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1.
Dandan Li Xijun Chang Zheng Hu Qihui Wang Zhifeng Tu Ruijun Li 《Mikrochimica acta》2011,174(1-2):131-136
A new sorbent was prepared by immobilization of 2,6-diaminopyridine on activated carbon and then used as a solid-phase extractant for trace Au(III), Pd(II) and Pt(IV) before their determination by ICP-AES. Effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the potentially interfering ions were investigated. The optimum pH value is 1. The maximum static adsorption capacity for the three ions is 202.7, 38.5 and 30.1?mg?g?1, respectively. The adsorbed metal ions can be completely eluted by 2?mL of the eluent solution that contains 0.05?mol?L?1 HCl and 5% thiourea. Common other ions do not interfere. The detection limits (3??) are 0.16, 0.33 and 0.29?ng?mL?1, respectively. The relative standard deviation (RSD) was lower than 3.0% (n?=?8). The new sorbent was applied to the preconcentration of the three ions in ore and rock samples with satisfactory results. Figure
Au(III), Pd(II), Pt(IV) are absorbed at pH 1. The maximum static adsorption capacity is 202.7, 38.5 and 30.1?mg?g?1. The eluent is 2?mL of the eluent solution that contains 0.05?mol?L?1 HCl and 5% thiourea. The relative standard deviation (RSD) was lower than 3.0% (n?=?8). 相似文献
2.
We describe a solid phase extractor for selective separation and preconcentration of Hg(II) ion. It was prepared by immobilizing the adduct of diethylenetriamine and thiourea on silica gel. The effects of solution acidity, preconcentration time, sample flow rate and volume were optimized. The results show that Hg(II) can be selectively extracted from acidic solutions and in presence of common other metal ions. The adsorbent is stable, can be reused more than 10 times, and the maximum adsorption capacity is 23 mg g?1. Hg(II) was quantified by inductively coupled plasma optical emission spectrometry. The method has a detection limit of 23 ng L?1, and the relative standard deviation is <2 %. The procedure was validated by analyzing two standard materials (river sediment and hair powder), and was successfully applied to the preconcentration of Hg(II) in real samples. Figure
A solid phase extractor was firstly prepared by immobilizing DETA-TU (equimolar adduct of diethylenetriamine and thiourea) on the silica gel, which was applied to selectively separate/preconcentrate trace Hg(II) from real samples 相似文献
3.
Imamoglu Mustafa Aydin Ali Osman Dundar Mustafa S. 《Central European Journal of Chemistry》2005,3(2):252-262
A preconcentration method of gold, palladium and copper based on the sorption of Au (III), Pd (II) and Cu (II) ions on a column
packed with 3-(2-aminoethylamino)propyl bonded silica gel is described. The modified silica gel was synthesized and characterized
by FT-IR and C, H, N elemental analysis. At column preconcentration, the effects of parameters such as pH, volume, flow rate,
matrix constituents of solutions and type of eluent on preconcentration of gold, palladium and copper were studied. The recoveries
of Au (III), Pd (II) and Cu (II) were 98.93±0.51, 98.81±0.36 and 99.21±0.42 % at 95 % confidence level, respectively. The
detection limits (δ) of the elements were 0.032, 0.016 and 0.012 μg ml−1, respectively. The preconcentration method was applied for determination of gold and palladium in certified reference material
SARM 7B and copper in river and synthetic seawater by FAAS. Gold, palladium and copper were determined with relative error
lower than 10 %. 相似文献
4.
Xiangbing Zhu Dong Yang Xijun Chang Yuemei Cui Zheng Hu Xiaojun Zou 《Mikrochimica acta》2008,161(1-2):115-122
A new method using acetylsalicylic acid (aspirin) modified SiO2 nanoparticles (nanometer SiO2-aspirin) as a solid-phase extractant (SPE) has been developed for the preconcentration of trace amounts of Fe(III) prior
to their determination by inductively coupled plasma optical emission spectrometry. The preconcentration conditions of analytes
were investigated, including the pH value, the shaking time, the mass of sorbent, the sample flow rate and volume, the elution
condition and the interfering ions. At pH 4, the sorption capacity of nanometer SiO2-aspirin was found to be 1.28 mmol g−1. The preconcentration factor is 50. The detection limit (3σ) for Fe(III) was 0.49 ng mL−1. The method was validated by analyzing two certified reference materials (GBW 08301, river sediment and GBW 08303, polluted
farming soil), and the results obtained are in good agreement with standard values. The method was also applied to the determination
of trace Fe(III) in biological and water samples with satisfactory results.
Correspondence: Xiangbing Zhu, Department of Chemistry, Lanzhou University, Lanzhou 730000, P.R. China 相似文献
5.
A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4. And the adsorbed metal ions could be completely eluted by using 2.0 mL 2.0 mol L−1 HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.8, 39.9, 77.8 and 17.3 mg g−1 for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The detection limits of the method were found to be 0.15, 0.41, 0.27 and 0.36 ng mL−1 for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n = 8). The method was successfully applied for the preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) in natural and certified samples with satisfactory results. 相似文献
6.
Hua Tian Xijun Chang Zheng Hu Kang Yang Qun He Lina Zhang Zhifeng Tu 《Mikrochimica acta》2010,171(3-4):225-232
Activated carbon was chemically modified with 4-(8-hydroxyquinoline-azo)benzamidine and used for separation and preconcentration of trace amounts of Pb(II) in environmental samples by solid-phase extraction prior to the measurement by inductively coupled plasma atomic emission spectrometry. The effects of pH, shaking time, eluent concentration and volume, sample flow rate and potential interfering ions were studied. Under the optimum conditions, the enrichment factor was 100, the detection limits (3ó) is 0.43 ng?mL?1, and the relative standard deviations are <2.1% (n?=?8). The adsorption capacity of the sorbent is 53.58 mg of lead(II) per gram of the material. The sorbent was successfully applied to the preconcentration of trace Pb(II) in the reference materials GBW 08301 (river sediment) and GBW 08302 (Tibet soil). The recovery of lead(II) from Yellow river water, Huangshui water, and tap water is in range of 99.3–101.6%. 相似文献
7.
In this study, a new 4-(2-morinyldiazenyl)-N-(3-(trimethylsilyl)propyl)benzamide modified silica gel (SG-MTPB) sorbent was prepared and characterized by FT-IR spectroscopy and studied for separation and preconcentration of Sc(III) prior to its determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace Sc(III) were optimized using both batch and column procedures. At pH 3, Sc(III) could be quantitatively adsorbed on the new sorbent. And the adsorbed Sc(III) could be completely eluted by using 2 mL of 6 mol L(-1) of HCl+2% CS(NH(2))(2). Most common coexisting ions did not interfere with the separation and preconcentration of Sc(III) at optimal conditions. The maximum static adsorption capacity of the sorbent for Sc(III) was 600 micaromol g(-1) while the time of 95% adsorption was less than 2 min. The detection limit of present method was found to be 0.085 micarog g(-1), and the relative standard deviation (R.S.D.) was lower than 1.3%. The method was also successfully applied to the preconcentration of trace Sc(III) in the environmental samples with satisfactory results. 相似文献
8.
A simple classification of various sorbents and solid-phase extraction procedures used for preconcentration of trace levels of Au, Pd, and Pt from different sample types is proposed in this review article. The large variety of available sorbents/procedures has been organized according to expected mechanisms of sorption process (complex formation; ion exchange; adsorption; ion-imprinted or molecularly imprinted polymers); according to the kind of monomeric units of the polymer matrix as well as on the basis of the kind of functional group responsible for main performance characteristics (selectivity, capacity) of the sorbent. Advantages of chemically modified sorbents, sulfur-containing sorbent extractants, and ion-imprinted polymers, together with rational pretreatment by means of microwave treatments, scaling down of enrichment, and quantification by means of flow and flow injection approaches are given. Preferred instrumental techniques for quantification of ppb levels of Au, Pd, and Pt in prepared concentrates/column eluates are multielement instrumental techniques: inductively coupled plasma optical emission spectrometry (ICP-OES), and inductively coupled plasma mass spectrometry (ICPMS). Excellent limits of detection at picogram levels of these analytes are provided by electrothermal atomic absorption spectrometry (ETAAS), generally in single-element mode and the neutron activation analysis (NAA), while X-ray fluorescence spectrometry and flame AAS are rarely applied because of lack of sensitivity at sub-ppm levels of Au, Pd, and Pt. Some problems of atomic spectrometric quantification techniques and their representative limits of detection are given. Recent applications to geological, industrial, pharmaceutical, biological, and other materials are tabulated. References have been selected mostly from the period 1995 to 2010. 相似文献
9.
The use of ethyl-ga-isonitrosoacetoacetate (HEINA) for determination of palladium is reported. Pd can be estimated quantitatively from 0.5M to 2M HCl solution. Accurate results are obtained in 1M solution with an accuracy better than 1%. Decontamination values against platinum metals and other metals usually associated with Pd are greater than 105. The time required for gravimetric determination is about an hour, for radiochemical separation about 25 min and the recovery is better than 90%. 相似文献
10.
The extraction of Pd(II), Rh(III), Ir(III), Au(III) and Pt(IV) from hydrochloric and hydrobromic acid with 5% tri-iso-octylamine solution in carbon tetrachloride has been studied. The gold extract from hydrochloric acid is yellow and absorbs at 325 nm, the palladium compound is red and absorbs at 290 nm and 467 nm, and the platinum compound is blood-red and shows absorption at 268 nm. The gold, palladium and platinum extracts from hydrobromic acid are crimson. reddish brown and blood-red, with maximum absorption at 260, 345 and 300 nm respectively. Methods have been devised for the separation of gold from platinum and for its determination and also for the simultaneous determination of palladium and platinum. 相似文献
11.
Zahra Monsef Khoshhesab Narjes Najafi 《International journal of environmental analytical chemistry》2017,97(13):1237-1252
In this research, nickel ferrite (NiFe2O4) magnetic nanoparticles were synthesised by a simple method and applied as sorbent for magnetic solid-phase extraction of trace amounts of Au(III) from water samples. Detection in this technique was performed by flame atomic absorption spectrometry. The effects of sample pH, amount of sorbent, extraction time, desorption solvent and its volume on the extraction process were optimised. The effects of interfering ions on the recovery of the analyte were also evaluated in model solutions. The best results were obtained at pH 6.5 with 5 mL of eluent solution (0.1 mol L?1 sodium thiosulphate) and an extraction time of 30 min. Under optimal conditions, the sorption capacity was 34.6 mg g?1. Also, enhancement factor (for 100 mL of sample solution) was found to be 19.3. The calibration graph was linear in the range of 4.4–800.0 µg L?1 gold concentration and the limit of detection was 1.32 µg L?1. The relative standard deviation of the method (for n = 8) was 1.57%. The method was successfully applied to the extraction of Au(III) from water samples. 相似文献
12.
Mehrorang Ghaedi Javad Tashkhourian Morteza Montazerozohori Mustafa Soylak 《International journal of environmental analytical chemistry》2013,93(4):386-400
The efficiencies and performances of silver nanoparticle loaded activated carbon modified with 2-(4-isopropylbenzylideneamino)thiophenol (IPBATP-Ag-NP-AC) and activated carbon modified with IPBATP (IPBATP-AC), as new sorbents, were evaluated for separation and preconcentration of Cu2+, Zn2+, Co2+, Cd2+ and Pb2+ ions from real environmental samples. The retained metals content was reversibly eluted using 5?mL of CH3COOH (6.0?mol?L?1) and/or 10?mL of 4.0?mol?L?1 HNO3 for IPBATP-Ag-NP-AC and IPBATP-AC, respectively. The experimental parameters influence the recoveries of metal ions including pH, amounts of ligand and supports, condition of eluents, sample and eluent flow rates of has been investigated. The preconcentration factors were found to be 100 for Zn2+, Cd2+, Co2+, Cu2+ and 50 for Pb2+ ions using IPBATP-Ag-NP-AC, and 50 for Zn2+, Cd2+, Co2+, Cu2+ and 25 for Pb2+ ions using IPBATP-AC. The detection limit of both SPE-based sorbents was between 1.6–2.5?ng?mL?1 for IPBATP-AC and 1.3–2.5?ng?mL?1 for IPBATP-Ag-NP-AC. The proposed methods have been successfully applied for the extraction and determination of the understudy metal ions content in some real samples with extraction efficiencies higher than 90% and relative standard deviations (RSD) lower than 2.4%. 相似文献
13.
A platinum plate coated with single-walled carbon nanotubes (SWCNTs@Pt) was prepared by means of electrophoretic deposition. Using the SWCNTs@Pt plate, an electrosorption-enhanced solid-phase microextraction (EE-SPME) technique was proposed for the extraction of trace anions in water, described as follows: a positive potential was applied to the SWCNTs@Pt plate to extract F−, Cl−, Br−, NO3− and SO42− from water using electrosorption, and then a negative potential was applied to the plate placed in ultra-pure water for the desorption of the absorbed anions, and finally the desorbed anions were analyzed using ion chromatography (IC). The EE-SPME parameters, including extraction potential and time as well as desorption potential and time, were investigated. An analytical method based on the above procedures, i.e., EE-SPME-IC, was established and used for the analysis of trace anions in water. The results showed that the application of potential on the SWCNTs@Pt plate significantly enhanced the ion extraction efficiency, and an enrichment factor of 15-38 was achieved. The SWCNTs@Pt plate could be used more than 50 times without significant decay. The linear range, the limit of detection (S/N = 3), the limit of quantification (S/N = 10) and repeatability (n = 7) of our EE-SPME-IC method were 1.0-150.0 μg/L, 0.06-0.26 μg/L, 0.19-0.85 μg/L and 2.1-8.0%, respectively. The proposed method was successfully applied for the analysis of trace anions in deionized water, and acceptable recoveries between 65.3 and 121.1% were obtained for the spiked deionized water samples. 相似文献
14.
Summary An organic precipitant, p-dimethylaminobenzilidenerhodanine (DABR), is used as the gatherer in precipitate flotation to enrich trace amounts of gold, silver, palladium and platinum from acidic media in the presence of surfactants. The DABR dissolved in dimethylformamide (DMF) does not affect the determination of the enriched metals with electrothermal atomic absorption spectrometry. The presence of a 102- to 104-fold excess of other usual ions does not interfere with the flotation owing to the high selectivity of DABR for the noble metals in acidic media. As little as 1 ng/l of gold in aqueous solution can thus be determined by AAS. The method has been applied to determine the noble metals in various ore samples with satisfactory results.Dedicated to Prof. Kuang Lu Cheng, University of Missouri, Kansas City, USA on the occasion of his 70th birthdayPresented in part at the Third China-Japan Joint Symposium on Analytical Chemistry, Hefei, China, May, 1988 相似文献
15.
V. V. Yakshin O. M. Vilkova I. G. Tananaev B. F. Myasoedov 《Russian Journal of General Chemistry》2011,81(9):1966-1971
Extraction of Pt, Ir, Pd by the macrocyclic polyethers dibenzo-18-crown-6 (DB18C6) and cis-syncis-dicyclohexyl-18-crown-6 (DCH18C6, isomer A) in organic solvents (chloroform, dichloroethane) from 3–10 M aqueous HCl was studied. It was found that DCH18C6 in dichloroethane
excellently extracted Pt, Ir, and Pd in the presence of KSCN. Re-extraction of Pt, Ir, and Pd from the organic phase can be
fulfilled by 1 M HNO3. Thus, the macrocyclic polyethers are effective reagents for isolation of Pt, Ir, and Pd from HCl solutions. 相似文献
16.
17.
Methyl (E)-2-(acetylamino)-3-cyanoprop-2-enoate ( 2a ), and its 2-benzoyl analog 2b ere prepared from the corresponding methyl (Z)-2-(acylamino)-3-(dimethylamino)propenoates 1 Multifunctional compounds 2 are versatile synthons for preparation of polysubstituted heterocyclic systems such as pyrroles 4 , pyrimidines 5 and 6 , pyridazines 7 , pyrazoles 8 , 9 , and 11 , and isoxazoles 10 . 相似文献
18.
Yoshiko Murakami Kaoru Hiraiwa Yoshiaki Sasaki Isamu Fujiwara Shoji Tagashira 《Analytical sciences》2007,23(9):1147-1149
A micellar solution of cetylpyridinium chloride (CPC) can separate into two phases due to a temperature change or to the addition of salts. Platinum(II), (IV) and palladium(II) reacted with chloride ions to form stable anionic complexes of PtCl4(2-), PtCl6(2-) and PdCl4(2-), respectively, and were adsorbed onto the CPC gel phase. The CPC phase plays the role of an ion-exchange adsorbent for the anionic complexes. By such a procedure, the precious metals of platinum and palladium could be separated from base metals such as copper, zinc and iron. The kinetic separation was performed by a ligand exchange reaction of the palladium(II) chloro-complex with EDTA at 60 degrees C. The anionic palladium(II)-EDTA complex could not bind the opposite charged CP+ and was desorbed from the CPC phase. In the aqueous phase, the recovery of palladium(II) by the double-desorption was 101.1 +/- 1.2%. The platinum(II) and (IV) chloro-complexes were stable for at least 30 min and remained in the CPC phase. 相似文献
19.
A new method that utilizes 1-(2-aminoethyl)-3-phenylurea-modified silica gel as a solid-phase extractant has been developed for preconcentration of trace Sc(III) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace level of Sc(III) were optimized using batch and column procedures in detail. The optimum pH value for the separation of Sc(III) on the new sorbent was 4 and complete elution of Sc(III) from the sorbent surface was carried out using 1.0 mL of 0.1 mol L−1 HCl. Common coexisting ions did not interfere with the separation and determination of the analyte. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 32.5 mg g−1 while the time of 95% adsorption was less than 2 min. The detection limit of present method was found to be 0.091 μg g−1, and the relative standard deviation (RSD) was lower than 3.0% (n = 8). The method was successfully applied for the preconcentration of trace Sc(III) in the environmental samples with satisfactory results. 相似文献
20.
L. K. Neudachina A. Ya. Golub A. S. Kholmogorova 《Russian Journal of Applied Chemistry》2014,87(7):923-929
Sorption of palladium(II) from model solutions with polysiloxanes modified with amine and thiourea groups was stidied and it was found that the maximum sorption on aminopropyl polysiloxane is shifted slightly to alkaline region compared with a sulfur-containing sorbent. First time an effect of a series of external factors on a sorption kinetics of palladium with polysiloxanes was researched, diffusion coefficients of sorbate ions were calculated, and evaluation of their dependence on an initial concentration of metal, a grain diameter of the sorbent, and a temperature of sorption environment was carried out. It is shown that quantitative desorption of palladium from thiocarbamoylated polysiloxane is achieved by double treating the sorbent with hydrochloric acid solution of thiourea at high temperature. 相似文献