23.4 West and Cruz: Cashew-nut Oil 339 



methyl esters, 6 which were fractionally distilled. The composi- 

 tion of the saturated acids was estimated by calculating the 

 data obtained from the methyl esters. 



SEPARATION OF SATURATED AND UNSATURATED ACIDS 



The lead-salt-ether method does not give complete separation of 

 saturated and unsaturated acids, since the saturated acids are 

 always contaminated by a small quantity of unsaturated acids, as 

 shown by the iodine value of the saturated acids. The unsatu- 

 rated acids are also likely to be contaminated with a small 

 quantity of saturated acids, but this error can usually be reduced 

 to an unappreciable amount by not washing very thoroughly 

 with ether the lead salts of the saturated acids. 7 



In separating the saturated and unsaturated acids by the lead- 

 salt-ether method the unsaponifiable matter originally present in 

 the oil goes with the unsaturated acids. 8 The percentage of im- 

 pure unsaturated acids, as determined, should therefore be cor- 

 rected, not only for the small amount of unsaturated acids 

 present in the saturated acids, but also for the unsaponifiable 

 matter which they contain. 



The results of separating the saturated and unsaturated acids 

 of cashew-nut oil by the lead-salt-ether method are given in 

 Table 3. 



Table 3. — Separation of saturated and unsaturated acids of casheiv-nut 



Impure saturated acids (determined) 

 Unsaturated acids and unsaponifiable l 



Jamieson, G. ,S., and Baughman, W. F., Journ. Am. Chem. Soc. 42 

 (1920) 1200. 



7 Baughman, W. F., Brauns, D., and Jamieson, G. S., Journ. Am. Chem. 

 Soc. 42 (1920) 2398. 



* Lewkowitsch, J., Chemical Technology and Analysis of Oils, Fats, and 

 Waxes 1 (1921) 584; Baughman, W. F., and Jamieson, G. S., Journ. Am. 

 Chem. Soc. 43 (1921) 2679. 



