Thornton, Jr. — Separation of Thorium from Iron. 151 



Art. XIX. — The Separation of Thorium from Iron with the 

 Aid of the A mmonium Salt of Nitrosophenylhydroxylamine 

 (" Cupferron ") ; by William M. Thornton, Jr. 



The ammonium salt of nitrosophenylhydroxylamine, which 

 was first introduced into analytical chemistry by O. Baudisch,* 

 has been made a subject of study by several chemists. f 

 Because of its selective action as a precipitant many clean 

 cut separations have been effected ; thus solving a variety of 

 analytical problems which without the use of the reagent 

 would involve much difficulty. Bellucci and Grassi X have 

 shown that in solutions decidedly acid with either sulphuric 

 or hydrochloric acid, the substance precipitates quantitatively 

 titanium and that under like conditions titanium can be 

 completely separated from aluminum in one precipitation. 

 Following the work of Bellucci and Grassi, the author § 

 has demonstrated that, after throwing down the iron as ferrous 

 sulphide from a solution containing sufficient ammonium tar- 

 trate to hold up titanium, and after acidifying the iron free fil- 

 trate, the titanium can be quantitatively precipitated by the "cup- 

 ferron " reagent notwithstanding the presence of tartaric acid ; 

 and, further, that, if the above-mentioned filtrate be strongly 

 acidified with sulphuric acid and contain also a sufficient 

 quantity of tartaric acid, titanium can be quantitatively sepa- 

 rated from both aluminum and phosphoric acid in one operation. 

 Pursuing a similar technique, E. M. Hayden, Jr. and the 

 authorf succeeded in separating zirconium from both iron and 

 aluminum. During the same year,!" Ferrari, by means of the 

 " cupferron " reagent, separated zirconium from aluminum ; 

 but did not consider the more complicated case of iron being 

 present as a third ingredient. Owing to the fact that thorium 

 bears a marked resemblance to zirconium in its chemical 

 relations, the author has seen fit to study the former element 

 with respect to the "cupferron" reagent. The outcome of 

 this investigation has been to establish conditions under 

 which thorium is quantitatively precipitated by the reagent 



* Cheni. Zeitung, xxxiii, 1298, 1909 ; xxxv. 913, 1911 ; Baudisch and King, 

 Jour. Ind. Eng. Chem., iii, 629, 1911. 



f Nissenson, Z angew. Chem., xxiii, 969, 1910 ; Chem. Zeitung, xxxiv, 539, 

 1910; Biltz and Hodtke, Z. anorg. Chem., lxvi, 426, 1910; Hanus and 

 Soukup, ibid., lxviii, 52, 1910 ; B. Fresenius, Z. anal. Chem., 1, 35, 1911 ; 

 Bellucci and Grassi, Gazz. chim. Ital., xliii, I, 570, 1913; Rodeja, Anal. Fis. 

 Quim., xii, 305. 1914; xii, 379, 1914; Ferrari, Annali Chim. Appi., ii, 

 276. 1914 ; iv, 341, 1915 ; Turner, this Journal, xii, 339, 1916. 



X Loc. cit. 



gThis Journal, xxxvii, 173, 1914 ; ibid., xxxvii, 407, 1914. 



| This Journal, xxxviii, 137, 1914. 



IT Loc. cit. 



