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 ACS_Fa2003 WSU-TC 2 Research Objectives 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. ACS_Fa2003 WSU-TC 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. ACS_Fa2003 WSU-TC
Hanford Underground Tanks 149 Single Shell Tanks (SSTs) - Built 1943-1964. - Capacity of 55,000 to 1 million gal. 28 Double Shell Tanks (DSTs) - Built 1966-1986. - Capacity of 1.25 million gal. each. Contain about 54 million gal. Waste. ACS_Fa2003 WSU-TC 4 What the Tank waste looks like 5 Sludge Supernate 177 Hanford Tanks Waste Composition by Volume
34% Ref: HNF-EP-0182, Rev. 179 20% Saltcake Sludge Saltcake Supernatant 46% ACS_Fa2003 WSU-TC Waste Treatment Process ACS_Fa2003 6
WSU-TC Overview of Characterization at Hanford Tank Safety Issues Criticality & Corrosivity Drivers Regulatory Characterization Tri-Party Agreement. Nuclear regulations. Waste Treatment Plant Needs Contract & Process Drivers. ACS_Fa2003 WSU-TC
7 Challenges of Hanford Waste Characterization Analytical challenges are due but not limited to ACS_Fa2003 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 8
Challenges in Hanford Waste Characterization Waste characterization challenges Radioactivity constraints Sample Handling - Dose rate. Remote Hot Cell techniques. Blank contamination. Matrix Problems RSD/RPD failures. Matrix spike failures. ACS_Fa2003
WSU-TC 9 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 10 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 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 ACS_Fa2003 WSU-TC 13 SPE STRATEGY & CONDITIONS SPE Sorbent: Varians 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: ACS_Fa2003 EPA SW-846 Method 8082 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 TCX DCB Aroclor 1016
Aroclor 1260 % Recovery 75 113 94 106 %RSD 12 6 3 3 MDL(g/L) 8.9 6.2 2.9 2.8 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 % Recovery TCX DCB Aroclor 1016 96 Aroclor 1260 93 ACS_Fa2003 80 109 5 6 RSD
MDL (g/L) 10 12 6.9 5.3 7.5 10.8 5.0 5.3 WSU-TC 16 Analytical Results EVALUATION OF INTERFERENCES* IN SIMULATED SY-101 LIQUID WASTE AT VARIOUS SPIKE LEVELS SAMPLE SPIKE DCP AROCLOR 1016 AROCLOR 1260 (ppb) 31.67 15.47 14.53 23.88
25.89 min min min min min SY-101 10.0 152% 104% 104% 123% 120% SY-101 100.0 115% 99% 127% 120% 104% SY-101 500.0 104% 91% 98% 110% 82% * A mixture containing 1 ppm of each: carbon tetracholride, dibutyl phosphate, tributyl phosphate, dibutyl butylphosphonate, decane, tridecane, and tetradecane. ACS_Fa2003 WSU-TC 17
Analytical Results Chromatogram of Real Hanford Tank Waste Spiked with PCBs ACS_Fa2003 WSU-TC 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 ACS_Fa2003 WSU-TC 19 Conclusions 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. ACS_Fa2003 WSU-TC 20 Acknowledgements 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. ACS_Fa2003 WSU-TC
