HIGH-RESOLUTION HPLC METHOD WITH REVERSE-PHASE C18 SYMMETRY(TM) COLUMN FOR THE ANALYSIS OF TETRACYCLINES PRODUCED BY STREPTOMYCES-AUREOFACIENS IMMOBILIZED IN CA-ALGINATE GEL

To analyse the effect of immobilization of Streptomyces aureofaciens i n Ca-alginate on tetracycline production, an HPLC technique for direct injection of the culture medium has been developed. The high resoluti on obtained with this method is achieved by using a Symmetry C18(TM) r everse phase HPLC column. The comparison of our results with those pre viously described by different authors, shows that highest performance s are obtained without using relatively drastic conditions such as 0.2 M oxalic acid at pH 2. Thus, our method, which has shown a very good reproducibility for hundreds of injections, is also better for life-ti me column preservation.