Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

Abstract

DISCLAIMERThis report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.Reproduced from the best available copy. Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal.Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7%for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec.Supercritical fluid extraction reduces the extraction solvent volume to 10-15 mL, a factor of 20-30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30-45 min are used compared to 16-18 h for Soxhlet extraction.