the second step , designed to detect the three 17-keto estrogens , begins with the selective sodium borohydride reduction of the conjugated 17-keto estrogens to the corresponding 17-hydroxyl compounds ( the beta-epimer being formed in vast predominance over the alpha-epimer ) , followed by acid hydrolysis , dansyl derivatization , and hplc separation of the derivatives as in the first step .
C0014939
estrogens
C0014938
conjugated