On-site profiling and speciation of polycyclic aromatic hydrocarbons at manufactured gas plant sites by a high temperature transfer line, membrane inlet probe coupled to a photoionization detector and gas chromatograph/mass spectrometer.
A new high temperature transfer line, membrane inlet probe (HTTL-MIP) coupled to a photoionization detector (PID) and gas chromatograph/mass spectrometer (GC/MS) was used to rapidly profile and speciate polycyclic aromatic hydrocarbons (PAH) in the subsurface. PID signals were in agreement with GC/MS results. Correlation coefficients of 0.92 and 0.99 were obtained for discrete and composite samples collected from the same exact location. Continuous probe advancement with PID detection found coal tar, a dense nonaqueous phase liquid, in soil channels and saturated media. When samples were collected conventionally, split, solvent extracted, and analyzed in the field and confirmation laboratory, GC/MS measurement precision and accuracy were indistinguishable; despite the fact the field laboratory produced data five times faster than the laboratory using standard EPA methods. No false positive/negatives were found. Based on these findings, increased confidence in site conceptual models should be obtained, since PID response indicated total PAH presence/absence in "real-time", while GC/MS provided information as to which PAH was present and atwhat concentration. Incorporation of this tool into a dynamic workplan will provide more data at less cost enabling environmental scientists, engineers, and regulators to better understand coal tar migration and its impact on human health and the environment.
Considine
Thomas
T
Tufts University, Chemistry Department, Center for Field Analytical Studies and Technology, 62 Talbot Avenue, Medford, Massachusetts 02155, USA.
Robbat
Albert
A
D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation*; D005740:Gases; D006358:Hot Temperature; D007202:Indicators and Reagents; D011083:Polycyclic Compounds / Q000032:analysis*; D012015:Reference Standards
D005740:Gases; D007202:Indicators and Reagents; D011083:Polycyclic Compounds