270 



C. NEUBERG, A. GRAUER 

 URANIUM 



VOL. 12 (1953) 



A mino acids or salts 



Precipitate 



Remarks 



Na hippurate 



Tyrosine 



Leucyltyrosine 



Glycyltyrosine 



Tryptophane 



Acetyltryptophan 



Arginine HCl 



Lysine HCl 



Histidine HCl 



Asparagine 



Na glutamate 



Methionine 



Glutathione Na 



Witte-peptone 



Silk peptone 



+ s. in excess of glutamate 



+ ppt. yellow-white, indistinct needles 



+ s. in NH4 citrate 



In order to obtain some criteria for the practical applicability of the process as 

 described above some experiments were carried out to determine the minimum quan- 

 tities which are detectable. 



a. Fructose- i ,6-diphosphate 



0.1 ml of an M/100 solution + 0.9 ml H2O yield a flaky precipitation with thorium- 

 nitrate, uranylacetate or lanthanumchloride, especially on warming. The precipitants 

 were applied in suitable concentrations. 



b. Phosphoglycerate 



The limits of precipitability were similar to those under a. 



c. Glycerophosphate 



Precipitation was obtained only in tenfold concentration with LaClg and Th(N03)4, 

 but not with uranyl acetate. 



d. Na-phytate 



Phytic acid will react in similar concentration as a. and b. 



e. The same is true for Fumarates. 



f. Citrate 



Will precipitate in similar concentration as a., b. and d, with Th(N03)4 ^"^ LaClg; 

 uranyl acetate yields no precipitation. 



There should be an excess of the metal salts over the compounds to be precipitated, 

 since the latter tend to redissolve the resulting i)recipitatcs more or less readily. 



For the purposes of the present investigations the composition of the insoluble or 

 hardly soluble compounds in itself is immaterial. In the following some of the analyses 

 will be reported. 

 References p. 2j2. 



