Arsenic Speciation Analysis Research Articles

Research progress on speciation analysis of arsenic in traditional Chinese medicine

Abstract Traditional Chinese medicine contains arsenic (As), which in the natural environment accumulates in plants during the growth of Chinese medicinal materials; there are mineral medicines containing As in Chinese patent medicine such as As4S4, As2S3, etc. Due to the toxicity of As-containing compounds and its role in inflammation and treatment of cancers such as leukemia, it is necessary to analyze the chemical form of As. A comprehensive investigation of the compound forms of heavy metals rather than the simple total amount of elements will lay the foundation for the scientific and objective evaluation of the safety of heavy metals. This article summarizes the speciation of As in bulk Chinese medicinal materials and Chinese patent medicines in recent years, and reviews the main research methods of As speciation analysis. The separation and detection combined analysis method focuses on the high-performance liquid chromatography-plasma mass spectrometry and high-performance liquid chromatography-hydride generation-atomic fluorescence spectroscopy, etc. Taking the advanced synchrotron radiation source as the research platform, the use of X-ray near edge absorption fine structure spectrum and micro-area X-ray fluorescence analysis as a microscopic analysis technique supports direct analysis of the As speciation in situ. It is the most promising morphological analysis method.

Sensitive online speciation analysis of arsenic in biological samples by ambient mass spectrometry

Various arsenic species in biological samples were directly molecularly analyzed by ambient EESI-HG-MPT-MS with enhanced sensitivity.

Up-regulation of PUMA caused the activation of p53 phosphorylation and acetylation, enhancing the interaction between PUMA and Bcl-X and mediating arsenic-induced apoptosis

Arsenic is a toxic metalloid vastly dispersed all over the occupational environments, manifesting multiple adverse health issues related to apoptosis. PUMA (p53 up-regulated modulator of apoptosis) is a crucial member of the Bcl-2 protein family and plays a key role in pro-apoptosis. The purpose of this work was to determine whether inorganic arsenic (NaAsO2) and its metabolites influenced the expression of PUMA in vivo and vitro, followed by investigating the mechanisms. RNA was extracted from serum and used to determine the expression of PUMA in vivo. The urine samples performed arsenic speciation analysis. This trial tested three-dose proportions in two cell lines (A549: 20, 40, 60 μM/L; 16HBE: 1.5, 3.0, 4.5 μM/L), respectively. According to the results of qRT-PCR and western blotting, NaAsO2 caused the overexpression of PUMA, not its metabolites. Furthermore, NaAsO2 induced phosphorylation of p53 at Ser315, 376, 392, and Thr55, and acetylation of p53 at K370, 382 with a dose-response relationship, suggesting the contribution of PUMA up-regulation to p53 phosphorylation and acetylation. CCK-8, JC-1 (5, 5′, 6, 6′-tetrachloro-1, 1′, 3, 3′-tetramethylbenzimi-dazolylcarbocyanine iodide), Hoechst33342/PI and the caspase3 and PARP1 blots were utilized to reveal apoptosis responding to NaAsO2 exposure. The co-immunoprecipitation assay showed that the interaction between PUMA and Bcl-X enhanced in intensity responding to NaAsO2 exposure, disrupting the complexes of Bcl-X with other pro-survival Bcl-2-related proteins. To our knowledge, we first reported that NaAsO2 activated phosphorylation of p53 at Ser315, 376, and Thr55, as well as acetylation of p53 at K370.

New Method for Simultaneous Arsenic and Selenium Speciation Analysis in Seafood and Onion Samples.

This paper presents a new method for the simultaneous speciation analysis of arsenic (As(III)-arsenite, As(V)-arsenate, DMA-dimethylarsinic acid, MMA-methylarsonic acid, and AsB-arsenobetaine) and selenium (Se(IV)-selenite, Se(VI)-selenate, Se-Methionine, and Se-Cystine), which was applied to a variety of seafood and onion samples. The determination of the forms of arsenic and selenium was undertaken using the High-Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry (HPLC–ICP–MS) analytical technique. The separation of both organic and inorganic forms of arsenic and selenium was performed using two analytical columns: an anion exchange column, Dionex IonPac AS22, containing an alkanol quaternary ammonium ion, and a double bed cation–anion exchange guard column, Dionex Ion Pac CG5A, containing, as a first layer, fully sulfonated latex for cation exchange and a fully aminated layer for anion exchange as the second layer. The ammonium nitrate, at pH = 9.0, was used as a mobile phase. The method presented here allowed us to separate the As and Se species within 10 min with a suitable resolution. The applicability was presented with different sample matrix types: seafood and onion.

A combination approach using two functionalized magnetic nanoparticles for speciation analysis of inorganic arsenic

Mercapto- and amino-functionalized magnetic nanoparticles, Fe3O4@SiO2@MPTMS (SMNPs-MPTMS) and Fe3O4@SiO2@APTES (SMNPs-APTES), have been applied as magnetic solid-phase extraction (MSPE) sorbents to directly extract arsenite (As(III)) and arsenate (As(V)) respectively, followed by inductively coupled plasma-mass spectrometry (ICP-MS) detection. Various MSPE parameters were optimized including dose of magnetic adsorbent, pH of sample solution, loading and elution conditions of analytes, adsorption capacity and reusability of SMNPs-MPTMS and SMNPs-APTES for As(III) and As(V) respectively. Under the optimized MSPE conditions, this combined scheme possesses excellent selectivity and strong anti-interference ability without any oxidation or reduction prior to capture of these two species. It is found that with a 25-fold enrichment factor, the limits of detection of As(III) and As(V) were 23.5 and 10.5 ng L−1, respectively. To verify the reliability of the proposed protocol, a certified reference material of environmental water was analyzed, and the results for inorganic arsenic species were in close agreement with the certified values. The applicability of the combination strategy for speciation analysis of inorganic arsenic was evaluated in spiked tap, river, lake and rain water samples. Good recoveries of 89%–96% and 90%–102% were achieved for As(III) and As(V), respectively, with the relative standard deviation ranges of 3.2%–8.0% and 2.5%–7.6%. Through the characterization of functionalized magnetic nanoparticles and the optimization of MSPE experiment, it is confirmed that the existence of mercapto and amino groups on SMNPs-MPTMS and SMNPs-APTES sorbents are responsible for the extraction of As(III) and As(V), respectively, via coordination and electrostatic interactions.

Extraction and HPLC-ICP-MS Determination of Five Arsenic Species in Rice

Accurate quantitative analysis of the content of different species of arsenic in rice is the key to evaluate its quality. By using high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS), the extraction and analysis methods of five common arsenic species were optimized, including arsenite [As(III)], arsenate [As(V)] and monomethyl arsenic (MMA), dimethyl arsenic (DMA) and arsenicbetaine (AsB). The results showed that a mixed solution of 10 mmol/L anhydrous sodium acetate (CH3CHOONa), 3 mmol/L ammonium nitrate (NH4NO3), 2 mmol/L sodium dihydrogen phosphate (NaH2PO4) and 0.2 mmol/L disodium ethylenediaminetetraacetic acid with a pH value of 10.22~10.27 was used as the flow phase, which can well separate the five species of arsenic in rice. The extraction efficiencies of nitric acid-water, phosphoric acid-water, hydrochloric acid-water, methanol-water, and pure water for five arsenic species in rice were compared, and the extraction solvent concentration, extraction time, auxiliary heating method and other conditions were compared and modified. The results showed that using 1% HNO3 aqueous solution as an extraction reagent, with treatment at a constant temperature of 90 ℃ for 3 hours, has a better extraction effect on arsenic in rice. The recovery rates of the five arsenic species in samples were between 84.24% and 112.75%, the relative standard deviation (RSD) was less than 7.74%, and the detection limits were between 0.2~0.5 µg/L. This study indicates that this method is suitable for the analysis of arsenic species in arsenic-containing rice.

Clinimetallomics: Arsenic Speciation in Urine from Patients With Arsenism by HPLC-ICP-MS

Clinimetallomics is proposed as a branch of metallomics that focuses on the study of the metallome in clinical samples of urine, blood, and tissues. As the clinical diagnosis of arsenic poisoning is mainly based on the concentration of total arsenic in urine, the toxicity of arsenic varies greatly in different speciation. Analysis of arsenic speciation with excessive total arsenic in urine can provide a basis for precise treatment. It can also be used to understand the fate of arsenic in the body of patients with arsenic poisoning after treatment with sodium dimercaptopropane sulfonate. In this study, a HPLC-ICP-MS method was established for the determination of arsenic species in urine samples from patients diagnosed with arsenism. Use the established method to detect urine samples, which can be directly assayed after simple sample dilution with 20 mmol/L EDTA-2Na. With the concentration of arsenic speciation in the range of 1.0~100.0 ng/mL, the linear correlation coefficient was higher than 0.99996. The recoveries were between 92.4% and 109.0%. The precision of the concentration and retention time (n = 3) were less than 3.0% and 0.3%, respectively, and the detection limit was between 1.42 ng/mL and 1.86 ng/mL. This method can be applied to arsenic speciation in the urine of healthy people, in patients treated for arsenic poisoning, and in patients diagnosed with arsenism.

Parallel and comparative non-targeted metabolomic speciation analysis of metalloids and their non-metal analogues by HPLC-ICPMS/MS in mushrooms.

With the introduction of tandem mass spectrometry to inductively coupled plasma mass spectrometry (ICPMS/MS), the potential for non-targeted elemental metabolomic analysis has been expanded to many non-metals of pivotal biological importance. Arsenic and selenium are trace elements that share chemical similarity with the non-metals phosphorus and sulfur, respectively, and this similarity can be exploited to gain more insight into the incompletely understood biological significance of these metalloids and the evolution of their biochemical pathways. As a proof of concept, we show the applicability of HPLC-ICPMS/MS for non-targeted and parallel speciation analysis of arsenic, selenium, phosphorus, and sulfur in mushrooms-metabolically diverse organisms. Incredibly contrasting levels of diversity were found in the metabolomic profiles of the four investigated elements among the various species along with sharp discrepancies among related elements (e.g. phosphorous vs. arsenic) in certain mushroom species. The present work shows that ICPMS/MS offers a new dimension in non-targeted metabolomic analysis and enables a unique comparative approach in investigating and tracking the biochemistry of related elements in moderately complex organisms.

A Novel Pretreatment Device Integrating Magnetic-Assisted Dispersive Extraction and Ultrasonic Spray Separation for Speciation Analysis of Arsenic in Whole Blood by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry.

Speciation analysis of arsenic in blood is essential for identifying and quantifying the exposure of arsenic and studying the metabolism and toxicity of arsenic. Herein, a novel pretreatment device is rationally designed and used for speciation analysis of arsenic in whole blood by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). The sample centrifuge tubes containing blood, reagents, and a magnetic stir bar are placed on the fidget spinner of the pretreatment device. When flicking the fidget spinner rotation with the finger, the magnetic stir bar in the tube rotates in three dimensions under the magnetic field, thereby assisting dispersive extraction of arsenic species by the mixing of blood with reagents. Afterward, the arsenic extract is separated in situ from the blood matrix using an ultrasonic spray sheet covered with a filter and ultrafiltration membrane, which is directly used for subsequent IC-ICP-MS analysis. For 100 μL of blood, the whole pretreatment operation can be completed within 10 min. With As(III), As(V), MMA, and DMA in blood as analytes, the use of the present pretreatment device will hardly lead to the loss and transformation of arsenic species, and the extraction efficiency of the total arsenic is more than 96%. When the pretreatment device is coupled to IC-ICP-MS, the detection limits of four arsenic species in whole blood are 0.017-0.023 μg L-1, and precisions are within 2.3-4.2%. This pretreatment device provides a simple, fast, efficient, and low-cost tool for extraction and separation of arsenic species in whole blood, opening a new idea for the pretreatment of complex samples.

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

On-line speciation analysis of arsenic compounds in commercial edible seaweed by HPLC–UV-thermo-oxidation-HG-AFS

Arsenic speciation analysis in dried seaweeds was carried out using an on-line HPLC–UV-thermo-oxidation-HG-AFS system. Species separated and quantified were: arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and different arsenosugars. Extraction efficiency ranged between 38 and 83%. Chromatographic separation was achieved in gradient elution mode using (NH4)2CO3 as mobile phase in the pH range 9–10.3. Total As concentration was quantified by ICP-MS after microwave digestion. Limits of detection were in the range 3.0 to 6.0 ng g−1 for the species under study based on peak height and the relative standard deviation was <8% at 10 µg L−1 As. The accuracy of the procedure was verified by analyzing the CRM BCR-279 Ulva lactuca. Results for total As were in agreement with the certified values. The HPLC-(UV)-HG-AFS system resulted suitable for quantification of eight As compounds. Results showed that arsenosugars are the most abundant compounds in the investigated seaweeds.

Sequential Extraction Analysis of Arsenic in Soil Samples Collected in an Agricultural Area of Brindisi, Apulia (Italy), in the Proximity of a Coal-Burning Power Plant

In order to evaluate the local environmental risk deriving from coal transport and burning, 30 soil samples were collected along the coal conveyor belt and around the coal-burning power plant Federico II of Brindisi (Apulia, southern Italy). Since soil pollution of metals and metalloids is measured not only by their total concentration but also by evaluating their mobility and availability, arsenic sequential extraction, leaching test and speciation analysis were performed. The analytical results showed that the most abundant As amount was contained in the final residue of the sequential extraction procedure, the so-called occluded As, embedded in rock formations such as sulphides. Moreover speciation chemical analysis showed that As(V) was by far the most abundant species, whereas As(III), which represents the most soluble and available species, was only a very small fraction. No arsenic organic species were detected in the soil samples.

Pleistocene sands of the Mississippi River Alluvial Aquifer produce the highest groundwater arsenic concentrations in southern Louisiana, USA

Geostatistical and geospatial analysis techniques were employed to evaluate relationships between high arsenic (As), iron (Fe), and manganese (Mn) concentrations in groundwaters from the Pleistocene Mississippi River Alluvial Aquifer (MRAA) in south-central Louisiana. The MRAA is recharged by the Mississippi River, and its groundwater contains Fe concentrations that range from 0.43 to 179 µmol kg−1 (n = 40) and As concentrations that range from 26 nmol kg−1 up to 8500 nmol kg−1 (i.e., 637 µg kg−1). Arsenic speciation analysis reveals a mix of redox states with As(V) accounting for between ca. 18% and ca. 84% of the total dissolved As (mean ± 1σ = 61.6 ± 24.4%, n = 6). Spatial distributions of As, Fe, and Mn concentrations suggest that the reductive dissolution of Fe/Mn oxides/oxyhydroxides is the likely source of As to the MRAA groundwaters. Geostatistical and geospatial analyses were employed to produce interpolation maps that show concentrations of As, Fe, and Mn decrease with distance from the Mississippi River. Spatial correlations are stronger between groundwater As and Fe concentrations (r = 0.710, PAs*Fe < 0.0005) than those between the As and Mn concentrations (r = 0.404, PAs*Mn < 0.0005). More specifically, regions of the MRAA characterized by high dissolved As concentrations spatially correlate with regions of high dissolved Fe concentrations, and to a lesser degree, high dissolved Mn concentrations. We hypothesize that recharge of the MRAA by Mississippi River water introduces labile organic carbon into the MRAA that subsequently fuels microbial respiration, which reduces Fe/Mn oxides/oxyhydroxides, and mobilizes adsorbed and/or co-precipitated As into MRAA groundwaters. Once mobilized, As is transported away from the riverbank by flowing groundwaters but is rapidly removed from solution by re-adsorption onto Fe/Mn oxides/oxyhydroxides within the regionally oxidized aquifer sediments. Our investigation indicates that oxidized Pleistocene sand aquifers in large river delta plains can also produce groundwater with dangerously high As concentrations if redox conditions shift to suboxic/ferruginous conditions.

Aqueous arsenic and sulfur speciation analysis and solid phase characterization in the dissolution of arsenic trisulfide

Arsenic removal from metallurgical waste streams in the form of arsenic trisulfide (As2S3) is promising due to its high arsenic content. However, the major barrier to widely implementing the sulfidization process is the stability of arsenic trisulfide. Our previous study has shown that the release rate of arsenic and sulfur increased with pH, the dissolved oxygen concentration, and temperature. The rate-limiting step was proposed to be surface chemical reaction based on the magnitude of the reaction orders and the activation energy. To further support the proposed mechanism, we analyzed aqueous arsenic and sulfur speciation and examined the changes in the solid surface properties during leaching. The speciation analyses indicate that arsenic was initially released in the form of arsenite, which was subsequently oxidized to arsenate. The extent of oxidation increased with pH, the dissolved oxygen concentration, and temperature. Thiosulfate was the predominant dissolved sulfur species, which was subsequently converted to sulfate via two different pathways. The oxidation pathway was favored at pH higher than 8. The disproportionation pathway was favored at pH 8 and below, where elemental sulfur was generated and precipitated out of solution as a solid. The SEM/EDX and XRD analyses of the solid residues confirmed the formation of elemental sulfur on the solid surfaces at pH 8 but not at pH 9. The formation of elemental sulfur reduced the sulfur concentration in the leachates, resulting in the aqueous As/S ratio being higher than the stoichiometric value in the As2S3 structure. The elemental sulfur produced did not act as a barrier to diffusion of reactants, as evidenced by the leaching being insensitive to the removal of elemental sulfur.

Non-chromatographic arsenic speciation analyses in wild shrimp (Farfantepenaeus brasiliensis) using functionalized magnetic iron-nanoparticles

A new iron-magnetic nanomaterial functionalized with organophosphorus compound was used as solid-phase for arsenic speciation analysis in seafood samples by ICP-MS. The procedure was optimized using chemometric tools and the variables pH = 4.0, 15 min extraction time, and 20 mg of mass of material were obtained as the optimum point. The inorganic arsenic (iAs) extracted using nanoparticles presented concentrations between 20 and 100 µg kg−1 in the evaluated samples. The method was validated for accuracy using CRMs DOLT-5 and DORM-4. It was possible to reuse the same magnetic nanomaterial for 6 successive cycles, and we obtained a detection limit of 16.4 ng kg−1. The proposed method is suitable for the use of inorganic speciation of As, presenting good accuracy, precision, relatively low cost, and acquittance to green chemistry principles.

Determination of total arsenic and hydrophilic arsenic species in seafood

Marine organisms are vital sources of staple and functional food but are also the major dietary route of human exposure to total arsenic. We surveyed the total arsenic content and the mass fractions of hydrophilic arsenic species from five different marine food types cutting across the food chain from microalgae, macroalgae, bivalve clam, crustaceans and finfish. Total arsenic was determined using inductively coupled plasma-mass spectrometry (ICP-MS) while arsenic speciation analysis was performed using high-performance liquid chromatography (HPLC) coupled to ICP-MS as the detector. The total arsenic contents ranged from 133 ± 11 ng/g to 26,630 ± 520 ng/g. The mass fractions of inorganic arsenic (iAs), arsenobetaine (AsB), dimethylarsinic acid (DMA), and the four commonly occurring arsenosugars (AsSugars) are reported. Extractable hydrophilic arsenic species accounted for 10 % (aquacultured shrimp) to 95 % (kelp) of the total arsenic. DMA was established to be a byproduct of the decomposition of AsSugars in acid extracts of samples known to contain these species.

Speciation analysis of arsenic in coal and its combustion by-products in coal-fired power plants

The speciations of Arsenic (As) in coal will inevitably convert during the combustion process. The As speciations in coal and its by-products are closely related to human health and environmental safety which is urgent to be identified. However, there is a lack of pretreatment procedure and analysis method on the As species in coal-related products in power plants. In this study, the As species in coal, fly ash (FA), and gypsum were successfully determined by high performance liquid chromatography coupled with hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS). The instrument parameters, extract reagents, and pretreatment methods (i.e. ultrasound and microwave-assisted) were optimized. The whole separation time of inorganic As was shorten to 7 min after optimization, with the detection limit of 1.8 and 4.6 ng/g for As(III) and As(V), respectively. The efficient As extract reagent was the mixture of 1.0 mol/L H3PO4 and 0.1 mol/L ascorbic acid solution. Microwave-assisted (2000 W, 80°C, 40 min) and ultrasound-assisted (40 kHz, 20°C, 40 min) schemes were the optimal extraction methods for coal/FA and gypsum samples, respectively. Under the proposed microwave and ultrasound extraction procedure, the recovery of As(III) and As(V) could reach to 95.8%/104.5% and 90.6%/89.7%, respectively. The dominant occurrence of As species in coal was As(V) with a small percentage of As(III), while As(V) was the only occurrence form observed in FA and gypsum. It is indicated that revealing the transformation of As(III) to As(V) is the key for gaseous As capture. The As species distribution investigation provides a scientific insight to the controlling of As emission from power plant.

A universal method for the speciation analysis of arsenic in various seafood based on microwave-assisted extraction and ion chromatography-inductively coupled plasma mass spectrometry

The speciation analysis of arsenic in seafood is of great significance for objectively and scientifically assessing arsenic health risks in seafood. In general, different types of seafood contain a variety of different arsenic species and have quite different matrix. Thus, the detection of arsenic species in different types of seafood required different extracting and analytical methods. In this study, a universal microwave-assisted extraction was developed to extract each arsenic species including As(V), As(III), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), arsenosugars and so on in various seafood with a extraction efficiency > 95% and without altering their original species, and a universal cation exchange IC-ICP-MS (ion chromatography-inductively coupled plasma mass spectrometry) method was developed for the detection of arsenic species in various seafood (seaweed, fish, shellfish and shrimp) with a method detection limit of 8.0 ng As/g dried seafood–12.0 ng As/g dried seafood. Especially, the extract of seafood obtained with our microwave-assisted extraction can be directly used for the following IC-ICP-MS detection without any additional pretreatment. By using the extraction method and IC-ICP-MS method, we have successfully detected each arsenic species including As(V), As(III), MMA, DMA, AsB, arsenosugars and so on in seaweed, fish, shellfish and shrimp samples with a recovery of 92%–104% and a relative standard deviation (RSD, n = 5) < 5%. The developed microwave-assisted extraction method and IC-ICP-MS detection method is simple, has broad applicability, high efficiency, excellent accuracy and strong resistibility to the complicated matrix, which promising a reliable approach for objectively and scientifically assessing arsenic health risks in various seafood to ensure the consumption safety of seafood.

Occurrence, speciation analysis and health risk assessment of arsenic in Chinese mitten crabs (Eriocheir sinensis) collected from China

Arsenic (As) is a major hazardous element in natural environments, and arsenic pollution is becoming an issue of concern worldwide. The more toxic inorganic arsenic, such as trivalent arsenite As(Ⅲ) and pentavalent arsenate As(Ⅴ), which normally can transform to organic arsenic compounds, such as arsenobetaine (AsB), arsenocholine (AsC), monomethyl arsenic acid (MMA), dimethyl arsenic acid (DMA), trimethyl arsenic acid (TMA), arsenosugars and arsenolipids. In this study, a total of 2130 individuals of Chinese mitten crabs were collected from seven locations and mixed to 71 samples. Total arsenic and six major species (AsC, AsB, DMA, MMA, As (Ⅲ), and As (Ⅴ)) were determined by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS), respectively. The target hazard quotient (THQ) was utilized to evaluate the human health risk. The total arsenic concentration and totals for the six arsenic forms are 0.25–1.66 mg/kg and 0.05–1.19 mg/kg wet mass, respectively. Except for HH and LH, the six arsenic species concentrations accounted for more than 50.0 % of the total arsenic. The less toxic AsB is the most predominant in crabs, comprising 50.0 %–90.0 % of the sum of six types of arsenic. The more toxic inorganic arsenic only range from 0.01 to 0.21 mg/kg wet mass, much less than the limit content of 0.50 mg/kg inorganic As in crustacea. The THQ values of inorganic arsenic through the consumption of Chinese mitten crabs are estimated, and the values are all less than 1, indicating that intaking Chinese mitten crabs collected from China will not cause an appreciable hazard risk to human health.

Monitoring Arsenic Species Content in Seaweeds Produced off the Southern Coast of Korea and Its Risk Assessment

Seaweed, a popular seafood in South Korea, has abundant dietary fiber and minerals. The toxicity of arsenic compounds is known to be related to their chemical speciation, and inorganic arsenic (iAs) is more detrimental than other species. Due to the different toxicities of the various chemical forms, speciation analysis is important for evaluating arsenic exposure. In this study, total arsenic (tAs) and six arsenic species (arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, and arsenocholine) were analyzed in 180 seaweed samples. Although there were differences between seaweed species, the concentration of tAs was detected at levels ranging from 1 to 100 µg/g, and the distribution of six arsenic species differed depending on the seaweed species. No correlation between the concentration of iAs and tAs was found in most seaweed species. Through statistical clustering, hijiki and gulfweed were seen to be the seaweeds with the highest ratios of iAs to tAs. Using the iAs concentration data from the arsenic speciation analysis, a risk assessment of seaweed intake in South Korea was conducted. The margin of exposure values showed no meaningful risk for the general population, but low levels of risk were identified for seaweed consumers, with high intakes of gulfweed and hijiki.