OZONATION PRODUCTS OF ORGANOSOLVOLYTIC EXTRACTS FROM VEGETAL MATERIALS

The ozonation of lignin in an organic solution was used to produce oxy aromatic compounds. Corn (Zea mays) stalk and poplar (Populus deltoide s) wood lignin solutions (organosolvolytic juices) obtained from their respective autohydrolyzed materials and an organosolv lignin were tre ated with ozone, and the time course trend of the identified reaction products was studied. GC/MS and GC/FID were used to identify and quant ify (internal standard method) the reaction products. The following ac ids were identified: glycolic, oxalic, malic, glyceric: p-hydroxybenzo ic, and vanillic. In addition, p-hydroxybenzaldehyde, vanillin, syring aldehyde, and hydroquinone were also identified. All the oxyaromatic a ldehydes reached maximum yields at short reaction times (between 1 and 8 min). These results were used to determine the ratio between the di fferent phenylpropane units of their constitutive Lignins. The ratio o f p-hydroxyphenyl:guaiacyl:syringyl units for corn stalk, poplar wood, and organosolv lignins was 5.3:2:1, 0.1:1:1.1, and 0:1:1.1, respectiv ely.