Mass chromatography is currently being adapted by many forensic laboratorie
s as the preferred approach for interpreting GC/MS data from fire debris sa
mples. This paper first describes software approaches for minimizing interf
erences and for facilitating the identification of petroleum liquids when u
sing this approach. Next, guidelines are developed for recognizing chromato
graphic distortion that often occurs when petroleum liquids are recovered u
sing the popular solid adsorption/elution method. It is seen that for a giv
en petroleum liquid, paraffinic:aromatic ratios can vary eight fold dependi
ng on the recovery conditions and sample concentration. Finally, the applic
ation of these software tools and guidelines to case samples is illustrated
, and an approach for categorizing an exemplar collection on the basis of q
ualitative features and peak height ratios is demonstrated.