography at the hanging mercury drop electrodeDetermination of Cu, Pb, Cd and Zn

The efficiency of anodic stripping pulse polarography at the H.M.D.E. is tested. In routine work the analysis of 10^–9 M solutions of Cu, Pb, Cd, Zn offers no difficulty. The determination of the elements in alkali salts in the 10^–7 to 10^–8% range is possible. The detection limit for Cd was found to be 5×10^–11 M. The sensitivity of the method was compared with those of related voltammetric techniques.

     

Polarographic study of a triazolobenzodiazepine: Estazolam

Summary The polarographic behaviour of 8-chloro-6-phenyl-4H-s-triazolo(4,3-a)-(1,4)-benzodiazepine (estazolam) was studied in the pH range 3–10. The reduction process is irreversible and the current is diffusion-controlled. The linear relationship between current and estazolam concentration permits its polarographic determination in the range 3.4·10^–7–1.0·10^–4 M. The detection limit was 1.7·10^–7 M. The reproducibility of the method in terms of its relative standard deviation was 1.00% and 1.14% using ten determinations at the 2.4·10^–5 M and 3.4·10^–6 M levels respectively.

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Polarographische Untersuchung des Triazolbenzodiazepins Estazolam