1. The reducing method of Talbot, Saltzman, Wixom & Wolfe [1945], and the formaldehyde method of Corcoran & Page [1948], as well as a modification of that of Daughaday, Jaffe & Williams [1948] for the estimation of urinary corticosteroids, have been critically examined.
2. A study has been made of the distribution of reducing material, of formaldehydogenic material and of reducing and Δ4-3-ketosteroids, in the various fractions obtained during the various purification procedures applied to the crude CHCl3 extract.
3. Caustic soda washing does not remove significant quantities of the steroids investigated, although non-steroid reducing and uncharacterized formaldehydogenic material is removed.
4. The water fraction of the benzene-water partition contains all the reducing and Δ4-3-ketosteroids so far detected in urine.
5. The formaldehydogenic method of Corcoran & Page gives slightly higher results than the modified method of Daughaday et al.
6. The acid hydrolysis curves obtained with the Talbot method resembled those described by Paterson, Cox & Marrian [1950], but no regular form of hydrolysis curve was obtained when either formaldehydogenic method was used.
7. A comparison of normal values obtained by the authors using the chemical and paper chromatography techniques revealed that the formaldehydogenic methods estimate a very high proportion of uncharacterized material, whereas results by the reducing method of Talbot et al. approximate relatively closely to those obtained by semiquantitative paper chromatography.
Kinetic study of hydrolysis of ethyl acetate using caustic soda
