United States Environmental Protection Agency Office of Solid Waste and Emergency Response Publication 9200.5-160FS PB95-963501 EPA 540/F94/059 July 1994 The Penta Wood Products Site: Analysis of Pentachlorophenol Using A Mobile Laboratory Equipped With State-of-the-Art Instrumentation Office of Emergency and Remedial Response Emergency Response Division Environmental Response Branch MS-101 Introduction The Penta Wood Products Site is an inactive wood treating facility located in Siren, Wisconsin. The site covers an area of 120 acres, 80 of which were actively used. The fa- cility operated from 1953 until 1992, when it was forced to close because of its inability to comply with the Re- source Conservation and Recovery Act (RCRA) of 1976 drip track regulations. From 1956 to 1975, pentachlorophenol (PCP) was used to chemically treat wood products. After 1975, ammoniacal- copper-arsenate (ACA) was in use. PCP was also com- bined with No. 2 fuel oil to create a five to seven percent solution, which was stored in vats for a wood pressure treatment process. The process involved submerging white wood products in the solution. The United States Environmental Protection Agency's En- vironmental Response Team (U.S. EPA/ERT) examined the site to determine the extent and degree of contamina- tion and to assess the ecological and human health con- cerns. Because of the size of the site and the hazardous nature of the pollutants (possible dioxin contamination), the U.S. EPA/ERT's High Hazard Mobile Laboratory, lo- cated in Brunswick, Georgia was activated to support the remediation of the site. This field laboratory is equipped with the capability to analyze a high volume of dioxin contaminated samples for creosote/PCP and provide ana- lytical results within 24 hours, which allows quick deci- sion making at a site. The majority of the samples taken were soil, which was classified as either surficial or subsurface. Over a four- week period, 685 samples were collected for PCP analysis. Two Gas Chromatography/Mass Spectrometry (GC/MS) chemists were sent to Brunswick, Georgia on April 6, 1994, and completed the entire extraction and instrumental analyses by May 6, 1994. During that time, the tabulated PCP results were transmitted to the site task leader on a daily basis. Quick Reference Fact Sheet U.S. EPA/ERT Field Analytical Methods for PCP The use of GC/MS provides good overall sensitivity and positive identification for specific compounds such as PCP. Field GC/MS methods developed by the U.S. EPA/ERT, in conjunction with the Response Engineering Analytical Contract (REAC), provide rapid turnaround of sample results while incorporating rigorous Quality Assur- ance/Quality Control (QA/QC) procedures to ensure reli- ability of the analytical data. When combined with a quick, efficient extraction proce- dure, the analytical method provided by the mobile lab al- lows for the timely and successful completion of any site investigations requiring on-site analytical support. For the Penta Wood Products investigations, the GC/MS analyti- cal method incorporated three key factors: • Selected Ion Monitoring (SIM) for achieving high sensitivity and a low method detection limit, allowing for minimum sample amount and solvent volume to be used. • A GC oven temperature program designed to analyze a sample extract every 15 minutes. • A capillary column capable of adequately resolving the compounds of interest under rapid temperature ramping. The end result of the analytical method is the processing of 96 sample extracts every 24-hour period, while still meeting the prescribed QA/QC cri- teria. Of equal importance, and in addition to the analytical method, an extraction procedure was developed to handle the large numbers of samples received by the mobile labo- ratory on a daily basis. Conventional soil extraction proce- ------- dures such as sonication or Soxhlet extraction would not be practical for a field mobile laboratory. Ten grams of sample were extracted in sealed 100 millili- ters (ml) serum vessels. The soil samples and blanks were spiked with 500 microliters (|il) of 1000 jig/ml 2,4,6-tri- bromophenol surrogate solution and mixed with anhy- drous sodium sulfate. The samples were then extracted with 100 rnl acetone/methylene chloride mixture. With two shaker tables operating simultaneously, this procedure easily enabled the laboratory personnel to extract 50 sam- ples per day. Field Analytical QA/QC Criteria and Performance A GC/MS HP 5971A system, equipped with a quadrupole mass spectrometer and a DOS/CHEM station, was oper- ated in SIM mode. The standard concentrations ranged from a low of 0.5 Hg/ml (ppm) to a high standard concen- tration of 50 ng/ml. The percent relative standard devia- tions (RSD) achieved for a six-point range was always within the 30 percent limits indicating the linearity of PCP. The 0.5 standard enabled the lab to report a 5 mg/kg detection limit on a wet weight basis for soil samples. Val- ues for sample results were reported at or above 0.1 Hg/ml in the sample extract. On a daily basis, a 50 (ig/ml de- cafluorotriphenylphosphine (DFTPP) tune standard was analyzed to pass the U.S. EPA Contract Laboratory Pro- gram (CLP SOW OLMO1.0 3/90) tune criteria, and a 5.0 ppm daily check standard was analyzed to compare with the average response factors from the calibration range. A ±25 percent difference for daily check response factors was the expected criteria for daily sample analyses to con- tinue. The CLP recovery limits were used as a guideline during the entire analysis. Since the mobile GC/MS field labora- tory is using modified methods, the surrogate and Metric Spike/Metric Spike Duplicate (MS/MSD) recoveries were compiled in order to monitor the laboratory data quality. Statistical data was gathered from 782 sample analyses and 37 pairs of matrix spike analyses to generate the ac- ceptable recovery ranges for this particular method. Using a 95 percent confidence interval, the recovery ranges for the surrogate, 2,4,6-tribromophenol are between 44 and 126 and the ranges for the matrix spike compound PCP are between 75 and 144. These criteria reflect the normal expected ranges for these two compounds analyzed at the GC/MS mobile laboratory, using the previously described analytical and extraction methods. Conclusions Utilization of field-modified GC/MS methods has proven to be an effective approach to meet contaminant analysis needs at wood treating hazardous waste sites, such as Penta Wood Products. High-quality results are achieved quickly. Providing results within 24 hours of sample re- ceipt allows the Site Project Managers to quickly make de- cisions in the field and to effectively conduct any required changes in clean-up operations, hese analytical results from the mobile field laboratory are the results of proven field methodologies incorporating rigorous QA/QC proce- dures, On-going operations at the high hazard mobile field labo- ratory continue to provide fast, cost-effective analysis of PCP and other organic analytes. By analyzing samples from the Penta Wood Products Site at the field laboratory instead of at an in-house contracted lab, approximately $200,000 was saved. The mobile field laboratory has proven to be an ideal concept for characterization and re- mediation/removal activities at many hazardous waste sites. For further information, please contact: Raj Singhvi (908) 321-6761 (908) 321-6660 (24-hour hotline) U.S. EPA/ERT ------- |