title: SPE speciation of inorganic arsenic in rice followed by hydride-generation atomic fluorescence spectrometric quantification.
abstract: Due to high toxicity, inorganic arsenic (iAs) species are the focus of monitoring effort worldwide. In this work arsenic was first extracted from rice by microwave-assisted digestion in HNO3-H2O2, during which As(III) was oxidized to As(V). Silica-based strong anion exchange cartridges were used to separate As(V) from organic forms. After prereduction by iodide, iAs was quantified by hydride-generation atomic fluorescence spectrometry (HG-AFS). This method achieved 1.3 ng g(-1) limit of detection (LOD), and 94 ± 3% and 93 ± 5% recoveries, respectively, for As(III) and As(V) at 100 ng g(-1). Validation was performed using standard reference material NIST 1568a (102 ng g(-1)) and ERM BC211 (124 ng g(-1)) rice flour. By eliminating chromatography, SPE speciation gained throughput and cost advantages. HG-AFS, at 10% budget and operation cost of a typical inductively-couple plasma mass spectrometer (ICPMS), proved highly sensitive and specific for iAs quantification.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, PA 19038, USA. Electronic address: guoying.chen@ars.usda.gov.
authors.forename: Guoying
authors.initials: G
authors.lastname: Chen
authors.affiliation: College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
authors.forename: Tuanwei
authors.initials: T
authors.lastname: Chen
mesh_terms: D001151:Arsenic / Q000032:analysis / Q000302:isolation & purification*; D006859:Hydrogen / Q000737:chemistry*; D057230:Limit of Detection; D012275:Oryza / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D006859:Hydrogen; D001151:Arsenic
keywords: Atomic fluorescence spectrometry; Hydride generation; Inorganic arsenic; Rice; SPE; Speciation