CHEMICAL-ANALYSIS OF HIGH ASH BRAZILIAN COAL-TAR .2. ACID BASIC/NEUTRAL SEPARATION OF RESINS/

Resins, obtained by chromatographic separation on silica-gel as descri bed in a previous work (Lancas and Caramao, 1992), were fractionated b y acid/basic/neutral separation in modified silica gel (acidic and bas ic) and characterized by infrared and elemental analysis. Resins were the major components found in the preparative liquid chromatographic f ractionation of coal tar, and, for this reason, we tried to fractionat ed them into simpler fractions with the purpose of identifying their c onstituents. Six distinct cuts of coal tar (A to F) are subject to fra ctionation into acid/basic/neutral fractions, with large amounts of ne utral compounds being found. The percent of acids found varied from 21 .0 to 36.5, and the percent of bases varied from 3.2 to 8.0. The chara cterization of the individual fractions, confirm the success of the fr actionation of the resins.