- Development and Validation of a Novel Free Fatty Acid Butyl Ester Gas Chromatography Method for the Determination of Free Fatty Acids in Dairy Products
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Accurate quantification of free fatty acids in dairy products is important for both product quality control and legislative purposes. In this study, a novel fatty acid butyl ester method was developed, where extracted free fatty acids are converted to butyl esters prior to gas chromatography with flame ionization detection. The method was comprehensively validated to establish linearity (20-700 mg/L; R2 > 0.9964), limits of detection (5-8 mg/L), limits of quantification (15-20 mg/L), accuracy (1.6-5.4% relative error), interday precision (4.4-5.3% relative standard deviation), and intraday precision (0.9-5.6% relative standard deviation) for each individual free fatty acid. A total of 17 dairy samples were analyzed, covering diverse sample matrices, fat content, and degrees of lipolysis. The method was compared to direct on-column injection and fatty acid methyl ester methods and overcomes limitations associated with these methods, such as either column-phase absorption or deterioration, accurate quantification of short-chain free fatty acids, and underestimation of polyunsaturated free fatty acid.
- Mannion, David T.,Furey, Ambrose,Kilcawley, Kieran N.
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p. 499 - 506
(2019/01/08)
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- Novel H3PW12O40: Catalysed esterification reactions of fatty acids at room temperature for biodiesel production
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The catalytic activity of Bronsted acids on fatty acid (FA) esterification at room temperature has been investigated. Noticeably, the H 3PW12O40 heteropolyacid (HPW) showed a very high activity than other catalysts herein evaluated, i.e. p-toluene sulfonic acid and sulfuric acid. High yields in ethyl esters (ca. 90%) were reached after a 4 h reaction at 25 °C on a HPW catalysed reactions. Despite the fact that HPW catalyst was used in a homogeneous phase, it could be efficiently recovered and reused through out a simple recycling protocol, without any activity loss. The effects of alcohol and the FA nature on yield reaction were also investigated.
- De Godoi Silva, Vinicius Wilker,Laier, Leticia Oliveira,Silva, Marcio Jose Da
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experimental part
p. 207 - 211
(2010/08/03)
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