Garcia Salgado, Sara and Quijano Nieto, M. Angeles and Bonilla Simon, M. Milagros
Microwave-assisted extraction and HPLC-HG-ICP-AES as analytical tools for arsenic speciation in alga samples.
In: "2nd International Congress "Arsenic in the environment: Arsenic from nature to humans", 21/05/2008-23/05/2008, Valencia (España).
Arsenic is a toxic element widely distributed in the environment, due to both natural sources and anthropogenic applications, and its speciation has received significant attention over the last years due to its species-dependent toxicity. It is known that marine algae can accumulate toxic elements up to ug/g level, one of these elements being arsenic, whose potentially toxic inorganic species can be found in high percentages (Bhattacharya el al, 2007). Therefore, it is necessary not only to determine the total arsenic concentration, but also to evalúate the arsenic species present. In this regard, total arsenic determination in alga samples was carried out by ICP-AES, after the samples were mineralized in a microwave oven. In addition, an analytical procedure was developed for arsenic speciation in algae (Sargassum fulvellum and Hizikia fusiformis). In order to optimise the extraction procedure, several extraction methods and extractant agents were tested, leading to an optimised microwave-assisted extraction method of arsenic species, which employs deionised water as extractant. The species separation was performed by anión exchange HPLC, using a 17 raM phosphate buffer at pH 5.5 as mobile phase. Finally, HPLC-HG-ICPAES was employed for species determination, using 0.5% (w/v) NaBH4 and 4.0 M HC1 (García Salgado et al, 2006).