Simultaneous determination of antimony,arsenic and copper by neutron activation analysis

A rapid procedure has been developed for the mutual separation of antimony and arsenic using tribenzylamine as the extracting agent. The extraction behaviours of Sb(III), Sb(V), As(III), As(V) and Au(III) have been studied as a function of the acidity of the aqueous phase. Various factors which affect the extraction of these complexes have been studied and optimized. The procedure was then applied to lead base alloy for the simultaneous determination of antimony, arsenic and copper. Chemical recoveries were quantitative and only about one hour is required for the chemical processing of duplicate samples.     

Determination of antimony in tin by radiochemical neutron activation analysis

New types of correction for chemical yield and counting geometry in conjunction with the comparator method provide significant improvements in reproducibility and sensitivity compared to direct neutron activation analysis.     

Simultaneous determination of arsenic and antimony in environmental samples by radiochemical neutron activation analysis

A radiochemical separation procedure using an inorganic exchanger, tin dioxide (TDO), for the separation of arsenic from antimony is reported here. This separation avoids the interference of 564 keV gamma-ray of¹²²Sb in the measurement of the 559 keV gamma-ray of⁷⁶As in neutron activation analysis. Environmental samples, after neutron irradiation and digestion, are taken up in 1M HCl–0.1M HF and passed through a TDO column which selectively retains arsenic. The effluent from the TDO column, after proper conditioning, is passed through an anion exchange column for quantitative retention of antimony. The procedure has been utilized for arsenic and antimony determination in NBS Orchard Leaves and NBS Albacore Tuna.     

A procedure for simultaneous determination of arsenic,cadmium, copper,tin and zinc in beef extract by neutron activation analysis

A radiochemical procedure developed by the authors for neutron activation analysis of As, Cd, Cu, Sn, and Zn in beef extract samples is described, based on combined precipitation steps to isolate the elements to be determined. Nuclides are separated with high degree of purity and good chemical yields. Interferences from threshold reactions are discussed and calculated. Results are shown for analysis of six samples.     

A radiochemical neutron activation analysis method for the determination of total mercury in coal

A radiochemical neutron activation analysis method has been developed based on pyrolysis followed by double gold amalgamation for the determination of mercury in solid samples. Accurate results were obtained for mercury in six standard reference materials of varying matrices, including coal. Linearity was demonstrated up to mercury concentrations of 10,000 ng/g. The method is capable of yielding precise, reproducible values with a detection limit of 5 ng/g for mercury in coal.     

Determination of arsenic and antimony in niobium by radiochemical neutron activation—γ-spectrometry

A method for the determination of arsenic and antimony in niobium, with simultaneous determinations of Au, Cu and Mo, is described. The samples are irradiated for 12 h in a thermal neutron flux of 8 × 10¹³ n cm^-2 s^-1 and then dissolved in hydrofluoric —nitric acid. After addition of various masking agents, and reduction with potassium iodide, As(III) and Sb(III) are extracted with diethylammoniumdiethyldithiocarbamate in chloroform. Before reduction, Au, Cu and Mo can be extracted as dithiocarbamates and determined. For samples of about 100 mg, the limits of detection are 10 pg g^-1 for As, 20 pg g^-1 for Sb, 0.8 pg g^-1 for Au, 10 pg g^-1 for Cu and 25 ng g^-1 for Mo. Results are given for niobium samples of different grades of purity.     

Determination of copper,lead, tin and antimony by controlled-potential electrolysis : General method of analysis

A controlled-potential electrolysis method is described, by means of which it is possible to deposit copper, lead, tin and antimony from the same solution in successive stages. The behaviour of each metal during deposition as well as the best working conditions are discussed. The determinations are not affected by moderate amounts of Ni, Zn, Mn, Fe, Al     

A rapid radiochemical method for antimony and arsenic : Development and testing of the method

The formation of stibine and arsine by flash electrolysis is applied to the rapid separation of radioactive isotopes of antimony and arsenic from a mixture of fission products. A chemical yield of 45% for both antimony and arsenic was achieved in 10 sec. The conditions necessary for the clean separation of antimony and arsenic from one another and from other fission products are described. The method proved successful both in the laboratory and in a nuclear reactor.     

Substoichiometric determination of Hg by radiochemical neutron activation analysis

A rapid method has been developed for the determination of mercury in environmental samples by thermal neutron activation analysis. Radiochemical separation involves the extraction of Hg/II/ with substoichiometric amounts of 2-mercaptobenzothiazole /2-HMBT/ into chloroform¹. The time required for radiochemical purification and counting of two samples and a standard is about 2 h. Water, sludge and IAEA standard samples were analyzed for Hg concentration by this method.     

A radiochemical method for neutron activation analysis of arsenic in biological samples and its potential use in epidemiology studies

Epidemiology studies that examine As toxicity rely on the accurate measurement of As in biological matrices to determine exposure. Accurate measurement of As in biological matrices is challenging by instrumental NAA due to the production of high and variable activities of ²⁴Na, ¹²²Sb and ⁸²Br which contribute to increased background and difficulty quantifying the ⁷⁶As peak at 559 keV. This paper describes a novel radiochemical NAA method for As analysis in biological matrices. Samples were irradiated at the University of Missouri Research Reactor in a flux of 6.5E + 13 n/cm²/s. Following irradiation samples were transferred to polypropylene tubes with As carrier and digested using a combination of nitric acid and hydrogen peroxide. Arsenic was separated by absorption on magnetite nanocyrstals followed by vacuum filtration. Samples were counted using an automated sample changer and HPGe detector with a Canberra Lynx digital signal analyzer. The accuracy and precision of the RNAA results were evaluated by measuring As in NIST SRM 1575 Pine Needles, 1571 Orchard Leaves, 1566 Oyster Tissue, 1577 Bovine Liver, and NCS DC 73347 Hair. Arsenic was measured in duplicate nail samples by instrumental neutron activation analysis followed by radiochemical neutron activation analysis.     

Application of hydride generation for the determination of antimony and arsenic in biological material by neutron activation analysis

A rapid and sensitive procedure for the determination of antimony and arsenic in biological material is described. It is based on thermal neutron activation to ¹²²Sb (t_{$\text{1}\text{2}$} = 2.7 d) and ⁷⁶As (t_{$\text{1}\text{2}$} = 26.4 h), dry ashing with magnesium nitrate as the oxidizing agent and volatilization of the hydrides which are collected on an active carbon trap. This carbon adsorber is counted. The limit of determination is 5 ng g^-1 for both elements.     

Detection of arsenic, antimony and tin in forensic toxicology by paper chromatography

Summary A paper chromatographic technique for the detection of arsenic, antimony and tin as applied to toxicological analysis has been described.     

Measurement uncertainty of iodine determination in radiochemical neutron activation analysis

The measurement uncertainty of iodine determination in NIST standard reference material (SRM) 1549 using radiochemical neutron activation analysis (RNAA) was studied. This method is based on ignition of the irradiated sample [¹²⁷I(n,)¹²⁸I, t_1/2=25 min, E=422.9 keV] in an oxygen atmosphere, followed by absorption of iodine in a reducing acid solution and its purification by a selective extraction–stripping–reextraction cycle. The purified solution of iodine in CHCl₃ was transferred to a well-type HPGe detector for -ray measurement of the induced radionuclide ¹²⁸I. The detection limit of the method employed under the conditions described was 1 ng/g. The reproducibility of iodine determination in the SRM was 3.6% (12 determinations within 1 month), calculated by the analysis of variance procedure. Using the commercially available software program GUM Workbench and the recommendations of the Eurachem/CITAC Guide, we evaluated the uncertainty budget for this RNAA method and the relative uncertainty obtained was 3.6%. The largest uncertainty contributions were due to the repeatability of the chemical yield determination, the count rate of the induced nuclide in the standard and sample, the mass of the carrier and the mass of the irradiation standard.     

Simultaneous determination of trace uranium and thorium by radiochemical neutron activation analysis

A method for the simultaneous, radiochemical neutron activation analysis of uranium and thorium at trace levels in biological materials is described, based on a technique known as LICSIR, in which a double neutron irradiation is employed. In the first, long irradiation²³³Pa (27.0 d) is induced by neutron capture on²³²Th and then the sample is cooled for several weeks. A second short irradiation to induce²³⁹U (23.5 m) is followed by a rapid sequential radiochemical separation by solvent extraction of²³⁹U with TBP and²³³Pa with TOPO. Chemical yields of²³⁹U and²³³Pa were measured for each sample aliquot using added²³⁵U and²³¹Pa tracers from the -spectra of the separated fractions. The technique was validated by quality control analyses.     

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.     

The atomic absorption determination of antimony,arsenic, bismuth, cadmium, lead, and tin in iron, copper,and zinc alloys with the graphite furnace

Antimony, arsenic, bismuth, cadmium, lead, and tin can be determined in metallurgical samples by flame atomic absorption spectrometry at levels of 0.005 wt%, but lower concentrations frequently necessitate preconcentration. The graphite furnace allows determination of these elements at concentrations 1–2 orders of magnitude lower than is possible with flame techniques. All six elements have detection limits at or below 1μg g⁻¹ in a variety of alloys. Calibration for antimony and load was done with standards containing the principal component of the alloy as a synthetic matrix. Bismuth, cadmium, and tin could be determined accurately only by the standard addition method. Arsenic could be determined in iron alloys with synthetic standards, but standard additions were required for copper alloys.     

电位溶出分析法同时测定锡, 铅, 铜

本文应用电位溶出分析法进行同时测定锡、铅和铜的研究。结果发现在草酸溶液中锡、铅和铜有分离清晰的平台,其溶出讯号与浓度呈线性关系,可用于定量分析。用这一方法测定了某些罐头食品中痕量锡、铅和铜,获得满意的结果。     

Determination of copper in high-purity tin by reactor neutron activation analysis

For the determination of very low concentrations of copper in tin, an analytical method involving reactor neutron activation was developed whereby the copper activity was separated from the tin matrix by extraction of the Cu(I) cuproin complex in n-amyl alcohol. A new decontamination technique was sought in order to remove the copper contamination present on the tin surface. Pre-irradiation removal of the tin surface combined with post-irradiation etching appeared to be the most efficient.