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1.
Solid-phase extraction (SPE) method for preconcentration and determination of Cd(II), Pb(II), Co(II), Ni(II), and Cu(II) aqueous
samples by inductively coupled plasma optical emission spectrometry is described. The preconcentration of analytes is accomplished
by retention of their chelates with 1.10-phenanthroline in aqueous solution on a solid phase containing carboxylic acid (COOH)
bonded to silica gel in a column. The limits of detection values (defined as “3s” where “s” is standard deviation of the blank
determination) are 3.6 μg/L for Cd(II), 17.5 μg/L for Pb(II), 3.1 μg/L for Co(II), 2.1 μg/L for Ni(II), and 4.4 μg/L for Cu(II)
and corresponding limit of quantification (6s) values are 7.2, 35, 6.2, 4.2 and 8.8 μg/L, respectively. As a result, a simple
method was elaborated for the group concentration and determination of the above mentioned metals in reference material and
in samples of plant material.
The article is published in the original. 相似文献
2.
C. Pohl 《Accreditation and quality assurance》1997,2(1):2-10
The aim of this intercomparison exercise was to assess the comparability of trace metal analyses of blank filters and of
marine suspended particulate matter (SPM) on filters performed by laboratories in ICES member countries. Fifteen experts from
the United Kingdom, Canada, France, Germany, the Netherlands, Norway, Poland, Russia, and the United States were invited to
participate in this exercise for trace metal analyses of Cu, Pb, Zn, Cd, Al, Li, Fe, Mn, Ni and Co (tentative) in SPM. Each
filter analysed in this project was an individual sample, the absolute loadings on the filters varying from 0.8 to 2 mg of
SPM. The inter-laboratory means and the relative standard deviations (RSD) from the grand mean for the metals determined were:
Al 67.5 mg/g, 8.3%, Fe 51.7 mg/g, 10.9%, Cd 1.5 μg/g, 22.7%, Cu 39 μg/g, 13.3%, Pb 38 μg/g, 34.7%, Mn 1060 μg/g, 13%, Ni 49.2
μg/g, 29%, Zn 182 μg/g, 32.5%, Li 52.8 μg/g, 26.1%, Co 15.4 μg/g, 23.6%. In general, the exercise demonstrated that it is
possible for the various participants to collect very small amounts of SPM and analyse it by the different determination techniques.
Compared to earlier exercises, comparability between laboratories was still difficult to achieve and limited.
Received: 27 June 1996 Accepted: 15 August 1996 相似文献
3.
E. Morosanova A. Velikorodny Y. Zolotov 《Fresenius' Journal of Analytical Chemistry》1998,361(3):305-308
Two approaches to immobilize complex-forming analytical reagents (PAN, PAR, Xylenol orange, Brombenzothiazo, Crystal violet,
Cadion, and Sulfochlorophenolazorhodanine) for the preparation of new sorbents and indicator powders are suggested: on-line
coating of reversed-phase silica gel by reagents or doping of porous sol-gel silica with reagents. The retention of Ag, Cd,
Cu(II), Co(II), Fe(III), Mn(II), Ni, Pb, and Zn on the sorbents developed was investigated. Quantitative sorption and desorption
conditions were optimized. Procedures for the determination of Cd, Cu(II), Fe(III), Pb, and Zn with flame atomic absorption,
spectrophotometric, and diffusion scattering spectrometric detection were elaborated. Detection limits for Cd, Cu(II), Fe(III),
Pb, and Zn were 3 μg/L, 6 μg/L, 5 μg/L, 40 μg/L, and 1 μg/L, respectively. The procedures were used for the analysis of various
real samples, e.g., natural and waste waters, and food.
Received: 17 July 1997 / Revised: 20 January 1998 / Accepted: 5 February 1998 相似文献
4.
Sayed Zia Mohammadi Daryoush Afzali Davood Pourtalebi 《Journal of Analytical Chemistry》2011,66(7):620-625
In this article, a sensitive cloud point extraction procedure for the preconcentration of trace amounts of palladium, gold
and nickel prior to their determination by flame atomic absorption spectrometry has been developed. The cloud point extraction
method is based on the complexation of Pd(II), Au(II), and Ni(II) ions with 1-(2-pyridylazo)-2-naphthol and entrapping in
non-ionic surfactant Triton X-114. The main factors affecting cloud point extraction efficiency, such as pH of sample solution,
concentration of 1-(2-pyridylazo)-2-naphthol and Triton X-114, equilibration temperature and time, were investigated in detail.
Under the optimized conditions, calibration curves were constructed for the determination of palladium, gold and nickel according
to the general procedure. Linearity was maintained from 0.01 to 1.0 μg/mL for palladium, 10.0 μg/mL to 1.5 μg/mL for gold,
and 10.0 μg/mL to 0.5 μg/mL for nickel. Detection limits based on three times the standard deviation of the blank divided
by the slope of analytical curve (3Sb/m) for Pd(II), Au(III), and Ni(11) ions were 3.4, 3.9, and 2.4 μg/mL, respectively.
Seven replicate determination of a mixture of 0.5 μg/mL palladium and gold and 0.2 μg/mL nickel gave a mean absorbance of
0.174, 0.150, and 0.201 with relative standard deviation ±1.5, ±1.3, and ±1.8%, respectively. The high efficiency of cloud
point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed method has
been applied for determination of trace amount of palladium, gold and nickel in certified reference material and water samples
with satisfactory results. 相似文献
5.
S. C. F. Au-Yeung S. Y. Fan J. C. Yu W. L. A. K. Chiu 《Fresenius' Journal of Analytical Chemistry》1998,361(2):210-213
A novel analytical approach is described that combines the preconcentration power of solvent extraction with the resolution
and sensitivity of a 500 MHz 1H NMR spectroscopic detection method for the quantitative determination of metals. Co(II), Cr(VI), Ni(II) and Pb(II) in water
are extracted into chloroform as dithiocarbamate complexes. By decoupling the protons and employing a solvent-induced shift
method, the 1H NMR spectrum containing the dithiocarbamate complexes of Co(II), Cr(VI), Ni(II) and Pb(II) is fully resolved at CDCl3/ C6D6 below 40%/60%. The detection limits for Co(II), Cr(VI), Ni(II) and Pb(II) are estimated to be 0.12, 0.073, 0.11 and 0.27
μg/mL, respectively, in the sample solution.
Received: 31 July 1997 / Revised: 24 October 1997 / Accepted: 31 October 1997 相似文献
6.
A cloud-point extraction (CPE) process using the nonionic surfactant Triton X-114 to simultaneous extraction and spectrophotometric
determination of Zn(II), Co(II) and Ni(II) from aqueous solution using partial least squares (PLS) regression is investigated.
The method is based on the color reaction of these cations with 1-(2-pyridylazo)2-naphthol and subsequent micelle-mediated
extraction of products. The optimum extraction and reaction conditions such as pH, reagents concentration and effect of time
have been studied. Linearity was obeyed in the range 2–150, 5–250 and 2–150 ng mL−1 of Zn(II), Co(II) and Ni(II) respectively. The relative standard error (RSE) for the simultaneous determination of 15 test
samples of different concentrations of Zn(II), Co(II) and Ni(II) was 4.38%;, 1.18% and 2.42%, respectively. The total relative
standard error (RSEt) for applying the PLS method to 15 synthetic samples in the linear ranges of these metals was 2.36%. The interference effect
of some anions and cations was also tested. The method was applied to the simultaneous determination of Zn(II), Co(II) and
Ni(II) in water and human urine samples. 相似文献
7.
E. A. Osipova E. N. Shapovalova M. N. Ofitserova S. V. Podlesnykh 《Journal of Analytical Chemistry》2000,55(1):52-57
It was demonstrated that Pb(II), Cd(II), Hg(II), Ni(II), Co(II), and Cu(II) can be indirectly determined as their unithiol
complexes by amperometric detection under static and HPLC conditions. Factors affecting the Chromatographic separation and
amperometric detection of metal complexes of unithiol were studied. Two designs of flow electrochemical cells (thin-layer
and wall-jet cells) and three electrode materials (platinum, graphite, and glassy carbon) were compared. The best sensitivity
was attained for an amperometric detector with wall-jet flow cell and a graphite indicator electrode. The detection limits
for Hg(II), Pb(II), and Cd(II) were 0.9, 0.3, and 0.1 μg/mL, respectively. The Chromatographic determination of heavy metals
in a sample of waste water was carried out using the amperometric detector 相似文献
8.
M. B. Gholivand Y. Mozaffari Sh. Sobhani J. Ghasemi 《Journal of Analytical Chemistry》2008,63(3):232-238
A spectrophotometric method for the determination of trace amounts of cobalt(II), nickel(II), and copper(II) after the adsorption
of their 2-aminocyclopentene-1-dithiocarboxylate complexes on microcrystalline naphthalene has been developed. These complexes
are adsorbed on microcrystalline naphthalene at pH 4.5 by shaking for 5 min. The formed solid mass is separated by filtration,
and dissolved in dimethylformamide. The absorption spectra were processed using the partial least-squares multivarate calibration
method for the analysis of a ternary mixture of Co(II), Ni(II), and Cu(II). The detection limits for Co(II), Ni(II), and Cu(II)
were 3.3, 10.0, and 0.8 ng/mL, respectively. The total relative standard error for applying the method to 20 synthetic samples
in the concentration ranges of 20–400 ng/mL Co(II), 60–400 ng/mL Ni(II), and 4–400 ng/mL Cu(II) was 1.53%. The proposed method
was also successfully applied to the determination of Co(II), Ni(II), and Cu(II) in alloys.
The text was submitted by the authors in English. 相似文献
9.
2-Quinolinethiol forms very stable cobalt and nickel complexes, which are strongly chemisorbed on the hanging mercury drop electrode (HMDE). This allows the simultaneous determination of cobalt, nickel and labile zinc traces; Co and Ni by differential pulse adsorptive stripping voltammetry (DPAdSV) and Zn by differential pulse sweep voltammetry (DPSV), even in the presence of a large amount of surfactant like Triton X-100. This is advantageous for determining these metals directly in natural waters, without previous UV-irradiation or acid digestion. The surfactant does not only not interfere, but shows a beneficial effect with respect to the resolution between copper and nickel peaks. The method has been tested in estuary waters. The determination limits are 1 nmol/l Ni, 10 nmol/l Co and 1 mol/l Zn, with RSD less than 6.3%. 相似文献
10.
The conditions for the flow determination of Al(III), Bi(III), Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Nd(III), Ni(II), Pb(II), Pr(III), and Zn(II) by reaction with Xylenol Orange in aqueous solutions at pH 4.5 and the determination of Cd(II), Co(II), Cu(II), Fe(II), Ni(II), Pb(II), and Zn(II) by reaction with 4-(2-thiazolylazo)resorcinol in water–ethanol mixtures (5 : 1) at pH 5.0 using an injected sample volume of 80 L were proposed. The limits of detection were n × 10–8–n × 10–7 mol/L; the linearity ranges in the calibration graphs were of about three orders of magnitude; the relative standard deviation was of 3–7%. 相似文献
11.
A new chelating resin, 1-(2-pyridylazo)-2-naphthol (PAN) coated Amberlite XAD-1180 (AXAD-1180), was prepared and used for
the preconcentration of Cd(II), Mn(II), Ni(II), Pb(II) and Zn(II) ions prior to their determination by flame atomic absorption
spectrometry (FAAS). The optimum pH for simultaneous retention of the elements and the best elution means for their simultaneous
elution were pH 9.5 and 3 M HNO3, respectively. The sorption capacity of the resin was found to be 5.3 mg/g for Cd and 3.7 mg/g for Ni. The detection limits
for Cd(II), Mn(II), Ni(II), Pb(II) and Zn(II) were 0.7, 10, 3.1, 29 and 0.8 μg/L, respectively. The effects of interfering
ions for quantitative sorption of the metal ions were investigated. The preconcentration factors of the method were in the
range of 10–30. The recoveries obtained were quantitative (≥95%). The standard reference material (GBW07605 Tea sample) was
analysed for accuracy of the described method. The proposed method was successfully applied to the analysis of various water,
urea fertilizer and tea samples.
The article is published in the original. 相似文献
12.
Morteza Bahram Khalil Farhadi Abbas Afkhami Donya Shokatynia Farzin Arjmand 《Central European Journal of Chemistry》2009,7(3):375-381
A partial least squares (PLS-1) calibration model based on kinetic—spectrophotometric measurement, for the simultaneous determination
of Cu(II), Ni(II) and Co(II) ions is described. The method was based on the difference in the rate of the reaction between
Co(II), Ni(II) and Cu(II) ions with 1-(2-pyridylazo)2-naphthol in a pH 5.8 buffer solution and in micellar media at 25°C.
The absorption kinetic profiles of the solutions were monitored by measuring the absorbance at 570 nm at 2 s intervals during
the time range of 0–10 min after initiation of the reaction. The experimental calibration matrix for the partial least squares
(PLS-1) model was designed with 30 samples. The cross-validation method was used for selecting the number of factors. The
results showed that simultaneous determination could be performed in the range 0.1-2 μg mL−1 for each cation. The proposed method was successfully applied to the simultaneous determination of Cu(II), Ni(II) and Co(II)
ions in water and in synthetic alloy samples.
相似文献
13.
Potentiometric investigations on metal complexes of various bivalent metal ions, viz. UO2(II), Cu(II), Ni(II), Co(II), Cd(II), Pb(II), Zn(II) and Mn(II) with benzilmonol(lepidy!)hydrazone (BLH) have been carried
out at different ionic strengths and at different temperatures in order to determine stability constants of the complexes.
Thermodynamic parameters ΔC, ΔH and ΔS have also been evaluated from temperature coefficient data. The effect of varying the
dielectric constant of the medium on the stability constants of complexes has also been investigated at 30±0.5°C and μ = 0.1MNaCl.
Thermodynamic stability constants and thermodynamic stabilization energies for the first transition metals have also been
discussed. 相似文献
14.
Wiesława Ferenc Agnieszka Walków-Dziewulska Maria Wojciechowska J. Sarzyński 《Journal of Thermal Analysis and Calorimetry》2006,86(2):359-364
Physico-chemical properties of 4-chloro-2-nitrobenzoates of Co(II),
Ni(II), and Cu(II) were studied. The complexes were obtained as mono- and
trihydrates with a metal ion to ligand ratio of 1:2. All analysed 4-chloro-2-nitrobenzoates
are polycrystalline compounds with colours depending on the central ions:
pink for Co(II), green for Ni(II), and blue for Cu(II) complexes. Their thermal
decomposition was studied only in the range of 293–523 K, because it
was found that on heating in air above 523 K 4-chloro-2-nitrobenzoates decompose
explosively. Hydrated complexes lose crystallization water molecules in one
step and anhydrous compounds are formed. The final products of their decomposition
are the oxides of the respective transition metals. From the results it appears
that during dehydration process no transformation of nitro group to nitrite
takes place. The solubilities of analysed complexes in water at 293 K are
of the order of 10–4–10–2
mol dm–3. The magnetic moment values of Co2+,
Ni2+ and Cu2+ ions in
4-chloro-2-nitrobenzoates experimentally determined at 76–303 K change
from 3.89 to 4.82 μB for Co(II) complex, from 2.25
to 2.98 μB for Ni(II) 4-chloro-2-nitrobenzoate,
and from 0.27 to 1.44 μB for Cu(II) complex. 4-chloro-2-nitrobenzoates
of Co(II), and Ni(II) follow the Curie–Weiss law. Complex of Cu(II)
forms dimer. 相似文献
15.
Mohamed M. Shoukry Ihsan M. Kenawy Afkar K. Abdel Hadi Eman M. Shoukry 《Journal of Chemical Sciences》1988,100(5):381-388
The formation constants of salicyl-4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-one (SAAP) complexes with 3d transition metal
ions [Cu(II), Ni(II), Co(II), Zn(II) and Mn(II)] have been determined in 60% ethanol-water medium ofμ = 0.1M (NaCl) at 25°C. It is observed that the formation constants for chelates with 3d transition metals follow the order
Mn(II) < Co(II) < Ni(II) < Zn(II) < Cu(II). The effects of metal ions, ionic radii, electronegativities and ionization potentials
on chelate formation constants are discussed.
Complexes of UO2(II) and Pd(II) have been synthesized and characterised by elemental analysis, electrolytic conductance, IR spectra and magnetic
measurements. The ligand forms the complexes PdLCl and UO2L2,2H2O, where L is a uninegatively charged tridentate ligand (ONO donor sets). 相似文献
16.
E. Gómez J. M. Estela V. Cerdà M. Blanco 《Fresenius' Journal of Analytical Chemistry》1992,342(4-5):318-321
Summary A new method for the simultaneous determination of the divalent ions of cadmium, cobalt, copper, lead, manganese, nickel and zinc in binary, ternary and quaternary mixtures based on the application of a multiple linear regression programme to the spectra of the complexes of these ions with 4-(pyridyl-2-azo)resorcinol (PAR) was developed. The detection limits afforded by the proposed method range from 0.02 g/ml for Co(II), Mn(II), Ni(II) and Zn(II) to 0.10 g/ml for Pb(II). The method is rapid and quite simple as it entails no prior separation, and was successfully applied to the analysis for the above-mentioned ions in synthetic samples and real alloys. 相似文献
17.
M. M. Palrecha 《Fresenius' Journal of Analytical Chemistry》1995,351(8):800-801
A sensitive method for the simultaneous determination of trace amounts of nickel and cobalt in pure aluminium has been described using differential pulse adsorptive stripping voltammetry (DPASV) by adsorptive accumulation of the dimethyl glyoxime (DMG) complex on the hanging mercury drop electrode (HMDE). As supporting electrolyte 0.1 mol/l ammonia buffer, pH 9.0, containing ammonium citrate and 5×10–4 mol/l DMG has been used. The determination limit obtained has been as low as 0.5 g/g for Ni and 0.2 g/g for Co (using about 100 mg sample) with a relative standard deviation of 13% and 22%, respectively. 相似文献
18.
M. A. Kabil S. E. Ghazy A. A. El-Asmy Y. E. Sherif 《Analytical and bioanalytical chemistry》1997,357(4):401-404
A sensitive and selective flotation procedure for the separation of microamounts of Co(II), Ni(II) and Cu(II) separately
or in admixture is described. The maximum separation rate (∼1) for 0.1 mmol/L of each analyte is achieved using 1 mmol/L of
both oleic acid (HOL) surfactant and 4-phenylthiosemicarbazide (HPTS) as a collector in the pH range 6–7. A method for the
simultaneous separation and microdetermination of the analytes is elaborated, based on adding excess HPTS and floating the
species with HOL at pH ∼6. The filtrate (which is clear brownish-yellow) obtained from the scum is used for the spectrophotometric
determination of Co(II) at 350 nm. The formation constants of 1:1 and 1:2 [Co(II):HPTS] species are 6.9×105 and 1.22×1010 L mol-1, respectively. Beer’s law is obeyed up to 9 μg/mL of Co(II) with a molar absorptivity of 1.15×104 L mol-1 cm-1. The precipitate in the scum layer is quantitatively collected, dissolved in aqua regia and aspirated directly into the flame
for the (AAS) determination of Ni and Cu. The procedure is successfully applied to some natural water samples. A mechanism
for the separation of the analytes is proposed.
Received: 23 January 1996/Revised: 1 April 1996/Accepted: 9 April 1996 相似文献
19.
Manganese, nickel, cobalt, and zinc are elements that appear together in many real samples. In this work, a simple, rapid, and sensitive method has been used for the simultaneous separation and preconcentration of trace amounts of these elements using water-soluble polyacrylic acid on alumina as a sorbent in a glass column system. A solution containing Mn, Ni, Co, and Zn was passed through the column at pH 7, and desorption was carried with 5.0 mL of 0.03 M nitric acid. Linearity was maintained between 0.25-5.0 x 10(3), 0.04-6.0 x 10(3), 0.10-8.0 x 10(3), and 0.028-1.0 x 10(3) ng/mL for Ni, Mn, Co, and Zn, respectively, in the original solution. Eight replicate determinations of a mixture containing 1.0 microg/mL of each of the elements in the final solution gave relative standard deviations of 1.4, 1.5, 2.4, and 1.2% for Ni, Mn, Co, and Zn, respectively. The sorption capacities for Mn (mg/g sorbent) obtained were 16.0 for Mn, 9.0 for Ni, 12.0 for Co, and 10.0 for Zn. By using 5.0 mL elution solution, preconcentration factors of 400, 500, 700, and 460 could be obtained for Ni, Mn, Zn, and Co, respectively. 相似文献
20.
A new chelating resin, Xylenol Orange coated Amberlite XAD-7, was prepared and used for preconcentration of Cd(II), Co(II), Cu(II), Fe(III), Ni(II) and Zn(II) prior to their determination by flame atomic absorption spectrophotometry. The optimum pH values for quantitative sorption of Cd(II), Co(II), Cu(II), Fe(III), Ni(II) and Zn(II) are 4.5-5.0, 4.5, 4.0-5.0, 4.0, 5.0 and 5.0-7.0, respectively, and their desorptions by 2 mol L(-1) HCl are instantaneous. The sorption capacity of the resin has been found to be 2.0, 2.6, 1.6, 1.6, 2.6 and 1.8 mg g(-1) of resin for Cd, Co, Cu, Fe, Ni and Zn, respectively. The tolerance limits of electrolytes, NaCl, NaF, NaI, NaNO3, Na2SO4 and of cations, Mg2+ and Ca2+ in the sorption of the six metal ions are reported. The preconcentration factor was between 50 and 200. The t1/2 values for sorption are found to be 5.3, 2.9, 3.2, 3.3, 2.5 and 2.6 min for the six metals, respectively. The recoveries are between 96.0 and 100.0% for the different metals at preconcentration limits between 10 to 40 ng mL(-1). The preconcentration method has been applied to determine the six metal ions in river water samples after destroying the organic matter (if present in very large amount) with concentrated nitric acid (RSD < or = 8%, except for Cd for which it is upto 12.6%) and cobalt content of vitamin tablets with RSD of approximately 3.0%. 相似文献