Carboxylic acids and hydroxycarboxylic acid

Figure S.3 Separation of carboxylic acids and hydroxycarboxylic acids on lonPac ICE-AS6. Eluent 0.4 mmol/L heptafluorobutyric acid flow rate 0.4 mL/min detection suppressed conductivity injection volume 50 pU peaks 5mg/L oxalic acid (1), lOmg/L tartaric add (2), 15mg/L citric acid (3), 20mg/L malic add (4),...

A final class of sulfated alkyl surfactants is that of the sulfated fats and oils in which the sulfate esters are obtained by the treatment of a variety of hydroxylated or unsaturated natural fats and oils with sulfuric or chlorosulfonic acids. These materials represent the oldest types of commercial synthetic surfactants, dating back to the original turkey red oils. Because of the nature of the starting materials and preparation processes, the sulfated fats and oils are chemically heterogeneous materials whose properties are very sensitive to their history. In fact, the preparation of such materials may correctly be considered to be more art than science. They will contain not only sulfated glycerides similar to those discussed above but also sulfated carboxylic acids and hydroxycarboxylic acids produced by hydrolysis of the starting materials. With the increased availability of more chemically pure surfactant materials, the use of the sulfated fatty oils has decreased considerably. They do still have their uses, however, especially where purity is not a major concern and cost is important. 

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