IMPROVED METHODS FOR FAT ANALYSIS. 



133 



Acetyl Gravimetric Process on Original Product. 

 Glycerides. 



Monoglycerides. 



Monopalmitin, 

 Monostearin, 

 Monolein, . 



330.304 

 358.336 

 356.320 



414.336 

 442.368 

 440.352 



.254408 

 .234506 

 .235833 



3.93069 

 4.26428 

 4.24029 



Diglycerides. 



Dipalmitin, 



Distearin, 



Diolein, 



568.54-i 

 624.608 

 620.576 



610.560 

 666.624 

 662.592 



.073901 13.53162 



.067268 14.86591 



.067705 14.76996 



' Acetyl number = 1335.39604 i. 



Supplementary Notes. — The various hydroxy compounds that occur in 

 oils, fats and waxes form derivatives on heating with acetic anhydride, 

 the acetyl radical displacing the hydrogen of the alcoholic hydroxyl 

 groups. Tliis property serves as the basis of analytical methods for the 

 quantitative determination of monohydroxy and dihydroxy acids and 

 their glycerides, monogl3'cerides and diglycerides, and free alcohols. 



Glycerides of hydroxy acids are a natural constituent of certain oils 

 and fats, although they do not appear to be very widely distributed in any 

 considerable amount. Castor oil, composed largely of ricinolein, is an 

 excellent illustration. Hydroxy acids probably occur more frequently as 

 the result of oxidation of unsaturated acids. Oleic acid has been shown 



