title: Selective determination of four arsenic species in rice and water samples by modified graphite electrode-based electrolytic hydride generation coupled with atomic fluorescence spectrometry.
abstract: This work describes a novel non-chromatographic approach for the accurate and selective determining As species by modified graphite electrode-based electrolytic hydride generation (EHG) for sample introduction coupled with atomic fluorescence spectrometry (AFS) detection. Two kinds of sulfydryl-containing modifiers, l-cysteine (Cys) and glutathione (GSH), are used to modify cathode. The EHG performance of As has been changed greatly at the modified cathode, which has never been reported. Arsenite [As(III)] on the GSH modified graphite electrode (GSH/GE)-based EHG can be selectively and quantitatively converted to AsH3 at applied current of 0.4A. As(III) and arsenate [As(V)] on the Cys modified graphite electrode (Cys/GE) EHG can be selectively and efficiently converted to arsine at applied current of 0.6A, whereas monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) do not form any or only less volatile hydrides under this condition. By changing the analytical conditions, we also have achieved the analysis of total As (tAs) and DMA. Under the optimal condition, the detection limits (3s) of As(III), iAs and tAs in aqueous solutions are 0.25μgL(-1), 0.22μgL(-1) and 0.10μgL(-1), respectively. The accuracy of the method is verified through the analysis of standard reference materials (SRM 1568a).
authors.affiliation: Department of Applied chemistry, Anhui University of Technology, Maanshan, Anhui 243002, PR China. Electronic address: 13087641@qq.com.
authors.forename: Xin-An
authors.initials: XA
authors.lastname: Yang
authors.affiliation: Department of Applied chemistry, Anhui University of Technology, Maanshan, Anhui 243002, PR China. Electronic address: 1589572323@qq.com.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Lu
authors.affiliation: Department of Applied chemistry, Anhui University of Technology, Maanshan, Anhui 243002, PR China. Electronic address: 1114805728@qq.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Applied chemistry, Anhui University of Technology, Maanshan, Anhui 243002, PR China. Electronic address: 1161306667@qq.com.
authors.forename: Miao-Bin
authors.initials: MB
authors.lastname: Chi
authors.affiliation: Department of Applied chemistry, Anhui University of Technology, Maanshan, Anhui 243002, PR China.
authors.forename: Hui-Hui
authors.initials: HH
authors.lastname: Hu
authors.affiliation: Department of Applied chemistry, Anhui University of Technology, Maanshan, Anhui 243002, PR China. Electronic address: ahutwbzh@163.com.
authors.forename: Wang-Bing
authors.initials: WB
authors.lastname: Zhang
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D012275:Oryza / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D006108:Graphite; D001151:Arsenic
keywords: Arsenic; Atomic fluorescence spectrometry; Electrolytic hydride generation; Modified electrode; Species analysis