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1.
A new and efficient Hg(II) back-elution method for the desorption of Cd, Cu, and Pb from Chelex-100 chelating resin was developed.
A smaller eluent volume and shorter elution time can be achieved using an Hg(II) containing eluent rather than pure nitric
acid. Owing to the remaining Hg(II) ion in the effluent, a mercury thin-film electrode is formed in-situ during the anodic
stripping voltammetric determination without any further addition of Hg(II). The results indicate that all the analytes in
seawater matrix can be completely adsorbed on Chelex-100 resin from the sample at pH 6.5, and subsequently eluted from the
resin with an acid solution of 5 × 10–4 mol/L Hg2+ + 1 mol/L HClO4. The detection limits obtained from the differential-pulse anodic (μg L–1 to ng L–1) stripping voltammetry are at sub-ppb to ppt (μg L–1 to ng L–1) levels permitting to determine Cd, Cu and Pb traces in seawater. The analytical reliability was confirmed by the analysis
of the certified reference material CASS-II (open ocean seawater).
Received: 22 April 1997 / Revised: 5 August 1997 / Accepted: 7 August 1997 相似文献
2.
D. Desideri M. A. Meli C. Roselli 《Journal of Radioanalytical and Nuclear Chemistry》2010,285(2):373-382
In various samples of marine organisms from the central Adriatic Sea 210Po was determined by alpha spectrometry and thirteen heavy metals (Mn, Fe, Co, Cr, V, Ni, Cu, Zn, Cd, As, Sn, Hg and Pb) by
energy dispersive, polarised X ray fluorescence spectrometry (EDPXRF). 210Po activity concentration ranged between 0.3 and 44.6 Bq kg−1 fresh weight. The data obtained depend upon the type of the marine organism; among the pelagic species, anchovy displayed
the highest polonium concentration. Typical concentration
( \upmu \textg·\textg(\textfresh) - 1 ) \left( {\upmu {\text{g}}\cdot{\text{g}}_{{({\text{fresh}})}}^{ - 1} } \right) ranges were as follows: Mn: <1.32–1.73; Fe: 4.11–94.27; Co < 0.13–0.23; Ni: <0.13–0.52; Cu: 0.37–145.31; Zn: 0.46–16.46;
Cd: <0.10–0.25; As: 0.36–60.52; Hg: <0.13–0.70; Pb: <0.13–0.35, Sn: <0.20–12.67; V and Cr were always <1.32. The data obtained
are also compared with those obtained by other authors for the same organism coming from other Italian seas. 相似文献
3.
Arvydas Survila Dalia Bražinskienė Stasė Kanapeckaitė Zenius Mockus Vitalija Jasulaitienė 《Journal of Solid State Electrochemistry》2010,14(4):507-514
Voltammetry and electrochemical impedance spectroscopy technique were applied to study the effect of polyethylene glycols
(PEG) with different molecular mass on Cu(II) and Sn(II) reduction kinetics in acidic sulfate solutions. Tetraethylene glycol
was found to be the surface-active oligomer on both Cu and Sn substrates that holds the shortest (–CH2–CH2–O–)m chain. The exchange current density of the rate-limiting step Cu2+ + e → Cu+ falls drastically with an increase in the molecular mass of PEG. An addition of PEG into halide-free Sn(II) solutions results
in the significant inhibition of Sn(II) reduction in the entire range of cathodic polarizations including the region of limiting
current. Inhibition degree also increases with PEG molecular mass. In contrast with Cu|Cu(II) system, formation of adsorption
layers on Sn electrodes proceeds significantly slower. Underpotential deposition of Sn(II) is observed in the region of Cu(II)-limiting
current. The characteristic current minimum arises in the region where free Sn phase is thermodynamically stable. It deepens
with the length of the hydrocarbon chain of PEG. The fall of current density seems to arise from the inhibitive PEG adsorption
on tin atoms that are still not incorporated into general Cu–Sn lattice. 相似文献
4.
D. Desideri M. A. Meli C. Roselli L. Feduzi 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(2):591-600
In various samples of Mytilus galloprovincialis, 210Po was determined by alpha-spectrometry while Mn, Fe, Ni, Cu, Zn, Cd, Sn, Hg and Pb by energy dispersive, polarised X-ray
fluorescence spectrometry (EDPXRF). The mussels of different sizes were taken from 7 sites in the central Adriatic Sea along
the Marche coastal region during the four seasons of the year. 210Po activity concentration ranged between 57 and 343 Bq·kg−1 dry weight. The concentration ranges of heavy metals (μg·g−1 dry weight) were as follows: Mn: 72.9–83.1; Fe: 45.1–754; Ni: 1.3–7.6; Cu: 17.9–156; Zn: 60.9–189; Cd: 0.6–1.0; Sn: 0.6–3.9;
Hg always <0.5; Pb: 2.0–9.0. The data obtained depend upon the site and the period of the sampling and they are also compared
with those obtained by other authors for the same organism in the Mediterranean and other Italian seas. 相似文献
5.
H. Cesur 《Chemical Papers》2007,61(5):342-347
A new solid-phase extraction method has been developed for the selective extraction of Cu(II) in an aqueous system using freshly
precipitated lead diethyldithiocarbamate (Pb(DDTC)2) as a reagent. The method is based on the quantitative replacement of Pb(II) ions in the solid Pb(DDTC)2 phase by Cu(II) ions present in aqueous phase. The obtained solid Cu(DDTC)2 phase was dissolved in chloroform and determined spectrophotometrically at 435 nm. Beer’s law was obeyed over the concentration
range of 0.2–5 mg dm−3. The molar absorptivity and the Sandell’s sensitivity coefficients of the solutions were 1.0689 × 104 dm3 mol−1 cm−1 and 0.0060 μg cm−2, respectively. The optimum conditions for each parameter were experimentally determined and possible interferences of various
salts were also studied. The method has been validated and applied to determine Cu(II) in various alloys and water samples. 相似文献
6.
dos Santos EJ Herrmann AB Frescura VL Welz B Curtius AJ 《Analytical and bioanalytical chemistry》2007,388(4):863-868
Among the “traditional” hydride-forming elements, lead is probably the most difficult, and its determination in this form
has rarely been reported in the literature. In this paper a simple and rapid method, axial-view inductively-coupled plasma
optical-emission spectrometry using on-line hydride generation (HG–ICP–OES) from samples prepared as slurry, is proposed for
determination of lead in environmental samples. The samples (20–50 mg, particle size ≤120 μm) were treated with 1 mL aqua
regia in a 40-kHz ultrasonic bath for 60 min. The slurry was diluted to a final volume of 50 mL with a 10% m/v solution of (NH4)2S2O8. The concentrations of NaBH4, tartaric acid, and (NH4)2S2O8, used for on-line plumbane generation were optimized by means of a complete factorial analysis applied to an aqueous standard
solution and to the slurry of a sediment certified reference material (CRM). External calibration against aqueous standards
in the concentration range 10–100 μg L−1 was used for analysis of six CRM—three marine sediments, one river sediment, and two sewage sludges. Analysis of the filtered
slurry showed that Pb was only partially extracted into the liquid phase. Several major concomitants tested did not affect
the Pb signal. The detection limit (3s, n = 10) for 20 mg sample in a final volume of 50 mL was 5.0 μg g−1. Tin was the only other hydride-forming analyte that could be determined satisfactorily with Pb; for tin the detection limit
was 1.0 μg g−1. The values obtained for Pb and Sn were not significantly different from the certified concentrations, according to the t-test at the 95% confidence level. Nine river sediments collected locally were also analyzed and the concentrations were in
agreement with results obtained after total digestion. 相似文献
7.
The determination of cadmium in different samples such as coal fly ashes, soils and sediments by Graphite Furnace Atomic
Absorption Spectrometry (GFAAS) was studied. The best analytical conditions and instrumental parameters were deduced. Different
types of matrix modifiers were tested and an optimization of several conditions (pyrolysis and atomization temperatures, heating
rate, use of L’vov platform, etc.) was carried out. A mixture of 2% NH4H2PO4 + 0.4% Mg(NO3)2 in 0.5 mol L–1 HNO3 as matrix modifier provided the highest sensitivity and an efficient behaviour for the three types of samples. A detection
limit of 26 ng g–1 was achieved and other figures of merit are shown. Analytical results obtained by direct calibration using standard samples
prepared in the laboratory and by standard addition method were comparable.
Received: 6 November 1998 / Revised: 4 February 1999 / Accepted: 9 February 1999 相似文献
8.
A better repeatability and accuracy in the quantitative determination of trace elements in mussel shells or carbonate-based
materials by LA-ICP-MS was achieved by using a series of multielement calibration standards prepared by co-precipitation of
twelve elements into a CaCO3 matrix in order to improve the homogeneity of the resulting powder samples. Pressed powder discs of good mechanical stability
could be obtained at a pressure of 50 MPa, without the addition of a binder. An UV laser (modified Nd:YAG, 266 nm) was used
in the Q-switched mode at a repetition rate of 10 Hz and an energy level of 3.5 mJ. Correlation coefficients (R) for the linear
calibration graphs (concentration range: 1.5–400 μg/g) for Cr, Mn, Co, Cu, Zn, As, Cd, Sn, Ba, and Pb are generally better
than 0.997. The detection limits for all elements investigated are in the sub-μg/g range. Incorporation of elements into the
matrix by co-precipitation has shown as a superior method for producing calibration standards than the simple mixture of the
analytes (in carbonate or oxide form) with the matrix (CaCO3) or addition of standard solutions to a carbonate powder base. Two examples of the quantitative determination of toxic elements
in mussel shells will be presented.
Received: 10 January 2000 / Revised: 16 March 2000 / Accepted: 26 March 2000 相似文献
9.
Yosuke Imai Kei Shimamoto Takanori Takiue Hiroki Matsubara Makoto Aratono 《Colloid and polymer science》2010,288(9):1005-1011
The surface tension of aqueous mixtures of dodecyltrimethylammonium tetrafluoroborate (DTABF4) and sodium tetrafluoroborate (NaBF4) was measured as a function of total molality and composition of DTABF4 at 298.15 K. The results were analyzed by originally developed thermodynamic equations and compared with those of dodecyltrimethylammonium
bromide (DTAB)–sodium bromide (NaBr) mixed system. It was indicated that BF4− ions reduce the repulsion between DTA+ ions more effectively than Br− ions in the adsorbed film. To investigate this difference more closely, the surface tension of DTAB–NaBF4 and DTABF4–NaBr mixed system was also measured. The data analysis revealed that BF4− ions are adsorbed positively even for the pure NaBF4 system and preferentially to Br− ions in these mixtures. Furthermore, it was concluded that the side-by-side arrangement suggested in the adsorbed film of
1-hexyl-3-methylimidazolium tetrafluoroborate (HMIMBF4) is due to not only the positive adsorption of BF4− ions but also the capability of hydrogen bond formation between imidazolium ion and BF4− ions. 相似文献
10.
F. H. Assaf 《Journal of Solid State Electrochemistry》1998,3(1):39-47
The anodic polarization behaviour of Al-Sn alloy (5.6% Sn) was studied in aerated 1, 1.5 and 2 M H3PO4 acid solutions using potentiodynamic and potentiostatic techniques. Anodic behaviour of Al and Sn metals was investigated
for comparison. The results show that the alloy exhibits active-passive transition behaviour. The passivation of the examined
alloy is due to the formation of oxide film for both Al and Sn incorporated with their phosphates. In general, at constant
concentration of PO4
3− ion, the passive current density (I
pass) is decreased with increase of pH in the range 2.5–5. Further, the influence of Cl− ions on the passivity of the given alloy was studied. It was found that the aggressive effect of Cl− ions on the passive film is inhibited with increase in phosphate concentration and pH. However, the addition of organic compounds
(2- and 3-picoline and 2-aminopyridine) shows that only 2-aminopyridine inhibited the attack of Cl− ions.
Received: 24 October 1997 / Accepted: 5 February 1998 相似文献
11.
A novel silica sorbent, silica gel-immobilized 5-aminoisophthalohydrazide (SiO2-APH), was prepared by the condensation of 3-chloropropyl-functionalized silica gel with 5-aminoisophthalohydrazide (APH) derived from dimethyl 5-aminoisophthalate as a starting material and used for separation and preconcentration of Cu, Zn, and Pb metals in water samples using Flame Atomic Absorption Spectrometry (FAAS). The characterization of the new sorbent was carried out by Elemental Analysis, Thermogravimetric Analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR). Important analytical parameters including as pH, amount of sorbent, type and amount of eluting solvent, sample volume, vortex and ultrasonic bath time, matrix ions that effect the developed SiO2-APH-solid phase extraction (SPE) method were investigated and optimum parameters were detected. Recoveries of examined metals were obtained as 98% for Cu and Pb and 101% for Zn. The relative standard deviation (RSD, n = 8) of Cu, Zn and Pb metals were 3.2, 2.8 and 1.6%, respectively. Limit of detections (LODs) (n = 10) were found as 2.7 μg L−1 for Cu, 7.4 μg L−1 for Zn and 3.5 μg L−1 for Pb μg L−1. The accuracy of the new method was assessed by analyzing of TMDA-51.4 and TMDA-70.2 certified reference materials. The results obtained for metals were in a good agreement with certified values. Addition/recovery test was applied to the real well, river, dam and stream water samples to check the accuracy of the method. The results showed that the developed SiO2-APH-SPE method can be effectively used as an alternative method for determination of Cu, Zn, and Pb metals in water samples. 相似文献
12.
Ultrasonic slurry sampling electrothermal vaporization dynamic reaction cell inductively coupled plasma mass spectrometry
(USS–ETV–DRC–ICP–MS) for the determination of Cr, Cd and Pb in several plastic samples, using NH4NO3 as the modifier, is described. The influences of the instrumental operating conditions and the slurry preparation technique
on the ion signals are investigated. A reduction in the intensity of the background at signals corresponding to chromium masses
(arising from matrix elements) was achieved by using NH3 as the reaction cell gas in the DRC. The method was applied to determine Cr, Cd and Pb in two polystyrene (PS) samples and
a polyvinyl chloride (PVC) sample using two different calibration methods, namely standard addition and isotope dilution.
The results were in good agreement with those for digested samples analyzed by ultrasonic nebulization DRC–ICP–MS. The precision
between sample replicates was better than 17% with the USS–ETV–DRC–ICP–MS method. The method detection limits, estimated from
standard addition curves, were about 6–9, 1–2 and 8–11 ng g−1 for Cr, Cd and Pb, respectively, in the original plastic samples. 相似文献
13.
A systematic investigation of the M+BF4
− (M = Li or NH4) ion-pair conformers has been carried out using an electrostatic docking model based on the molecular electrostatic potential
topography of the free anion. This method provides a guideline for the subsequent ab initio molecular orbital calculations
at the Hartree-Fock (HF) and second-order M?ller-Plesset perturbation theory (MP2) levels. It has been demonstrated that the
model presented here yields more than 75% of the HF interaction energy when Li+ is the cation involved and more than 90% for the case of NH4
+. Inclusion of MP2 correlation in the HF-optimized geometries leads to stationary point geometries with different numbers
of imaginary frequencies and in some places where the energies of two adjacent conformers are very close, the energy rank
order is altered. The HF lowest-energy minima for the Li+BF4
− and NH4
+BF4
− show a bidentate and tridentate coordinating cation, respectively, whereas at the MP2 level, this ordering is reversed.
Received: 9 September 1997 / Accepted: 5 November 1997 相似文献
14.
Hongnian Ji Zhenhuan Liao Junmei Sun Zucheng Jiang Hongnian Ji Zhenhuan Liao Junmei Sun Zucheng Jiang 《Fresenius' Journal of Analytical Chemistry》1998,360(6):721-723
Using active carbon-silica gel as adsorbent and sodium diethyldithiocarbamate (NaDDTC) as chelating reagent in a flow injection
system, an ICP-AES method has been developed for preconcentration and determination of trace metallic elements in high purity
rare earth oxides. The experimental parameters such as pH, flow rate, amount of adsorbent, length of reaction coil and eluent
acidity were optimized. At pH 4.6 Al,Cr,Cu,Fe,Pb,V,Zn could be preconcentrated, and subsequently determined by ICP-AES. This
method can eliminate matrix effects. Its enrichment factors were 8.1–12.6 with detection limits in the ng/mL range and RSD
of 2.3–5.0. This method was applied to the analysis of high purity of La2O3 and Eu2O3 with satisfactory results.
Received: 24 April 1997 / Revised: 22 September 1997 / Accepted: 7 October 1997 相似文献
15.
Hongnian Ji Zhenhuan Liao Junmei Sun Zucheng Jiang Hongnian Ji Zhenhuan Liao Junmei Sun Zucheng Jiang 《Analytical and bioanalytical chemistry》1998,360(6):721-723
Using active carbon-silica gel as adsorbent and sodium diethyldithiocarbamate (NaDDTC) as chelating reagent in a flow injection
system, an ICP-AES method has been developed for preconcentration and determination of trace metallic elements in high purity
rare earth oxides. The experimental parameters such as pH, flow rate, amount of adsorbent, length of reaction coil and eluent
acidity were optimized. At pH 4.6 Al,Cr,Cu,Fe,Pb,V,Zn could be preconcentrated, and subsequently determined by ICP-AES. This
method can eliminate matrix effects. Its enrichment factors were 8.1–12.6 with detection limits in the ng/mL range and RSD
of 2.3–5.0. This method was applied to the analysis of high purity of La2O3 and Eu2O3 with satisfactory results.
Received: 24 April 1997 / Revised: 22 September 1997 / Accepted: 7 October 1997 相似文献
16.
Roberta Eliane Santos Froes Waldomiro Borges Neto Nilton Oliveira Couto e Silva Rita Lopes Pereira Naveira Clésia Cristina Nascentes José Bento Borba da Silva 《Spectrochimica Acta Part B: Atomic Spectroscopy》2009
A method for the direct determination (without sample pre-digestion) of microelements in fruit juice by inductively coupled plasma optical emission spectrometry has been developed. The method has been optimized by a 23 factorial design, which evaluated the plasma conditions (nebulization gas flow rate, applied power, and sample flow rate). A 1:1 diluted juice sample with 2% HNO3 (Tetra Packed, peach flavor) and spiked with 0.5 mg L− 1 of Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Sn, and Zn was employed in the optimization. The results of the factorial design were evaluated by exploratory analysis (Hierarchical Cluster Analysis, HCA, and Principal Component Analysis, PCA) to determine the optimum analytical conditions for all elements. Central point condition differentiation (0.75 L min− 1, 1.3 kW, and 1.25 mL min− 1) was observed for both methods, Principal Component Analysis and Hierarchical Cluster Analysis, with higher analytical signal values, suggesting that these are the optimal analytical conditions. F and t-student tests were used to compare the slopes of the calibration curves for aqueous and matrix-matched standards. No significant differences were observed at 95% confidence level. The correlation coefficient was higher than 0.99 for all the elements evaluated. The limits of quantification were: Al 253, Cu 3.6, Fe 84, Mn 0.4, Zn 71, Ni 67, Cd 69, Pb 129, Sn 206, Cr 79, Co 24, and Ba 2.1 µg L− 1. The spiking experiments with fruit juice samples resulted in recoveries between 80 and 120%, except for Co and Sn. Al, Cd, Pb, Sn and Cr could not be quantified in any of the samples investigated. The method was applied to the determination of several elements in fruit juice samples commercialized in Brazil. 相似文献
17.
Karadjova IB Lampugnani L D'Ulivo A Onor M Tsalev DL 《Analytical and bioanalytical chemistry》2007,388(4):801-807
A rapid, accurate, and precise method is described for the determination of Pb in wine using continuous-flow hydride generation
atomic fluorescence spectrometry (CF-HGAFS). Sample pretreatment consists of ten-fold dilution of wine followed by direct
plumbane generation in the presence of 0.1 mol L−1 HCl and 1% m/v K3[Fe(CN)6] with 1% m/v NaBH4 as reducing agent. An aqueous standard calibration curve is recommended for Pb quantification in wine sample. The method
provides a limit of detection and a limit of quantification of 0.3 μg L−1 and 1 μg L−1, respectively. The relative standard deviation varies between 2–6% (within-run) and 4–11% (between-run) at 3–30 μg L−1 Pb levels in wine. Good agreement has been demonstrated between results obtained by CF-HGAFS and direct electrothermal atomic
absorption spectrometry in analyses of red and white wines within the concentration range of 9.2–25.8 μg L−1 Pb. 相似文献
18.
T. V. Baukova L. G. Kuz'mina A. V. Churakov N. A. Oleinikova P. V. Petrovskii 《Russian Chemical Bulletin》1998,47(2):343-348
The reaction of [O(AuPPh3)3]+BF4
− with a Li, K derivative ofo-cresol followed by the interaction of the reaction product with CO2 gave (triphenylphosphine)gold acetate. The reaction of ClAuPPh3 witho-LiC6H4SLi afforded (triphenylphosphine)gold thiophenoxide. According to the data of X-ray structural analysis, the latter occurs
as a dimer formed through an intermolecular secondary Au…Au bond. The reaction of this complex with diazomethane was accompanied
by insertion of carbene into the Au−S bond to form a new gold complex, PhSCH2AuPPh3. The reactions with PPh3Au+BF4
− or HBF4 yielded a new tetranuclear gold thiocluster, {[PhS(AuPPh3)2]2+(BF4
−)}2, which involves Au…Au bonds that differ in strength. The structures of the compounds obtained were established by X-ray structural
analysis1H and31P NMR spectroscopy, and FAB mass spectrometry.
For Part 4, seeIzv. Akad. Nauk, Ser. Khim., 1997, 2244 [Russ. Chem. Bull., 1997,46 2127 (Engl. Transl)].
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 350–355, February, 1998. 相似文献
19.
W. Yawar 《Journal of Analytical Chemistry》2010,65(5):489-491
A simple, rapid and reliable method was developed for the determination of copper, nickel, iron and lead in fresh and used
lubricating oil samples by flame atomic absorption spectrophotometry (FAAS). In the present study, a mixture of organic solvents containing propionic acid and iso-butylmethyl ketone (1: 1) was used to extract the metals from lubricating oil samples followed by FAAS analysis. Aqueous
standard solutions can be easily employed with the proposed mixed solvent system instead of organometallic standards. The
analytical results obtained by employing the proposed solvent extraction system were found to be in good agreement with the
results for aqueous media obtained after the destruction of oil samples matrix. Percentage recovery studies showed 88–98%
for Cu, 92–95% for Fe, 96–106% for Ni and 84–100% for Pb with relative standard deviation of 2–6%. The developed method was
effectively applied to routine determination of Cu, Ni, Fe, and Pb in lubricating oil samples. 相似文献
20.
Dimitrios V. Stergiou Spyros C. Karkabounas Panayotis G. Veltsistas Nicholaos P. Evmiridis Athanasios G. Vlessidis 《Mikrochimica acta》2007,158(1-2):59-64
A kinetic-potentiometric method is described for the quantitative assay of formaldehyde (HCHO) in pharmaceutical and industrial
preparations. It is based on the reaction of HCHO with (ethylenediamine)-Cu(II)-sulfate [Cu(CH2NH2)2(H2O)2] · SO4. The changes in potential, resulting from the release of the Cu(II) cations, are monitored with a Cu(II)-ion selective electrode.
The calibration curve for the HCHO is linear in the concentration range 50–250 mg L−1, with a limit of detection of 8.5 mg L−1. The method shows very good reproducibility with an RSD of 2.6% for successive injections (n = 5) of 150 mg L−1 HCHO primary solution, while it is interference free. The method was successfully tested in various industrial and pharmaceutical
preparations. 相似文献