Comment on the Paper “Simple Evaluation of Enantiomer-Selectivity of Crown Ether Using Membrane Electrode” by Y. Yasaka Et Al.

In the paper mentioned in the title the authors describe the evaluation of enantiomer-selectivity of chiral crown ethers by measuring electrical potential differences on electrochemical cell assemblies with PVC membranes containing these chiral ionophores. Their communication gives the impression that the evaluation of enantiomer-selectivity of chiral ionophores by electrochemical methods, which were developed in our laboratory beginning 1966, is a novel one because they do not refer to our previous work. We would like to point out that we published our first paper on electrochemical detection of enantiomer-selectivity in 1975, and that several subsequent papers from our laboratory appeared since then not only in the primary and referring journals, but also in review articles.