“…On the other hand, Cope and Hurlock (101) found that the results of conventional corticoid assays are more reliable if the urine extract has been previously purified by partition chromatography. Normal human urine has been analyzed by paper chromatography before and after hydrolysis by various methods (74,456,76,346,83,84,146,109,443,446,103,18,334,333,65,186). The urine of mice (305) and guinea pigs (66) has been so investigated, and A4-pregnene-6/3, 11/3,17 , 21-tetrol-3,20-dione and 17-hydroxycorticosterone were isolated from the latter (67).…”