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Hilditch and Lea ( 3 5 5 ) first described the oxidation cf natural triglyceride mixtures in acetone solution by refluxing with powdered K M n 0 4 . This procedure with its subsequent modifications (4,77,166,193,366,562) is only semiquantitative due to three limitations. The reaction is usually incomplete, and oxidized samples often have an iodine value of 2 to 8 (193,358,562). Appreciable hydrolysis occurs during oxidation, probably because of alkaline products formed by permanganate reduction (163,165,253,451).

Spectrophotometry H y d r o x a m i c acid R e a c t w i t h H O N H 2 H C l a n d ferric P e r c h l o r a t e t o form ferric h y d r o x a m a t e s . M e a s u r e a b s o r p t i o n a t 520 n m . Glycerol R e a c t w i t h K O H or L i A l H 4. R e c o v e r glycerol a n d a d d i n t e r n a l s t a n d a r d such as b u t a n e - l , 4 - d i o l . A n a l y z e free alcohols or t h e i r a c e t a t e or t r i m e t h y l s i l y l e t h e r d e r i v a t i v e s . G a s - l i q u i d chromatography M e t h y l esters A d d i n t e r n a l s t a n d a r d such as t r i h e p t a d e c a n o i n or m e t h y l p e n t a d e c a n o a t e .

Bromination Bromine can be added to the double bonds of unsaturated triglycerides to appreciably change their relative solubilities and thus improve their separation characteristics. A commonly used bromination procedure has been the dropwise addition of a dilute CHCL 3 solution of bromine to a dilute CHC1 3 solution* of the sample near —10° and with vigorous agitation until a faint yellow color persists (259,645,919,930). However, the quantitative aspects of this reaction have never been rigorously tested with pure triglycerides; and while the yield is undoubtedly high, the reaction may not go entirely to completion.