共查询到20条相似文献,搜索用时 204 毫秒
1.
Investigations were carried out on the optimization of excitation and projection conditions of the axially-observed inductively
coupled plasma (ICP) concerning simultaneous measurements. For minimized background equivalent concentration (BEC) it can
be shown that the optimal excitation conditions of the atomic and ionic lines also vary in the case of axial plasma observation.
A relationship was confirmed between the high frequency power and the excitation energy of the analytical lines. The main
contribution of this work is the displacement of the axial viewing inductively coupled plasma by means of an x,y,z sliding
carriage.The displacement showed that under the selected experimental conditions the point of observation is spatially identical
for all analytical lines.
Received: 30 May 1997 / Revised: 20 November 1997 / Accepted: 25 November 1997 相似文献
2.
Investigations were carried out on the optimization of excitation and projection conditions of the axially-observed inductively
coupled plasma (ICP) concerning simultaneous measurements. For minimized background equivalent concentration (BEC) it can
be shown that the optimal excitation conditions of the atomic and ionic lines also vary in the case of axial plasma observation.
A relationship was confirmed between the high frequency power and the excitation energy of the analytical lines. The main
contribution of this work is the displacement of the axial viewing inductively coupled plasma by means of an x,y,z sliding
carriage.The displacement showed that under the selected experimental conditions the point of observation is spatially identical
for all analytical lines.
Received: 30 May 1997 / Revised: 20 November 1997 / Accepted: 25 November 1997 相似文献
3.
V. M. Ostrovskaya 《Analytical and bioanalytical chemistry》1998,361(3):303-305
New test tools have been developed for the rapid determination of trace metals: Ag, Cd, Co, Cu(II), Fe(II,III), Hg(II), Pd
and Zn, using polydentate irregular α-celluloses, containing in the 6 position the fragments heterylformazane or heterylhydrazone,
with a pocket device for preconcentration.
Received: 17 June 1997 / Revised: 1 November 1997 / Accepted: 6 November 1997 相似文献
4.
V. M. Ostrovskaya 《Fresenius' Journal of Analytical Chemistry》1998,361(3):303-305
New test tools have been developed for the rapid determination of trace metals: Ag, Cd, Co, Cu(II), Fe(II,III), Hg(II), Pd
and Zn, using polydentate irregular α-celluloses, containing in the 6 position the fragments heterylformazane or heterylhydrazone,
with a pocket device for preconcentration.
Received: 17 June 1997 / Revised: 1 November 1997 / Accepted: 6 November 1997 相似文献
5.
H. Erxleben L. N. Moskvin T. G. Nikitina J. Simon 《Fresenius' Journal of Analytical Chemistry》1998,361(3):324-325
Chromatomembrane (CM) cells operate in computer-aided FIA systems as unique manifolds for extraction and preconcentration
procedures. By coupling with ion chromatography an instrumentation was obtained allowing sample preparation and detection
of nitrogen oxides in air in a quick and automated way. The aim of this paper is to study the absorption of acid components
from air inside the new devices.
Received: 11 September 1997 / Revised: 12 November 1997 / Accepted: 16 November 1997 相似文献
6.
A. Akhmetshin V. Baranovsky A. Akhmetshina 《Fresenius' Journal of Analytical Chemistry》1998,361(3):282-284
Even with small selectivity of electrodes the application of multi-factorial design produces good results for complex ion
mixtures. Carrying out serial analyses with this method, the time for the preparation of specimens is shortened and the accuracy
of the determination is increased. The electrode selectivity is characterized using regression equations and an interference
level diagram. A graphical representation of data is suggested taking into account the dependence of response on the number
of interfering cations.
Received: 17 June 1997 / Revised: 3 November 1997 / Accepted: 8 November 1997 相似文献
7.
An analytical method for the determination of trace amounts of Galaxolide? (HHCB) by HPLC is presented. It is based on the separation of HHCB in different samples by a C18-column and a gradient elution
by water and acetonitrile, both containing some acetic acid. The detection is carried out with a combination of a fast scanning
UV detector and a fast scanning fluorescence detector. The fluorescence detection limit is 5 μg/L HHCB without sample pretreatment.
HHCB adsorbed on solids or suspended solids can be extracted by ethanol.
Received: 17 October 1997 / Revised: 24 November 1997 / Accepted: 24 November 1997 相似文献
8.
The capability of double focussing magnetic sector inductively coupled plasma mass spectrometry (HR-ICP-MS) for the determination
of trace elements in different body fluids was investigated in commercially available control materials. The elements included
in this study were: Al, As, Cd, Cr, Co, Cu, Hg, Mn, Ni, Pb, Sb, Se, Tl and Zn. Sample preparation, instrument stability and
the results, which are in very good agreement to the given values, are presented and discussed.
Received: 27 August 1997 / Revised: 19 November 1997 / Accepted: 23 November 1997 相似文献
9.
The capability of double focussing magnetic sector inductively coupled plasma mass spectrometry (HR-ICP-MS) for the determination
of trace elements in different body fluids was investigated in commercially available control materials. The elements included
in this study were: Al, As, Cd, Cr, Co, Cu, Hg, Mn, Ni, Pb, Sb, Se, Tl and Zn. Sample preparation, instrument stability and
the results, which are in very good agreement to the given values, are presented and discussed.
Received: 27 August 1997 / Revised: 19 November 1997 / Accepted: 23 November 1997 相似文献
10.
J. W. Einax O. Kampe D. Truckenbrodt 《Fresenius' Journal of Analytical Chemistry》1998,361(2):149-154
Partial least squares regression (PLS) as a method for multivariate data analysis has been applied to environmental data
of the German rivers Saale, Ilm and Unstrut. Main aspects of the study are to describe the relationships of the distribution
of metals between river water and river sediment using PLS. A simulation of the distribution of metals between the liquid
and solid phase by variation of some parameters (e.g. conductivity, DOC, dissolved oxygen, pH, phosphate and suspended matter)
is presented and compared with experimental results.
Received: 15 July 1997 / Revised: 6 November 1997 / Accepted: 7 November 1997 相似文献
11.
A calibration model of multielement methods for simultaneous determination of micro- and macro-concentrations of elements
by computing the arc atomic-emission spectra has been developed. A calibration procedure for the analytical line group of
the elements to be determined is offered. It allows the lower and upper limits of the concentration range for each line of
the determined element to be calculated by means of the least-square method (LSM) and the Weibull distribution law is used
to extend the concentration region. The calibration model was successfully tested for different arc optical emission spectroscopy
(OES) methods.
Received: 17 June 1997 / Revised: 3 November 1997 / Accepted: 7 November 1997 相似文献
12.
H. Wang Jun-Ling Gu Han-Fang Hu Tian-Hui Ding Ruo-Nong Fu 《Fresenius' Journal of Analytical Chemistry》1998,361(5):419-423
The systematic optimization of capillary electrophoretic separations using a dynamic scouting optimum method-controlled weighted
centroid variable size simplex algorithm is described. The factors affecting the efficiency of the separation are simultaneously
considered during the optimization procedures. The established optimization method is applied to amino acid separation by
capillary zone electrophoresis (CZE) with on-column indirect UV detection and to the separation of local anesthetics by micellar
electrokinetic chromatography (MECC) with on-column UV detection. The optimization procedures include the pH and the background
absorption electrolyte (BGAE) concentrations together with the applied voltage in the CZE separation of amino acids. The pH,
the SDS concentrations together with the percentage of methanol are considered in the MECC separation of local anesthetics.
Two methods, i.e., the Long Coefficient and Uniform Design Table, are used to define the start vertexes during the optimization
procedure and similar final experimental conditions for the separations are achieved. Thirteen native amino acids are baseline
separated by CZE and 4 local anesthetics are satisfactorily separated by MECC.
Received: 10 November 1997 / Revised: 19 January 1998 / Accepted: 24 January 1998 相似文献
13.
Irina E. Vasilyeva Elena V. Shabanova 《Fresenius' Journal of Analytical Chemistry》1998,361(3):280-282
A calibration model of multielement methods for simultaneous determination of micro- and macro-concentrations of elements
by computing the arc atomic-emission spectra has been developed. A calibration procedure for the analytical line group of
the elements to be determined is offered. It allows the lower and upper limits of the concentration range for each line of
the determined element to be calculated by means of the least-square method (LSM) and the Weibull distribution law is used
to extend the concentration region. The calibration model was successfully tested for different arc optical emission spectroscopy
(OES) methods.
Received: 17 June 1997 / Revised: 3 November 1997 / Accepted: 7 November 1997 相似文献
14.
V. Heber J. Siebers H.-G. Nolting H.-J. Vetten R. Kreuzig M. Bahadir 《Fresenius' Journal of Analytical Chemistry》1998,360(6):739-741
Two commercially available ELISA kits for water analysis, a microtiter plate-ELISA based on polyclonal antibodies (p-ELISA)
and a magnetic particle tube-ELISA based on monoclonal antibodies (t-ELISA), were used to determine chlorpyrifos residues
in soils. Comparison with a gas chromatographic method frequently applied was carried out by fortification experiments and
by analyses of real soil samples. At concentration levels of 1.0, 0.1, 0.05 and 0.01 mg/kg, chlorpyrifos was reliably determined
by the GC method. Application of the p-ELISA did not permit a reliable quantitation, while the t-ELISA was applicable in a
concentration range of 0.05–1.0 mg chlorpyrifos/kg dry soil.
Received: 23 July 1997 / Revised: 10 November 1997 / Accepted: 14 November 1997 相似文献
15.
M. A. González-Martínez S. Morais R. Puchades A. Maquieira M. P. Marco D. Barceló 《Fresenius' Journal of Analytical Chemistry》1998,361(2):179-184
Intensive agriculture associated with the use of large amounts of different pesticides, together with the growing concern
about the potential contamination of ground water, have brought about the need for developing fast screening methods. This
work presents the automation of an enzyme-linked immunosorbent assay for atrazine by means of a flow-through system. Three
different solid supports for antibody immobilization were compared in a direct competitive assay format. Sensitivity reached
in all cases was below the maximum level allowed in the EU (100 ng L–1). Cross-reactivity of atrazine-related compounds was also studied. The performance of the different supports is discussed
regarding sensitivity and immunosurface regeneration.
Received: 21 July 1997 / Revised: 7 November 1997 / Accepted: 11 November 1997 相似文献
16.
ELISAs (enzyme-linked immunosorbent assays) are generally used in environmental analytical chemistry for screening purposes.
In this work the applicability of a polyclonal-based 1-nitropyrene-ELISA for the quantification of the target analyte in air
particulate matter was investigated. Validation was performed using an HPLC method with fluorescence detection of the reduced
form of 1-nitropyrene. It was found that the immunoassay is not only sensitive for the target analyte but to a certain extent
also for other cross-reacting molecules present in the sample, such as 2-nitropyrene and 2-nitrofluoranthene, which were identified
by GC-HRMS and are considered to be products of photochemically induced reactions of pyrene or fluoranthene, respectively.
The degree of correlation between ELISA and HPLC results for collected samples of air particulate matter was inversely dependent
on the distance between the sampling location and the source.
Received: 20 August 1997 / Revised: 25 November 1997 / Accepted: 27 November 1997 相似文献
17.
An expert system for identification of parts of chemical molecules from IR and UV spectra is described. To develop the system,
the intelligent knowledge engineering program environment SCANKEE1 (elaborated at the Department of Computer Chemistry) was applied. The expert systems for identification of a chemical compound
described in the literature use hand-crafted knowledge bases. To eliminate the time-consuming writing of the rules, a module
for the automatic creation of rule knowledge bases was developed. The knowledge derives from the collection of molecular spectra
of organic compounds and their structural formulae. The algorithm for the automatic generation of the production rules (in
the rule knowledge base) is realized in two steps: (i) the creation of the correlation tables and (ii) the generation of the
production rules base.
Received: 1 July 1997 / Revised: 3 November 1997 / Accepted: 7 November 1997 相似文献
18.
Pierluigi Barbieri Gianpiero Adami Andrea Favretto E. Reisenhofer 《Fresenius' Journal of Analytical Chemistry》1998,361(4):349-352
Within research on the quality of the waters of the Gulf of Trieste, this study on patterns of trace metal contents in the
inner part of the gulf (Muggia Bay) discusses data of Cu, Pb, Cd and Zn, determined voltammetrically (DPASV), and collected
in three sites with a 10-day frequency over the period of one year. Two of the sites lie inside the dam system which protects
the harbour of Trieste, while the third one is situated outside for comparison purposes. Principal component analysis pointed
out different metal patterns inside and outside the dam system; PC scores were related to meteorological information: rain
plays a major role in conditioning the estuarine inner site: wind stirring action was detectable for the outer site. Both
univariate graphics and canonical correlation analysis suggest a diffuse source for Pb, probably atmospheric deposition.
Received: 1 August 1997 / Revised: 20 November 1997 / Accepted: 23 November 1997 相似文献
19.
The reliability of the voltammetric determination of the cadmium and copper content (at pH 1.0), inherent to metallothionein
(MT) isolated from the digestive gland of Mytilus galloprovincialis, was investigated. An artifact signal enhancement of copper, caused by the cupric-thionein complex adsorption at the mercury
electrode, was established. This artifact was removed by UV-digestion of the sample for 15–20 h prior to analysis. A similar
artifact was not detected for cadmium, because at this pH the cadmium-thionein complex has dissociated, and cadmium exists
in the ionic form. Therefore, the voltammetric analysis of the cadmium content can be performed directly at pH 1.0, without
prior UV-digestion of the sample.
Received: 4 August 1997 / Revised: 12 November 1997 / Accepted: 16 November 1997 相似文献
20.
Complementarity of ion-spray MS and ICP-MS as detection techniques in reversed-phase HPLC for the characterization of metals
complexed by biomacromolecules is discussed by the example of the speciation of metallothionein-bound cadmium. The commercially
purified rabbit liver MT-2 isoform is eluted from a microbore C8 column with a gradient of up to 50% methanol in acetate buffer (pH 6.0) to give one major and three minor peaks detected
at 254 nm. The preparation is further characterized by using an ICP mass spectrometer interfaced with HPLC via a direct injection
nebulizer which allows for the specific detection of cadmium down to the 10 ng mL–1 level. On-line detection by mass spectrometry with an ion-spray (pneumatically-assisted electrospray) ion source further
allows the determination of the molecular masses of the eluted compounds.
Received: 30 July 1997 / Revised: 7 November 1997 /Accepted: 11 November 1997 相似文献