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Batchwise extraction of methyl linolenate (18:3, ALA) from fatty acid methyl esters derived from soybean and canola oils using silver nitrate/silica gel
Author(s) -
McWilliams Kevin M.,
Angelici Robert J.
Publication year - 2016
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/ejlt.201500084
Subject(s) - chemistry , silver nitrate , linolenate , incipient wetness impregnation , silica gel , extraction (chemistry) , canola , adsorption , fatty acid methyl ester , chromatography , biodiesel , soybean oil , nuclear chemistry , fatty acid , hexane , yield (engineering) , organic chemistry , selectivity , food science , materials science , catalysis , metallurgy
The incipient wetness impregnation (IWI) method was used to prepare a series of AgNO 3 /SiO 2 adsorbents that were used for the extraction of unsaturated FAMEs from hexane solutions of methyl soyate and methyl canolate. The AgNO 3 /SiO 2 ‐IWI adsorbents with the highest AgNO 3 loadings (40 or 50% w/w) were the most selective for the removal of methyl linolenate (18:3). For example, extractions with 40% AgNO 3 /SiO 2 ‐IWI reduce the amount of 18:3 from 7.0% in methyl soyate (1.00 mL) to 1.3% while extracting only 9% of the original FAMEs mixture. The extracted FAMEs fraction has a very high 18:3 (55.6%) and 18:2 (41.9%) composition. This adsorbent maintained its selectivity for 18:3 in at least four successive extractions. Similar extractions of methyl canolate yield a biodiesel that contains much smaller amounts of 18:3. The amounts of 18:3 and 18:2 that are extracted can be controlled by the AgNO 3 loading and the amount of AgNO 3 /SiO 2 ‐IWI that is used. Practical applications: Results of the reported studies show that AgNO 3 /SiO 2 is able to preferentially remove methyl linolenate (18:3, ALA) from methyl soyate and methyl canolate. This batchwise process makes these biodiesels a source of the omega‐3 fatty acid ALA and gives a biodiesel that is less sensitive to oxidative deterioration. FAMEs derived from soybean and canola oils, when treated with AgNO 3 /SiO 2 , are separated into a portion that is enriched in 18:3 (ALA) and a biodiesel that contains the more saturated FAMEs.