EXTRACTION OF 7-AMINOCEPHALOSPORANIC ACID WITH SECONDARY, TERTIARY, AND QUATERNARY AMINES

Extraction of 7-aminocephalosporanic acid (7-ACA) has been investigate d using secondary and tertiary amines and a quaternary ammonium salt ( Aliquat-336) as the carriers. The values of the distribution coefficie nts have been reported in a range of aqueous-phase pH values and conce ntrations of 7-ACA using different carriers in n-butyl acetate as the diluent. As expected, ion-pair extraction with secondary and tertiary amines exhibits lowerings of the distribution coefficient with increas e of pH, whereas the ion exchange extraction with quaternary ammonium chloride (Aliquat-366) exhibits an opposite but more pronounced pH dep endence, providing at the same time higher values of distribution coef ficient at high values of pH. Both the extraction principles can be ex ploited to achieve extraction and reextraction of 7-ACA in the pH rang e of 5 to 8 in which it is relatively stable.