[Comparative study on determinations of BTEX in soils from industrial contaminated sites]

In order to ascertain BTEX measurements of soils from industrial contaminated sites, static headspace, purge-and-trap and solid phase microextraction (SPME) combined gas chromatography were selected to determine BTEX in the soils. This method of SPME could not be used to analyze BTEX isomers in soils from highly contaminated sites because the high concentration of organic contaminants eroded the SPME probe head. The recoveries for added standard ranged from 95.2% - 98.2% for static headspace-GC and 99.2% - 101.3% for purge-and-trap-GC. When the soil samples contained low concentrations of BTEX (< 60 mg/kg), the concentration determined by purge-and-trap-GC was 12.6% - 37.6% higher than the value from static headspace-GC. For soil samples containing high concentrations of BTEX, the static headspace-GC result was higher than that from purge-and-trap-GC. The correlation trend lines of individual BTEX isomers to total BTEX were similar for both static headspace-GC and purge-and-trap-GC results.