23, s West and Balce: Composition of Pili-nut Oil 271 



In investigating the composition of pili-nut oil the saturated 

 and unsaturated acids, which are present as glycerides in the 

 oil, were separated by the lead-salt-ether method. 5 The unsat- 

 urated acids were determined by means of the bromo-derivative 

 method. 6 The saturated acids were converted into their methyl 

 esters 7 which were fractionally distilled. The composition of 

 the saturated acids was estimated by calculating the data ob- 

 tained from the methyl esters. 



SEPARATION OF SATURATED AND UNSATURATED ACIDS 



The lead-salt-ether method does not give a 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. T^he 

 unsaturated 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. 



In separating the saturated and unsaturated acids by the lead- 

 salt method the unsaponifiable matter originally present in the 

 oil goes with the unsaturated acids. 8 The percentage of impure 

 unsaturated acids, as determined, must therefore be corrected, 

 not only for the small amount of unsaturated acids present in the 

 saturated acids, but also for the unsaponifiable matter which 

 they contain. Since pili-nut oil contained only 0.19 per cent 

 of unsaponifiable matter (Table 1), it was not considered neces- 

 sary to correct the unsaturated acids for this small percentage 

 of unsaponifiable as this slight correction may be applied directly 

 to the unsaturated glycerides, thus giving the same result. 



The percentage of impure saturated acids separated by the 

 lead-salt method was 51.45, and the percentage of unsaturated 

 acids, 43.87. The iodine value of the impure saturated acids 

 was 23.32, and of the unsaturated acids, 89.92. The percentage 



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

 Waxes 1 (1921) 556. 



•Ibid. 1 (1921) 585. , o An 



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

 (1920) 1200. 



8 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) 2697. 



