title: Hollow fiber liquid-liquid-liquid microextraction followed by solid-phase microextraction and in situ derivatization for the determination of chlorophenols by gas chromatography-electron capture detection.
abstract: A method based on the combination of hollow fiber liquid-liquid-liquid microextraction and solid-phase microextraction (SPME) followed by gas chromatography-electron capture detection was developed for the determination of chlorophenols in water and wastewater samples. Silica microstructures fabricated on the surface of a stainless steel wire were coated by an organic solvent and used as a SPME fiber. The analytes were extracted through a hollow fiber membrane containing n-decane from sample solution to an alkaline aqueous acceptor phase. They were then extracted and in situ derivatized on the SPME fiber using acetic anhydride. Experimental parameters such as the type of extraction solvent, acceptor phase NaOH concentration, donor phase HCl concentration, the amount of derivatizing reagent, salt concentration, stirring rate and extraction time were investigated and optimized. The precision of the method for the analytes at 0.02-30μgL(-1) concentration level ranged from 7.1 to 10.2% (as intra-day relative standard deviation) and 6.4 to 9.8% (as inter-day relative standard deviation). The linear dynamic ranges were in the interval of 5-500μgL(-1), 0.05-5μgL(-1), 0.02-1μgL(-1) and 0.001-0.5μgL(-1) for 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol, respectively. The enrichment factors were between 432 and 785. The limits of detection were in the range of 0.0004-1.2μgL(-1). Tap water, well water and wastewater samples were also analyzed to evaluate the method capability for real sample analysis.
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran. Electronic address: saraji@cc.iut.ac.ir.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Saraji
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
authors.forename: Milad
authors.initials: M
authors.lastname: Ghani
mesh_terms: D000089:Acetic Anhydrides; D002733:Chlorophenols / Q000032:analysis*; D002849:Chromatography, Gas; D059627:Liquid Phase Microextraction / Q000379:methods; D052617:Solid Phase Microextraction / Q000379:methods; D012997:Solvents; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000089:Acetic Anhydrides; D002733:Chlorophenols; D012997:Solvents; D062065:Wastewater; D014874:Water Pollutants, Chemical; C031800:acetic anhydride; C030683:2-chlorophenol; C024564:2,4,6-trichlorophenol; C004762:2,4-dichlorophenol
keywords: Chlorophenols; Hollow fiber-based liquid–liquid–liquid microextraction; In situ derivatization; Solid-phase microextraction; Water analysis