Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 1995-1999  (2)
  • Inorganic aninos  (1)
  • Isotachophoretic sample pretreatment  (1)
  • 1
    ISSN: 0173-0835
    Keywords: Preparative capillary isotachophoresis ; Capillary zone electrophoresis ; Nitrophenols ; Water analysis ; Isotachophoretic sample pretreatment ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Preparative capillary isotachophoresis (ITP) operating in a discontinuous frationation mode was studied as a sample pretreatment technique for capillary zone electrophoresis (CZE) trace analysis of a group of ten nitrophenols. Different separation mechanisms employed by these capillary electrophoresis techniques made possible a group isolation of the studied analytes by ITP while their CZE resolutions based on differences in the interactions with polyvinylpyrrolidone (PVP) provided suitable conditions for a final analytical evaluation. Experiments with model and practical water samples revealed high and reproducible recovery rates of the ITP pretreatment for nitrophenols when sample loadability limits of the preparative ITP equipment were met. A main disadvantage of the studied ITP-CZE combination was an inefficient use of the pretreated sample as only 0.5% of the fraction containing nitrophenols was used in the final CZE step. Despite these limitations associated with the CZE sample injection, the concentration limit of detection (LOD) for nitrophenols in practical water samples could be reduced to 2-8 ppb concentrations (photometric absorbance detector operating at a 254 nm wavelength) when 200 μL sample volumes were taken for the ITP pretreatment. This was accompanied by an efficient sample clean-up as no other trace ionic constituents originating from the samples were detected on CZE.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Electrophoresis 17 (1996), S. 1890-1897 
    ISSN: 0173-0835
    Keywords: Capillary zone electrophoresis ; Inorganic aninos ; Conductivity detection ; Hydrodynamically closed separation system ; Water analysis ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: A carrier electrolyte system for capillary zone electrophoresis (CZE) resolving chloride, bromide, iodide, fluoride, nitrite, nitrate, sulfate, and phosphate in a hydrodynamically closed separation compartment is described. The carrier electrolyte combines the effects of pH, polyvinylpyrrolidone (PVP) and the counterionic constituent on the effective mobilities of the anions. In 300 μm ID capillary tubes made of fluorinated ethylene-propylene copolymer (FEP), and with detection of analytes with the aid of an alternating current conductivity detector, detection limits in the range of 3-10 ppb could be achieved for 200 nL sample volumes. The separation efficiencies were in the range of 1.5-2.5 × 105 theoretical plates per meter for an adequate sample load. The reproducibility was evaluated for two concentration levels. For concentrations close to the limits of quantitation (50-120 ppb), the RSD values ranged from 1.5-12.6%, with the highest scatter for fluoride and phosphate. The RSD values were in the range of 0.4-1.5% for 300-1200 ppb concentrations of the anions. Typical analysis times were 2-5 min, depending on the anion species. A series of water samples (drinking, river, rain) was used to assess the practical applicability of the CZE method. The method is a suitable alternative for the determination of both anionic macro- and microconstituents in water with a good overall selectivity.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...