ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The determination of iodine, bromine, sulphur and phosphorus using different modes of sampling in ICP-AES is described. Detection limits in the range of some 10 μgL−1 have been obtained using directly aqueous solutions with pneumatic nebulization. The influence of several anions and metals has been investigated. The addition of methanol and ethanol have improved sensitivities but decreased signal-to-background ratios and detection limits due to extended blank values and increased standard deviations. Using ultrasonic nebulization the sensitivities and the detection limits could be enhanced for these elements in aqueous solutions, but a significant decrease in sensitivity has been observed using additives as methanol or ethanol. By coupling of pneumatic nebulization and gas generation of iodine by addition of oxidizing agents, the detection limits of iodine could be improved to 6 ngL−1 at the 178.28 nm line. Electrothermal vaporization has sucessfully been applied for microsampling of nonmetals and ICP-AES determination. Using aqueous solutions without any modifier the following absolute detection limits at the S (180.73 nm), P (178.27 nm), I (178.28 nm) and Br (163.34 nm) lines have been obtained: 0.25 ng of S, 0.44 ng of P, 0.36 ng of I and 43 ng of Br.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Heavy metal levels in tooth compartments would appear to be a suitable indicator of long-term exposure. A method has been developed to assess the heavy metal levels (Mn, Cu, Zn, Cd and Pb) in tooth compartments like dentin and enamel. For the simultaneous determination of these elements in small dentin sample amounts (in some cases less than 1 mg) inductively coupled plasma mass spectrometry with electrothermal vaporization was the method of choice. Sample preparation, method development and first results of the application of the method for the analysis of tooth compartments have been described. Variation in the elemental concentrations depending on the kind of tooth and the sampling position have been observed. The method is useful for epidemiological studies of the heavy metal exposure of children.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The potential of furnace techniques and of laser evaporation for the analysis of dry solution residues and of solids by different atomic emission procedures is described. The new one-step FANES technique (furnace atomic nonthermal emission spectrometry) is compared with the two-step procedure ETV-ICP-AES (electrothermal vaporisation—inductively coupled plasma—atomic emission spectrometry). In case of dry solution residues the sensitivity of the FANES is higher (1–2 orders of magnitude) as a result of better discharge conditions (low background) and direct sample introduction, particularly for volatile and moderately volatile substances. For refractory elements the higher gas temperature of the ICP plasma causes better atomisation, which can lead to higher sensitivity of the ETV-ICP-AES. A new Laser-FANES hybride technique is introduced for microanalysis in solid samples and compared with Laser-ICP-AES. The Laser-FANES is shown to combine the advantages of Laser-ETA-AAS (high sensitivity) and of Laser-ICP-AES (multielemental determinations), particularly for volatile and moderately volatile elements.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The laser-ICP-AES, a typical two step procedure, was used for the direct simultaneous multielemental analysis of solids. Microamounts of all solids are ablated by laser-pulse radiation. The solid-gas aerosol formed is transported into the ICP, where the material is vaporized again, atomized and excited. The analytical performance of this technique is better than that of the laser microanalysis, which is characterized by an one-step procedure. Using the multishot technique in laser-ICP-AES the detection power of the laser AAS-ETA can be achieved (ppm level). The reproducibility of the technique is relatively good (RSD〈10%) in consequence of both the stability of the ICP and the application of inner standards. Calibrations are possible by application of compact solid standard materials (alloys), pressed powder materials and by using the method of multiple shots for compact rocks.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The laser-ICP-AES, a typical two step procedure, was used for the direct simultaneous multielemental analysis of solids. Microamounts of all solids are ablated by laser-pulse radiation. The solid-gas aerosol formed is transported into the ICP, where the material is vaporized again, atomized and excited. The analytical performance of this technique is better than that of the laser microanalysis, which is characterized by an one-step procedure. Using the multishot technique in laser-ICP-AES the detection power of the laser AAS-ETA can be achieved (ppm level). The reproducibility of the technique is relatively good (RSD〈10%) in consequence of both the stability of the ICP and the application of inner standards. Calibrations are possible by application of compact solid standard materials (alloys), pressed powder materials and by using the method of multiple shots for compact rocks.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The suitability of eleven modifiers (Pd-, Mg-, K-, Ca- and NH4-salts) for electrothermal vaporization coupled to inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the determination of Mn, Cu, Zn, Cd and Pb has been studied. Solutions containing varying quantities (10–2000 ng absolute) of these salts have been added to four different amounts of analyte to study their suitability as modifier and their mass dependent influence. The best sensitivity enhancement for all elements tested was achieved with IrCl3 and PdCl2. From a comparison of the effect of PdCl2 vs. Pd(NO3)2 it could be concluded that the mechanism of matrix modification also depends on the chemical form of the modifier. Particularly, for the volatile elements Cd and Zn differences in the behavior of the different chemical compounds of one metal (e.g. Pd) is evident, which shows that the enhancement effect is a result of the stabilization of the analytes in the graphite tube prior to vaporization and the improvement of the transport efficiency after vaporization.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Electrothermal vaporization inductively coupled plasma atomic emission spectrometry was applied to the determination of sulfur species in aqueous solutions. The sensitivity for sulfur as sulfate was found to be depending on the cations in the sample. For understanding this phenomenon the thermal behavior of sulfuric acid, ammonium sulfate and the sulfates of sodium, zinc, magnesium and silver was studied. There were significant differences in the thermal release of sulfur from these sulfates. To explain these phenomena different reaction mechanisms were calculated using thermodynamic data. Pd(NO3)2 and Ge in KOH were successfully applied as modifiers for the stabilization of the sulfates during the thermal pre-treatment step and to establish a uniform thermal behavior of different sulfates. The stabilization of sulfur using Ge and Pd as modifiers is based on the reduction of the sulfates in presence of carbon, resulting in the formation of GeS and PdS, respectively. This explanation has been supported by comparing the experimental results with thermodynamic calculations considering different reactions for the thermal decomposition of the sulfates. Applying Ge (in KOH) as modifier the absolute detection limit was 300 pg sulfur (e.g. LOD 30 ng mL–1). The significant influence of phosphates on the determination of sulfur could be essentially reduced by Pd as modifier.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Ion chromatographic separation coupled with ICP-MS was used to determine arsenic species in plant and soil extracts. A scheme for growth, harvesting, sample pre-treatment and analysis was developed for the arsenic species to enable determination. Preliminary results obtained with ten herb plants grown on arsenic-contaminated soil compared to non-contaminated soil show a heterogeneous pattern of accumulation rate, metabolization and detoxification mechanisms in monocots and dicots. Arsenite appears to be the major component in plants with good growth. Organic arsenic species were even detected at very low concentrations (〈 150 μg kg–1 (dry mass)).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The determination of iodine in aqueous solutions suffers from several serious problems, caused by the formation of iodine species, derived from the oxidative pretreatment of biological materials. For the determination of these iodine species an ion chromatograph was coupled with an ICP-mass spectrometer. Because of the possible interconversion of the iodine species depending on the pH-value, different eluent-column combinations were used for acidic or alkaline sample solutions, respectively. Iodide, iodate, and several not identified, presumably organo-iodine species could be separated and detected. Unfortunately, the iodine (I2) itself could not be determined with the method proposed. The reaction products of pretreatment are influenced strongly by the matrix. Mixtures of different iodine containing components are received, dependent on the matrix composition and particularly on the pH-value.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract High-performance capillary electrophoresis is applied to the separation of different inorganic and organic arsenic and selenium compounds. In comparison with UV-detection, an approach with conductivity detection is described expecting higher sensitivity and universality. In this case the capillary was statically modified with CTAB before the electromigration procedure. The separation was performed with an electrolyte system consisting of CHES and Triton X-100. Detection limits of 0.06 mg/L or lower were obtained for As(V) and Se(VI). Water samples of an arsenic-polluted tailing of tin mining processes were analysed for anions as well as arsenic and selenium species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...