title: Speciation of mercury by hydrostatically modified electroosmotic flow capillary electrophoresis coupled with volatile species generation atomic fluorescence spectrometry.
abstract: A novel method for speciation analysis of mercury was developed by on-line hyphenating capillary electrophoresis (CE) with atomic fluorescence spectrometry (AFS). The four mercury species of inorganic mercury Hg(II), methymercury MeHg(I), ethylmercury EtHg(I), and phenylmercury PhHg(I) were separated as mercury-cysteine complexes by CE in a 50-cm x 100-microm-i.d. fused-silica capillary at 15 kV and using a mixture of 100 mmol L(-1) of boric acid and 12% v/v methanol (pH 9.1) as electrolyte. A novel technique, hydrostatically modified electroosmotic flow (HSMEOF) in which the electroosmotic flow (EOF) was modified by applying hydrostatical pressure opposite to the direction of EOF was used to improve resolution. A volatile species generation technique was used to convert the mercury species into their respective volatile species. A newly developed CE-AFS interface was employed to provide an electrical connection for stable electrophoretic separations and to allow on-line volatile species formation. The generated volatile species were on-line detected with AFS. The precisions (RSD, n = 5) were in the range of 1.9-2.5% for migration time, 1.8-6.3% for peak area response, and 2.3-6.1% for peak height response for the four mercury species. The detection limits ranged from 6.8 to 16.5 microg L(-1) (as Hg). The recoveries of the four mercury species in the water samples were in the range of 86.6-111%. The developed technique was successfully applied to speciation analysis of mercury in a certified reference material (DORM-2, dogfish muscle).
authors.affiliation: State Key Laboratory of Functional Polymer Materials for Adsorption and Separation, and Central Laboratory, Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071, China. xpyan@nankai.edu.cn
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Yan
authors.forename: Xue-Bo
authors.initials: XB
authors.lastname: Yin
authors.forename: Dong-Qing
authors.initials: DQ
authors.lastname: Jiang
authors.forename: Xi-Wen
authors.initials: XW
authors.lastname: He
mesh_terms: D000818:Animals; D004284:Dogfish; D004563:Electrochemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry; D006874:Hydrostatic Pressure; D008628:Mercury / Q000032:analysis* / Q000737:chemistry*; D009132:Muscles / Q000737:chemistry; D009995:Osmosis; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D014873:Water Pollutants; D008628:Mercury