... 153 A Chiral Sensor Based on a Peroctylated a-Cyclodextrin Paul S. Bates, Ritu Kataky and David Parker* Department of Chemistry, University of Durham, South Road, Durham DHI 3L€, UK A peroctylated a-cyclodextrin is used in a potentiometric ion-selective electrode to measure the enantiomeric purity of ephedrine in the presence of serum cations. ... 4 W. A. Konig, Carbohydr. Res., 1989, 51; WA Konig, S. Lutz and G. Wenz, Angew. Chem., Int. Ed. ...