Ann C. Casey, Northeast Analytical, Inc., 2190 Technology Dr., Schenectady, NY 12308, Tel: 518-346-4592, Fax: 518-381-6055, Email annc@nealab.com
Robert E. Wagner, Northeast Analytical, Inc., 2190 Technology Dr., Schenectady, NY 12308, Tel: 518-346-4592, Fax: 518-381-6055
Inga C. Hotaling, Northeast Analytical, Inc., 2190 Technology Dr., Schenectady, NY 12308, Tel: 518-346-4592, Fax: 518-381-6055
Heather Carlson, Northeast Analytical, Inc., 2190 Technology Dr., Schenectady, NY 12308, Tel: 518-346-4592, Fax: 518-381-6055

The determination of PCB in aqueous samples is an analysis carried out by many environmental testing laboratories. Traditional methodologies typically involve manual separatory funnel or continuous liquid-liquid extraction (CLLE) of the water samples with dichloromethane. Subsequently, the extract is dried using specially prepared anhydrous sodium sulfate, concentrated through an evaporation step, solvent exchanged to hexane, and analyzed using conventional split/splitless GC-ECD.  These methods are labor intensive, use large amounts of solvents, and require contaminate free glassware. Demands have been placed upon environmental testing laboratories to increase sample throughput, shorten sample turnaround times, achieve reproducible results, and provide lower detection limits.  NEA has met this challenge by optimizing a Solid Phase Extraction (SPE) method based on the Horizon Technology SPE-DEX 4790 instrumentation that is rugged, fast, cost effective, and achieves low MDLs and reproducible results. Horizon Technology SPE-DEX 4790 units are programmable multipurpose automated SPE systems, capable of processing aqueous samples directly from their original containers. Once initiated, each SPE-DEX 4790 unit sequentially delivers all the necessary solvents to precondition the sorbent material within the SPE disk, passes the water sample through the disk and, after a preset air-dry time, extracts the sorbed analytes from the disk into a collection vessel using the required amounts of solvents. NEA routinely extracts 1L, 2L, 4L and 8L water samples using this technology. NEA uses a modified congener-specific analysis, which employs a GC/ECD equipped with a DB-1 capillary column.  This method utilizes a mixed Aroclor standard (Aroclor 1232/1248/1262 in the ratio of 25:18:18) for calibration based on the Green Bay Mass Balance method. A total of 112 chromatographic peaks are detected, containing 209 PCB congeners in various ratios. This allows an almost complete profile of environmentally occurring PCBs. This system allows for detection limits of 9.34ng/L for 1L samples and 1.06ng/L for 8L samples.

Distinguishing Between Multiple Chlorinated Solvent Plumes: A Comprehensive Approach

Ijaz S. Jamall, Ph.D., Risk-Based Decisions, Inc., 2033 Howe Avenue, Suite 240, Sacramento, California 95825, Tel: 916-923-0570, Fax: 916-923-0611, Email: ijamall@riskbaseddecisions.com
Tex Lu, Ph.D., Risk-Based Decisions, Inc., 2033 Howe Avenue, Suite 240, Sacramento, California 95825, Tel: 916-923-0570, Fax: 916-923-0611, Email: texlu@riskbaseddecisions.com
William A. Huber, Ph.D., Quantitative Decisions, 539 Valley View Road, Suite 300, Merion Station, Pennsylvania 19066, Tel: 610-771-0606, Fax: 610-771-0607, Email: wahuber@quantdec.com

This paper describes a unique approach to distinguishing between multiple chlorinated volatile organic compound (CVOC) plumes in groundwater. The investigation began with the collection of soil gas samples collected just above groundwater in an area extending some 1,000 feet downgradient from a known source area.  The soil gas samples were analyzed for CVOCs.  Chemical fingerprinting of perchlorethylene (PCE), trichloroethylene (TCE), cis- and trans-1,2-dichloroethylene (cis- and trans-1,2-DCE) in these samples revealed the presence of at least three distinct CVOCs plumes in groundwater.  The data were used to push cone penetrometer tests (CPTs) to 30 feet below ground surface to characterize the subsurface stratigraphy.  At each CPT location, a grab groundwater sample was also collected and analyzed for CVOCs.  The logs of 296 CPTs were classified by depth as “sand” or “clay”.  Sand, sandy silt and silty sand were interpreted as sand while clay and silty clay were interpreted as “clay”.  The depths were then converted to elevations above mean sea level using the surface surveyed elevations.  A geostatistical analysis was used to create a detailed solid model of the subsurface. The accuracy of the model was quantified and the model used to create fence diagrams and other 3D images of the subsurface.  These images revealed the existence of two discrete sand channels which were connected by a sand bridge located precisely at the point where the soil gas fingerprints showed a separation of CVOC plumes.  Thus, a geologic basis for the presence of different plumes was established. Finally, chemical analysis of the grab groundwater samples confirmed the existence of multiple CVOCs plumes and revealed that these plumes were separated at specific locations which could be understood by the distinctions in geology and hydrogeology.

Nylon-Mesh Passive Samplers and 1,4-Dioxane: A Case Study in Fractured Rock in Florida

P. James Linton, Blasland, Bouck and Lee, Inc., 3350 Buschwood Park Drive, Suite 100, Tampa, FL 33618, Tel: 813-933-0697, Fax: 813-932-9514, Email: pjl@bbl-inc.com
John C. Alonso, Blasland, Bouck and Lee, Inc., 3350 Buschwood Park Drive, Suite 100, Tampa, FL 33618, Tel: 813-933-0697, Fax: 813-932-9514, Email: jca@bbl-inc.com

Passive diffusion samplers provide a potential time-saving and cost-effective sampling alternative to standard sampling procedures, such as low-flow purging and sampling, with the added benefit of limiting the generation of investigation-derived waste in the form of purge water.  First generation passive samplers were constructed of polyethylene film filled with laboratory-grade water, and have been proven effective for evaluating concentrations of volatile organic compounds; however, these samplers rely on diffusion across a membrane and are not suitable for other classes of analytes, specifically semi-volatile organic compounds and metals.  A new generation of passive samplers using a fine nylon mesh that allows a direct water-to-water interface, has shown a potential application to these other classes of analytes.

The use of 1,4-dioxane as a solvent stabilizer has become an increasing concern at former electronics component manufacturing facilities with soil and groundwater impacts from chlorinated solvents.  At one such facility in west-central Florida, a 1,4-dioxane/chlorinated solvent plume is present in the fractured rock aquifer beneath the site.

Rock aquifer monitoring wells present at the site were constructed in the early 1990’s, and are generally open-hole wells with a monitoring interval greater than 50 feet, limiting the understanding of the potential vertical distribution of the contaminants in groundwater.  A plan to evaluate vertical distribution, using down-hole vertical and horizontal flow measurement and multiple-level sampling with nylon-mesh samplers, was presented to the Florida Department of Environmental Protection, and received approval for implementation.

This paper presents the approach provided to the regulatory agency, and the results of the subsequent study.

Analysis of NDMA by Modified Method 1625 utilizing Chemical Ionization and Large Volume Injection

Scott McLean, James F. Occhialini, Arin Jones and James Todaro, Alpha Analytical Labs, Eight Walkup Dr., Westborough, MA 01581, Tel: 508-898-9220  

In this paper, the authors describe a robust analytical procedure based on a modification of EPA Method 1625.  It is a GC/MS analysis utilizing isotope-dilution, chemical ionization and large volume injection.  This technique is very powerful, capable of reaching low parts per trillion (PPT) reporting limits. 

Speciation of Metal Ions in Aqueous Systems Using X-ray Photoelectron Spectroscopy

Hylton G. McWhinney, Department of Chemistry, Prairie View A&M University, P.O. Box 2502, Prairie View, TX 77446, USA, Tel: 936-857-2616, Fax: 936-857-2095, Email: hylton_mcwhinney@pvamu.edu
Tony L. Grady, Department of Chemistry, Prairie View A&M University, P.O. Box 2502, Prairie View, TX 77446, USA, Tel: 936-857-2616, Fax: 936-857-2095, Email: tgrady_2000@yahoo.com
Mankata Inkumsah, Department of Chemistry, Prairie View A&M University, P.O. Box 2502, Prairie View, TX 77446, USA, Tel: 936-857-2616, Fax: 936-857-2095, Email: minkumsah@yahoo.com

Assessment of bioavailability, mobility and risk of toxic metals in the environment has taken on added proportions in recent years.  While the analysis and detection of hazardous metal ions have seen significant gains in the form of lower detection limits and improved sensitivity of analytical measurement techniques, the area of metals speciation analysis has not experienced the depth of development as elemental quantitation methods.  Although elemental information provides key parameters for remedial practices and risk assessment exercises, it is now necessary to incorporate other parameters, such as valence state and molecular structure in models to determine treatment feasibility, bioavailability and risk determination.  It is thus necessary to preserve the integrity of the chemical state of the matrix containing the metal by minimizing sample preparation and derivitized products. Results from the application of XPS, a well established surface characterization technique (gives semi-quantitative and qualitative chemical information) are presented on the oxidation state of several oxidation states of several metal ions in aqueous media. Aqueous systems containing 1-20 ppm Cr (VI) and Cr (III) singly and as mixtures were analyzed.  Binding energy shifts of core level 2p electrons at approximately 579 and 577 eV were identified for Cr (III) and Cr (VI) respectively.  Photoelectron peaks identifying Cr (III) and Cr (VI) were also identified in aqueous systems (1 ppm) containing Fe (III), Pb (II) and Zn (II).

Four Tips for the Handling of Aqueous Diffusion Samplers

Charles D. Springer, EA Engineering, Science, and Technology, Inc., 333 Turnpike Road, Southborough, MA 01772, Tel: 508-485-2982 Ext. 212, Fax: 508-485-5742
Alexander C. Easterday, P.G., EA Engineering, Science, and Technology, Inc., 333 Turnpike Road, Southborough, MA 01772, Tel: 508-485-2982 Ext. 209, Fax: 508-485-5742

Aqueous diffusion bag (ADB) sampling is an innovative method for the collection of volatile organic compound groundwater samples from monitoring wells.  This sampling technique offers considerable time and cost savings compared to other sampling methods.  An ADB sampler is made of semi-permeable polyethylene membranes filled with de-ionized water.  The major advantage of using ADB samplers is that there is no need for onsite sampling equipment, well purging, or disposal of purge liquids, thereby reducing costs and effort.

The ADB sampling technique provides a cost effective and time saving alternative to low-flow sampling in a long-term monitoring program.  In order to realize the maximum benefits of ADBs, EA has identified 4 setup and handling tips:

1. For easier deployment, use a weight to counteract the ADB’s natural buoyancy.  Make sure the weight will not affect other possible sampling parameters (i.e., metals).

2. Assemble ADB setup in a clean, offsite location including the single or multiple bag setups and weight.  By creating each well setup prior to mobilizing to the sampling point, labor time in the field can be reduced.

3. Transport ADB setup in pre-cleaned, lay-flat containers from preparation location to sampling point to avoid accidental breakage or cross-contamination.  Large “Under the Bed” polyvinyl chloride storage containers with lids have been found to be effective.

4. For long-term use, install dedicated bag setup made of stainless steel wire with bag clips attached at predetermined levels.  For each sampling event, the ADBs are clipped onto the wire and lowered into the well.  By creating a setup that can be used for multiple events, significant time savings can be realized. 

Utilizing ADBs can reduce the total cost of the sampling event by 40-60 percent, the majority of the savings coming from labor.  For example, the total time for an event decreased from 12 days to 5 days (1 day to fill and setup bags, 2 days to deploy bags, and 2 days to retrieve bags and collect samples).  Following the above 4 tips helped provide the long-term monitoring program with cost and time efficient savings.

Analysis of Contaminated Soils and Sediments Using X-ray Tube and Isotope Source Portable XRF Instruments

Laura Stupi, Niton LLC, 900 Middlesex Turnpike, Building 8, Billerica, MA, 01821, Tel: 978-670-7460, Fax: 978-670-7422, Email: lstupi@niton.com
David Mercuro, Niton LLC, 900 Middlesex Turnpike, Building 8, Billerica, MA, 01821, Tel: 978-670-7460, Fax: 978-670-7422, Email: dmercuro@niton.com

In January of 2005, NITON LLC participated in the Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) of X-ray Fluorescence (XRF) Technologies for Measuring Trace Elements in Soil and Sediment. Two field portable handheld instruments, the XLi 700 Series equipped with Radioactive Isotopes and the XLt 700 Series equipped with Miniaturized X-ray Tube technology, were used to analyze 326 samples from 9 different locations across the continental U.S.A. Thirteen elements: Antimony (Sb), Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Iron (Fe), Lead (Pb), Mercury (Hg), Nickel (Ni), Selenium (Se), Silver (Ag), Vanadium (V), and Zinc (Zn) with varying concentrations were analyzed on both analyzers. Correlation data obtained from both field portable analyzers, as compared to the reference laboratory, will be presented. 

Sampling and Analysis of Cranberries in an Area of Plume Discharge

Nigel Tindall, P.G., CH2M HILL, 318D East Inner Road, Otis ANG Base, MA 02542-5028, Tel:  508-968-4670 x 5620, Fax:  508-968-4916, Email: Nigel.Tindall@ch2m.com
Jon Davis, P.E., Air Force Center for Environmental Excellence, 322 East Inner Road, Otis ANG Base, MA 02542-5028, Tel:  508-968-4670 x 4952, Fax:  508-968-4476, Email: jon.davis@brooks.af.mil
Pat de Groot, P.G., LSP, CH2M HILL, 318D East Inner Road, Otis ANG Base, MA 02542-5028, Tel:  508-968-4670 x 5634, Fax:  508-968-4916, Email: Patricia.deGroot@ch2m.com
Marc Slechta, P.G., LSP, CH2M HILL, 318D East Inner Road, Otis ANG Base, MA 02542-5028, Tel:  508-968-4670 x 5988, Fax:  508-968-4916, Email: Marc.Slechta@ch2m.com

Detectable levels of tetrachloroethene (PCE) and trichloroethene (TCE) in surface water samples collected from a network of cranberry bog ditches led to concerns about the marketability of a 57 acre cranberry crop.   Low-level detections in surface water resulted from the upwelling and discharge of the Ashumet Valley groundwater plume at the Massachusetts Military Reservation (MMR).  Disposal of treated wastewater from the former MMR sewage treatment plant (STP) between 1936 and 1995 and residuals from fire training activities at MMR formed the Ashumet Valley plume.  Both the STP and the Fire Training Area are located near the southern boundary of MMR, approximately 4 miles upgradient of the cranberry bogs.  To determine whether plume discharge had impacted the marketability of the cranberry crop, a multi-stakeholder group was assembled to develop guidelines for sampling and analyzing cranberries for PCE and TCE.  Challenges included: 1) formulating a procedure that provided representative samples; 2) establishing a sample preparation procedure 3) procuring a laboratory that had the required experience, instrumentation, and capacity to meet accelerated data delivery requirements; and 4) a fast-track schedule to gain full stakeholder concurrence prior to the 2004 harvest.  For sample analysis, the SW8260B GC/MS Selected Ion Monitoring method was chosen.  Advantages in using this method included lower method detections limits (MDL) over standard SW8260 analysis and the ability to target specific compounds.  A critical component was the performance of a MDL study for this non-traditional environmental media (i.e., homogenized cranberry fruit) that gained stakeholder approval.  The results of the study established MDLs sufficiently low to meet the project data quality objectives.  Neither PCE nor TCE were detected above the MDL in any of the cranberry samples.  Based on the sampling results, the cranberry crop was considered suitable for market.

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