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Biomedical subjects

J Janák

Publications and source records attributed to J Janák.

11 recordsLinked to original sources
PubMed1994

Separation of selenium analogues of sulphur-containing amino acids by high-performance liquid chromatography and high-resolution gas chromatography.

The historically conditioned adaptation of living organisms to chemically corresponding elements is influenced in nature by anthropogenic activities in many regions, the selenium-sulphur pair being one example of such a case. The separation of selenomethionine, selenoethionine and selenocystine was studied by HPLC and high-resolution GC. Ion-exchange chromatography followed by temperature-programmed GC gives the possibility of the analytical separation of trace amounts of selenomethionine in a complex mixture of common amino acids. Diastereoisomers of selenocystine were identified by HPLC in the AccQ-Tag mode.

Amino Acids, Sulfur↗
PubMed1986

Pneumatoamperometric determination of sulfur dioxide in air on ppb level.

A simple device for the determination of sulfur dioxide at ppb concentrations in air is described. The device is composed of an enrichment unit operating continuously on the basis of gas extraction into polydisperse aerosol of a liquid transferring sulfur dioxide from liter amount of air into microliter amount of liquid. The analyte is determined pneumatoamperically from the concentrate on a gold-plated porous Teflon electrode. The detection limit is 0.3 ppb (v), i.e. 0.87 microgram/m3 of sulfur dioxide, the linear range covers several orders of magnitude. The analytical response is obtained few tenths of seconds after the gas contaminated with sulfur dioxide has entered the enrichment unit.

Air Pollutants, Occupational↗
PubMed1976

Separation of some typical Krebs cycle acids by high-speed isotachophoresis.

In order to perform a required separation, an experimental procedure for the selection of suitable operating conditions is suggested and discussed. It is based on measurements of the dependences of the relative effective mobilities of the components under investigation on the pH of the leading electrolyte. The procedure was applied to a set of typical Krebs cycle acids and the values of the relative effective mobilities measured are given in tables and graphs. A pH of 3.8 was selected as the most suitable. At this value, the acids investigated were successfully separated in less than 4 min using 0.011 M hydrochloric acid + beta-alanine as the leading electrolyte.

Citric Acid Cycle↗