The use of liquid scintillation counting in the studies of coal and coal-derived liquids

Abstract

Coal and coal derived liquids were treated with radio labeled ( 14 C or 3 H) acetic acid, ethanol, methanol and water. Coal derived liquids were allowed to react with 1- 14 C-acetic anhydride in pyridine to form acetate derivatives of phenols, alcohols, primary and secondary amines. The samples were then oxidized and collected 14CO 2 or 3 H 2 O measured in a liquid scintillation counter. Good reproducibility and quantitative recovery of 14 CO 2 and 3 H 2 O were observed. The liquid scintillation counting method was very useful for quantitation of hydroxyl groups and primary and secondary amines in coal derived liquids. The amount of adsorption of acetic acid, ethanol, methanol, and water was also measured. They found it to be irreversibly adsorbed on coal. Other techniques, such as 1 H and 13 C nmr as well as titration of liberated acetic acid, are inefficient in quantitative determination of acid groups in coal. Only tracer methodology was able to determine adsorption of solvent on coal efficiently.