The objective of this work is to compare various extraction and quanti
tation techniques for the determination of adsorbed polynuclear aromat
ic hydrocarbons (PAHs) on coal ash. Aliquots of a 'clean' fly ash from
coal combustion doped with four PAHs have been extracted, using thr-e
e solvents, three methods and three GC/MS programs. Factorial analysis
shows solvent to exert the greatest primary effect: CH2Cl2 > toluene
much greater than o-xylene. Highest recoveries were obtained using the
reflux slurry extraction procedure with CH2Cl2 and a relatively fast
(20 degrees/min) temperature ramp to 310 degrees. With both CH2Cl2 and
toluene solvents, ultrasonic assisted extraction affords the best rep
eatability. Published by Elsevier Science B.V.