Section III, 1919 [2431 Trans. R.C.s. 



A Study of the Estimation of Iron and the Separation of Manganese from 

 Iron by Notroso-phenylhydroxylamine Ammonium (Cupferron) 



By E. H. Archibald, Ph.D., F.R.S.C, and Ruth V. Fulton, M.A. 



(Read May Meeting, 1919.) 



Introduction 



The use of cupferron as a reagent for the separation of iron from 

 aluminium^ has been the subject of a limited number of investigations. 

 Several of the conditions which ensure a complete precipitation of 

 the iron have, however, received little if any attention. The results 

 thus far obtained for the separation of iron from manganese^ would 

 indicate that a complete separation can be obtained here as well, 

 but the evidence on this point is not sufficient to warrant the con- 

 clusion that this method may be substituted for the older and very 

 troublesome methods. 



In view of these conditions, it seemed very desirable to make a 

 study of the precipitation of iron and its separation from manganese, 

 under varying conditions, by means of cupferron. 



Other Methods for the Separation of Iron 

 FROM Manganese 



It will be sufficient to remember here four of the more reliable 

 methods for the separation of iron from manganese. We have first 

 the basic acetate method by means of which iron, aluminium, titan- 

 ium, zirconium and vanadium may be separated from manganese, 

 zinc, cobalt and nickel. By treatment with the proper reagents these 

 several metals are converted into their acetates, the solution being 

 slightly acid. The acetates of the first group of metals decompose on 

 heating, forming insoluble basic acetates. The other group of metals 

 remains in solution. Sodium acetate is added to reduce the ionization 

 (and thus the dissolving power of acetic acid). 



By means of Rothe's "Ether extraction method" iron can be 

 separated from chromium, aluminium, manganese, cobalt, nickel and 

 copper. In this case advantage is taken of the fact that ferric chloride 

 can be completely extracted by ether from a hydrochloric acid solution 



1 Baudisch, Chem.— Ztg., 33, 1298. 



Bilty and Hodke, Zeit. Anorg. Chem., 66, 426. 



Fresenius, Zeit. Anal. Chem., 50, 35. 

 ^Fresenius, ibid, Brown, Jour. Am. Chem. Soc. 39, 2358 (1917) 



