Membrane sensors based on Schiff bases as chelating ionophores--a review.

The development of chemical sensors has received widespread attention during the past two decades because of their extensive use in environmental monitoring and clinical analysis via rapid, accurate, reproducible, and low-cost methods. Chemically modified CPEs have frequently been employed as potentiometric sensors in trace analysis for metal ions, organic pollutants and biological substances. Most of these electrodes are operated via the ion-exchange process of the active component incorporated into the carbon paste matrix.

Separation of structurally related flavonoids by GC/MS technique and determination of their polarographic parameters and potential carcinogenicity.

The present study deals with the investigation of the naturally occurring derivatives of the benzo[b]pyran-4-one - flavonoids - chrysin, tectochrysin and galangin, and with the effect of minor changes in their chemical structure on their separation using GC/MS. In the relation to their close chemical structure, their basic polarographic parameters were also investigated. Their potential carcinogenicity index tg alpha was determined by DC polarography experiments in the presence of alpha-lipoic acid.