Field detection of organochlorine pesticides, explosives, and volatile organic compounds

Field-practical gas chromatography/mass spectrometry (GC/MS) methods for quantitative to screening measurements of organochlorine pesticides, explosives, and volatile organic compounds have been developed and evaluated. A rugged, mobile thermal desorption GC/MS (TDGC/MS) was applied to provide on-site chemical analysis via two different detection modes: selective ion monitoring (SIM) and total ion current/selective ion extraction (TIC/SIE). The SIM mode, with measurement precision of ;The field methods were evaluated by analyzing both fortified and real-world soil and water samples. Inter-method and inter-laboratory data comparison studies demonstrated that field TDGC/MS detection was capable of providing comparable detection limit, measurement accuracy and precision with the EPA standardized laboratory methods. The field TDGC/MS methods developed in this research have been employed in several site characterization studies in the midwest United States. Near real time TDGC/MS results effectively supported on-site decision making and significantly expedited site investigation.