Identification of Ethyl and t-Butyl Glyceryl Ethers Using Gas Chromatography Coupled with Mass Spectrometry

Abstract

The ethers produced through the etherification reaction of glycerol with ethanol or t-butanol are used as oxygenated fuel additives, intermediates in the pharmaceutical industry, and non-ionic surfactants. However, the identification of these ethers has not been accurately done, because only some mass spectra of these compounds are available in the libraries. Moreover, there is a lack of discussion on their identification in the literature. In this work, a detailed identification of all ethers produced in the etherification of glycerol with ethanol or t-butanol was performed considering the mass spectra of isolated products and the comparison of the retention times. The elution order of the products was: tri-alkyl, 1,3-dialkyl, 2,3-dialkyl, 3-monoalkyl and 2-monoalkyl. In all mass spectra of the ethyl ethers, the base peak was m/z 61, while in the case of t-butyl ethers it was m/z 57.

Biofuel additive production from glycerol and determination of its effect on some fuel properties

“…No peak was observed for TTBG and indicating that TTBG did not form. This result is in agreement with earlier reported results [26,32,41]. The reason for this is attributed to the steric hindrance [17,32].…”

“…Besides, the formed of water from tert-butyl alcohol by dehydration has an inhibition effect on the Amberlyst-15 catalyst, which decreases the formation of high ethers of glycerol [25,28,31]. GC-MS results are in close agreement with those obtained by Jamróz et al [40], Özbay [42], and Paula et al [41].…”

“…MS spectra of glycerol tert-butyl ethers are unavailable in Masshunter libraries. Therefore, the products were confirmed by the retention time and mass fragmentation pattern with the previously published papers, wherein a detailed spectroscopic study on tert-butyl ethers of glycerol is carried out [40,41]. It can be easily seen in Fig.…”

Zeolite-assisted etherification of glycerol with butanol for biodiesel oxygenated additives production

“…Unfortunately, also by GC-MS analysis, it was not easy to make an unequivocal identification of each ether formed, as almost all MS spectra were very similar to each other and the base peak at m/z = 57, corresponding to fragment ion [C 4 H 9 ] + , was detected in all spectra. However, although the mass spectra of butyl ethers of glycerol are not available in MS libraries, the MS spectra of 1a and 2a, 1b and 2b, 1c and 2c have been individuated by using GC standards and by comparing them with literature data [26][27][28] . Then, di -butyl ethers, 3a and 4a , have been individuated by their characteristic peak at m/z = 175, corresponding to the fragment ion [ Anyhow, it is possible to assert that, 1-butyl-di -glycerylmonoether ( 1d ) and 2-butyl-di -glyceryl-monoether ( 2d ) could form mainly at 200 °C and not at lower temperature, considering that, differently from what occurs at 200 °C when glycerol isomerizes to di -glycerol, at 180 °C, di -glycerol is hardly formed.…”

The role of mechanochemical treatment of carbon nanotubes in promoting glycerol etherification

“…[4][5][6] MTBGEs were also confirmed to be useful as gasoline boosters; however, due to their poor miscibility with hydrocarbons, they often need to be converted into the appropriate derivatives or mixed with higher-substituted tert-butyl glycerol ethers. 5,7 It is also worth noting that TBGEs are considered sustainable substitutes for methyl tert-butyl ether (MTBE), which has been restricted in some countries for ecological and economic reasons. 4,8 Typically, tert-butyl glycerol ethers are obtained in the reaction between glycerol and tert-butyl alcohol (TBA) or isobutene (IB) using strong Brönsted acid catalysts, preferably heterogeneous ones.…”