Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: V. Madajová x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

Separation conditions suitable to a rapid resolution of a group of eight nitrophenols by capillary zone electrophoresis (CZE) were found. Required differences in their effective mobilities were achieved via host-guest complexation of -cyclodextrin combined with intermolecular interactions involved by polyvinylpyrrolidone. When both additives were present in the carrier electrolyte at pH=9.1 nitrophenols could be separated in the column of a, 300 m I.D. and 180 mm in the length within 8–9 minutes. It is shown that the column of such an I.D. providing enhanced sample load capacity, can operate with high separation efficiencies as maintaining zone dispersions due to Joule heating on a tolerable level. CZE on-line coupled with isotachophoretic sample pretreatment is shown to provide the concentration limits of detection at low ppb concentrations by using an on-column photometric detector operating at 254 and 405 nm detection wavelengths.

Restricted access

Abstract  

Various sorbents recommended for solid phase extraction (SPE) in sample preparation procedures were studied for use in combination with capillary isotachophoresis (ITP). They were very efficient in achieving trace concentration levels (low ppb, i.e., low parts per 109) for different types of ITP analytes present in environmental and biological matrices. A macroporous carbon sorbent was convenient for sample preparation in ITP analysis of short chain fatty acids (C4–C9) in drinking water. Chelating sorbents based on hydroxyalkyl methacrylate matrix with salicylate, thioglycolate and 8-hydroxyquinolinate functionalities were found to be very suitable for preconcentration of heavy metals with an inherent sample clean-up. An octadecyl-bonded silica sorbent enabled in ITP a photometric detection of -aminobutyrate (labeled with a 2,4,6-trinitrophenyl group) at concentrations considerably lower than required for the determination of this amino acid in cerebrospinal fluid (5·10–8 mol/l).

Restricted access