Evaluation of Proton Nuclear Magnetic Resonance Spectroscopy for Determining the Yield of Fatty Acid Ethyl Esters Obtained by Transesterification

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• 作者：Maria dos Prazeres Menezes de Jesus ; Lucas Nat茫 de Melo ; Jhosianna Patr铆cia Vilela da Silva ; Alessandre Carmo Crispim ; Isis Martins Figueiredo ; Jana铆na Heberle Bortoluzzi ; Simoni Margareti Plentz Meneghetti
• 刊名：Energy & Fuels
• 出版年：2015
• 出版时间：November 19, 2015
• 年：2015
• 卷：29
• 期：11
• 页码：7343-7349
• 全文大小：413K
• ISSN：1520-5029

文摘

This study systematically evaluates the use of proton nuclear magnetic resonance (¹H NMR) spectroscopy for determining the composition of soybean oil ethyl transesterification product mixtures by comparing the compositions measured by ¹H NMR spectroscopy and high-performance liquid chromatography (HPLC). The influence of the sample composition on the results is also discussed. For many of the samples, the triacylglycerol (TAG), diacylglycerol (DAG), monoacylglycerol (MAG), and fatty acid ethyl ester (FAEE) contents could be determined by HPLC. When the conversion of the TAGs into FAEEs is incomplete, the evaluation of the FAEE content by ¹H NMR spectroscopy must be performed with caution because of overlapping signals in the spectrum. In this study, three equations were used to calculate the ethyl ester content from the ¹H NMR results. The contents calculated using eq 3 agree with the HPLC results the best, as shown by the slope obtained by linear regression of the two data sets.