Extraction and detection of arsenicals in seaweed via accelerated solvent extraction with ion chromatographic separation and ICP-MS detection

Abstract

An accelerated solvent extraction (ASE) device was evaluated as a semi-automated means of extracting arsenicals from ribbon kelp. The effect of the experimentally controllable ASE parameters (pressure, temperature, static time, and solvent composition) on the extraction efficiencies of arsenicals from seaweed was investigated. The extraction efficiencies for ribbon kelp (approximately 72.6%) using the ASE were fairly independent (< 7%) of pressure, static time and particle size after 3 ASE extraction cycles. The optimum extraction conditions for the ribbon kelp were obtained by using a 3 mL ASE cell, 30/70 (w/w) MeOH/H2O, 500 psi (1 psi = 7 KPa), ambient temperature, 1 min heat step, 1 min static step, 90% vol. flush, and a 120 s purge. Using these conditions, two other seaweed products produced extraction efficiencies of 25.6% and 50.5%. The inorganic species present in the extract represented 62.5% and 27.8% of the extracted arsenic. The speciation results indicated that both seaweed products contained 4 different arsenosugars, DMA (dimethylarsinic acid), and As(V). One seaweed product also contained As(III). Both of these seaweed products contained an arsenosugar whose molecular weight was determined to be 408 and its structure was tentatively identified using ion chromatography-electrospray ionization-mass spectrometry/mass spectrometry (IC-ESI-MS/MS).

Ion chromatography–inductively coupled plasma mass spectrometry determination of arsenic species in marine samples

“…These may possibly be arsenosugar compounds (phosphatearsenoriboside (Unknown 1) and sulfonate-arsenoriboside (Unknown 2)), by means of comparison with published literature. 29,36 A detailed investigation is necessary in order to label them specifically. Fig.…”

Peer Reviewed: Arsenic Speciation

“…Extraction in combination with enzyme digestion using various proteases, lipases, and cellulases has shown some promise. Sequential, accelerated solvent, and microwave-assisted extraction techniques have also improved extraction efficiency (50). However, extraction efficiency for arsenic in some materials, such as seaweed, remains low and is not quantitative (50).…”

“…Sequential, accelerated solvent, and microwave-assisted extraction techniques have also improved extraction efficiency (50). However, extraction efficiency for arsenic in some materials, such as seaweed, remains low and is not quantitative (50). A need still exists to develop methods for extracting arsenic species from food, soil, and biological tissues.…”

Aqueous Extraction of Water-soluble Inorganic Arsenic in Marine Algae for Speciation Analysis

“…11,12 A lot of studies on As species in marine algae concerned with environmental monitoring and food safety have been published. [13][14][15][16][17][18][19] In addition, many techniques for As speciation in seafood were reported. [20][21][22][23][24][25] Nowadays, we must develop a simple monitoring technique to determine inorganic As in algae, since a large amount of samples should be treated at one time to estimate various risks posed by ingestion inorganic As (i-As: As(III) and As(V)).…”