Asopuru Okemgbo Washington State University Tri-Cities 2710 University Drive, Richland, WA 99352

1. 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 99352 American Chemical Society National Conference, September 7-11, 2003 WSU-TC

2. Research Objectives 2 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. WSU-TC

3. Hanford Site Background Information 3 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. WSU-TC

4. Hanford Underground Tanks 4 • 149 Single Shell Tanks (SST’s)- Built 1943-1964. - Capacity of 55,000 to 1 million gal. • 28 Double Shell Tanks (DST’s)- Built 1966-1986. - Capacity of 1.25 million gal. each. • Contain about 54 million gal. Waste. WSU-TC

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

6. Waste Treatment Process 6 WSU-TC

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

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

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

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

11. SW-846 Methods 11 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! WSU-TC

12. CURRENT PCB EXTRACTION METHODS AT 222-S 12 • 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 WSU-TC

13. SPE STRATEGY & CONDITIONS 13 • 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 1260. • Eluent: Hexane • Sample treatment: 25% sodium nitrate added to increase ionic strength for preferential sorption of PCBs • GC Conditions: EPA SW-846 Method 8082 WSU-TC

14. Analytical Results 14 Evaluation SPE of 1% Synthetic Hanford Waste in 25% nitrate spiked with 40 mg/L TCX, DCB, Aroclor 1016/1260 Compound % Recovery %RSD MDL(mg/L) TCX 75 12 8.9 DCB 113 6 6.2 Aroclor 1016 94 3 2.9 Aroclor 1260 106 3 2.8 Surrogates: TCX – Tetrachloro-m-xylene, DCB – Decachlorobiphenyl WSU-TC

15. Analytical Results 15 Evaluation SPE of 10% Synthetic Hanford Waste in 25% nitrate spiked with 40 mg/L TCX, DCB, Aroclor 1016/1260 Compound % Recovery RSD MDL (mg/L) TCX 80 10 7.5 DCB 109 12 10.8 Aroclor 1016 96 5 6.9 5.0 Aroclor 1260 93 6 5.3 5.3 WSU-TC

16. 16 Analytical Results WSU-TC

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

18. 18 Analytical Results • Evaluation SPE of Real Hanford Tank Waste Spiked with TCX, DCB, Aroclor 1016/1260 • Test Sample % TCX % DCB % Ar1254 • Acceptable % 26-87 % 27-123 % 51-128 % • Check Standard 97 101 92 • Tank Waste 29 61 - • Spike 29 29 49 WSU-TC

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

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