title: Removing perfluorooctane sulfonate and perfluorooctanoic acid from solid matrices, paper, fabrics, and sand by mineral acid suppression and supercritical carbon dioxide extraction.
abstract: The removal of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from solid matrices has received considerable attention because of the environmental persistence, bioaccumulation, and potential toxicity of these compounds. This study presents a simple method using concentrated HNO(3) as a suppression agent, and methanol-modified supercritical carbon dioxide (Sc-CO(2)) extraction for removing PFOS and PFOA from solid matrices. The optimal conditions were 16 M HNO(3) and 20% (v/v) methanol containing Sc-CO(2), under a pressure of 20.3 MPa and a temperature of 50 °C. Extraction time was set at 70 min (40 min for static and 30 min for dynamic extraction). PFOA and PFOS were identified and quantitated by liquid chromatography/mass spectrometry. The extraction efficiencies (with double extractions) were close to 100% for PFOA and 80% for PFOS for both paper and fabric matrices. The extraction efficiencies for sand were approximately 77% for PFOA and 59% for PFOS. The results show that this method is accurate, and effective, and that it provides a promising and convenient approach to remediate the environment of hazardous PFOA and PFOS contamination.
authors: Department of Chemistry, Chung Yuan Christian University, Chung-Li, Tao-Yuan 320, Taiwan, ROC.
authors: Hsiang-Yu
authors: HY
authors: Chen
authors: Weisheng
authors: W
authors: Liao
authors: Ben-Zen
authors: BZ
authors: Wu
authors: Hungchi
authors: H
authors: Nian
authors: KongHwa
authors: K
authors: Chiu
authors: Hwa-Kwang
authors: HK
authors: Yak
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry / Q000302:isolation & purification*; D002210:Caprylates / Q000737:chemistry / Q000302:isolation & purification*; D002245:Carbon Dioxide / Q000737:chemistry*; D005591:Chemical Fractionation / Q000379:methods*; D004785:Environmental Pollutants / Q000737:chemistry / Q000302:isolation & purification*; D005466:Fluorocarbons / Q000737:chemistry / Q000302:isolation & purification*; D000432:Methanol / Q000737:chemistry; D017942:Nitric Acid / Q000737:chemistry; D010209:Paper; D011312:Pressure; D012822:Silicon Dioxide / Q000737:chemistry*; D012995:Solubility; D013696:Temperature; D013997:Time Factors
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D004785:Environmental Pollutants; D005466:Fluorocarbons; D002245:Carbon Dioxide; D017942:Nitric Acid; D012822:Silicon Dioxide; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid; D000432:Methanol