An isotope dilution inductively coupled plasma quadrupole mass spectrometric (ID-ICP-QMS) method was developed for the simultaneous determination of the platinum group elements Pt, Pd, Ru, and Ir in environmental samples. Spike solutions, enriched with the isotopes 194Pt, 108Pd, 99Ru, and 191Ir, were used for the isotope dilution step. Interfering elements were eliminated by chromatographic separation using an anion-exchange resin. Samples were dissolved with aqua regia in a high pressure asher. Additional dissolution of possible silicate portions by hydrofluoric acid was usually not necessary. Detection limits of 0.15 ng x g(-1), 0.075 ng x g(-1), and 0.015 ng x g(-1) were achieved for Pt, Pd, Ru, and Ir, respectively, using sample weights of only 0.2 g. The reliability of the ID-ICP-QMS method was demonstrated by analyzing a Canadian geological reference material and by participating in an interlaboratory study for the determination of platinum and palladium in a homogenized road dust sample. Surface soil, sampled at different distances from a highway, showed concentrations in the range of 0.1-87 ng x g(-1). An exponential decrease of the platinum and palladium concentration with increasing distance and a small anthropogenic contribution to the natural background concentration of ruthenium and iridium was found in these samples. 相似文献
Laser ablation inductively coupled plasma isotope dilution mass spectrometry (LA–ICP–IDMS) was applied to the direct and simultaneous
determination of the platinum group elements (PGEs) Pt, Pd, Ru, and Ir in geological and environmental samples. A special
laser ablation system with high ablation rates was used, along with sector field ICP–MS. Special attention was paid to deriving
the distributions of PGEs in the pulverized samples. IDMS could not be applied to the (mono-isotopic) Rh, but the similar
ablation behavior of Ru and Rh allowed Rh to be simultaneously determined via relative sensitivity coefficients. The laser
ablation process produces hardly any oxide ions (which usually cause interference in PGE analysis with liquid sample injection),
so the ICP–MS can be run in its low mass resolution but high-sensitivity mode. The detection limits obtained for the geological
samples were 0.16 ng g−1, 0.14 ng g−1, 0.08 ng g−1, 0.01 ng g−1 and 0.06 ng g−1 for Ru, Rh, Pd, Ir and Pt, respectively. LA–ICP–IDMS was applied to different geological reference materials (TDB-1, WGB-1,
UMT-1, WMG-1, SARM-7) and the road dust reference material BCR-723, which are only certified for some of the PGEs. Comparisons
with certified values as well as with indicative values from the literature demonstrated the validity of the LA–ICP–IDMS method.
The PGE concentrations in subsamples of the road dust reference material correspond to a normal distribution, whereas the
distributions in the geological reference materials TDB-1, WGB-1, UMT-1, WMG-1, and SARM-7 are more complex. For example,
in the case of Ru, a logarithmic normal distribution best fits the analyzed concentrations in TDB-1 subsamples, whereas a
pronounced nugget effect was found for Pt in most geological samples. 相似文献
A method is proposed for determining platinum-group elements, Ru, Pd, Os, Ir, Pt, and Re in geological samples by isotope dilution with mass spectrometric ending after sample decomposition with a mixture (1: 3) of conc. HCl + HNO3 in a microwave system and the chromatographic separation of the analytes from the matrix on an AG 50W × 8 cation exchanger. The concentrations and isotope ratios are determined on high-resolution mass spectrometers ELEMENT and ELEMENT2. The attained detection limits range from 0.005 ng/g (Ir) to 0.2 ng/g (Pd) in solid samples. The use of isotope dilution improves the accuracy of determination and takes into account the matrix effect and changes in plasma parameters on the analytical signal. The method is tested in the analysis of standard samples of spinel lherzolite (GP-13) and serpentinite (UB-N). The relative standard deviation of the results of analysis is 5–22%, depending on the element and its concentration level (Ru, Pd, Re, Pt). In determining Os and Ir, a certain decrease in the accuracy and repeatability of the results is noticed. 相似文献
Platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), and osmiun (Os) are platinum-group elements with similar physic-chemical properties, and have important applications in geochemistry and environmental chemistry. However, due to their low abundance and inhomogeneous distribution in natural ores as well as the nugget effect, the accurate determination of the platinum-group elements has been a challenge for geological analysis. In this work, self-prepared and purified sodium carbonate (NiCO3) instead of commercial nickel oxide (NiO) was used as the fire assay collector in order to greatly reduce the reagent blank and method detection limits. In addition, the fuming time of HClO4 was strictly controlled at 10?min and a high sensitive method was developed for the simultaneous determination of ultra-trace Pt, Pd, Ru, Rh, and Ir in minerals by inductively coupled plasma-mass spectrometry (ICP-MS) following preconcentration with the nickel sulfide fire assay. Under the optimized conditions, the linear ranges of Pt, Pd, Ru, Rh, and Ir were between 0 and 100?ng mL?1, with correlation coefficients exceeding 0.9997. The detection limits were 0.015, 0.056, 0.014, 0.004, 0.012?ng mL?1 (for 10?g sample) for Pt, Pd, Ru, Rh and Ir, respectively. The developed method was successfully applied to analyze Chinese Certified Reference Materials (CRMs) GBW07288, GBW07289, GBW07290, GBW07291, GBW07292, GBW07293, GBW07294, GBW07101, GBW07102 and GBW07201 and the determined values were in good agreement with the certified values. The relative standard deviations (n?=?5) of Pt, Pd, Ru, Rh and Ir were between 3.42% and 6.87% for the determination of GBW07291. 相似文献
A method for the determination of low Ru, Pd, Re, Os, Ir and Pt abundances in geological reference materials by isotope dilution inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion in a high pressure asher (HPA-S) is presented. The digestion technique is similar to that using Carius tubes but easier to handle and reaches higher temperatures. Osmium can be determined as OsO4 with ICP-MS directly after digestion through a sparging technique. The remaining elements are preconcentrated by means of anion column chromatography. The resin is digested directly without elution leading to high yields but this causes problems if Zr is present at higher levels in the silicate rich materials. The analytical results for international platinum group element (PGE) reference materials, chromitite CHR-Bkg, basalt TDB-1 and gabbro WGB-1, are presented and compared with literature data, demonstrating the validity of the described method. Although higher in concentration, PGEs determined for reference material WGB-1 were worse than for TDB-1 indicating a more inhomogeneous distribution of the platinum group mineral phases. The low PGE abundance chromitite standard, CHR-Bkg, is likely to be homogeneous for Ru, Re, Os and Ir and is recommended as a reference material for the study of chromitites. Detection limits (3s x total procedure blank) range from 0.012 ng (Re and Os) to 0.77 ng (Pt), which could be further improved by applying higher quality acids. 相似文献
The method developed for determining platinum and palladium in rocks and soils is based on extraction of iodo complexes of these elements into methyl isobutyl ketone (MIBK), followed by electrothermal atomic absorption spectrometry of the extracts. The limit of detection is 10 ng g?1 for platinum and 3 ng g?1 for palladium. Analysis of the standard noble metal ore PTC-1 with recommended values of 12.7 μg g?1 for palladium and 3.0 μg g?1 for platinum gave precisions of 4.4% and 5.6%, respectively, and deviations of 5.0% and 1.2% from the recommended values. The method is applicable to the determination of both elements in a wide variety of rocks and soils. 相似文献
ABSTRACT A specific method for the spectrophotometric determination of palladium with N.N'-diphenylbenzimidoylthiourea (DPB1TU) is described. The method in new, simple, rapid and applicable over 0.3-1.0 M HC1 and free from interferences of the precious metals i.e. Ag, Au, Pt, Ir, Rh, Ru, Os. The value of molar absorptivity of the complex in the term of Pd is (2.50)x104 L mole?1 cm?1at λmax 365 nm in chloroform. The detection limit of the method at 3 σ a is 80 ppb Pd. The composition of the complex and effect of diverse ions in the determination of Pd are discussed. The application of the method has been tested for the analysis of the metal in catalytic material. 相似文献
The determination of palladium in a road dust sample taken close to the highway (wPd=450 ng g−1) was carried out by the ICP-MS method after sample decomposition by aqua-regia. Analyses were evaluated by two methods: external calibration accompanied with mathematical correction of spectral interferences (EC) and isotope dilution measurement after separation of Pd by extraction to dibutyl sulfide solution (ID). In both cases, the uncertainties and accuracy of results were investigated. Although in the case of ideally homogeneous sample the repeatability of EC results (11 ng g−1 Pd) was somewhat lower than those of ID results (16 ng g−1 Pd), the uncertainties of results of both techniques were almost the same and they reached the level of 19 ng g−1 Pd. The main uncertainty source of the EC method is represented by the correction of spectral interferences. In case of real non-homogeneous sample, the main uncertainty component represents the soil sampling. The uncertainty of results (approx. 75 ng g−1 Pd) only slightly exceeded the repeatability (approx. 70 ng g−1 Pd). The accuracy of results was proven by analyses of CRM TDB–1 Diabas Rock (in case of ID) and by the standard addition method (in case of EC). 相似文献
The effect of pre-reduced Pt and Ir modifiers towards simultaneous determination of As, Se and In in a sodium sulphate matrix was investigated. In spite of application of very isothermal THGA atomizer, negative influence of the matrix is pronounced. The efficiency of iridium modifier is somewhat higher than that of platinum modifier. However compared to palladium modifier both are significantly less effective in sulphate media. Taking into account our previous data, effectiveness of platinum group metal (PGM) modifiers in the determination of As, Se and In in the presence of sodium sulphate increases in the order Ru<Rh≈Pt<Ir<Pd. This order is opposite to the data on enthalpy of formation of PGM sulphides. This supports our hypothesis that effectiveness of PGM modifiers in the presence of sulphate matrix is determined mainly by stability of the corresponding sulphides. Efforts to enhance the effectiveness of Pt modifier mixing it with small (10-20%) amounts of Pd, Rh or Ir were not successful. Although mixture containing equal amounts of Pd, Pt, Rh and Ru is relatively effective, pure pre-reduced Pd is the best modifier for the simultaneous determination of As, Se and In in a sulphate media. 相似文献
The six platinum group elements (Ru, Rh, Pd, Os, Ir and Pt) can be determined in geological samples down to the μg kg?1 level, by using nickel sulphide fire assay and neutron activation of the residue ramaining after dissolution of the nickel sulphide button in concentrated hydrochloric acid. Losses for the platinum group elements during this dissolution step are usually insignificant, except when the elements are present at ultra-trace levels. The can be recovered from the filtrate by coprecipitation with tellerium. The latter approach also permits determination of silver, which is significantly lost in the hydrochloric acid treatment (recovery <98% instead of typically ≈ 10%). The coprecipitation with tellurium considerably improves the results for gold (recovery ≈ 95% instead of typically 75%). 相似文献
We report on the use of mesoporous silica microparticles (μPs) functionalized with quarternary amino groups for the isolation of platinum and palladium tetrachloro complexes from aqueous road dust digests. The μPs have a size ranging from 450 to 850 nm and are suspended directly in the aqueous digests, upon which the anionic Pt and Pd complexes are retained on the cationic surface. Subsequently, the μPs are separated by centrifugation. Elements that cause spectral interferences in ICP-MS determination of Pt and Pd can be quantitatively removed by adding fresh 0.240 mol L−1 HCl to the μPs and by repeating the centrifugation step. The analyte-loaded μPs are then dissolved in 0.1 mL of 2 mol L−1 HF, diluted to 2 mL, and the solutions thus obtained are analyzed by quadrupole ICP-MS. This method avoids analyte elution from the sorbent. This “dispersed particle extraction” approach yielded a run-to-run relative standard deviation ≤ 5 % for Pt and ≤ 4 % for Pd (at 0.1 ng mL−1, n = 4 road dust digests). Method detection limits (expressed as concentrations in the dust samples) are 2 and 1 ng g−1 for Pt and Pd, respectively. The method was validated by analysis of a reference material (BCR CRM 723) and applied to the analysis of road dust samples collected in downtown Vienna. Pt and Pd concentrations in samples collected in summer and in winter were compared, with concentrations ranging from 205 to 1445 ng g−1 for Pt and from 201 to 1230 ng g−1 for Pd.
Designing highly active catalysts at an atomic scale is required to drive the hydrogen evolution reaction (HER). Copper–platinum (Cu‐Pt) dual sites were alloyed with palladium nanorings (Pd NRs) containing 1.5 atom % Pt, using atomically dispersed Cu on ultrathin Pd NRs as seeds. The ultrafine structure of atomically dispersed Cu‐Pt dual sites was confirmed with X‐ray absorption fine structure (XAFS) measurements. The Pd/Cu‐Pt NRs exhibit excellent HER properties in acidic solution with an overpotential of only 22.8 mV at a current density of 10 mA cm−2 and a high mass current density of 3002 A g−1(Pd+Pt) at a −0.05 V potential. 相似文献
A sensitive procedure for the simultaneous determination of trace levels of iridium, palladium and silver in a platinum stock, by thermal-neutron activation analysis utilizing gamma-ray spectrometry, was developed. The radiochemical-separation scheme involved an elution of the chloro complexes of iridium and silver, and subsequently palladium, through a strongly-basic anion-exchange resin, followed by further chemical-separation methods. The ion-exchange method served to greatly reduce the hazard from radiations emitted by the bulk of the activities in the matrix. Activities of 13.5-hr109Pd, 74.2-d192Ir and 255-d110mAg were monitored by accumulation of pulses from a 3-in diam. NaI(T1) crystal detector. Further discrimination was attained by resolution of decay curves. The procedure provided analyses for a platinum stock of 0.015±0.0021 ppm Ir; 0.028±0.0043 ppm Pd and 2.4±0.27 ppm Ag. 相似文献
A flow injection online displacement solid-phase extraction (DSPE) via magnetic immobilization of mercapto-functionalized magnetite microspheres onto the inner walls of a knotted reactor (KR) coupled with inductively coupled plasma mass spectrometry was developed for selective preconcentration and determination of trace noble metals (Ru, Rh, Pd, Pt, Ir and Au) in complex matrices. Online DSPE of 2.7 mL aqueous solution gave the enhancement factors of 32-46 for the six noble metals in comparison with direct nebulization of aqueous sample solution, and the detection limits (3 s) of 2.1 ng L(-1) for Ru, 1.9 ng L(-1) for Rh, 2.5 ng L(-1) for Pd, 1.8 ng L(-1) for Ir, 1.9 ng L(-1) for Pt and 1.7 ng L(-1) for Au. The sample throughput of the developed method was about 20 samples h(-1), and the relative standard deviation for eleven replicate determinations of the noble metals at the 30 ng L(-1) level ranged from 1.2% to 2.1%. The recoveries of Ru, Rh, Pd, Pt, Ir and Au still maintained 90% even after successive 140 cycles of DSPE. The developed method was successfully applied to selective determination of trace Ru, Rh, Pd, Pt, Ir and Au in complex matrices. 相似文献
Bi- and trimetallic platinum–ruthenium and platinum–ruthenium–palladium catalysts with specified atomic ratios Pt: Ru = 1: 1 and Pt: Ru: Pd = 1: 1: 0.1, respectively, were synthesized from the coordination compounds of the metals deposited on highly dispersed carbon black. The catalysts were characterized by powder X-ray diffraction, electron dispersive analysis, and transmission electron microscopy. According to voltammetry data, the highest activity in the dimethyl ether (DME) electrooxidation is exhibited by the catalyst Pt0.43Ru0.47Pd0.1/C; hence, it may be considered as a promising anode material for direct DME fuel cells. 相似文献
The economic and geological importance of platinum group of elements has led to the development of analytical methods to quantify them in different types of samples. In the present paper the quantitative information for spectral interference in radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometry in the determination of Pt, Pd and Rh in the presence of complex matrix, containing Al, Ca, Fe, Mg, Mn, P and Ti as matrix constituents was obtained. The database was used for optimum line selections. By using the selected analysis lines the following detection limits in ng g− 1 were obtained: Pt 1700, Pd-1440, Rh-900. The reached detection limits determine the possibilities and limitation of the direct ICP-AES method in the determination of Pt, Pd and Rh in geological and environmental materials. The database for spectral interferences in the presence of aluminum can be used for the determination of platinum group of elements in car catalysts. 相似文献
Osmium, ruthenium, iridiuim and gold can be determined simultaneously in 100-mg platinum samples after irradiation for 11 days at a thermal neutron flux of 4'1011 n.cm-2.sec-1. An addition method of analysis is used; samples are dissolved in small sealed silica tubes before activation. After irradiation, Os and Ru are distilled from sulfuric acid-sodium bromate, Ru being determined by counting the 498-keV peak of 103Ru; Os is determined after a second distillation. Gold is extracted with ethyl acetate from the residue of the first distillation; the ratio 198Au/199Au is a direct measure for the gold content, with appropriate correction for the second-order reaction 196Pt(n,γ)197Pt→197Au(n,γ)198Au. Ir is determined in the residual aqueous phase using the 317-keV peak of 192Ir; a correction for the platinum activity (191Pt) is made. The lower limit of determination is ca. 0.5 p.p.m. for ruthenium, ca. 0.2 p.p.m. for osmium, ca. O.1 p.p.m. for gold and ca. O.1 p.p.m. for iridium. After a separation of Pt from Ir, the sensitivity for Ir can easily be improved to < 10 p.p.b. 相似文献