Radoykova T.Nenkova S.Valchev I.2024-07-162024-07-162024-07-162024-07-162013-11-051314-74711314-7978SCOPUS_ID:84886738632https://rlib.uctm.edu/handle/123456789/1015By extraction with toluene and ethyl acetate monomeric lignin compounds: 2-methoxyphenol, 2,6-dimethoxyphenol, 4-hydroxy-3-methoxybenzaldehyde, 4-hydroxy-3,5-dimethoxybenzaldehyde, 1-(4-hydroxy-3-methoxyphenyl) ethanone, 1-(4-hydroxy-3,5-dimethoxyphenyl) ethanone, etc. were isolated from black liquor and sulfate lignin, and identified through GC/MS analysis. The identified low-molecular mass lignin compounds do not contain organic bonded sulphur. The sulfate lignin, separated from black liquor after acidification with acid was subjected to an alkaline treatment (4 h; 180oC; 5 % NaOH; lignin/NaOH ratio -1:8).enArticle