195 



iNVESTIGATIOlSr CONCERNIXG ThE ReICHERT-MeISSL No. AND 



THE Rate of Distillation of the Volatile 

 Acids in Butter Fat. 



By George Spitzeb. 



In ltK)6 J. Delaite and J. Legrand (Bui. Soc. Chim. Belg. ) investigated 

 tlie determination of the volatile acid. He found the R. M. No. to increase 

 when saponiflication was continued from one-fourth to six hours. This 

 they claimed was due to depolymerization. 



In the regular work of the laboratory no such variation was ob- 

 served in the routine work of determining the volatile acids. The time, 

 of saponification varied from one to one and one-half hours. 



To determine the effect of continuing the saponification on the per cent, 

 of volatile acids obtained by the Reichert-Meissl process, 10 determinations 

 were made using the same butter fat and following the A. O. A. C. method, 

 (p. 189. I9€S), the saponification being carried out under method (a), imder 

 pressure with an alcoholic solution of potassium hydrate. The saponifica- 

 tion flasks \^'ere completely submerged in a steam bath at a temperature 

 of 105° C. This was done to insure a more uniform temperature during the 

 time of saponification. 



The time of saponification varied from 1.^. minutes to two and one-half 

 hours. The quantity of butttr fat taken was as near five grams as could 

 be weighed accurately. The result calculated on the basis of five grams. 



In distilling the volatile acids the coiidiiions were kept as uniform as 

 it was practical, the rate of distillation being so regulated that 110 c.c, 

 the required amount was distilled in 30 minutes. 



Ten determinations were made. The results are shown in the follow- 

 ing table. 



Table I. 

 « Showing the Effect of Time of Saponification. 



Time in minutes 



Reichert-Meissl No 



Per cent. Vol. Acid as Butyric. 



15 



30 



45 60 



75 



90 



105 



28.32 



28.25 



28.35 28.29 



28.29 



28.28 



28.35 



4.93 



4.97 



4.99 4.98 



4.98 



4.97 



4.99 



120 , 135 



i 

 28.32 28.28 



4.98 4.97 



150 

 28.31 

 4.98 



