Depth profiling by ARXPS in surface analysis

A method of nondestructive depth profiling in near surface regions of solids is described. Models have been discussed from which algorithms for evaluation of measured data are obtained. The algorithms, based on standard profiles with free parameters, have been adjusted to the data resulting from angle resolved XPS (ARXPS) by means of least squares fits. Depth profile analyses and segregation studies were performed on Pt-Ni and Fe-S specimens.     

Depth profiling by ARXPS in surface analysis

A method of nondestructive depth profiling in near surface regions of solids is described. Models have been discussed from which algorithms for evaluation of measured data are obtained. The algorithms, based on standard profiles with free parameters, have been adjusted to the data resulting from angle resolved XPS (ARXPS) by means of least squares fits. Depth profile analyses and segregation studies were performed on Pt–Ni and Fe–S specimens.     

Determination of depth profiling of metal trace impurities on Si surface using total reflection X-ray fluorescence

Summary Total reflection X-ray fluorescence (TXRF) is used for non-destructive determination of depth profiling. A numerical processing is presented as impurity quantification in the continuum excitation TXRF without using standards. Dependences of concentration of impurities on depths ranging from a few tens to thousands Angströms are given for Fe and Cu on Si-wafer. The detection limits are in the range of 10¹⁰ atoms/cm². The method was checked with Secondary Ion Mass Spectrometry (SIMS) and the agreement is reasonably good.     

Solid-liquid extraction as a preconcentration technique in trace element analysis Extraction of trace impurities from metal chlorides

Microgram quantities of iron, cobalt, copper, zinc and cadmium are extracted with various aqueous, organic and mixed solvents from chlorides of sodium, potassium, nickel, cadmium, barium and lead prepared by evaporation of aqueous sample solutions. An ultrasonic field accelerates the extraction, and satisfactory trace recoveries and separation factors are achieved in several systems within a reasonable time. The application to a polarographic determination and a two-stage separation technique are also described.     

ICP-MS法测定金属镝中的非稀土杂质

用ICP-MS法对高纯金属镝中10种非稀土杂质Al、Fe、Ni、Ti、Co、Cd、Mn、Pb、Cu、Ba、Mg的测定进行了研究。估算了元素的测定下限；研究了酸度影响；并进行了不同方法的结果对照实验；采用In作内标，方法的加标回收率在80.5%-110.2%之间，相对标准偏差低于12%。     

高纯二氧化锗中痕量杂质的ICP-MS法测定

建立了高纯二氧化锗中痕量杂质Mg、Al、Ni、Cu、Zn、In、Pb的ICP-MS测定方法。选择了仪器最佳工作条件,研究了锗基体对被测元素的干扰,方法回收率为94％～114％,RSD为11．1％～57％。     

Depth profiling in surface regions of oxidized metal alloys by low energy PIXE

As a nondestructive technique for depth profiling of elements the PIXE-method was applied to determine the concentration profile of elements in the near surface of oxidized metal alloys. The outer region of about 1 m was investigated using low energy protons for X-ray excitation. A set of X-ray yield measurements was carried out at proton energies of 150 to 300 keV. The unfolding of the X-ray yields was performed by calculation of proton energy loss, X-ray production cross section and X-ray attenuation.     

Determination of trace impurities in rhodium metal by destructive and non-destructive neutron activation analysis

Trace amounts of Ir, Au, Cu, Pd and Pt were determined in rhodium metal by instrumental neutron activation analysis with Ge(Li) spectrometry as well as by the radiochemical version of the method. The latter was based on a specially developed procedure of the dissolution of Rh, followed by group separation with the aid of ion exchange chromatography. The results obtained by destructive and non-destructive methods are critically discussed and compared. Special attention was paid to self-shielding effect and an accurate method of the correction of this effect is presented.     

Automated matrix separation and preconcentration for the trace level determination of metal impurities in ultrapure inorganic salts by high-resolution ICP-MS

A rapid and simple analytical method for the determination of transition metals and rare earth elements at sub-ng/g levels in alkaline and earth alkaline salt matrices was developed. Automated solid-phase extraction was utilized for matrix separation and analyte preconcentration from highly concentrated brine solutions. The HPLC system used was equipped with a chelation column packed with an iminodiacetate-based resin. Detection was accomplished by means of high-resolution inductively-coupled plasma mass spectrometry (ICP-MS), which allowed quasi-simultaneous multi-element determinations. A microconcentric nebulizer was employed for HR-ICP-MS to determine the elements of interest in small volumes of sample extracts. The method was shown to be very sensitive with limits of quantification in the range of 1–40 ng/g for all investigated elements. The method exhibited excellent precisions, high analyte recoveries, linear responses of least three orders of magnitude, high accuracy and low contamination susceptibility. A comparison of automated solid-phase extraction with methodologies utilizing traditional liquid-liquid extraction showed that the former offered similar analytical performance but was clearly easier to use and faster to perform, resulting in substantial time, labor and cost savings.     

Automated matrix separation and preconcentration for the trace level determination of metal impurities in ultrapure inorganic salts by high-resolution ICP-MS

A rapid and simple analytical method for the determination of transition metals and rare earth elements at sub-ng/g levels in alkaline and earth alkaline salt matrices was developed. Automated solid-phase extraction was utilized for matrix separation and analyte preconcentration from highly concentrated brine solutions. The HPLC system used was equipped with a chelation column packed with an iminodiacetate-based resin. Detection was accomplished by means of high-resolution inductively-coupled plasma mass spectrometry (ICP-MS), which allowed quasi-simultaneous multi-element determinations. A microconcentric nebulizer was employed for HR-ICP-MS to determine the elements of interest in small volumes of sample extracts. The method was shown to be very sensitive with limits of quantification in the range of 1–40 ng/g for all investigated elements. The method exhibited excellent precisions, high analyte recoveries, linear responses of least three orders of magnitude, high accuracy and low contamination susceptibility. A comparison of automated solid-phase extraction with methodologies utilizing traditional liquid-liquid extraction showed that the former offered similar analytical performance but was clearly easier to use and faster to perform, resulting in substantial time, labor and cost savings. Received: 12 February 1999 / Revised: 23 March 1999 / Accepted: 25 March 1999     

ICP-MS法测定电子级高纯硝酸中的金属杂质

用ICP-MS的不同状态（标准状态、冷等离子体技术、碰撞池技术）直接测定电子级高纯硝酸中的34个痕量金属杂质,用铟作内标可补偿基体效应,方法检出限为0.1-70ng/L,加标回收费率为90%-110%,相对标准偏差为4.0%,样品测定结果与ICP-AES测定结果基本一致。     

Determination of trace impurities in palladium by neutron activation analysis

Trace amounts of Ir, Au, Ag, Pt, Zn, Mn, and Cu were determined in high purity palladium by destructive and instrumental neutron activation analysis (NAA). The latter version of NAA was employed for the determination of Ir, Au and Ag. Special attention was paid to a new non-destructive method for the determination of silver traces in palladium. The results obtained by both versions of NAA are critically discussed and compared.     

Determination of trace impurities in tin by neutron activation analysis

Two methods are described to determine indium and managenese in high-purity tin. In the first method indium and manganese are separated from the tin and antimony matrix activities on Dowex 1X8 anion exchanger. Tin and antimony are adsorbed in 10M HF while indium and manganese are eluted. In the second method the incident γ-ray intensity due to the tin matrix is reduced by placing a lead absorber between the sample and the detector. The reproducibility and the sensitivity of both methods are of the order of 10 ppb for manganese and of 1 ppb for indium for 1 g samples and a neutron flux of 10¹¹ n·cm⁻²·sec⁻¹. Aspirant of the N. F. W. O.     

Determination of trace impurities in tin by neutron activation analysis

Arsenic, selenium and antimony were determined in four different tin samples. After distillation from HBr?H₂SO₄ medium arsenic and selenium were precipitated with thioacetamide, and antimony was subsequently separated by deposition on iron powder. The separated samples were counted on a high-resolution Ge(Li) γ-spectrometer. The sensitivity of the method is highly satisfactory.     

Study of trace impurities in heroin by neutron activation analysis

Sixty-two heroin samples were analyzed for their contents of 15 trace elements (Au, Ba, Br, Ca, Ce, Co, Cr, Fe, La, Na, Sb, Sc, Sm, Th, and Zn) by neutron activation analysis (NAA). Large variations of elemental concentrations between samples were found to possess statistical significance. Of all the elements calcium was the most abundant element, followed by zinc and sodium. The concentrations of Au, Ce, Co, La, Sb, Sc, Sm, and Th in all the samples were below 1 mg·g⁻¹. Classification of these heroin samples was achieved by the application of hierarchical cluster analysis. The results show that NAA can provide useful information on the origin of the illicit drugs. This revised version was published online in July 2006 with corrections to the Cover Date.     

Determination of trace impurities in platinum by neutron activation analysis

Determination of trace impurities in platinum by neutron activation analysis was carried ont by combining the advantages of ion exchange chromatography and Ge(Li spectrometry. Owing to the development of a new ion exchange separation scheme which assures high decontamination factors with respect to matrix activities and practically quantitative yields, ppm and sub ppm amounts of Au, Cu, Ir, K, La, Mn, Pd and Zn were determined in 10 mg samples of pure platinum metal. No determinations of the chemical yield were necessary. Several other elements could be determined, if present, without essentially changing the procedure.     

Determination of trace level impurities in uranium compounds by ICP-AES after organic extraction

The determination was studied of Al, B, Be, Cd, Ca, Co, Cu, Mg, Mn, Mo, Pb, Si, Sn, V, Cr, Ni, and Fe as trace level impurities in uranium compounds by ICP-AES after extraction of uranium with three different mixtures of di-(2-ethyl-hexyl) phosphate (D2EHP) and tri-(2-ethyl-hexyl)-phosphate (T2EHP) in solvents like toluene, carbon tetrachloride, hexane and cyclohexane. The study was carried out in presence of different concentrations of HCl and HNO₃. A single extraction with D2EHP in cyclohexane using nitric acid as matrix was sufficient to reduce the U₃O₈ concentration from 100 g/l to 100 g/ml. The ICP-AES instrumentation applied, allowed the determination of metal concentrations ten-times lower than those usually found in nuclear grade U₃O₈. To check the efficiency of the extraction and the accuracy of the proposed method, Certified Reference Materials were used in the dissolution and extraction steps. The method described can be used for the determination of trace metals in nuclear grade U₃O₈.     

Determination of trace impurities in tin by neutron activation analysis

A method was developed for the determination of 15 trace elements in tin. High-purity tin samples (99.9999% and 99.999%) as well as tin of technical quality were analysed. Reactor neutron activation of the tin samples was followed by distillation of the matrix activities from a HBr−H₂SO₄ medium and Ge(Li) gamma-ray spectrometry of the distillation residue. The sensitivity of the method is generally high. For the high-purity samples the detection limits vary from 0.02 ppb (scandium) to 200 ppb (iron) for irradiation of 1 g of tin for 1 week at a thermal flux of 5·10¹²n·cm⁻². ·sec⁻¹. To decontaminate the surface of the tin samples, pre- and post-irradiation etching procedures were applied. The efficiency of these etching techniques was studied.     

Determination of trace level impurities in uranium compounds by ICP-AES after organic extraction

The determination was studied of Al, B, Be, Cd, Ca, Co, Cu, Mg, Mn, Mo, Pb, Si, Sn, V, Cr, Ni, and Fe as trace level impurities in uranium compounds by ICP-AES after extraction of uranium with three different mixtures of di-(2-ethyl-hexyl) phosphate (D2EHP) and tri-(2-ethyl-hexyl)-phosphate (T2EHP) in solvents like toluene, carbon tetrachloride, hexane and cyclohexane. The study was carried out in presence of different concentrations of HCl and HNO(3). A single extraction with D2EHP in cyclohexane using nitric acid as matrix was sufficient to reduce the U(3)O(8) concentration from 100 g/l to 100 microg/ml. The ICP-AES instrumentation applied, allowed the determination of metal concentrations ten-times lower than those usually found in nuclear grade U(3)O(8). To check the efficiency of the extraction and the accuracy of the proposed method, Certified Reference Materials were used in the dissolution and extraction steps. The method described can be used for the determination of trace metals in nuclear grade U(3)O(8).     

Integrated approaches for reducing sample size for measurements of trace elemental impurities in plutonium by ICP-OES and ICP-MS

A novel microsphere adsorbent based upon carboxymethyl cellulose sodium/prussian blue composite loaded with Lanthanum(III) (CMC/PB-La) was successfully synthesized via electrostatic ejection device for removal of cesium from contaminated water, and characterized by FT-IR, SEM, EDX and XPS. Influencing factors to adsorption cesium were investigated, including solution pH, adsorbent dosage, contact time, initial concentration, temperature and competing ions. Linear Freundlich isotherm was fitted satisfactorily to the adsorption data, and the adsorption kinetic data was fitted well with pseudo-second-order model. Moreover, the results of γ-irradiation experiments indicate that CMC/PB-La has good radiation stability.