title: Application of HPLC-ICP-MS and HPLC-ESI-MS procedures for arsenic speciation in seaweeds.
abstract: Speciation of arsenic in seaweeds was carried out using ion chromatography (IC) for separation and inductively coupled mass spectrometry (ICP-MS) for detection. The arsenic species studied were arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), and arsenocholine (AsC). Chromatographic separation of all the species was achieved in <9 min in gradient elution mode using (NH(4))(2)CO(3) and methanol at pH 8.5. The outlet of the IC column was directly connected to the nebulizer of ICP-MS for the determination of arsenic. The speciation of arsenic has been carried out in several seaweed samples. A microwave-assisted extraction method was used for the extraction of arsenic species from seaweed samples. With a mixture of mobile phase A and methanol as extractant, the extraction efficiency was >84%, and the recoveries from spiked samples were in the range of 90-106%. The unknown compounds detected in different seaweeds were identified by coupling IC directly with electrospray ionization-mass spectrometry (ESI-MS). Two arsenosugars and tetramethylarsonium ion (TETRA) were identified in different seaweeds. A fat-soluble arsenolipid compound was identified in the extract of certified reference material BCR-279  Ulva lactuca  when 1% HNO(3) was used as the extractant. The precision between sample replicates was >9% for all determinations. The limits of detection were in the range of 0.006-0.015 μg L(-1) for various arsenic species based on peak height.
authors.affiliation: Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan.
authors.forename: Yu-Jhe
authors.initials: YJ
authors.lastname: Hsieh
authors.forename: Shiuh-Jen
authors.initials: SJ
authors.lastname: Jiang
mesh_terms: D001151:Arsenic / Q000032:analysis; D001152:Arsenicals / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000379:methods*; D012624:Seaweed / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D001152:Arsenicals; D001151:Arsenic