CLEANUP AND ANALYSIS OF CARBAZOLE AND ACRIDINE TYPE POLYCYCLIC AROMATIC NITROGEN HETEROCYCLICS IN COMPLEX SAMPLE MATRICES

A HPLC method for the analysis of polycyclic aromatic nitrogen heteroc yclics (PANHs) in complex sample matrices is presented. It isolated an d separated carbazole and acridine type PANHs with an absolute recover y of between 79-98%. Open column chromatography is used as an initial step to isolate a PANH fraction. By applying normal-phase liquid chrom atography using a dimethylaminopropyl silica stationary phase and util ising back-flush technique it was possible to separate the PANH fracti on into two fractions containing acridine type and carbazole type PANH s, respectively. The method applied on a sample of solvent refined coa l heavy distillate (SRC II HD). A number of 3-5 ring acridines and car bazoles were identified with GC-electron impact MS and quantified with GC-nitrogen-phosphorous detection. Polycyclic aromatic hydrocarbons ( PAHs) were determined in the SRC II HD sample by automated on-line cle an-up and analysis of the obtained PAH fraction with coupled LC-GC-fla me ionization detection. There was no overlap between the PANH and the PAH fractions with this method, and carbazoles and acridines were eff iciently separated. (C) 1997 Elsevier Science B.V.