Application of Sorptive Extractions to Analysis of Organic Compounds in Hanford Waste Tank Simulant - 23554

Analysis of organic compounds in radioactive waste in tank supernate is difficult due to its matrix and radioactivity. Current methods of extraction such as purge and trap and solvent-solvent extractions are labor intensive, use large quantities of solvents, and do not provide the required limits of detection to meet the wastewater standards for many compounds present in the Hanford waste tanks. A study was performed to investigate the potential of using Stir Bar Sorptive Extraction (SBSE) and Thin Film Solid Phase Microextraction (TF-SPME) to analyze volatile organic compounds (VOC) and semi-volatile organic compounds (SVOC) in Hanford tank waste simulant. The SBSE used is a 1.5 cm long magnetic stir bar sealed in glass that was coated with high-capacity Polydimethylsiloxane (PDMS). Three TF-SPME devices (20 mm long and 4.75 mm wide) that employ PDMS coated with hydrophilic lipophilic balanced (HLB), divinylbenzene (DVB), and carboxen (CAR) particles were also tested. The efficiencies of extraction of 143 volatile and semi-volatile organic compounds from tank waste simulant spiked with known standards were evaluated. Further testing was performed under varying conditions of pH, salt concentrations, and stirring durations. After extraction, the SBSE and TF-SPME were thermally desorbed and analyzed by gas chromatography/mass spectrometry (GC/MS). (authors)