Gas Chromatography Control of Synthesis of N,N-Dimethylaminopropylamids of Fatty Acids

Abstract

Catalytic-free interaction of methyl esters of fatty acids of coconut oil with an equimolar amount of N,N-dimethylaminopropylamine has been studied during twelve hours. Sample for analysis are collected once per hour. Identification of the reaction products has been performed using a Scion TQ mass spectrometer and NIST11 mass spectra library. The degree of the reaction completeness was assessed by determining the residual content of methyl esters by gas chromatography using as internal standard methyl heptadecanoate, the values of the relative standard deviation in the determination of methyl esters do not exceed 0.030. The analysis was carried out on a Bruker 451 GC with flame ionization detector (FID). The selected chromatographic conditions provided low duration of analysis (32 min) and the absence of peak overlapping. The correction factors are calculated proceeding from the results of analysis of standard mixture (Supelco) to compemsate the response FID upon FAME determination. After 12-h catalytic-free synthesis a residual amount of methyl esters of the fatty acids was 10.8%. The obtained results are attractive for the experts in the field of organic synthesis of surfactants and can be used in estimating of the rate of conversion of methyl esters of fatty acids in the synthesis of N,N-dimethylaminopropylamides.