ACS_Fa2003 WSU-TC Solid Phase Extraction (SPE)/GC-ECD Analysis for Polychlorinated Biphenyls (PCBs) in Real Liquid Hanford Nuclear Waste Samples Asopuru Okemgbo Washington State University Tri-Cities 2710 University Drive, Richland, WA American Chemical Society National Conference, September 7-11, 2003

ACS_Fa2003 WSU-TC To evaluate sample preparation method for the determination of polychlorinated biphenyls (PCBs) in Hanford nuclear waste that would –Significantly reduce the volume of waste generated during analysis. –Eliminate methylene chloride as a solvent for the extraction of PCBs. –Lower detection limit and meet regulatory requirements for PCB –Reduce radiation exposure of analysts. 2 Research Objectives

ACS_Fa2003 WSU-TC Hanford Tank Waste –Nuclear waste accumulated between1944 and 1987 was one of the aftermaths of World War II and Cold War nuclear bomb production. –It is the biggest US environmental restoration, waste management, and waste treatment project. Tank Safety, Closure Programs & River Protection Project –Risk issues, research & resolution. –Regulatory requirements. –A $5.8 billion DOE Waste Treatment Project. Hanford Site Background Information 3

ACS_Fa2003 WSU-TC Hanford Underground Tanks Single Shell Tanks (SST’s) - Built Capacity of 55,000 to 1 million gal. 28 Double Shell Tanks (DST’s) - Built Capacity of 1.25 million gal. each. Contain about 54 million gal. Waste.

ACS_Fa2003 WSU-TC 5 What the Tank waste looks like Supernate Sludge Saltcake

ACS_Fa2003 WSU-TC 6 Waste Treatment Process

ACS_Fa2003 WSU-TC Tank Safety Issues l Criticality & Corrosivity Drivers Regulatory Characterization l Tri-Party Agreement. l Nuclear regulations. Waste Treatment Plant Needs l Contract & Process Drivers. Overview of Characterization at Hanford 7

ACS_Fa2003 WSU-TC Analytical challenges are due but not limited to l High ionic strength. l Large number of analytes & degradation products. l Caustic matrices. l High radiation levels. l Matrix interference. l Inadequate EPA Sample Prep Methods for Regulatory Analyses. 8 Challenges of Hanford Waste Characterization

ACS_Fa2003 WSU-TC Waste characterization challenges l Radioactivity constraints l Sample Handling - Dose rate. l Remote Hot Cell techniques. l Blank contamination. l Matrix Problems l RSD/RPD failures. l Matrix spike failures. 9 Challenges in Hanford Waste Characterization

ACS_Fa2003 WSU-TC 10 Challenges in Hanford Waste Characterization Sample size limitations High MDL in real waste. EQL/MRQ failures. Dose rate issues. ALARA requirements.

ACS_Fa2003 WSU-TC 11 SW-846 Methods EPA Methods for Organic Constituents 8081A, Organochlorine Pesticides by Gas Chromatography (GC)/Electron Capture Detector (ECD) 8082, Polychlorinated Biphenyl (PCBs) by GC/ECD 8151A, Chlorinated Herbicides by GC 8260B, Volatile Organic Analysis (VOA) by GC/Mass Spectrometry (MS) 8270C, Semivolatile Organic Analysis (SVOA) by GC/MS The associated Sample Prep Methods are the real issues!

ACS_Fa2003 WSU-TC 12 CURRENT PCB EXTRACTION METHODS AT 222-S Aqueous Samples: Continuous liquid-liquid extraction (LLE). Solid Samples: Soxhlet extraction. Disadvantages and Limitations Interference problems Uses hazardous organic solvents such as methylene chloride Large volume of mixed radioactive waste generated Laborious Time consuming High costs

ACS_Fa2003 WSU-TC 13 SPE STRATEGY & CONDITIONS SPE Sorbent: Varian’s Bond Elut, 200mg Extractor: Positive Pressure Manifold Sample Size:1.0 to 10.0 mL Spike levels: 0.01 to 500 ug/L aroclors 1016 and Eluent: Hexane Sample treatment: 25% sodium nitrate added to increase ionic strength for preferential sorption of PCBs GC Conditions:EPA SW-846 Method 8082

ACS_Fa2003 WSU-TC 14 Analytical Results Evaluation SPE of 1% Synthetic Hanford Waste in 25% nitrate spiked with 40  g/L TCX, DCB, Aroclor 1016/1260 Compound% Recovery%RSDMDL(  g/L) TCX DCB Aroclor Aroclor Surrogates: TCX – Tetrachloro-m-xylene, DCB – Decachlorobiphenyl

ACS_Fa2003 WSU-TC 15 Analytical Results Evaluation SPE of 10% Synthetic Hanford Waste in 25% nitrate spiked with 40  g/L TCX, DCB, Aroclor 1016/1260 Compound% RecoveryRSDMDL (  g/L) TCX DCB Aroclor Aroclor

ACS_Fa2003 WSU-TC Analytical Results 16

ACS_Fa2003 WSU-TC Analytical Results Chromatogram of Real Hanford Tank Waste Spiked with PCBs 17

ACS_Fa2003 WSU-TC Evaluation SPE of Real Hanford Tank Waste Spiked with TCX, DCB, Aroclor 1016/1260 Test Sample% TCX% DCB% Ar1254 Acceptable %26-87 % % % Check Standard Tank Waste2961- Spike Analytical Results 18

ACS_Fa2003 WSU-TC Conclusions 19 l Solid Phase Extraction was found to be efficient for the extraction of PCBs in Hanford Nuclear Waste. l Addition of 25% sodium nitrate favored selective extraction of PCBs in the presence of potential competing organic compounds. l Very low sample size has the desired reduction of radiation dose & ALARA principles. l Elimination of methylene chloride is huge contribution to reduced health risks to the analysts. l Regulatory requirements are achievable.

ACS_Fa2003 WSU-TC l Mikhail Arinbasarov Centre of Instrumental Methods of Analysis Institute of Biochemistry and Physiology of Microorganisms Pushchino, Moscow region, Russia. l Ed Rykiel Washington State University Tri-Cities. l Steve Metcalf & Jerry Kunkel 222-S Laboratory, Hanford Site, WA. l Len Pingel Waste Sampling and Characterization Facility Hanford Site, WA. Acknowledgements 20