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

Abstract

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.

Polycyclic Aromatic Hydrocarbon Analysis with the Mars Organic Analyzer Microchip Capillary Electrophoresis System

“…PAH pollution stems from auto exhaust, wood and cigarette smoke, lumber processing plants, and so forth, leading to PAH contamination in, for example, marine environments and in the air over major cities . Currently, terrestrial sampling and analysis is focused on the cleanup of environmental contamination sites. , While there have been recent advances in the analysis of PAHs from these samples including micellar electrokinetic chromatography and supercritical fluid chromatography, − reverse-phase HPLC remains one of the most commonly used methods . Because of the long analysis times, high cost, and sample blending and destruction of these methods, it would be useful to have inexpensive, rapid, nondestructive, in situ techniques for the measurement of PAH contamination in sediments …”

New Spectral Deconvolution Algorithms for the Analysis of Polycyclic Aromatic Hydrocarbons and Sulfur Heterocycles by Comprehensive Two-Dimensional Gas Chromatography-Quadrupole Mass Spectrometery

“…PAH and PASH concentrations in the sediment sample shown in Figure were measured by both GC × GC/MS and GC/MS to assess data quality differences. The U.S. Environmental Protection Agency (EPA) benchmark for accuracy is contingent on the site-specific action levels (AL) required to clean hazardous waste sites. , If we assume the site is adjacent to residential properties, the concentrations in the sample must meet the relative percent difference (RPD) shown in Table . , Parent PAH concentrations are well within EPA criteria for accuracy, and although homologue specific action levels are not reported, results are in excellent agreement and meet the same criteria as parent PAH. Some homologues exceed the low concentration benchmark, presumably due to sensitivity differences, while others are only detected by GC × GC/MS.…”

A Triggered Depth‐Dependent Sampling System to Overcome the Carry‐Over Effects of the Membrane Interface Probe

“…In particular, to reduce the carry‐over effect of the conventional transfer line (double‐paired polytetrafluoroethylene [PTFE] tube) different concepts have been tested and are commonly used. For example, the use of materials than PTFE, such as polyether ether ketone (PEEK) and stainless steel and/or heating of the transfer line, have been used (Costanza and Davis ; Neuhaus ; Considine and Robbat ; Pipp and Christy ). Other approaches to improve the MIP system's performance are multidirectional probing for a better determination of the upper and lower plume boundaries of highly‐loaded areas (Bumberger et al ; Adamson et al ).…”

“…The multidirectional probing consists of sensing while advancing the rods as well as sensing while retracting the rods. In terms of a better qualification and quantification of VOCs under observation, concepts of combining MIP with depth‐dependent gas sampling using sample loops, sorbent or freeze trapping have been tested and published (Rogge et al ; Bronders et al ; Considine and Robbat ; Robbat et al ). It can also be shown that better interpretation qualification and semi‐quantification of MIP data can be achieved using a mobile mass spectrometer compared to the conventional photoionization (PID), flame ionization (FID), or halogen specific (XSD) detectors (Costanza and Davis ; Bumberger et al ).…”