Evaluating the performance of three GC columns commonly used for the analysis of ignitable liquid mixtures encountered in fire debris

The analysis of debris recovered from fire scenes for the presence of ignitable liquids is of increasing importance for fire scene investigation. Increasingly this is carried out using Gas chromatography-mass spectroscopy (GCMS) using a standard dimethylpolysiloxane capillary column. Various publications in the available literature and survey data from forensic science laboratories favour HP-1 or HP-5 columns or their equivalent but no direct comparison of the sensitivity, selectivity or resolution of these columns for test mixtures relevant to ignitable liquid matrices have been published. This present work addresses this by analysing a matrix matched test mixture and an ignitable liquid test mixture using three different commercially available dimethylpolysiloxane columns currently referenced in the literature for ignitable liquid analysis. The ASTM standard method for analysis of ignitable liquids using GCMS was adopted and systematically modified for each column to afford maximum separation of the analytes and the results are presented.