共查询到20条相似文献,搜索用时 31 毫秒
1.
Analytical methodologies for chromium speciation in solid matrices: a survey of literature 总被引:1,自引:0,他引:1
M. J. Marqués A. Salvador A. E. Morales-Rubio M. de la Guardia 《Fresenius' Journal of Analytical Chemistry》1998,362(3):239-248
The analytical literature about chromium speciation in solid samples has been surveyed. From 451 articles published on the
speciation of chromium from 1983 to 1997, the methodologies to do speciation in solids after sample pretreatment are discussed,
through consideration of the types of samples and their dissolution, the analytical techniques employed for chromium measurement,
and the figures of merit of the 86 papers reported in the Analytical Abstracts data base.
Received: 6 February 1998 / Revised: 6 March 1998 / Accepted: 7 March 1998 相似文献
2.
Capabilities of high resolution inductively coupled plasma mass spectrometry for trace element determination in plant sample digests 总被引:1,自引:0,他引:1
Ilia Rodushkin 《Fresenius' Journal of Analytical Chemistry》1998,362(6):541-546
The analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for the analysis of plant sample digests
was evaluated using double focusing sector field ICP-MS (ICP-SMS). Instrumental detection limits of ICP-SMS are superior to
those obtained by quadrupole systems (ICP-QMS) and reach the fg mL–1 range for elements with high m/z ratios. Matrix effects caused by a plant digest after sample preparation resulting in 200-fold
dilution were found to be negligible. The usefulness of high mass resolution for overcoming some spectral interferences is
demonstrated. Mathematical correction possibilities could be necessary to improve accuracy. The concentrations of more than
20 elements can be determined in 5 min and only one internal standard is necessary to correct for instrumental drift.
Received: 30 March 1998 / Revised: 4 May 1998 / Accepted: 16 May 1998 相似文献
3.
Ilia Rodushkin 《Analytical and bioanalytical chemistry》1998,362(6):541-546
The analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for the analysis of plant sample digests
was evaluated using double focusing sector field ICP-MS (ICP-SMS). Instrumental detection limits of ICP-SMS are superior to
those obtained by quadrupole systems (ICP-QMS) and reach the fg mL–1 range for elements with high m/z ratios. Matrix effects caused by a plant digest after sample preparation resulting in 200-fold
dilution were found to be negligible. The usefulness of high mass resolution for overcoming some spectral interferences is
demonstrated. Mathematical correction possibilities could be necessary to improve accuracy. The concentrations of more than
20 elements can be determined in 5 min and only one internal standard is necessary to correct for instrumental drift.
Received: 30 March 1998 / Revised: 4 May 1998 / Accepted: 16 May 1998 相似文献
4.
S. Apfalter R. Krska T. Linsinger A. Oberhauser W. Kandler M. Grasserbauer 《Fresenius' Journal of Analytical Chemistry》1999,364(7):660-665
Sixty laboratories of five different countries participated in a large-scale interlaboratory comparison test for the determination
of halogenated hydrocarbons in water. Participants used their in-house method with 44 laboratories applying head space GC
ECD analysis and 5 using liquid/liquid extraction. A set of two artificially produced samples was prepared; the halogenated
hydrocarbons investigated were trichloroethylene, tetrachloroethylene, 1,1,1-trichloroethane, trichloromethane, tetrachloromethane,
1,1-dichloroethylene, dichloromethane, dibromochloromethane, bromodichloromethane, 1,2-dichloroethane and tribromomethane.
The procedure of sample preparation, storage and distribution was monitored by an extensive quality assurance system including
homogeneity tests, stability tests, and trend analysis of the submitted data. The analytical results submitted by the participants
exhibited RSD values of up to 35% and outlier rates of up to 19%. The percentage of false positive and false negative results
was at the highest 12% for selected substances. Recovery rates varying from 86% to 106% proved the correctness of the analytical
results submitted by the participants and showed that the procedure developed in this study for sample preparation and distribution
is well suited for the performance of large-scale interlaboratory comparison tests of halogenated hydrocarbons in water.
Received: 7 December 1998 / Revised: 23 March 1999 / Accepted: 24 March 1999 相似文献
5.
Development, recent historical background and analytical applications of promising sensor instruments based on sensor arrays
with data processing by pattern recognition methods have been described. Attention is paid to the “electronic tongue” based
on an array of original non-specific (non-selective) potentiometric chemical sensors. Application results for integral qualitative
analysis of beverages and for quantitative analysis of biological liquids and solutions, containing heavy metals are reported.
Discriminating abilities and precision obtained allow to consider “electronic tongue” as a perspective analytical tool.
Received: 17 July 1997 / Revised: 19 February 1998 / Accepted: 24 February 1998 相似文献
6.
N. Binding Holger Kl?ning U. Karst Wilhelm P?tter Peter A. Czeschinski Ute Witting 《Fresenius' Journal of Analytical Chemistry》1998,362(3):270-273
Solid sorbents coated with the fluorescent reagent 5-dimethylaminonaphthalene-1-sulfohydrazide (dansylhydrazine, DNSH) have
been used for derivatization and quantitative determination of airborne carbonyl compounds, for example in investigations
on atmospheric pollution. The evaluation of this derivatization reaction presented here revealed that, for several reasons,
it may not be recommended when sampling is performed with impingers containing liquid reagent solutions. Derivative yields
came out to be strongly influenced by water and phosphoric acid which are essential for sufficient derivatization rates, but
also responsible for the degradation of derivatives. Even at water and acid concentrations considered as an optimal compromise
between accelerating and degrading effects, the analytical reliability of the method can only be guaranteed under controlled
laboratory conditions. The reduced or lacking reactivity of DNSH towards aromatic aldehydes or aliphatic and aromatic ketones
is an additional finding discarding the DNSH method for routine air monitoring at least when impingers are used for sampling.
Received: 8 January 1998 / Revised: 9 March 1998 / Accepted: 15 March 1998 相似文献
7.
Different schemes of analytical testing including the sampling, sample preparation and sample analysis operations are considered
as applied to a lot of raw material containing recoverable precious metal. The errors resulting from the step-by-step operations
of the analytical testing are estimated. Sampling and sample preparation operations are found to be significant contributors
to the total error of determination of the percentage and /or weight of a precious metal of interest in a lot. Some ways to
diminish both the sampling error and the total error of the analytical testing procedure are recommended.
Received: 28 December 1998 · Accepted: 22 February 1999 相似文献
8.
N. Huppert Marion Würtele Hermann H. Hahn 《Fresenius' Journal of Analytical Chemistry》1998,362(6):529-536
A rapid, inexpensive and solvent-free method for the simultaneous determination of the polyamide plasticizer N-butylbenzenesulfonamide
(NBBS) and the widely used pharmaceutical Ibuprofen by solid phase microextraction (SPME) combined with gas chromatography/mass
spectrometry (GC/MSD) in wastewater samples was developed. Besides the optimized analytical conditions, results of investigations
with varying analytical parameters are reported. Problems, which may occur during the analytical procedure (e.g. salt deposits,
adsorption phenomena, carry-over), are discussed. For the determination of Ibuprofen, it is important to carry out the extraction
under acidic conditions with sufficiently buffered samples; the GC/MSD system must be very clean and well maintained. SPME
allows an extraction of Ibuprofen without derivatization of its carboxylic group. For quantification in complex matrices,
the standard addition technique is necessary. Limit of detection and limit of determination are 0.1 μg/L for both analytes.
NBBS and Ibuprofen were detected in several raw and treated wastewater samples from municipal wastewater treatment plants
in the range from < 0.1 to 3.5 μg/L.
Received: 13 March 1998 / Revised: 16 June 1998 / Accepted: 19 June 1998 相似文献
9.
10.
D. J. Strike M. G. H. Meijerink M. Koudelka-Hep 《Fresenius' Journal of Analytical Chemistry》1999,364(6):499-505
Electronic noses are a new class of analytical instruments anticipated to have an impact in many areas. They are based around
an array of sensors each having a partial specificity and thus producing an odour fingerprint that can be identified by a
pattern recognition system. In this review the technologies involved are discussed, giving particular emphasis to the sensors
since these form the heart of the systems. The major sensor technologies are described, indicating both their strengths and
their weaknesses. Finally, after a brief discussion of data processing technologies, the review ends with an assessment of
the current state of the art and possible future directions.
Received: 2 November 1998 / Accepted: 29 December 1998 相似文献
11.
The aim of this paper is to optimize the analytical method for the characterisation of 17th–20th century calcographic and
xylographic inks. It is very important to use not only non destructive techniques, but also analytical instruments that require
a minimal amount of material so as to analyze unique or valuable samples, and simultaneously to obtain as much information
as possible about their composition. This study compares different ways of sample preparation for further analysis by Fourier
transform infrared spectroscopy. It has been possible to analyze the most important absorptions that appear in the spectra
and therefore to associate them with the compounds contained in inks. Some of the compounds identified are: hydroxyapatite
(calcium phosphate), Prussian blue (ferric ferrocyanide), linseed oil, carbonates, nitrates and sulfates.
Received January 10, 1999. Revision March 17, 1999. 相似文献
12.
Michael E. G. Lyons Judith Murphy Thomas Bannon Serge Rebouillat 《Journal of Solid State Electrochemistry》1999,3(3):154-162
The processes of reaction, diffusion and electromigration of a charged substrate within an electronically conducting polymer
film deposited on an inert supporting electrode are examined in terms of a quantitative analysis and solution of the pertinent
differential equations. An analytical expression for the concentration profiles of substrate within the polymer layer is derived
and a theoretical expression for the corresponding steady-state amperometric current response is presented. The transport
and kinetics of the substrate are discussed in terms of a dimensionless reaction/diffusion parameter γ and a migration/diffusion
parameter β.
Received: 13 March 1998 / Accepted: 17 July 1998 相似文献
13.
To obtain suitable geological reference materials for microanalytical purposes, a set of eight natural glasses was prepared
by direct fusion of rock chips. Multi-ion counting spark source mass spectrometry (MIC-SSMS) has been applied for trace element
analysis of these reference materials. The overall analytical uncertainty of the MIC-SSMS results was determined by considering
14 possible sources of errors. It generally ranges between < 2–7% depending on the element and its concentration. Nearly all
MIC-SSMS data agree with the reference values within 0–10%, indicating that the estimate of the overall analytical uncertainty
is reasonable.
Received: 21 December 1998 / Revised: 2 March 1999 / Accepted: 3 March 1999 相似文献
14.
To obtain suitable geological reference materials for microanalytical purposes, a set of eight natural glasses was prepared
by direct fusion of rock chips. Multi-ion counting spark source mass spectrometry (MIC-SSMS) has been applied for trace element
analysis of these reference materials. The overall analytical uncertainty of the MIC-SSMS results was determined by considering
14 possible sources of errors. It generally ranges between < 2–7% depending on the element and its concentration. Nearly all
MIC-SSMS data agree with the reference values within 0–10%, indicating that the estimate of the overall analytical uncertainty
is reasonable.
Received: 21 December 1998 / Revised: 2 March 1999 / Accepted: 3 March 1999 相似文献
15.
Iodine determination in biological materials
Options for sample preparation and final determination 总被引:1,自引:0,他引:1
G. Knapp B. Maichin P. Fecher S. Hasse P. Schramel 《Fresenius' Journal of Analytical Chemistry》1998,362(6):508-513
This paper describes the development of various new acid sample decomposition methods, as well as an extraction (leaching)
method and compares them with the “Sch?niger Combustion” technique. The methods have been developed as sample preparation
techniques for iodine determination in biological materials, especially in solid samples. ICP-MS (inductively coupled plasma
mass spectrometry) and a catalytic technique are employed and discussed for the final determination of iodine concentrations.
Accuracy and reliability of the different analytical methods are shown in the examples of different CRMs (certified reference
materials) available for iodine. The results of an interlaboratory comparison are specifically presented for the extraction
(leaching) method.
Received: 11 May 1998 / Revised: 14 June 1998 / Accepted: 16 June 1998 相似文献
16.
M. Rässler B. Michalke P. Schramel S. Schulte-Hostede A. Kettrup 《Analytical and bioanalytical chemistry》1998,362(3):281-284
A simple, but highly sensitive procedure for the determination of particular and colloidally bound arsenic and selenium species
in ground water samples with high concentrations of iron, manganese and sulfur is presented. Samples were first filtered through
a 0.45 μm filter to separate the particulate matter from the dissolved. Aliquots of the filtered sample were submitted to
ultrafiltration through membrane filters with pore diameters of 30 nm and 1 nm, respectively. Filtrates were analyzed by ETV-ICP-MS
for their arsenic and selenium concentration.
Received: 24 October 1997 / Revised: 17 March 1998 / Accepted: 28 March 1998 相似文献
17.
M. R?ssler B. Michalke P. Schramel S. Schulte-Hostede A. Kettrup 《Fresenius' Journal of Analytical Chemistry》1998,362(3):281-284
A simple, but highly sensitive procedure for the determination of particular and colloidally bound arsenic and selenium species
in ground water samples with high concentrations of iron, manganese and sulfur is presented. Samples were first filtered through
a 0.45 μm filter to separate the particulate matter from the dissolved. Aliquots of the filtered sample were submitted to
ultrafiltration through membrane filters with pore diameters of 30 nm and 1 nm, respectively. Filtrates were analyzed by ETV-ICP-MS
for their arsenic and selenium concentration.
Received: 24 October 1997 / Revised: 17 March 1998 / Accepted: 28 March 1998 相似文献
18.
F. C. Adams 《Accreditation and quality assurance》1998,3(8):308-316
The basic concepts of traceability as they are defined by the Comité Consultatif pour la Cluantité de Matière are contrasted
with the practical exploitation in chemical analysis. The applicability of traceability concepts are tested for their practical
applicability on four different analytical methodologies, neutron activation analysis, plasma mass spectrometry, beam microscopical
analysis and speciation analysis of organometallic compounds.
Received: 31 March 1998 · Accepted: 6 June 1998 相似文献
19.
The interfaces between low-pressure continuous sample treatment systems and high-level information instruments such as gas chromatographs, capillary electrophoresis equipment and graphite furnace atomic spectroscopic instruments, which are characterized by conventional discrete sample introduction devices, are presented. The present and future developments are discussed of (directly) linking real samples and those analytical equipments with the main objective of avoiding or minimizing manually implemented preliminary operations of the analytical process. 相似文献
20.
C. M. Davidson Lorna E. Wilson Allan M. Ure 《Fresenius' Journal of Analytical Chemistry》1999,363(1):134-136
The three-stage sequential extraction procedure recommended by BCR has been applied in the operational speciation of cadmium
and lead in a relatively unpolluted freshwater sediment, following various types of sample pre-treatment. Changes in speciation
occurred when the sediment was air-dried, oven-dried or frozen. Cadmium speciation was particularly perturbed by freezing,
whilst lead was more affected by oven-drying. Metals were determined by electrothermal atomic absorption spectrometry, using
direct calibration with reagent-matched standard solutions.
Received: 18 March 1998 / Revised: 22 June 1998 / Accepted: 26 June 1998 相似文献