Field Validation of Helium as a Tracer Gas During soil vapor Sample Collection
Jeffrey E. Banikowski, O'Brien & Gere Engineers, Inc., Syracuse, NY

A LC/MS Multi-Analyte Screening Method for Deleterious Organics in Water
Jim Krol, Waters Corporation, Milford, MA  

Chemical Field Screening for Real Time Decision Making During Remedial Investigations

Keir Craigie, Tetra Tech EC, 133 Federal St., 6^th Floor, Boston, MA, 02110, Tel: 617-457-8200, Fax: 617-457-8498, Email: kcraigie@ttfwi.com
Dr. Lewis Horzempa, Tetra Tech EC, 133 Federal St., 6^th Floor, Boston, MA, 02110, Tel: 617-457-8200, Fax: 617-457-8498, Email: lhorzempa@ttfwi.com
Scott Clifford, USEPA Region I – New England Regional Laboratory, 11 Technology Dr., North Chelmsford, MA, 01863, Tel: 617-981-8631, Email: clifford.scott@epa.gov

Chemical field screening techniques offer attractive analytical options to help mitigate the costs of hazardous waste site investigations. However, for many sites, litigation and risk assessment considerations, require that regulatory decisions are based upon thoroughly defensible high quality analytical data.  From these perspectives, perceived limitations in the use of field screening techniques frequently include unacceptably high reporting limits, insufficiently definitive data, and matrix interferences.

In order to balance data quality needs and cost effectiveness, an integrated multi-analyte field sceening and off-site analytical program was developed to drive field decision-making and chemical characterization, at a relatively complex 30-acre Superfund Site.  The Site was an old industrial ash and cinder landfill that has been redeveloped into a mixed residential and commercial neighborhood. The presence of several dis-similar classes of chemical contaminants, including numerous metals, PAHs and PCBs, presented particular chemical characterization challenges and precluded the use of a single field screening methodology.

Under the field program, over 110 soil samples were successfully screened for multiple metals (XRF), PAHs (immunoassay) and PCBs (GC) by one chemist within six working days. The field screening program was noteworthy for its role in providing a clear and concise decision process for off-site analysis that would effectively address multiple federal and state regulatory requirements and associated risk assessment needs.  The decision process was developed to utilize all of the field analytical data to determine an appropriate selection of samples for off-site analysis. Overall, the screening results demonstrated good correlation with off-site analytical results.  The integrated analytical program successfully provided a comprehensive yet cost effective data set that facilitated an effective three dimensional chemical characterization of this large site, supported by a core database of appropriate quality.

Field Validation of Helium as a Tracer Gas During Soil Vapor Sample Collection

Jeffrey E. Banikowski, O’Brien & Gere Engineers, Inc., 5000 Brittonfield Parkway, Syracuse, NY, 13221, Tel: 315-437-6100, Fax: 315-463-7554, Email: BanikoJE@OBG.Com
Swiatoslav Kaczmar, O’Brien & Gere Engineers, Inc., 5000 Brittonfield Parkway, Syracuse, NY, 13221, Tel: 315-437-6100, Fax: 315-463-7554, Email: KaczmaSW@OBG.Com
John Hunt, O’Brien & Gere Engineers, Inc., 5000 Brittonfield Parkway, Syracuse, NY, 13221, Tel: 315-437-6100, Fax: 315-463-7554, Email: HuntJF@OBG.Com
Russell Pellegrino, CENTEK Laboratories LLC, 143 Midler Park Drive, Syracuse, NY, 13206, Tel: 315-431-9730, Email: Russ@CentekLabs.com

The use of tracer gas is becoming a commonly specified field quality assurance method for identifying atmospheric short-circuiting during the collection of subsurface soil vapor samples. This paper presents the results of a field validation study of the use of helium as a tracer, utilizing a commercially available helium leak detector.  The paper also presents observations on the frequency and degree of short-circuiting observed in soil vapor sampling from replicate installations of implants installed in differing soil types and depths. 

The tracer gas field validation was conducted in two parts.  The first part examined the ability of the method to detect short-circuiting in implants installed at four and eight feet below the ground surface.  The implants were designed to short-circuit by introducing higher permeability material around the implant tubing and annular space.  Following installation, a container was placed directly over the implant at the ground surface and filled with helium. Soil gas was then withdrawn from the implant and measured for helium. Conditions were varied and replicates were performed to investigate factors contributing to short-circuiting, and to establish response times and detection levels.

The second phase of the study investigated the frequency and magnitude of leakage, under typical field conditions and standard installation protocols. A total of sixty-four soil replicate vapor implants were installed by a field team experienced in soil vapor sampling. Thirty-two implants were installed in a sandy soil horizon and thirty-two in glacial till, to depths of four and eight feet below the ground surface. The frequency of atmospheric short circuiting was monitored as per the validated helium tracer field protocol, with consideration of soil type, depth, time and total volume of soil gas collected.

A LC/MS Multi-Analyte Screening Method for Deleterious Organics in Water

Jim Krol, Sr. Applications Chemist; Joe Romano, Environmental Marketing Manager, Waters Corporation, 34 Maple St, Milford, Massachusetts, 01757, Tel: 508-482-2131, Email: Jim_Krol@Waters.com, Joseph_P_@Waters.com.
Lawrence Zintek, Sr. Chemist, EPA Region 5 Laboratory,  536 Clark St, Chicago, IL, 60605, Tel:  312-886-2925

The determination of deleterious organics in drinking water, or soil extract, is one of the particular areas of the Homeland Security Presidential Directive (HSPD-9) that will impact the EPA.  It mandates that the EPA Office of Water expand monitoring and surveillance systems for recognizing a terrorist attack, or a significant change in water quality.  This is a daunting task because of the breadth of organics, coupled with the numerous water sources required to be monitored.

The question is raised…what organics are present in this water?  Whether it is drinking water, surface water, soil leachates, or wastewater, where does a chemist begin to answer this question?  Time is critical.

The ability to perform a multi-analyte “screen” for numerous organics simultaneously would help maximize efforts to note the presence and significance of poisonous agents.  This requires a broad analytical approach strategy utilizing the specificity of Liquid Chromatography / Mass Spectrometry (LC/MS and LC/MS/MS).  Many of these organics are not amendable to Gas Chromatography / Mass Spectrometry) GC/MS.  Universal detection with high sensitivity is the key.  This approach can be adapted to any subset of analytes including explosives and perchlorate.

For non-MS detection methods, analyte resolution is critical for identification and quantification.  However, the capability of MS to detect a single m/z (molecular weight/charge) gives analyte detection specificity that does not require chromatographic resolution.  Thus, a “universal” reversed phase gradient providing a degree of analyte separation coupled with the specificity of mass spectrometry allows for the “screening” for multi-analytes simultaneously.

This presentation will discuss the development of a single, multi-analyte screening strategy for several deleterious pesticides and herbicides in drinking water using HPLC/ Electrospray Mass Spectrometry.  This work is being conducted in collaboration with USEPA Central Region Laboratory Region 5.  Several analytical issues will be raised to stimulate audience discussion and to solicit input to evolve this LC/MS strategy into a validated screening method template.

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