1993 Volume 9 Issue 5 Pages 599-603
An anion adsorbent was developed based on a Cobalt(III)-loaded chelating resin containing 1, 4, 8, 11-tetraazacyclo-tetradecane-5, 7-dione. Batchwise adsorption study has revealed that the adsorbent exhibits an anti-Hofmeister anion selectivity sequence (OH->SCN->NO2-) and that it takes up thiocyanate preferentially in the presence of excess perchlorate as well. Column-mode study has also clarified that the adsorbent takes up thiocyanate preferentially even in the presence of tenfold excess perchlorate. The adsorbed thiocyanate is rapidly and quantitatively eluted with 0.2M sodium hydroxide, unlike to the case of a conventional anion exchange resin (Bio-Rad AG 1-X4) column. In addition, the adsorbent was able to be regenerated with hydrochloric acid solution for repeated use. During repeated use of the adsorbent for a half year, no loss of the loaded cobalt(III) was observed.