Arsenosugars extracted from algae: Behavior study using dispersive solid-phase extraction
Alba Morales-Rodríguez1, Berta Vilarrúbies2, Yemna Badar2
1Departament d'Enginyeria Química i Química Analítica, Universitat de Barcelona, Martí i Franquès, 1-11, 08028 Barcelona, Spain; Departament de Nutrició, Ciències de l'Alimentació i Gastronomia, Campus de la Alimentació de Torribera, Universitat de Barcelona. Avda. Prat de la Riba, 171, 08921 Sta. Coloma de Gramenet, Barcelona, Spain; Institut de Recerca en Nutrició i Seguretat Alimentaria. Universitat de Barcelona (INSA-UB, Recognized as a Maria de Maeztu Unit of Excellence grant (CEX2021-001234-M)).
Abstract:
The acquisition of reliable speciation data for dietary exposure assessment is challenged by the lack of calibration standards for arsenosugars, the predominant arsenic species in algae. This limitation hinders their accurate identification and quantification. The study investigated the retention and elution behavior of anionic arsenosugars (PO4-Sug, SO3-Sug and SO4-Sug) using various dispersive solid-phase (d-SPE) sorbents - SAX, PSA, and HILIC. The aim was to assess their suitability for isolating and preconcentrating these compounds from aqueous algae extracts, not for quantification purposes but as a strategy for subsequent standards preparation. Key parameters examined included extract pH, adsorption time, ionic strength, and elution solvent. d-SPE eluates were analyzed by ICP-MS for total arsenic and IC-ICP-MS for arsenic speciation. Among the sorbents tested, SAX was the most effective, achieving approximately 90 % retention of arsenosugars. Two consecutive elution steps with 0,5 % ammonium formate enabled recoveries ranging from 75 to 88 % of the retained compounds in the studied algae samples.
