Issued June 15, 1910. 



United States Department of Agriculture, 



BUREAU OF CHEMISTRY Circular No. 56. 

 H. W. WILEY, Chief of Bureau. 



THE DETERMINATION OF TOTAL SULPHUR IN ORGANIC MATTER. 



By HERMAN SCHREIBER, 

 Assistant Chemist, Bureau of Chemistry. 



INTRODUCTION. 



A great many methods have been proposed for the determination of 

 total sulphur in organic matter, but probably only two of these are 

 either easy to manipulate or accurate, namel} T , the Barlow-Tollens," 

 or absolute method, and the Osborne, 6 or peroxid method. When the 

 latter is applied to solid material, however, it leaves much to be desired 

 in the way of ease of manipulation and speed, and has absolutely no 

 claim to exactness of detail. It is true that the water used for mois- 

 tening the sample is measured and the sodium carbonate is weighed, 

 but the amount of sodium peroxid added varies with the material ana- 

 lyzed and with the rate at which the reagent is added. The amount of 

 acid which must be added after fusion is also an unknown factor; it 

 varies in each case which necessitates making the solution alkaline 

 again, and then acid. These, however, are not all of the difficulties 

 encountered. The fusions have a tendency to burn and blow out of 

 the crucible, and this happens most frequently when the determina- 

 tions must be rapidly made, for the peroxid method has a dignity all its 

 own and will brook no haste or impatience. All of these objections 

 were keenly realized when it became necessary to make about 100 

 sulphur determinations in a recent research. 



An ideal method for this determination should embody several 

 features: First, it must not call for excessive amounts of reagents, 

 nor such as will interfere with the precipitation of the barium sulphate 

 or contaminate the precipitate; second, the reagents employed must 

 serve two purposes, i. e., they must destroy all of the organic matter 



J. Amer. Chem. Soc., 1904, 26: 341. 



&U. S. Dept. Agr., Bureau of Chemistry Bui. 107, Kevised, p. 23. 

 43669 Cir. 5610 



