Investigating the Arsenic Speciation in Algae of the Antarctic Region by Ion Chromatography LC-ICP-MS and LC-ESI-ITMS

WUILLOUD, RODOLFO G.; ALTAMIRANO, JORGELINA C.; SMICHOWSKI, PATRICIA; HEITKEMPER, DOUGLAS T.

JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY

Royal Society of Chemistry

Lugar: London; Año: 2006 vol. 21 p. 1214 - 1223

0267-9477

An investigation into presence and nature of As species in algae originating from the Antarcticregion is presented in this work. Arsenic speciation information in Antarctic algae samples wasobtained by using anion- and cation-exchange chromatography with on-line detection byinductively coupled plasma spectrometry (ICP-MS) or electrospray ionization ion trap massspectrometry (ESI-ITMS). Total arsenic concentrations found by ICP-MS in the Antarctic algaesamples ranged from 8.4 to 29.3 mg As g1 (dry weight). Arsenic species were efficiently extracted(83?108%) by using an MeOH : H2O (1 : 1) mixture. Anion-exchange chromatography utilizinggradient elution with 25 mM ammonium bicarbonate adjusted to pH 10 was used to separate theanionic As species present in the algae extracts. Additionally, gradient cation-exchangechromatography was performed using 4 mM pyridine solution adjusted to pH 2.4. This allowedthe separation of neutral and cationic As species present in the algae extracts. High volatility ofthe mobile phases allowed sample introduction compatibility with both ICP-MS and ESI-ITMSdetectors. Three arsenosugar species (arsenosugar?OH, ?SO3, and ?PO4) previously reported in marine algae samples accounted for B50?80% of the total extractable arsenic in 4 of the 5samples studied. In one algae sample, the presence of a previously unreported arsenic-containingcompound in algae samples was confirmed by ESI-ITMS isolation and fragmentation as5-dimethylarsinoyl-b-ribofuranose. This compound has been identified previously in marinebivalves but, to our knowledge, not in algae samples.