title: Automated dynamic hollow fiber liquid-liquid-liquid microextraction combined with capillary electrophoresis for speciation of mercury in biological and environmental samples.
abstract: A simple home-made automatic dynamic hollow fiber based liquid-liquid-liquid microextraction (AD-HF-LLLME) device was designed and constructed for the simultaneous extraction of organomercury and inorganic mercury species with the assistant of a programmable flow injection analyzer. With 18-crown-6 as the complexing reagent, mercury species including methyl-, ethyl-, phenyl- and inorganic mercury were extracted into the organic phase (chlorobenzene), and then back-extracted into the acceptor phase of 0.1% (m/v) 3-mercapto-1-propanesulfonic acid (MPS) aqueous solution. Compared with automatic static (AS)-HF-LLLME system, the extraction equilibrium of target mercury species was obtained in shorter time with higher extraction efficiency in AD-HF-LLLME system. Based on it, a new method of AD-HF-LLLME coupled with large volume sample stacking (LVSS)-capillary electrophoresis (CE)/UV detection was developed for the simultaneous analysis of methyl-, phenyl- and inorganic mercury species in biological samples and environmental water. Under the optimized conditions, AD-HF-LLLME provided high enrichment factors (EFs) of 149-253-fold within relatively short extraction equilibrium time (25min) and good precision with RSD between 3.8 and 8.1%. By combining AD-HF-LLLME with LVSS-CE/UV, EFs were magnified up to 2195-fold and the limits of detection (at S/N=3) for target mercury species were improved to be sub ppb level.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China.
authors.forename: Pingjing
authors.initials: P
authors.lastname: Li
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China.
authors.forename: Man
authors.initials: M
authors.lastname: He
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Chen
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China. Electronic address: binhu@whu.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
mesh_terms: D000818:Animals; D002614:Chelating Agents / Q000737:chemistry; D043844:Crown Ethers / Q000737:chemistry; D004284:Dogfish; D019075:Electrophoresis, Capillary / Q000379:methods; D005618:Fresh Water / Q000032:analysis; D006197:Hair / Q000737:chemistry; D006801:Humans; D059627:Liquid Phase Microextraction / Q000379:methods; D017669:Mercury Compounds / Q000032:analysis*; D018482:Muscle, Skeletal / Q000737:chemistry; D009941:Organomercury Compounds / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D002614:Chelating Agents; D043844:Crown Ethers; D017669:Mercury Compounds; D009941:Organomercury Compounds; D014874:Water Pollutants, Chemical; C015762:18-crown-6
keywords: Automatic dynamic liquid–liquid–liquid microextraction; CE/UV; Large volume sample stacking; Mercury species; Water and human hair