Acid-catalyzed oligomerization of glycerol was investigated by direct infusion electrospray ionization mass spectrometry in the positive ion mode, i.e. ESI(+)-MS. The ESI(+)-MS data revealed that at 280 ºC and in acidic medium (pH 2), glycerol undergoes successive intermolecular condensations to produce oligomeric species, i.e. [(glycerol)n - (n - 1) H2O] (n = 2-5). These ESI(+)-MS data, in association with the information provided by IR, ¹H and 13C NMR analyses, indicated that these oligomers undergo intramolecular dehydrations to form miscellaneous products comprised mainly by cyclic compounds as well as alkenes and carbonylic derivatives (aldehydes and ketones).
electrospray ionization; mass spectrometry; glycerol; oligomerization; monitoring
