350 



Scientific Proceedings (123). 



the acid was neutralized by addition of Ba(OH) 2 in slight excess 

 and the ammonia was removed by blowing air through the solu- 

 tion for several days. The electrolysis, which requires approxi- 

 mately three hours, is continued until a specimen of the fluid from 

 the center compartment, on addition of phosphotungstic acid, 

 gives no precipitate. The fluid in the cathode solution invariably 

 contained approximately 15 per cent, of non-basic nitrogen. A 

 small quantity of amino acids other than the hexone bases are 

 carried over into the cathode compartment by cataphoresis. On 

 reelectrolysis of the cathode solution the non-basic nitrogen was 

 reduced to an indeterminable quantity. 



The table shows the results which were obtained in a number 

 of experiments and indicates the applicability of the method for 

 the separation of the basic group of amino acids. Of particular 

 interest is the observation that when the reaction of the gelatin 

 hydrolysate is more alkaline than Ph 7-5, histidin is not carried 

 over into the cathode compartment while Ph 5-5 analysis of the 

 cathode solution shows the presence of the three basic amino 

 acids in approximately the same proportions as in the original 

 hydrolysate. This is not unexpected when it is recollected that 

 the isoelectric point of histidin is considerably lower than that of 

 either arginin or lysin. A further advantage possessed by this 

 method lies in the fact that the coloring matter contained in the 

 protein hydrolysate migrates to the anode and a clear colorless 

 cathode solution is obtained. 



The cathode solution is freed from sulphates by the addition 

 of Ba(OH) 2 in slight excess and the excess of barium is removed by 

 means of CO2. From the filtrate, containing arginin and lysin, 

 the former can be quantitatively separated by the addition of a 

 concentrated alcoholic solution of picrolonic acid in an amount 

 equivalent to the arginin present. The filtrate, after removal of the 

 arginin picrolonate, is freed from a trace of picrolonic acid by ex- 

 traction with ether in the usual manner. Lysin can now be isolated 

 from the concentrated solution by addition of picric acid. 



Further work on the application of this method to the separa- 

 tion of amino acids is in progress. 



