Thornton — Separation of Titanium from Iron. 173 



Art. XIII. — The Use of the Ammonium Salt of Nitrosophe- 

 nylhydroxylamine ("Cupferron") in the Quantitative 

 Separation of Titanium from Iron ; by William M. 

 Thobnton, Je. 



[Contributions from the Kent Chemical Laboratory of Yale Univ. — ccliv.] 



Nitrosophenylhydroxylamine was first synthesized by 

 Wohl.* The ammonium salt of nitrosophenylhydroxylamine 

 was brought into service in analytical chemistry by Baudischf 

 for the estimation of either copper or iron, the separation of 

 these two metals from various others, and indirectly for the 

 separation of the former from the latter. Owing to these 

 properties, the trivial name of " Cupferron " has been applied 

 to the ammonium salt of nitrosophenylhydroxylamine. The 

 analytical data given by Baudisch are few and not absolutely 

 confirmatory. Since then, however, various other workers 

 (notably Biltz and Hodtke,:}: Hanus and Soukup,§ and Frese- 

 nius|) have thoroughly demonstrated the value of this reagent 

 for the quantitative precipitation of either copper or iron and 

 their separation from various other bodies. In connection 

 with other work, Schroeder^f has made the statement** that 

 titanium and zirconium could be quantitatively precipitated 

 from their acid solutions by the "cupferron" reagent, and that 

 experiments were in progress for the estimation of these two 

 elements. Schroeder, however, gave no experimental data 

 and has not published further upon the subject. Bellucci and 

 Grassiff have shown that from solutions, moderately acidified 

 with either sulphuric or hydrochloric acid, titanium could be 

 quantitatively precipitated by the "cupferron" reagent, and 

 that titanium could also, under these conditions, be quantita- 

 tively separated from aluminum. Under these circumstances 

 the titanium comes clown as a very bulky, readily filterable, 

 precipitate of canary yellow color. In the opinion of the afore- 

 said authors the precipitate, after having been crystallized from 

 ethyl alcohol, is the titanic salt of nitrosophenylhydroxylamine, 



CH h -N=N-0' 



corresponding to the formula 



O 



Ti. 



*Ber. chem. Ges., xxvii, 1435, 1894. 



f Chem. Zeitung, xxxiii, 1298, 1909. 



JZeitschr. anorg. Chem., lxvi, 426, 1910. 



§Ibid., Ixviii, 52, 1910. 



|| Zeitschr. anal. Chem., 1, 35, 1911. 



■ffZeitschr. anorg. Chem., lxxii, 89, 1911. 



** Loc. cit., page 95. 



ft Gazetta Chimica Italiana, Anno xliii, parte I, 570, 1913. 



Am. Jour. Sci. — Fourth Series, Vol. XXXVII, No. 218. — February, 1914. 

 13 



