Source identification of aromatic hydrocarbons in sediments using GC/MS

A method that may distinguish between input of polycyclic aromatic hydrocarbons (PAH) from petroleum and combustion sources is demonstrated on sediment samples. Selected series of aromatics (unsubstituted compounds and their C/sub 1/-C/sub 3/ alkyl homologues) are quantified by computerized GC/MS. The alkyl homologue distribution (AHD) within each series and the sum of components in each series relative to the sum of all components measured (relative amount of each aromatic series (RAA)) are graphically visualized. In combination these parameters give a first-order indication of the PAH source. Pyrene/fluoranthene AHD series appear to be especially sensitive as an indicator for detecting PAH from combustion sources. Interestingly the dibenzothiophene AHD series does not discriminate between crude oil and soot samples. The method is demonstrated on sediments from the North Sea and from Norwegian and Swedish fjords.