“…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.…”