Planta Med 2015; 81 - PA2
DOI: 10.1055/s-0035-1545131

Arsenic speciation and Fucoxanthin analysis from seaweed dietary supplements using LC-ICP-MS

B Avula 1, YH Wang 1, IA Khan 1, 2, 3
  • 1National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS 38677, USA
  • 2Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS 38677, USA
  • 3Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia

The study involves the analysis of total arsenic in metallic form, organic and inorganic arsenic species from seaweeds and dietary supplements. The analysis provides data for dietary exposure estimates of inorganic species which are considered more toxic to humans than organic arsenic and total arsenic. Total arsenic was determined by acid digestion followed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The optimum arsenic speciation method was determined to be water extraction followed by anion exchange HPLC coupled with ICP-MS. Optimization of chromatographic conditions led to baseline separation for six arsenic species, including arsenic acid, arsenous acid, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, and arsenocholine, in approximately 8 min using gradient elution. Detection limits for all 6 compounds were in the range from 10 – 15 ng/mL. The data presented here will be valuable for the quality assurance of analytical method development and surveys of total arsenic and arsenic species in dietary supplements. The most abundant arsenic species found were arsenite (As III) and arsenate (As V). In addition, the dietary supplements purported to contain fucoxanthin, a carotenoid having pharmacological activities were analyzed using UHPLC-UV-MS.