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1.
Pickhardt C Brenner IB Becker JS Dietze HJ 《Fresenius' Journal of Analytical Chemistry》2000,368(1):79-87
Laser ablation inductively coupled plasma mass spectrometry using a quadrupole-based mass spectrometer (LA-ICP-QMS) was applied for the analysis of powdered zeolites (microporous aluminosilicates) used for clean-up procedures. For the quantitative determination of trace element concentrations three geological reference materials, granite NIM-G, lujavrite NIM-L and syenite NIM-S, from the National Institute for Metallurgy (South Africa) with a matrix composition corresponding to the zeolites were employed. Both the zeolites and reference materials were fused with a lithium borate mixture to increase the homogeneity and to eliminate mineralogical effects. In order to compare two different approaches for the quantification of analytical results in LA-ICP-MS relative sensitivity coefficients (RSCs) of chemical elements and calibration curves were measured using the geostandards. The experimentally obtained RSCs are in the range of 0.2-6 for all elements of interest. Calibration curves for trace elements were measured without and with Li or Ti as internal standard element. With a few exceptions the regression coefficients of the calibration curves are better than 0.993 with internal standardization. NIM-G granite reference material was employed to evaluate the accuracy of the technique. Therefore, the measured concentrations were corrected with RSCs which were determined using lujavrite reference material NIM-L. This quantification method provided analytical results with deviations of 1-11% from the recommended and proposed values in granite reference material NIM-G, except for Co, Cs, La and Tb. The relative standard deviation (RSD) of the determination of the trace element concentration (n = 5) is about 1% to 6% using Ti as internal standard element. Detection limits of LA-ICP-QMS in the lower microg/g range (from 0.03 microg/g for Lu, Ta and Th to 7.3 microg/g for Cu, with the exception of La) have been achieved for all elements of interest. Under the laser ablation conditions employed (lambda: 266 nm, repetition frequency: 10 Hz, pulse energy: 10 mJ, laser power density: 6 x 10(9) W/cm2) fractionation effects of the determined elements relative to the internal standard element Ti were not observed. 相似文献
2.
C. S. Erasmus H. W. Fesq E. J. D. Kable S. E. Rasmussen J. P. F. Sellschop 《Journal of Radioanalytical and Nuclear Chemistry》1977,39(1-2):323-334
The NIMROC reference materials NIM-D, NIM-G, NIM-L, NIM-N, NIM-P, and NIM-S and the precious metal ore PTO-1 have been analysed
using thermal and epithermal methods of instrumental neutron activation. The abundances of 40 major, minor and trace elements
are reported. The usefulness of the NIMROC reference materials is assessed in terms of the requirements of neutron activation
techniques. Of the seven reference materials, NIM-L is the most useful geochemical material for activation analysis. It contains
suitably high concentrations of most elements that can be determined. Inhomogeneity problems encountered in PTO-1 for some
elements give emphasis to the difficulty of selecting suitable geological material for ultra-trace elements where small quantities
of sample are used. 相似文献
3.
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
4.
R. P. Choudhury R. Acharya A. G. C. Nair A. V. R. Reddy A. N. Garg 《Journal of Radioanalytical and Nuclear Chemistry》2008,276(1):85-93
Four plant parts (leaves, roots, fruits and seeds) of twenty samples of sixteen antidiabetic herbs including three commercially
marketed capsules have been analyzed for 6 minor (Na, K, Ca, Cl, Mg, and P) and 21 trace (As, Ba, Br, Ce, Co, Cr, Cs, Cu,
Eu, Fe, Hg, La, Mn, Rb, Sb, Sc, Se, Sm, Th, V and Zn) elements by instrumental neutron activation analysis (INAA). Further,
Ni, Cd and Pb contents were determined by AAS. Elemental data were validated by simultaneously analyzing reference material
(RM), MPH-2 Mixed Polish Herbs. Several elements such as Cr and V (1–2 μg/g), Rb (10–40 μg/g), Cs (80–300 ng/g), Se (∼100
ng/g) and Zn (25–60 μg/g) play an important role in diabetes mellitus. Interelemental linear correlations have been observed
for Cu vs. Zn (r = 0.89) and Rb vs. Cs (r = 0.87). K/P ratio varies in a narrow range with a mean value of 6.2 ± 1.4. Toxic elements As and Hg were found in <1 μg/g
whereas Cd and Pb were in ∼5 μg/g and <10 μg/g, respectively. 相似文献
5.
M. Hyvönen-Dabek J. Räisänen J. T. Dabek 《Journal of Radioanalytical and Nuclear Chemistry》1981,63(1):163-175
A simple proton beam (PIXE) arrangement developed for a low energy accelerator was used for the determination of absolute
concentrations of nine trace elements in human bone samples. The 2.4 MeV proton beam was externalized through a thin (2 μm)
aluminiummylar foil. Using an air cooling system, the foil withstood a high current (0.5–1 μA) for a long time. The samples
were cooled to prevent damage and volatilization of elements. The induced X-rays were detected with a Si(Li) detector and
the external beam was monitored with a second detector, measuring K X-rays induced in atmospheric argon. The mean (SD) trace
element levels (ppm) measured in dense bone by comparison with hydroxyapatite/standard mixtures were: Cr<2.0, Mn<2.3, Fe 7.58
(1.55), Ni<2.4, Cu 3.58 (2.16), Zn 144 (27), Pb 12.2 (2.5), Br 12.4 (5.5) and Sr 47.7 (14.3). The detection limits for these
elements achieved in this work were about 1 ppm when rather short measuring times (∼10 min) were used. The coefficient of
variation of a single measurement, e.g. for Zn, was 3–4%. Because of the slow turnover of dense bone, such measurements provide
a means of monitoring long term trace element exposure. 相似文献
6.
Hitoshi Yamaguchi Sinji Itoh Shukuro Igarashi Kunishige Naitoh Ryosuke Hasegawa 《Fresenius' Journal of Analytical Chemistry》1998,362(4):395-398
Total reflection X-ray fluorescence (TXRF) analysis after the separation of matrix element was studied for the determination
of trace impurity elements (Ca, Sc, V, Cr, Mn, Fe, Co, Ni and Zn) in high purity copper. Matrix copper was removed by electrolysis
(0.2 A, 8 h) of a nitric acid solution. A 10 μL aliquot of the remaining solution of the electrolysis was dropped on a silicon-wafer
sample-carrier and dried in a vacuum. This was repeated five times and the precipitate of five 10 μL-aliquots was analyzed
by TXRF using a W-Lβ beam with an incident angle of 0.05 °. TXRF analytical values were obtained by using relative sensitivity
factors of the analytes to the internal standard element (Pd). Detection limits of the analytes ranges from 0.077 ng for Zn
to 0.785 ng for Ca.
Received: 25 December 1997 / Revised: 30 March 1998 / Accepted: 2 April 1998 相似文献
7.
G. A. Tavares E. Almeida J. G. G. de Oliveira J. A. Bendassolli V. F. Nascimento Filho 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(2):377-381
This study aimed to evaluate minor and trace elements in the water during different water purification steps of a deionized
water production plant, located at CENA, by total-reflection X-ray fluorescence (TXRF) technique, using Ga as internal standard
for elemental quantification. This approach was capable of determining Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Br, Rb at concentrations
higher than 40–100 μg L−1, and for K, Ca, Sc, Ti, V and Sr at concentrations higher than sub mg L−1 in the water samples. TXRF spectrometer encompasses an X-ray tube with a Mo target with a Zr filter. The elemental characteristic
X-rays were recorded by a Si(Li) semiconductor detector and the X-ray spectra deconvoluted by AXIL software. 相似文献
8.
Hüseyin Ba Mustafa Lale A. Rehber Türker 《Fresenius' Journal of Analytical Chemistry》1999,363(3):224-230
By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by
flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 ± 0.4% for Cu, 94.2 ± 0.3% for Zn, and 99.04 ± 0.04% for
Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of
the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 μmol/g
for copper, 128 μmol/g for zinc and 97 μmol/g for cadmium. After optimization the proposed method was applied to the trace
metal determination in sea and river water.
Received: 8 June 1998 / Revised: 8 September 1998 / Accepted: 16 September 1998 相似文献
9.
Determination of trace elements in granites by inductively coupled plasma mass spectrometry 总被引:66,自引:0,他引:66
Proposed is a simple and reliable method for the dissolution of granite and the determination of 38 elements by inductively coupled plasma mass spectrometry. One hundred milligrams of sample are digested with 1 ml of HF and 0.5 ml of HNO(3) in screw top PTFE-lined stainless steel bombs at 190 degrees C for 12 h. Insoluble residues are dissolved using 8 ml of 40% HNO(3) (v/v) heated to 110 degrees C for 3 h. Six granite standard reference materials (GSR-1, JG-2, G-2, NIM-G, SG-3, SG-1a) were studied. Analytical calibration was accomplished using aqueous standard solutions. Rhodium was used as an internal standard to correct for matrix effects and instrument drift. We report data for: Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Cs, Ba, Hf, Ta, W, Pb, Th, U and 14 of the rare earth elements. The recoveries for most of these elements in granite ranged from 90 to 110%. 相似文献
10.
M. I. Rucandio 《Analytical and bioanalytical chemistry》1997,357(6):661-669
An ion-exchange ICP-AES method for the determination of 14 rare earth elements (REEs) and Y in geological materials is described. The separation of REEs from Ba using a Dowex 50W-X8 cation resin is especially considered since Ba is an excellent internal standard for REE determination by this technique. Although total recovery with either HCl or HNO3 may be achieved, it is advantageous to use both acids sequentially. Volume and concentration of the acids are optimized attaining a quantitative separation of REEs from Ba by the introduction of the sample solution in a 1.75 mol/l HCl medium, followed by elution with 2 mol/l HNO3 to remove matrix elements and with 7 mol/l HNO3 to elute the analytes. The total elution volume is significantly reduced without decreasing the efficiency. The behaviour of the matrix constituents under the selected conditions is also studied, evaluating their elution percentages in each step. The final solution obtained contains only the REEs and Y, with the bulk of Sc and minor amounts of Cr, Fe, Hf and Ta. Experimental data for 5 geological reference standards (NIM-G, GSP-1, AGV-1, NIM-L and NIM-S) are reported. Good agreement between the present results and previously accepted values by various analytical techniques is observed. 相似文献
11.
Heinz F. Falk Bodo Hattendorf K. Krengel-Rothensee Nataly Wieberneit Sarah L. Dannen 《Fresenius' Journal of Analytical Chemistry》1998,362(5):468-472
An approach for the determination of trace element concentrations in high purity metals, using an inductively coupled plasma
mass spectrometer (ICP-MS) with a laser-ablation system for direct solid sample introduction after calibration with nebulized
liquid standards was made. Due to the inherent differences in the rate of sample introduction with laser-ablation and pneumatic
nebulization, a matrix element must be used as an internal standard. This is problematical for elements that have no isotope
with a relative abundance of less than 0.1 %, since the ion signals would be too high for direct measurement, and reduction
of the ablation rate would compromise the sensitivity for trace elements. Due to the high stability of ICP-unit and mass filter
of the instrument used, it was found that the tail of a mass-peak of the matrix element could be used as an internal standard.
Therefore, a position at –0.5 amu from the matrix-isotope (e.g. 62.5Cu in copper samples) was used for internal standardization. The standard deviation of this signal in a period of 2.5 h was
3.6% RSD with no notable drift when the laser ablation was used for sample introduction. The calibration of the matrix-element
by nebulizing liquid standards showed that the ion signal measured on the peak-tail is directly proportional to the element
concentration in the ICP. This indicates that the peak shape is not only stable, but also independent of the peak height.
The advantages of this method lie in the easy preparation of calibration standards for quantitative measurements with a laser-ablation
system and access to homogeneous standards for materials, that are difficult to homogenize in the solid state. The calibration
of the traces is performed relatively to a fixed concentration of the matrix element. Calibrations were carried out for trace
concentrations in high purity copper and good recoveries were obtained for high-purity reference standards.
Received: 23 February 1998 / Revised: 20 July 1998 / Accepted: 25 July 1998 相似文献
12.
Laser-ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) has been established as a very efficient and sensitive
technique for the direct analysis of solids. In this work the capability of LA–ICP–MS was investigated for determination of
trace elements in high-purity graphite. Synthetic laboratory standards with a graphite matrix were prepared for the purpose
of quantifying the analytical results. Doped trace elements, concentration 0.5 μg g–1, in a laboratory standard were determined with an accuracy of 1% to ± 7% and a relative standard deviation (RSD) of 2–13%.
Solution-based calibration was also used for quantitative analysis of high-purity graphite. It was found that such calibration
led to analytical results for trace-element determination in graphite with accuracy similar to that obtained by use of synthetic
laboratory standards for quantification of analytical results. Results from quantitative determination of trace impurities
in a real reactor-graphite sample, using both quantification approaches, were in good agreement. Detection limits for all
elements of interest were determined in the low ng g–1 concentration range. Improvement of detection limits by a factor of 10 was achieved for analyses of high-purity graphite
with LA–ICP–MS under wet plasma conditions, because the lower background signal and increased element sensitivity.
Received: 4 January 2001 / Revised: 27 March 2001 / Accepted: 28 March 2001 相似文献
13.
Determination of trace elements in residual oil by high-resolution inductively coupled plasma mass spectrometry 总被引:2,自引:0,他引:2
Hualin Xie Kelong Huang Jinchun Liu Xidu Nie Liang Fu 《Analytical and bioanalytical chemistry》2009,393(8):2075-2080
An analytical method using high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous
determination of 20 elements, including Na, Mg, Al, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Mo, Cd, Sn, Sb, Ba, and Pb
elements, in residual oil was described. The sample was dissolved in HNO3 by microwave digestion, and then the above 20 elements in the solution were analyzed directly by HR-ICP-MS. Most of the spectral
interferences could be avoided by measuring in the high-resolution mode. The matrix effect caused by the sample-digesting
solution and corrected by Sc, Rh, and Bi as the internal standard elements was studied in detail. The optimum condition of
the determination was also tested and discussed. The result showed that the detection limits of the method were in the range
of 0.014 to 11.6 μg L−1; the relative standard deviation was less than 3.8% and recoveries in the samples were in the range of 88.4% to 108.0%. This
method can be used to determine the trace elements in residual oil with the features of accurate, rapid, and convenient determination. 相似文献
14.
M. ?deg?rd S. H. Dundas B. Flem A. Grimstvedt 《Fresenius' Journal of Analytical Chemistry》1998,362(5):477-482
Results of the use of a double-focusing, magnetic sector inductively coupled plasma mass spectrometer (ICP-MS) with ultraviolet
(UV) laser ablation (LA) are presented for the bulk analysis of rare earth elements (REEs) in rocks fused with Li2B4O7. The sample preparation procedure used a sample to flux weight ratio of 1 : 7, and was identical with a procedure routinely
used for X-ray fluorescence (XRF) analyses of major and minor elements in geological materials. Calibration was based on a
total of 18 international standard reference materials (SRMs), and Ba was used as an internal standard element for all REEs.
The calibration curves were constructed using a weighted regression model. The use of internal standard, without exception,
improved the correlation coefficients significantly. The 3σ detection limits were established by a blank sample of SiO2 spiked with Ba, and were in the range from 0.003 μg g–1 (159Tb) to 0.051 μg g–1 (140Ce). The use of a large set of SRMs for calibration gave a good basis for the evaluation of analytical quality, and extensive
data for calculated analytical uncertainty are presented. Instrumental precision and the repeatability of the method were
studied separately, and no significant difference in these two sets of parameters were found, indicating that the spread of
results predominantly was connected to the instrumental measurements. Repeated ablations on the surface of a disk did not
influence subsequent measurements with XRF, showing that the fused disks can be stored for future use in XRF and/or LA-ICP-MS
analysis.
Received: 12 February 1998 / Revised: 6 April 1998 / Accepted: 17 April 1998 相似文献
15.
X. Querol A. Alastuey A. López-Soler A. Boix T. Sanfeliu V. V. Martynov P. I. Piven L. P. Kabina P. A. Souschov 《Analytical and bioanalytical chemistry》1997,357(7):934-940
This study focuses on the determination of trace element concentrations in total suspended particles by instrumental neutron
activation analysis (INAA) in two different areas in Northeastern Spain (a rural area influenced by the emissions of a large
coal-fired power station, and the urban and industrial areas of Castellón). Total suspended particles were sampled by means
of standard MCV high- and medium-volume captors, using cellulose membrane filters of 0.8 and 0.45 μm pore size. Preliminary
research was performed on the homogeneous distribution of elements in the sample filters and on the study of blank filters
for the calculations of the background average element contents. The results obtained allowed to distinguish different major
anthropogenic sources of trace elements in the atmosphere at the sampling sites: a) Zr, Hf, Sc, U and Th are related to atmospheric
pollution derived from the ceramic industry of the Castellón area; b) As, Cr, Cs, Rb, Sb, Se, Zn are related to traffic and
other industrial emission in the Castellón area, and As, Cr, Sb and Zn to power generation emissions in the rural area.
Received: 26 April 1996 / Revised: 29 July 1996 / Accepted: 2 August 1996 相似文献
16.
Boulyga SF Heilmann J Prohaska T Heumann KG 《Analytical and bioanalytical chemistry》2007,389(3):697-706
A method for the direct multi-element determination of Cl, S, Hg, Pb, Cd, U, Br, Cr, Cu, Fe, and Zn in powdered coal samples
has been developed by applying inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with laser-assisted
introduction into the plasma. A sector-field ICP-MS with a mass resolution of 4,000 and a high-ablation rate laser ablation
system provided significantly better sensitivity, detection limits, and accuracy compared to a conventional laser ablation
system coupled with a quadrupole ICP-MS. The sensitivity ranges from about 590 cps for 35Cl+ to more than 6 × 105 cps for 238U+ for 1 μg of trace element per gram of coal sample. Detection limits vary from 450 ng g−1 for chlorine and 18 ng g−1 for sulfur to 9.5 pg g−1 for mercury and 0.3 pg g−1 for uranium. Analyses of minor and trace elements in four certified reference materials (BCR-180 Gas Coal, BCR-331 Steam
Coal, SRM 1632c Trace Elements in Coal, SRM 1635 Trace Elements in Coal) yielded good agreement of usually not more than 5%
deviation from the certified values and precisions of less than 10% relative standard deviation for most elements. Higher
relative standard deviations were found for particular elements such as Hg and Cd caused by inhomogeneities due to associations
of these elements within micro-inclusions in coal which was demonstrated for Hg in SRM 1635, SRM 1632c, and another standard
reference material (SRM 2682b, Sulfur and Mercury in Coal). The developed LA-ICP-IDMS method with its simple sample pretreatment
opens the possibility for accurate, fast, and highly sensitive determinations of environmentally critical contaminants in
coal as well as of trace impurities in similar sample materials like graphite powder and activated charcoal on a routine basis.
Figure LA-ICP-IDMS allows direct multi-element determination in powdered coal samples 相似文献
17.
Heinz F. Falk Bodo Hattendorf K. Krengel-Rothensee Nataly Wieberneit Sarah L. Dannen 《Analytical and bioanalytical chemistry》1998,362(5):468-472
An approach for the determination of trace element concentrations in high purity metals, using an inductively coupled plasma
mass spectrometer (ICP-MS) with a laser-ablation system for direct solid sample introduction after calibration with nebulized
liquid standards was made. Due to the inherent differences in the rate of sample introduction with laser-ablation and pneumatic
nebulization, a matrix element must be used as an internal standard. This is problematical for elements that have no isotope
with a relative abundance of less than 0.1 %, since the ion signals would be too high for direct measurement, and reduction
of the ablation rate would compromise the sensitivity for trace elements. Due to the high stability of ICP-unit and mass filter
of the instrument used, it was found that the tail of a mass-peak of the matrix element could be used as an internal standard.
Therefore, a position at –0.5 amu from the matrix-isotope (e.g. 62.5Cu in copper samples) was used for internal standardization. The standard deviation of this signal in a period of 2.5 h was
3.6% RSD with no notable drift when the laser ablation was used for sample introduction. The calibration of the matrix-element
by nebulizing liquid standards showed that the ion signal measured on the peak-tail is directly proportional to the element
concentration in the ICP. This indicates that the peak shape is not only stable, but also independent of the peak height.
The advantages of this method lie in the easy preparation of calibration standards for quantitative measurements with a laser-ablation
system and access to homogeneous standards for materials, that are difficult to homogenize in the solid state. The calibration
of the traces is performed relatively to a fixed concentration of the matrix element. Calibrations were carried out for trace
concentrations in high purity copper and good recoveries were obtained for high-purity reference standards.
Received: 23 February 1998 / Revised: 20 July 1998 / Accepted: 25 July 1998 相似文献
18.
T. Yamaguchi M. Bando A. Nakajima M. Terai M. Suzuki-Yasumoto 《Journal of Radioanalytical and Nuclear Chemistry》1980,57(1):169-183
Fourteen trace elements (short-lived nuclides: Al, Br, Cu, Mn and V; long-lived nuclides: Ag, Au, Cd, Co, Cr, Fe, Sc, Se and
Zn) in human eye tissues are determined simultaneously by non-destructive neutron activation analysis. The quantity of Al,
Br, Fe, Se and Zn in the eye tissues (about 1 to more than 10 μg/g dry weight tissue) seems to be higher than that of other
trace elements, although content of each trace element in individual tissue are scattered in a wide range. Conjunctiva, iris
(+ciliary body) and choroid (+pigment epithelium) seem to contain larger amount of various trace elements than other eye tissues.
From correlation studies it is evident that the relative distribution of 14 trace elements in various eye tissues are similar,
and furthermore the content of trace elements in the eye tissues may be correlated in each of the three groups (group A: Cd,
Fe, Se and Zn; group B: Al, Cr, Fe, Se and V; group C: Al, Au, Fe and Se). 相似文献
19.
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
20.
A dual stage preconcentration system based on flow injection on-line ion-exchange and solvent-extraction has been developed
for flame atomic absorption spectrometry. Lead is taken as a model trace element. A column packed with Amberlite IRC-718 cation
exchanger is incorporated into the FI manifold. The analyte is retained on the column by time-based sample loading and eluted
by 1 mol/L HNO3. The eluate is subsequently merged with potassium iodide and tetrabutylammonium bromide (TBABr), and isobutyl methyl ketone
(IBMK). Lead is extracted on-line into IBMK as the ion-pair formed between the iodoplumbate anion and tetrabutylammonium cation.
The organic phase is separated from the aqueous phase by a gravity phase separator. 50 μL of concentrate is introduced into
the nebulizer-burner system of the spectrometer. An enhancement factor of 550 is achieved with a 30 mL sample consumption
at a sampling frequency of 30/h. The precision (relative standard deviation) is 2.4% at 10 μg/L level and the detection limit
is 0.3 μg/L (3 σ). The method was successfully applied to the determination of lead in water samples.
Received: 19 March 1997 / Revised: 24 June 1997 / Accepted: 27 June 1997 相似文献