A headspace gas chromatographic mass spectrometric (GC-MS) assay method was developed for the
simultaneous determination of methyl tertiary butyl ether (MTBE), tert-butyl alcohol (TBA) and benzene,
toluene, ethyl benzene and xylene (BTEX) in soil contaminated with gasoline. 2 g of soil sample were placed
in a 10 mL headspace vial filled with 5 mL of phosphoric acid solution (pH 3) saturated with NaCl, and the
solution was spiked with fluorobenzene as an internal standard and sealed with a cap. The vial was heated in a
heating block for 40 min at 80
o
C. The detection limits of the assay were 0.08-0.12 µg/kg for the analytes. For
five independent determinations at 10 and 50 µg/kg, the relative standard deviations were less than 10%. The
method was used to analyze fifty six soil samples collected from various regions contaminated with gasoline
in Korea. The developed method may be valuable for the monitoring of the analytes in soil.