Simultaneous third-derivative spectrophotometric determination of copper and nickel in iron alloys and aluminium alloy

A method is proposed for the simultaneous determination of copper and nickel by third-derivative spectrophotometry based on the absorption spectra of their complexes with cyanide ion in the ultraviolet range. The method allows the determination of 0.55-5.8 mug/ml of copper and 0.55-6.8 mug/ml of nickel. The relative standard deviation for 11 determinations of 1.5 mul/ml of copper and nickel were 0.78 and 0.72%, respectively. The detection limits were 0.10,mug/ml for nickel and 0.13 mug/ml for copper. The method has been applied to direct determination of copper and nickel in iron alloys and an aluminium alloy without any separation.     

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 zirconium and aluminium in alloys slags and fumes by 14-mev neutron activation analysis

Aluminium and zirconium have beendetermined in alloys, slags and fumes by 14-MeV neutron activation analysis. Nuclear reactions with zirconium have been investigated, and the radioisotopes produced by 14-MeV neutron activation have been determined. The results for alloys and slags agree well with those obtained by chemical methods; precisions of 1.8% were obtained in ideal cases. The neutron activation method is capable of analysing 10–12 samples, in duplicate, per man-day.     

The determination of carbon in aluminium by deuteron activation analysis

Carbon can be determined in aluminium by deuteron activation analysis via the ¹²C(d, n)¹³N reaction. ¹³N is separated from other activities by steam distillation. A carbon concentration of 0.25 μgg^-1 with a standard deviation of 0.05 μg g^-1 was obtained for aluminium of 99.5% purity.     

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.     

Determination of sulphur in fly ash by instrumental proton activation analysis

A method for the determination of sulphur in fly ash by instrumental proton activation analysis using the³⁴S/p,n/^34mCl reaction was developed. The 2128.5 keV and 3305.0 keV -rays of^34mCl /t=32.0 min/ were measured on a Ge/Li/ -spectrometer, shielded with a lead absorber to attenuate low energy -rays. Irradiation and measuring conditions were optimized. The detection limit for instrumental analysis is 0.3 to 1 mg g^–1 and the standard deviation is cca. 4% for a typical sample.     

Determination of copper in zinc by proton activation analysis

A method for the determination of copper in zinc by proton activation analysis using the⁶³Cu(p, n)⁶³Zn reaction has been developed.⁶³Zn has to be separated chemically from gallium and copper activities formed out of the zinc matrix and from indium activity formed out of cadnium impurity. Gallium radionuclides are retained on a cation exchanger in chloride medium and the residual activity is extracted in di-isopropyl ether. Copper and indium are subsequently extracted with cupferron in chloroform. The method was applied to BCR reference materials with a copper concentration at the μg.g^?1 level. The detection limit amounts to 0.5 μg.g^?1.     

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.     

Proton activation analysis for chromium,nickel and copper

Proton activation analysis has been applied to develop a procedure for the simultaneous determination of chromium, nickel and copper. The procedure involves the bombardment of the sample with protons to induce⁵²Cr(p, n)^52mMn,⁶⁰Ni(p, n)⁶⁰Cu and⁶³Cu(p, n)⁶³Zn reactions. These reactions have been studied for proton energies from 11 MeV to 15 MeV. Thick target yields for the production of the indicator radionuclides as well as the sensitivities of the determination have been measured in this energy region and are compared with results obtained for other charged particle induced reactions. Detailed data are given on nuclear and instrumental interferences. The trace elements have been determined nondestructively and simultaneously in cobalt with a relative precision of 8 to 15%.     

Spectrophotometric simultaneous determination of cobalt, copper and nickel using nitroso-R-salt in alloys by partial least squares

Partial least squares modeling as a powerful multivariate statistical tool applied to spectrophotometric simultaneous determination of cobalt, copper, and nickel in aqueous solutions. The concentration range for cobalt, copper and nickel were 0.4-2.6, 0.6-3.4, 0.5-5.5 ppm, respectively. The experimental calibration set was composed with 36 sample solutions using a mixture design for three component mixtures. The absorption spectra were recorded from 470 to 600 nm. The effect of pH on the sensitivity and selectivity was studied according to net analyte signal (NAS). The values of root mean square difference (RMSD) for cobalt, copper and nickel using partial least squares (PLS) were 0.0192, 0.0263 and 0.0446 ppm, respectively. The effects of various cations and anions were investigated. The method was used to determination of cobalt, copper and nickel in two sample alloys based on copper, nickel and cobalt (known as cunico) and based on cobalt, nickel and iron (known as conife).     

Determination of chromium,iron and copper in niobium by radiochemical proton activation analysis

Chromium, iron and copper were determined in niobium by radiochemical proton activation analysis (PAA). The main steps of the technique involved the irradiation of the samples with 13 MeV protons, the post-irradiation decontamination of the sample surface, a two-step separation procedure based on anion exchange from HF and HCl medium, and counting the separated indicator radionuclides with a well-type NaI detector. For a 5-hr irradiation, limits of detection for chromium, iron, and copper were 0.2, 5.0, and 15 ppb respectively. The results obtained by this technique are compared with data obtained by radiochemical neutron activation analysis (NAA) and atomic absorption spectrometry (AAS).     

Simultaneous determination of aluminium and phosphorus by neutron activation analysis

With the use of the pneumatic tube system of the BER II reactor, the irradiation position of which is equipped with a movable cadmium shield, the aluminium and phosphorus levels in bone powder and in human bone biopsies were determined. The contribution of aluminium and phosphorus to the²⁸Al activity could be separated mathematically after the samples had been irradiated with and without cadmium shielding. The sensitivity and limit of quantitative determination of the analytical procedure were determined using the addition method and the fact that the levels of each element measured was independent of the amount of the other element was proved.     

The determination of oxygen in copper by α-particle activation analysis

The determination of oxygen in copper by activation analysis with 45-MeV α-particles is described. The chemical separation of ¹⁸F produced from oxygen consists of steam distillation as fluosilicic acid, followed by precipitation of the interfering gallium activities as the hydroxide and of the fluoride as lead chlorofluoride or of cation exchange followed by lead chlorofluoride precipitation. This allows a total decontamination from matrix radiation in excess of 10⁶. As standard, mica foils are used, while, for the purp?ose of flux monitoring, the activity induced in a thin copper or mica foil, placed before the sample is counted. Alternatively, the intensity of the particle beam is measured. The method, which allows determination of oxygen at the 1 μg g^-1 level with a precision of about 10%, is applied to the determination of a concentration of 1.2 μg g^-1. Analysis of a reference material containing 70 μg O g^-1 proves the accuracy of the standardization methods applied.     

The determination of lead in environmental and geological materials by proton activation analysis

Lead is determined in environmental samples and in rocks using the^206,207,208Pb(p,xn)²⁰⁶Bi reaction. Bismuth is separated by anion exchange or by extraction with antimony diethyldithiocarbamate. Sources of errors such as volatilization of the matrix due to heating during the irradiation, variations of the abundance of the lead isotopes and the standardization were studied in detail. For concentrations between 11 mg/g and 3.7 g/g the relative standard deviation ranges from 2.6 to 5.4%. The detection limit is 10 ng/g.     

Simultaneous determination of iron,cadmium and lead in zinc by proton activation analysis

Iron, cadmium and lead are determined in zinc by proton activation followed by chemical separation of the indicator radionuclides. The method provides detection limits of 0.03, 0.008 ad 0.1 μg g^?1 for iron, cadmium and lead, respectively. The BCR Unalloyed Zinc reference material 321 was analysed. Concentrations of 2.23, 0.215 and 4.641 μg g^? with 1–7% relative standard deviation were obtained for iron, cadmium and lead, respectively. These results contributed to the provisional certification of the reference material.     

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.     

The determination of silver in aluminium alloys by atomic absorption spectroscopy

Atomic absorption spectroscopy is used to determine silver in aluminium alloys. The effects of the presence of alloying elements are discussed. The developed procedure is simple and rapid, and results obtained on various samples show satisfactory agreement with those obtained by the normal volumetric procedure.