Subfractionation of Coal Tar Neutral Fraction.
Jones-DR; Reilich-HG; O'Neill-NJ
NIOSH 1975 Aug:41 pages
A study was conducted to develop a fractionation scheme for a neutral coal-tar fraction which had been isolated from coal-tar pitch. Silica (7631869) gel chromatography was used to fractionate the neutral fraction of a 2kg sample of coal-tar. Class separation was affected by the sequential elution of the neutral fraction with solvents of increasing polarity over an activated silica gel of known activity. In three laboratory scale runs, multiple fraction collections (100 to 150) were conducted and characterized in order to evaluate optimal solvent ratios and volumes. The large pilot scale run was conducted in two stages under similar conditions and resulted in the collection of 16 class subfractions of the neutral fraction. The subfractions were characterized primarily by gas chromatography and nuclear magnetic resonance spectrometry with the input of infrared and ultraviolet spectrometry and thin layer chromatography. Individual fractions were stripped of solvent, weighed, packaged in tared low actinic glass containers, and submitted to NIOSH for biological screening. In all stages of the fractionation and particularly during the column separation, every effort was made to eliminate ultraviolet and thermal exposure of the sample.
NIOSH-Contract; Contract-099-74-0039; Tars; Pitches; Analysis; Analytical-methods; Chromatography; Analytical-chemistry; Analytical-instrumentation; Spectrometry;
NIOSH, Cincinnati, Ohio, Final Report