title: Time-weighted average SPME analysis for in planta determination of cVOCs.
abstract: The potential of phytoscreening for plume delineation at contaminated sites has promoted interest in innovative, sensitive contaminant sampling techniques. Solid-phase microextraction (SPME) methods have been developed, offering quick, undemanding, noninvasive sampling without the use of solvents. In this study, time-weighted average SPME (TWA-SPME) sampling was evaluated for in planta quantification of chlorinated solvents. TWA-SPME was found to have increased sensitivity over headspace and equilibrium SPME sampling. Using a variety of chlorinated solvents and a polydimethylsiloxane/carboxen (PDMS/CAR) SPME fiber, most compounds exhibited near linear or linear uptake over the sampling period. Smaller, less hydrophobic compounds exhibited more nonlinearity than larger, more hydrophobic molecules. Using a specifically designed in planta sampler, field sampling was conducted at a site contaminated with chlorinated solvents. Sampling with TWA-SPME produced instrument responses ranging from 5 to over 200 times higher than headspace tree core sampling. This work demonstrates that TWA-SPME can be used for in planta detection of a broad range of chlorinated solvents and methods can likely be applied to other volatile and semivolatile organic compounds.
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, Missouri, United States.
authors.forename: Emily M
authors.initials: EM
authors.lastname: Sheehan
authors.forename: Matt A
authors.initials: MA
authors.lastname: Limmer
authors.forename: Philipp
authors.initials: P
authors.lastname: Mayer
authors.forename: Ulrich Gosewinkel
authors.initials: UG
authors.lastname: Karlson
authors.forename: Joel G
authors.initials: JG
authors.lastname: Burken
mesh_terms: D004129:Dimethylpolysiloxanes; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D052617:Solid Phase Microextraction; D012997:Solvents / Q000032:analysis; D014197:Trees; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D004129:Dimethylpolysiloxanes; D004785:Environmental Pollutants; D006843:Hydrocarbons, Chlorinated; D012997:Solvents; D055549:Volatile Organic Compounds; C013830:baysilon