title: Evaluating and modeling the effects of surface sampling factors on the recovery of organic chemical attribution signatures using the accelerated diffusion sampler and solvent extraction.
abstract: In this study, an experimental design matrix was created and executed to test the effects of various real-world factors on the ability of (1) the accelerated diffusion sampler with solid phase micro-extraction (ADS-SPME) and (2) solvent extraction to capture organic chemical attribution signatures (CAS) from dimethyl methylphosphonate (DMMP) spiked onto painted wall board (PWB) surfaces. The DMMP CAS organic impurities sampled by ADS-SPME and solvent extraction were analyzed by gas chromatography/mass spectrometry (GC/MS). The number of detected DMMP CAS impurities and their respective GC/MS peak areas were determined as a function of DMMP stock, DMMP spiked volume, exposure time, SPME sampling time, and ADS headspace pressure. Based on the statistical analysis of experimental results, several general conclusions are made: (1) the amount of CAS impurity detected using ADS-SPME and GC/MS was most influenced by spiked volume, stock, and ADS headspace pressure, (2) reduced ADS headspace pressure increased the amount of detected CAS impurity, as measured by GC/MS peak area, by up to a factor of 1.7-1.9 compared to ADS at ambient headspace pressure, (3) the ADS had no measurable effect on the number of detected DMMP impurities, that is, ADS (with and without reduced pressure) had no practical effect on the DMMP impurity profile collected from spiked PWB, and (4) solvent extraction out performed ADS-SPME in terms of consistently capturing all or most of the targeted DMMP impurities from spiked PWB.
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99352, USA.
authors.forename: Kai-For
authors.initials: KF
authors.lastname: Mo
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99352, USA.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Heredia-Langner
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99352, USA. Electronic address: carlos.fraga@pnnl.gov.
authors.forename: Carlos G
authors.initials: CG
authors.lastname: Fraga
keywords: Chemical forensics; Chemical threat agents; Experimental design; Impurity profiling; Solid phase micro-extraction; Statistical analysis