Determination of indium,copper and nickel in glassmaking materials and NBS standard reference materials by substoichiometric radioactivation analysis

The paper describes a method of radioactivation analysis for the determination of indium, copper and nickel. In the determination of indium, ordinary and displacement substoichiometries were applied for glassmaking materials while ordinary substoichiometry was applied for NBS standard reference materials. Copper and nickel in glassmaking materials and NBS standard reference materials were also determined by the displacement and ordinary substoichiometries. Indium contents in glassmaking materials by the two methods agreed with each other. The analytical results of indium, copper and nickel in NBS' SRM were also in good agreement with published values and certified values by NBS.     

Trace determination of iron,cobalt, nickel and copper in zirconium fluoride by substoichiometric radioactivation analysis

Trace amounts of transition elements (Fe, Co, Ni and Cu) in zirconium fluoride and NBS SRM's were determined by substoichiometric radioactivation analysis. The contents of impurities in sublimed sample were less than those of high-purity material and of reagent grade. The detection limits of these elements in zirconium fluoride were 10 ng/g for iron, 0.01 ng/g for cobalt, 1 ng/g for nickel and 0.1 ng/g for copper. The analytical results for iron, cobalt, nickel and copper in NBS SRM's were in good agreement with certified values.     

Subtoichiometric determination of indium and tin by radioactivation analysis

A method of radioactivation analysis has been developed for the determination of indium and tin. It is based on substoichiometric extraction of indium diethyldithiocarbamate into carbon tetrachloride from a slightly ammoniacal solution in the presence of potassium cyanide. With this method, indium can be determined via^116m In (T=54 min) and tin via^113m In (T=104 min) which is formed by the reaction¹¹²Sn(n, ψ)¹¹³Sn. The method has been applied to the determination of indium in metallic zinc and of tin in tin-doped gallium arsenide, and 0.4 ppb of indium was analyzed in a zinc sample.     

Determination of indium in metallic tin and cadmium by substoichiometric neutron activation analysis

The paper deseribes the determination of indium in metallic tin and cadmium metals by the direct method, which is a variant of substoichiometric radioactivation analysis. It is based on substoichiometric extraction of indium diethyldithiocarbamate into carbon tetrachloride. Indium in tin metal was determined by^116mIn (T=54 min), while^115mIn (T=4.5 h), formed by the reaction¹¹⁴Cd(n, γ)¹¹⁵Cd was used for cadmium samples. The irradiated sample was dissolved and the radioactivity of^116mIn or^115mIn, A, was measured. After the separation of indium from the matrix, a known amount of indium, m, was separated substoichiometrically and the radioactivity, a, was measured. Indium was calculated as M_x=m A/a. If a known amount of the element, M, is added to the irradiated sample in advance, the equation for calculation is given as M_x-m A/a−M. By this method, indium can be determined without any consideration of self-shielding and secondary nuclear reaction of the matrix.     

Determination of iron in biological material by substoichiometric isotopic-dilution analysis

Iron is determined in biological material by wet oxidation, in the presence of (59)Fe tracer, extraction of iron(III) chloride into isopropyl methyl ketone, stripping with nitric acid, and substoichiometric separation of the Fe-EDTA complex on a cation-exchanger. The precision is good and the method has been applied to analysis of standard kale and blood.     

Certified reference material for the quality control of cadmium,copper nickel and zinc determination in estuarine water (CRM 505)

Analyses of estuarine water samples are routinely carried out by a number of laboratories to monitor the level of environmental contamination by toxic substances, e.g. heavy metals. A series of interlaboratory studies has been organised by the Community Bureau of Reference, BCR (now renamed Standards, Measurements and Testing Programme) to improve the quality of the determinations of selected trace metals in estuarine water samples. The improvement achieved allowed to produce a reference material (CRM 505) which was certified for its content of Cd, Cu, Ni and Zn. Further improvements were considered to be necessary for the certification of other trace elements, e.g. Pb. This material was collected in the Tagus Estuary, carefully prepared (filtered and acidified) and its homogeneity and long term stability were verified. This paper presents the work performed for the certification of Cd, Cu, Ni and Zn. Indicative values are reported for As, Co, Fe, Mn, Pb and V.     

Certified reference material for the quality control of cadmium, copper nickel and zinc determination in estuarine water (CRM 505)

Analyses of estuarine water samples are routinely carried out by a number of laboratories to monitor the level of environmental contamination by toxic substances, e.g. heavy metals. A series of interlaboratory studies has been organised by the Community Bureau of Reference, BCR (now renamed Standards, Measurements and Testing Programme) to improve the quality of the determinations of selected trace metals in estuarine water samples. The improvement achieved allowed to produce a reference material (CRM 505) which was certified for its content of Cd, Cu, Ni and Zn. Further improvements were considered to be necessary for the certification of other trace elements, e.g. Pb. This material was collected in the Tagus Estuary, carefully prepared (filtered and acidified) and its homogeneity and long term stability were verified. This paper presents the work performed for the certification of Cd, Cu, Ni and Zn. Indicative values are reported for As, Co, Fe, Mn, Pb and V.     

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).     

Continuous spectrophotometric determination of copper, nickel and zinc in copper-base alloys by flow-injection analysis

Flow-injection methods have been developed for the determination of copper, nickel and zinc in copper-base alloys, including several types of brasses, deoxidized copper, beryllium copper and German silver. The system for copper and nickel involves the measurement of the absorbance of the copper(II) and nickel(II) aquo-complexes at 805 and 410 nm, respectively, after simple dissolution of the sample in a nitric acid-phosphoric acid mixture. The system needs no further reagents and the sample solutions can be analysed at rates of up to 280 /hr for copper (or nickel in German silver) without any carry-over. The system for zinc consists of automatic dilution of the injected sample with a thiosulphate-acetate buffer solution and the subsequent measurement of the absorbance of the zinc-Xylenol Orange complex at 568 nm. This system permits analysis rates of up to 90/hr for zinc solutions, with no carry-over. The procedures have been applied to standard copper-base alloys. The results agreed satisfactorily with the certified values. The precision ranges are 0.2-0.7% for copper and nickel and 0.5-0.8% for zinc.     

The determination of sulphur in copper,nickel and aluminium alloys by proton activation analysis

The ³⁴S(p, n)^34mCl reaction induced by 13-MeV protons is used for the determination of sulphur in copper, nickel and aluminium alloys. The ^34mCl is separated by repeated precipitation as silver chloride. The results obtained were 3.08 ± 0.47, 1.47 ± 0.17 and <1μg g^-1 for copper, nickel and aluminium alloys, respectively.     

Determination of micro-amounts of indium in zinc and in gallium by radioactivation

Summary A method was developed to determine micro-amounts of indium in zinc and in gallium by radioactivation analysis, using 1 g Ra-Be as thermalneutron source. By activation of an amount of 10 g metallic zinc during 5 hours and counting the activity in a well-type NaI-scintillation counter, 17.4 counts per sec. per 10 g Zn were obtained. This activity is practically entirely due to the 13.8 h.⁶⁹Zn, the 52-mn isotope being a pure-emitter.By activation of indium in the same conditions the¹¹⁶In, 54-mn isotope, gives a counting rate of 28.9 counts per second per 10 mg metal, so that it was possible to determine amounts of indium in zinc, using 10 g samples varying from 0.004% to 0.16% with a mean error of 2.3%, without chemical separation. To determine trace amounts of Indium in Gallium by activation at the same conditions as described above, it was necessary to carry out a chemical separation. 1 g metallic Ga gave indeed rise to an activity of 115 counts per second, mainly due to the 14.1-h.⁷²Ga. The activation of the Ga-In samples was therefore carried out in an aqueous solution of their sulfates. After activation, potassium iodide and sulfuric acid were added as to obtain a 2 M solution of HI. The indium iodide was then extracted with diethyl ether and the ethereal solution introduced in a vial fitting the well-type crystal. Using 0.5-g Ga samples it was possible to determine indium amounts down to 0.2 mg, with a mean error of about 5%.

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Zusammenfassung Eine Methode zur Bestimmung kleiner Mengen Indium in Zink und in Gallium durch Aktivierungsanalyse wurde unter Verbindung von 1 g Ra-Be als thermische Neutronenquelle entwickelt. Nach Aktivierung von 10 g metallischem Zink durch 5 Stunden und Bestimmung der Aktivität in einem becherförmigen NaJ-Szintillationszähler wurden 17,4 Stöße pro Sekunde pro 10 g Zn beobachtet. Diese Aktivität kommt praktisch völlig dem⁶⁹Zn von der Halbwertszeit 13,8 Stunden zu, da das Isotop mit der Halbwertszeit 52 Minuten ein reiner-Strahler ist.Durch Aktivierung von Indium unter den gleichen Bedingungen gibt¹¹⁶In mit der Halbwertszeit 54 Minuten 28,9 Stöße pro Sekunde für 10 mg Metall, so daß es möglich war, unter Verwendung von 10 g Zink Indiummengen zwischen 0,004% und 0,16% mit einem mittleren Fehler von 2,3% ohne vorhergehende chemische Trennung darin zu bestimmen. Zur Bestimmung von Indiumspuren in Gallium durch Aktivierung unter den gleichen Bedingungen war es notwendig, eine chemische Trennungsmethode auszuarbeiten. 1 g metallisches Gallium zeigte tatsächlich einen Anstieg der Aktivität auf 115 Stöße pro Sekunde pro 1 g, die vor allem dem⁷²Ga der Halbwertszeit 14,1 Stunden zukommt. Die Aktivierung der Ga-In-Proben wurde daher in einer wäßrigen Lösung ihrer Sulfate durchgeführt. Nach der Aktivierung wurde Kaliumjodid und Schwefelsäure bis zu 2-m Konzentration an Jodwasserstoff zugesetzt. Das Indiumjodid wurde dann mit Diäthyläther extrahiert und die ätherische Lösung in eine dem becherförmigen Kristall angepaßte Schale gebracht. Unter Verwendung von 0,5 g Gallium war es möglich, Indiummengen bis herab zu 0,2 mg mit einem mittleren Fehler von etwa 5% zu bestimmen.

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Résumé On a mis au point une méthode de microdosage de 1'indium dans le zinc et le gallium par radioactivation à l'aide d'une source de neutrons thermiques de 1 g de Ra-Be. Après irradiation de 10 g de zinc métallique pendant 5 heures, on a compté 17,4 coups par seconde lors de la mesure de l'activité dans un compteur à scintillations à cristal creux d'iodure de sodium. Pratiquement, cette activité est entièrement due au⁶⁹Zn de période 13,8 h, son isotope de période 52 mn étant un émetteur-pur.Lorsqu'on active l'indium dans les mêmes conditions, l'isotope¹¹⁶In de période 54 mn donne au compteur 28.9 coups par seconde pour 10 mg de métal de sorte qu'il est possible de déterminer la teneur en indium du zinc sur des échantillons de 10 g pour des valeurs variant de 0,004% à 0 16%, avec une erreur moyenne de 2,3% et sans séparation chimique. Pour effectuer le dosage de traces d'indium dans le gallium par application de la même méthode d'activation, il est nécessaire d'effectuer une séparation chimique. 1 g de gallium métallique donne en effet naissance à une activité de 115 coups par seconde qui sont principalement dûs à l'isotope⁷²Ga de période 14,1 h. En conséquence, l'activation des échantillons de Ga-In a été effectuée dans une solution aqueuse des sulfates de ces métaux. Après activation, on ajoute de l'iodure de potassium et de l'acide sulfurique de façon à obtenir une solution 2 M d'acide iodhydrique. L'iodure d'indium est alors extrait dans l'éther diéthylique et la solution éthérée est introduite dans une fiole s'ajustant dans le cristal creux. En employant des échantillons de gallium de 0,5 g, il a été possible de déterminer des quantités d'indium de 0,2 mg avec une erreur moyenne d'environ 5%.

     

Substoichiometric determination of trace impurities in high-purity materials by radioactivation analysis

The substoichiometric determination of some impurities in gallium arsenide and selenium supplied by OEC and IUPAC, respectively, as reference materials for radioactivation analysis is described.     

Simultaneous determination of copper,mercury and antimony in biological samples by neutron activation and substoichiometric extraction

A simple and accurate method has been developed for the determination of copper, mercury and antimony by thermal neutron activation analysis involving substoichiometric extraction technique. The results of analysis indicate that copper, mercury and antimony in biological samples can be determined with an accuracy of 5.3%, 5.5% and 6.2%, respectively. Two samples and a standard can be analysed by the proposed method in about 4 hrs. Part of this work was presented at the International Conference on Modern Trends in Activation Analysis, Saclay, Paris, France, October 2–6, 1972.     

Determination of copper in biological samples by substoichiometric neutron activation analysis

A method has been described for the determination of trace amounts of copper in biological samples by thermal neutron activation analysis, involving radiochemical separation of copper from irradiated matrix employing substoichiometric extraction of Cu/II/ with 2-mercaptobenzothiazole /2-HMBT/ into chloroform. 4.01 g of Cu/II/ can be determined with an accuracy of 3.13% and precision of 1.08%.     

Determination of uranium in NBS biological standard reference materials by delayed neutron assay

Uranium was measured in eight biological standards at the part-per-billion level. Matrix effects encountered in the use of liquid standards are discussed. This work performed under auspices of the U.S. Department of Energy     

锌电解液中痕量铜、镉、镍和钴的快速同时测定

研究了丁二酮肟 氨 氯化铵 柠檬酸钠 明胶 抗坏血酸体系中Cu(Ⅱ )、Cd(Ⅱ )、Ni(Ⅱ )和Co(Ⅱ )的络合物吸附波 ,建立了同时、快速测定锌电解溶液中这些痕量元素的新方法。Cu(Ⅱ )、Cd(Ⅱ )、Ni(Ⅱ )和Co(Ⅱ )分别在 - 0 44V、- 0 76V、- 1 0 7V和 - 1 2 4V左右产生灵敏的络合物吸附波。信噪比为 3时 ,其检测限分别为 1 0× 1 0 - 8mol/L、1 3× 1 0 - 8mol/L、2 9× 1 0 - 1 0 mol/L和 3 6×1 0 - 1 1 mol/L。铜、镉、镍和钴的浓度分别为 2 0× 1 0 - 8mol/L～ 2 0× 1 0 - 5 mol/L、3 0× 1 0 - 8mol/L～ 3 0× 1 0 - 5mol/L、5 4× 1 0 - 1 0 mol/L～ 5 4× 1 0 - 7mol/L和 6 8× 1 0 - 1 1 mol/L～ 6 8× 1 0 - 8mol/L时 ,与相应峰电流之间有良好的线性关系。方法已用于锌电解液中铜、镉、镍和钴的快速同时测定 ,相对标准偏差分别小于或等于 4 7%、5 1 %、4 9%和 5 3 %。     

PAN as a reagent for the substoichiometric determination of nickel and manganese

The possibility of using PAN as a reagent for the substoichiometric determination of nickel and manganese has been investigated. Nickel forms a 11 red colour and manganese a 12 wine red colour complex with PAN, which are extractable into chloroform at pH 5.5 and 9.1, respectively. Tens of micrograms of Ni/II/ and Mn/II/ were determined with an accuracy 0.5% and ±0.2%, respectively. The effect of various metal ions was also studied.     

Simultaneous determination of copper, cadmium and nickel by ratio derivative polarography

Ternary mixtures of metals can be resolved by using the ratio derivative polarography without the need for any pre-separation step. The method is based on the simultaneous use of the first derivative of ratios of polarograms and measurements of zero-crossing potentials. The polarogram of the mixture is obtained and the amplitudes of the current at appropriate potentials are divided by the corresponding amplitudes in the polarogram of a standard solution of one of the components, and the subsequent derivation against potential results to the first derivative of the ratio polarogram. The concentrations of the other two components are then determined from their respective calibration graphs established by measuring the ratio derivative analytical signal at the selected zero-crossing points. The method has been successfully applied for resolving ternary mixtures of copper, cadmium and nickel, which have overlapped polarograms in pH 2.87 Britton-Robinson buffer. The concentration ranges to be determined are 0.30-1.40 mg l(-1) for copper, 0.90-4.50 mg l(-1) for cadmium and 0.20-1.20 mg l(-1) for nickel, and the recoveries are 88.3-101.9% for copper, 92.2-105.4% for cadmium and 95.0-107.0% for nickel.