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.     

Rapid determination of copper in plants by neutron activation analysis

A rapid and simple neutron-activation analysis method has been developed for the determination of copper in plant leaves. Irradiated samples are dissolved in a mixture of fuming nitric acid, 70% perchloric acid and concentrated sulphuric acid in the presence of copper carrier solution. The copper in the resulting solution is extracted as copper cupferronate into chloroform and back-extracted into concentrated ammonia solution. The copper is precipitated as sulphide with 3% aqueous thioacetanude solution and the precipitate is dissolved in nitric acid. The induced activity of copper-64 in the resulting solution is counted with a 400-channel analyser. The photopeak of the annihilation energy of copper-64 at 0.51 MeV is compared with that of a copper standard processed in the same manner. After counting, the chemical yield of the separated copper is found by re-irradiating aliquots of the copper nitrate solution and comparing the induced activity of coppcr-66 at 1.04 MeV with that of another standard processed in a similar manner. The time required to complete the analysis, including the second irradiation and all radioactivity measurements, is about 25 min. The accuracy of the method was checked by analysing a biological standard of known copper content. The proposed method was successfully applied to the determination of copper in the leaves of 10 different plants (copper content 4-30 ppm).     

Simultaneous determination of copper,manganese, zinc and sodium in plant materials by neutron activation analysis

Neutron activation analysis has been used for the simultaneous determination of Cu, Mn, Zn and Na in plant materials. The heterocyclic dye PAN has been applied as a chelating agent to achieve the group chemical separation of Mn, Cu, Ni and Zn. Various factors which affect the formation and extraction of the PAN-metal chelates have been studied and optimized, using suitable aqueous solutions to selectively strip these elements from the organic phase. This procedure has been applied to the determination of these elements in ‘Bowen’s Kale’ and U.S. NBS Citrus-leaves and Tomatoleaves samples.     

Substoichiometric determination of rhenium in copper ores and molybdenum concentrates by neutron activation analysis

A simple and rapid substoichiometric method is described for the estimation of rhenium in copper ores and molybdenum concentrates by neutron activation analysis. 2 μg of Re can be determined with an accuracy of 4%. The variation of the mean at 95% confidence limit does not exceed 2%. The time required for processing three samples is less than 60 min.     

P538萃取法从铂、钯、铑和铱混合物中纯化铑的研究

提出了从PT,Pd,Rh和Ir的混合物中纯化Rh的P538萃取法,首先将Rh(III)转化为水合阳离子,然后用P538的煤油溶液将其萃取到有机相,仍处于阴离子状态的Pt,Pd和Ir则留在水相,一次萃取Rh的直收率可达95%以上,Pt,Pd和Ir的萃取率在1%以下。     

The determination of sampling constants by neutron activation analysis

It has been found that sampling constants vary greatly not only from major elements to trace elements, but also between individual trace elements. A comprehensive investigation of a potential reference material therefore requires the determination of sampling constants for all elements to be certified, and other analytical methods therefore have to be included. For methods in statistical control the described strategy can be applied.     

The determination of bromine in rocks by neutron activation analysis

A neutron activation method for the determination of bromine in rocks and minerals is described. After removal of iodine, bromine is separated by oxidation with potassium permanganate and extraction with carbon tetrachloride. Bromine is thon precipitated as silver bromide; yields are from 60 to 84%. The method has a sensitivity of 0.001 p.p.m. of bromine and is free from interfering reactions. The values obtained for G-1 and W-1, 0.484 and 0.490 p.p.m. of bromine respectively, are lower than the average values for granites and basalts previously reported.     

Multielemental determination in water by neutron activation analysis

Instrumental neutron activation analysis (INAA) technique has been applied to a water sample to determine the elemental concentrations. The sample was irradiated at a neutron flux of 1.2·10¹² n·cm^–2·s^–1 for two different periods followed by counting at three different decay times, using two coaxial type high-resolution Ge(Li) detectors. The dominant elements detected in the water sample are Ca, Cl, Na, Mg, and K present in levels while Co, I, Mn, Sm, and Sb are present in smaller amounts approximately on the average 0.01 ppm. Only traces of other elements such as rare-earth elements, Ag, As, Ba, Cu, Cd, Fe, Sr, W, Zn, seem to be present in the water samples.     

The determination of rhenium in flue dust by neutron activation analysis

Rhenium was determined by radiochemical neutron activation analysis in flue dust samples of complex chemical composition. Two separation techniques were used; distillation from perchloric-hydrochloric acid solution and hydroxide scavenging followed by extraction with tetraphenylarsonium chloride in chloroform. ¹⁸⁶Re and ¹⁸⁸Re were measured with a Ge(Li) low-energy photon detector. Chemical yields were determined by reactivation. For a neutron flux of 5·10¹¹ n cm^-2 s^-1, an irradiation time of 6 h and samples of ca. l g, down to 50 p.p.b. of rhenium could be determined.     

The determination of iodide in sea water by neutron activation analysis

A simple and sensitive method for the determination of iodide in sea water by neutron activation analysis has been developed. Iodide is separated from most other anions by passing sea water through a strongly basic anion-exchange column, recovered by elution with 2 M sodium nitrate, and concentrated from the eluate by precipitation as palladium(II) iodide in the presence of excess of palladium(II) with elemental palladium as carrier; elemental palladium is generated by reduction of some of the palladium(II) with thiosulfate. The precipitate is separated from the supernatant liquid by filtration. Checks on the efficiency of separation by means of added ¹²⁵I showed recoveries of 100 ± 3 %. The filter paper containing the precipitate is pressed into a pellet for neutron activation analysis by irradiation for 5 min at a flux of 4 ·10¹² n cm^?2 s^?1 and counting the ¹²⁸I 442.7-keV photopeak.     

The determination of nickel in air dust by neutron activation analysis

The determination of nickel in atmospheric aerosols, collected on filter paper, is performed by thermal neutron activation analysis using the⁶⁵Ni (T=2.56 h) isotope. Liquid-liquid extraction and anion-exchange are applied in the chemical separation. The absolute sensitivity of the method is ≌0.02 μg Ni. The relative sensitivity is 0.005 μg Ni/m³ if an air sample of about 1000 m³ is used.     

The determination of fluorine in bone by fast neutron activation analysis

A routine method is presented for the determination of fluorine in small bone samples by activation analysis with fast conversion neutrons. Both the purely instrumental determination and the analysis by chemical separation are discussed. The activations are performed with the AVF cyclotron of Philips-Duphar at Petten. Use was made of a rabbit system equipped with a Be-target, which can be inserted in the internally deflected beam of the cyclotron. The sensitivity of the instrumental method is ≈1 μg. Application of chemical isolation results in a sensitivity of ≈0.1 μg.     

The determination of uranium and thorium in rocks by neutron activation analysis

A neutron activation method is described for the determination of thorium and uranium in rocks at the microgram and submicrogram levels. Radiochemical separations are carried out using the alpha-active nuclides protactinium-231 and neptunium-237 as tracers. The method is applied to the Standard granite XXX and the standard diabase XXX.     

The determination of sulphur and phosphorus in steel by neutron activation analysis

Sulphur and phosphorus in steel were determined by neutron activation analysis, being counted as ³⁵S and ³²P respectively. For steels with sulphur to phosphorus ratios larger than 10, it seems possible to determine both elements by counting ³²P, making use of a double irradiation technique at different fast to slow neutron fluxes.     

Substoichiometric determination of tungsten by neutron activation analysis

A method for the substoichiometric determination of tungsten by thermal neutron activation analysis has been developed based on the selective extraction of the tungsten dithiol complex into amyl acetate. The method is simple, rapid and accurate. It has been used in the determination of tungsten in alloy steel, meteorites and biological standard kale.     

Substoichiometric determination of gold by neutron activation analysis

A rapid method has been developed for the determination of gold in catalyst samples by thermal neutron-activation analysis incorporating substoichiometric solvent extraction of Au/III/ with 1,2,3-benzotriazole /1,2,3-BT/ into n-butanol. The time required for radiochemical purification and counting of two samples and a standard was 1 h.     

Substoichiometric determination of Cd by neutron activation analysis

A rapid method has been developed for the determination of cadmium in environmental samples by thermal neutron activation analysis involving substoichiometric extraction with 1,2,3-benzotriazole /1,2,3-BT/. Cd was radiochemically separated as CdS using 1-amidino-2-thiourea. The time required for radiochemical purification containing two samples and a standard was about 2 h. 4.63 g of Cd can be determined with an accuracy of 6.69% and precision of 6.25%. Mash potatoes, animal bones, raw sludge and cattle manure have been analyzed by this method.     

Substoichiometric determination of chromium by neutron activation analysis

A method of radioactivation analysis has been developed for the determination of chromium. It is based on the substoichiometric extraction of chromium diethyldithio-carbamate into methyl-isobutyl-ketone from acetate buffer solution in the presence of EDTA and potassium cyanide. The method has been applied for the determination of chromium in high-purity calcium carbonate and NBS glasses as standard reference materials.     

Substoichiometric determination of palladium by neutron activation analysis

A method is described for the substoichiometric determination of traces of palladium by neutron activation analysis involving the extraction of palladium with isonitrosoacetophenone. The sensitivity of the method is 0.005 μg of Pd. With 200 mg of silver alloy containing 0.0005% palladium, the average of three determinations of Pd is 0.98 μg, which varies between 1.07 μg and 0.91 μg at 95% confidence limit. The time required for radiochemical purification and counting of the sample does not exceed 12 minutes. Part of this work was presented at the International Conference on Modern Trends Activation Analysis, held in Gaithersburg, Maryland, USA, October 7–11, 1968.     

Substoichiometric determination of mercury by neutron activation analysis

A method has been developed for the substoichiometric determination of mercury by thermal neutron activation analysis, based on the selective extraction of the Hg(II)—Bindschedler's Green complex into 1,2-dichloroethane. The method has been applied for the determination of trace amounts of mercury in geological standards such as W-1, GR, Sye-1, and T-1, meteorite Allende de Publito, and biological materials such as kale, IR1 standard tobacco, and human blood serum.