Distribution Of Arsenic Species Research Articles

Arsenic Species Distribution and Toxicity in the Environment, Bioaccumulation, Biomethylation and Bioremediation by Microalgae: A Review

Arsenic (As) is a noxious metalloid that has been designated a priority pollutant and is present in the environment as a consequence of both anthropogenic and natural processes. Its toxicity in environmental and biological systems depends strongly on the chemical species. Interest in arsenic and microalgae interactions is important because microalgae are at the base of the aquatic food chain, are used in animal nutrition and has potential for As phytoremediation. This paper reviewed the current information on As species distribution in the environment especially as it relates to its toxicity to microalgae as well as its bioaccumulation, biomethylation and bioremediation by microalgae using appropriate methods. Information obtained revealed that Microalgae have evolved mechanisms for dealing with As in the environment with arsBHC operon mediating the reduction and extrusion of arsenite from the cells. They accumulate large amounts of arsenic from their surroundings which could lead to toxicity, As excretion from cells, reduction, methylation or complexation with metal binding peptides like glutathione and phytochelatins. This has made them suitable as ecological indicators to give an indication of As bioavailability and also in possible applications for the process of As remediation. Microalgae are been proposed for bioremediation purposes in aquatic environment since they show a high capacity for biosorption and bioconcentration of As and most importantly since they are able to methylate inorganic As to non-toxic organic and volatile As.

Spatial and seasonal variation of arsenic speciation in Pantanal soda lakes

The occurrence of high arsenic concentrations (up to 3000 μg L−1) in water of soda lakes of the Pantanal wetland is a remarkable case of natural arsenic contamination in South America. However, little is known about arsenic speciation in this environment, particularly regarding speciation changes related to lake trophic status and seasonal variations. To fill this gap, arsenic speciation analysis was carried out in surface (SW) and subsurface (SSW) waters sampled in five soda lakes with different eutrophication status, in two dry and one wet season. As(V) was the dominant species in these waters, while As(III), DMA, MMA and likely complex organic species were present in lower amounts. The results allow to conclude that the arsenic speciation in SW and SSW varies seasonally according to the regional wet or dry periods and lake water levels. In eutrophic turbid and in oligotrophic vegetated soda lakes, arsenic speciation was also characterized by spatial differences between edge and center or between the SW and SSW. Cyanobacteria or macrophytes/algae are involved in arsenic biotransformation in soda lakes through its metabolic and detoxification processes. Significant variation in surface water arsenic speciation occurs as a result of seasonal primary production fluctuation or water arsenic concentration changes in the soda lakes, increasing organoarsenics in dry periods, whereas in flood periods, As(V) prevails. Spatial distribution of arsenic species is significantly impacted by biogeochemical conditions at the water/sediment interface in soda lakes.

Determination of Arsenic Species Distribution in Arsenide Tailings and Leakage Using Geochemical and Geophysical Methods

This study describes the distribution of arsenic mobile species in the tailings of Cu–Co–Ni–arsenide using the sequential extraction and determining the contents of arsenate (AsV) and arsenite (AsIII). The object of this study is the tailings ponds of the Tuvakobalt plant, which contains waste from the hydrometallurgical arsenide ore processing of the Khovu-Aksy deposit (Republic of Tuva, Russia). A procedure of sequential extraction for arsenic was applied, and it includes the extraction of the following forms: water-soluble, potentially water-soluble and exchangeable, easily sorbed on the surface of carbonates, associated with Fe/Mn oxides/hydroxides, associated with easily oxidized minerals, and accounted for by non-oxidized arsenic minerals. This procedure, which takes into account the peculiarities of the physical and chemical composition of the waste, was supplemented by the analytical determination of the arsenite and arsenate content by using the methods of inductively coupled plasma atomic emission spectrometry (ICP-AES) combined with the hydride generation technique (HG-ICP-AES). The content of the most mobile forms of arsenic, which are water-soluble, potentially water-soluble, and exchangeable species, is equal to 56% of the total arsenic content, 23% and 33% of which are arsenite and arsenate, respectively. Unlike arsenic, the mobile forms of metals have been determined in small quantities. The largest proportion of water-soluble and exchangeable forms is formed by Mg, Ca, and Sr at 11, 9.4, and 20%, respectively (residual and redeposited carbonates). The proportion of water-soluble forms of other metals (Cu, Zn, Co, and Ni) is < 1% or 0. The main part of the metals is adsorbed on the surface of Fe and Mn hydroxides, enclosed in easily and hardly oxidized minerals. In addition to geochemical studies, the presence of leaks from the tailing ponds into ground waters was determined by using electrical resistivity tomography. The data obtained indicate a high environmental hazard of tailings and the possibility of water-soluble and highly toxic arsenic compounds entering ground waters and aquifers.

Effect of CaO and SO2 on the distribution of arsenic species during coal combustion at high temperature

ABSTRACT Arsenic emission from coal combustion is of great concern due to its high toxicity and ecological environment hazards. Toxicity of arsenic is related to its speciation. Effects of CaO and SO2 on arsenic emission during SH and HLH coal combustion at high temperature were obtained through thermodynamic calculation. It indicates that the volatilisation ratio of arsenic in the form of As4O6 (g) increases as the combustion temperature increasing. Coal type and content of CaO significantly affect the transition temperature of arsenic volatilisation. During SH combustion, with the addition of 10 wt % CaO, the inhibition rate of arsenic volatilisation is gradually increased to its maximum value of 30.46% at 900°C. The transition temperature of arsenic volatilisation is 1100°C and the inhibition rate is 42.74% with 20 wt % CaO added. As for HLH, either 10 wt % or 20 wt % CaO is added, the transition temperature are both 1200°C, with the inhibition rate of 36.46% and 48.37%, respectively. Moreover, competition is existed between SO2 and arsenic during coal combustion. When the temperature is above 1100°C, for the preferential reaction between CaSO4 and As4O6, the competition of SO2 on arsenic volatilisation is weakened.

Arsenic Trioxide Therapy During Pregnancy: ATO and Its Metabolites in Maternal Blood and Amniotic Fluid of Acute Promyelocytic Leukemia Patients.

Acute promyelocytic leukemia (APL) is extremely fatal if treatment is delayed. Management of APL in pregnancy is a challenging situation. Arsenic trioxide (ATO) is successfully applied to treat APL. ATO can be transformed into different arsenic species [arsenite (AsIII), monomethylated arsenic (MMA, consists of MMAIII and MMAV), dimethylated arsenic (DMA, consists of DMAIII and DMAV), and arsenate (AsV)], which produce different toxic effects. Investigating the maternal and fetal exposure to arsenic species is critical in terms of assessing maternal and fetal outcomes, choice of optimal treatment, and making decisions for attempting to preserve the obstetrical and fetal wellbeing. In this study, maternal blood and amniotic fluid (AF) from APL patients treated with ATO in pregnancy and blood samples of non-pregnant patients were collected. Concentrations of inorganic arsenic (iAs, iAs = AsIII+AsV), MMA, and DMA were analyzed by high-performance liquid chromatography–hydride generation–atomic fluorescence spectrometry (HPLC–HG–AFS). The difference in arsenic species of plasma between pregnant patients and non-pregnant patients, distribution of arsenic compounds in AF and maternal plasma, and arsenic penetration into AF were explored. The outcomes of pregnant women treated with ATO and their fetus were analyzed. No significant differences in arsenic concentration, percentage, and methylation index [PMI: primary methylation index (MMA/iAs); SMI: secondary methylation index (DMA/MMA)] between pregnant women and non-pregnant women (p > 0.05) were observed. The mean ratios of AF to maternal plasma were as follows: iAs, 2.09; DMA, 1.04; MMA, 0.49; and tAs, 0.98. Abortion rate is higher with the diagnosis at an earlier gestational age, with 0%, 67%, and 100% of pregnancies ending in abortion during the third, second, and first trimester, respectively. The age of the pregnant women, the dose of ATO, and the duration of fetal exposure in utero had no influence on fetal outcomes. All APL women achieved complete remission (CR). Collectively, ATO and its metabolites can easily cross the placenta. Levels and distribution of arsenic species in maternal plasma and AF gave evidence that arsenic species had a different ability to penetrate the placenta into AF (iAs > DMA > MMA) and indicated a relatively high fetal exposure to ATO and its metabolites in utero. Gestational age at diagnosis was more likely to be closely related to fetal outcomes, but had no effects on mother outcomes.

The accumulation and distribution of arsenic species and selected metals in the saltmarsh halophyte, spiny rush (Juncus acutus)

This study examined the accumulation of As species, Se, Cu, Zn, Cd and Pb in the halophyte Juncus acutus, collected from three anthropogenically impacted estuaries in NSW, Australia. As concentration ranged from 4 to 22 μg/g at Georges River, 2–16 μg/g at Lake Macquarie and 6 μg/g at Hunter Estuary. Inorganic As was accumulated mainly in roots with low translocation to culm with a greater abundance of AsV. However, AsIII (TF = 0.32) showed greater mobility from the roots to shoots than AsV (TF = 0.04), indicating a higher quantity of AsIII specific transporter assemblages in the plasmalemma of the endodermis or cytoplasmic reduction of AsV to AsIII in culms. Metal(loid)s, including As (90%), were predominantly in root tissues and very limited translocation to culm, indicating the species is a useful phytostabiliser. As and all other metal(loid)s in roots were correlated with sediment loads (p < 0.05, R2 = 0.10–0.52), indicating the species would be an accumulative bioindicator.

Microbes drive changes in arsenic species distribution during the landfill process

Landfills are considered an anthropogenic source of arsenic (As). The As species mediated by microbes in landfills vary significantly in toxicity. Based on random matrix theory, 16S rRNA genes were used to construct four microbial networks associated with different stages over 12 years of landfill ages. The results indicated that network size and microbial structure varied with landfill age. According to the network scores, about 208 taxa were identified as putative keystones for the whole landfill; the majority of them were Firmicutes, which accounted for 66.8% of all specialists. Random Forest analysis was performed to predict the keystone taxa most responsible for As species distribution under different landfill conditions; 17, 10 and 14 keystone taxa were identified as drivers affecting As species distribution at early, middle, and later landfill stages, respectively.

Effect of Milling and Parboiling Processes on Arsenic Species Distribution in Rice Grains

This study identified the role of milling and parboiling on arsenic (As) content and its species in large numbers of rice samples. Total As contents were 108±33μg/kg in polished rice grains (PR), 159±46μg/kg in unpolished rice grains (UR), 145±42μg/kg in parboiled polished rice grains (PPR) and 145±44μg/kg in parboiled unpolished rice grains (PUR). The percentages of inorganic As (iAs) were 66%±8% in PR and from 72% to 77% in other grain categories. The polishing process reduced the As content in the rice grains, removing outer part of the UR with high amount of As, whereas the parboiling technique transferred the semimetal content within the grain. Total As and iAs contents were not significantly different in UR, PPR and PUR, homogenizing its distribution inside the grains. The results allowed to understand how different operations affect As fate and its chemical forms in grains.

Selenium (Se) as well as mercury (Hg) may influence the methylation and toxicity of inorganic arsenic, but further research is needed with combination of Inorg-arsenic, Se, and Hg

Selenium (Se) as well as mercury (Hg) may influence the methylation and toxicity of inorganic arsenic, but further research is needed with combination of Inorg-arsenic, Se, and Hg

Evaluation of arsenic species in leukocytes and granulocytes of acute promyelocytic leukemia patients treated with arsenic trioxide

Concentrations of arsenic metabolites were important to clarify the sensitivity and resistance of APL (acute promyelocytic leukemia) patients to arsenic trioxide (As2O3). Our purpose was to evaluate levels and distributions of arsenic species in leukocytes and granulocytes of APL patients. Inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were measured by high performance liquid chromatography coupled inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Leukocytes were collected from 21 patients treated with As2O3 during induction, consolidation, and drug-withdrawal period. The upregulation of granulocytes in induction period was closely related to the differentiation of promyelocytes. Therefore, granulocytes were collected during induction period from 4 APL patients and purified by flow cytometry sorting using a panel of monoclonal antibodies specific for CD45, CD3, CD14, and CD19. The developed HPLC-ICP-MS method was precise and accurate with the limit of quantification of 0.5 ng/mL. During induction, consolidation, and drug-withdrawal period, the general trend of arsenic species was iAs > MMA > DMA (P < 0.05) in leukocytes. iAs was predominant arsenic species with median concentration of 10.84 (6.03–14.62) ng/mL. MMA was major methylated metabolite with median concentration of 0.94 (0.60–2.50) ng/mL. Moreover, arsenicals were detected in leukocytes during drug-withdrawal. In granulocytes, iAs was found during induction period with median concentration of 1.08 ng/mL, while MMA and DMA were not detected. These results showed that iAs was the primary arsenic species in leukocytes and granulocytes from APL patients treated with As2O3. This study suggested that iAs might play a dominant therapeutic role during the whole treatment process of APL.

Review on double-edged sword nature of arsenic: its path of exposure, problems, detections, and possible removal techniques

ABSTRACT Chemically, Arsenic is one of the double-edged sword element distributed ubiquitously in nature. Low concentration of arsenic is used to treat leukaemia where as the high concentration of arsenic intake in human body leads to critical diseases such as skin diseases, cancer, blackfoot disease, hypertension, neurological effect, DNA damage and others. Chronic exposure may lead to coma and death. This peer review provides an overview about the distribution of arsenic species in rock, mining, and their pH dependent mobility that are found in aqueous body. The study reviews information among the various routes of arsenic exposure, their toxicity mechanisms, and a variety of total arsenic concentration detection process such as spectroscopic techniques, kit detection. The heart context of this review covers best arsenic removal techniques such as coagulation, absorption, oxidation, osmosis, electro-coagulation and others reputed techniques.

Distribution of arsenic species and pathological characteristics of tissues of the mice fed with arsenic-supplemented food simulating rice.

The exposure and harm of arsenic have attracted wide attention. Rice is an arsenic-rich crop. The purpose of this study was to learn the distribution of arsenic species and the pathological changes in tissues of mice exposed to arsenic-supplemented food simulating rice. Test groups of mice were orally exposed with prepared arsenic feeds supplemented with four arsenic species (arsenite iAsIII, arsenate iAsV, monomethylarsonate MMA, and dimethylarsinate DMA) at three doses (total As concentration: 0.91, 9.1 and 30 μg/g), which simulated the arsenic species ratio in rice. After 112 days, the concentrations of the arsenic species in the spleen, thymus, heart, skin and hair were detected, and histopathology of the spleen, heart and skin was observed. Each arsenic species was detected and their total concentration increased in a dose-dependent manner with a few exceptions. One interesting phenomenon is that ratio of the organic arsenic to inorganic arsenic also increased in a dose-dependent manner. For the other, the order of tissues from high to low arsenic concentration was the same in the medium- and high-dose groups. The histopathological sections of the spleen, heart and skin showed dose-dependent debilitating alterations in tissue architecture. Hyperplasia, hyaline degeneration and sclerosis of fibrous connective tissue occurred in the spleen. Myocardial cell atrophy and interstitial edema occurred in the heart. Hyperpigmentation, hyperkeratosis and atypia of basal cells occurred in the skin. In summary, the long-term intake of high arsenic rice has a health risk. Further studies are needed to assess it.

Arsenic transformation behavior mediated by arsenic functional genes in landfills

Landfill arsenic pollution is a complicated problem because of the sophisticated species and transformation of fractions involved. This study investigated arsenic transformation behavior from the viewpoint of arsenic functional genes based on analysis of 29 aged refuse samples collected from 11 sanitary landfills in 10 cities in Zhejiang Province, China. Arsenic species distribution varied significantly with landfill process. Landfill contains rich arsenic resistant microbes. arrA genes were the key factor responsible for arsenic transformation and migration in landfill. Although the abundance of aioA genes was the lowest among the four tested arsenic functional genes, it was the second important genes for arsenic distribution. Microbial metabolic activity was the main cause of arsenic transformation, and arsenate reduction by microbes was a key driver of arsenic mobilization in landfills. Moreover, arsenate was reduced to arsenite and further methylated to monomethylarsine (MMA) and dimethylarsine (DMA), decreasing the total arsenic content during the landfill process, but also inducing a new risk because of the arsenic effluent will be more easily as the state of arsenite, MMA, and DMA in the liquid phase. Overall, this study provides a picture of arsenic species transformation and insight into key roles involved in arsenic pollution during landfill processes.

Occurrence, Seasonal Variation, and Size Resolved Distribution of Arsenic Species in Atmospheric Particulate Matter in an Urban Area in Southeastern Austria.

Extensive information is available on total arsenic in particulate matter (PM), but little is known about the relative contribution of each individual species. Recent studies often focus on inorganic arsenic as arsenite and arsenate, neglecting the organoarsenicals, i.e., methylarsine, dimethylarsine, and trimethylarsine or the corresponding oxidized forms methylarsonate, dimethylarsinate, and trimethylarsine oxide, although they were already first detected in PM in the mid-1970s. This work presents results from more than 300 daily PM10 and further size-resolved atmospheric PM samples in the size range from 15 nm to 10 μm collected in an urban environment in Austria during the course of a year. An ion-exchange-HPLC (with anion and cation exchange columns) and an ICPMS/MS system were used to study the seasonal variations of total arsenic and all species known to exist in PM. Inorganic arsenic was present in significant amounts in all samples with highest concentrations during winter, but also all organoarsenicals were detected throughout the year. We show that their contribution cannot be ignored, as particles smaller than <1 μm can contain up to 35% of the water+H2O2 extractable arsenic as methylated species, but only dimethylarsinate showed a clear seasonal trend throughout the year.

Arsenic concentrations, diversity and co-occurrence patterns of bacterial and fungal communities in the feces of mice under sub-chronic arsenic exposure through food

BackgroundArsenic, a global pollutant and a threshold-free primary carcinogen, can accumulate in rice. Previous studies have focused on arsenic poisoning in drinking water and the effects on gut microbes. The research on arseniasis through food, which involves the bio-transformation of arsenic, and the related changes in gut microbiome is insufficient. MethodMice were exposed from animal feed prepared with four arsenic species (iAsIII, iAsV, MMA, and DMA) at a dose of 30 mg/kg according to the arsenic species proportion in rice for 30 days and 60 days. The levels of total arsenic (tAs) and arsenic species in mice feces and urine samples were determined using ICP-MS and HPLC-ICP-MS, respectively. 16S rRNA and ITS gene sequencing were conducted on microbial DNA extracted from the feces samples. ResultsAt 30 days and 60 days exposure, the tAs levels excreted from urine were 0.0092 and 0.0093 mg/day, and tAs levels in feces were 0.0441 and 0.0409 mg/day, respectively. We found significant differences in arsenic species distribution in urine and feces (p < 0.05). In urine, the predominant arsenic species were iAsIII (23% and 14%, respectively), DMA (55% and 70%, respectively), and uAs (unknown arsenic, 14% and 10%, respectively). In feces, the proportion of major arsenic species (iAsV, 26% and 21%; iAsIII, 16% and 15%; MMA, 14% and 14%; DMA, 19% and 19%; and uAs, 22% and 29%, respectively) were evenly distributed. Microbiological analysis (MRPP test, α- and β-diversities) showed that diversity of gut bacteria was significantly related to arsenic exposure through food, but diversity of gut fungi is less affected. Manhattan plot and LEfSe analysis showed that arsenic exposure significantly changes microbial taxa, which might be directly associated with arsenic metabolism and diseases mediated by arsenic exposure, such as Deltaproteobacteria, Polynucleobacter, Saccharomyces, Candida, Amanitaceae, and Fusarium. Network analysis was used to identify the changing hub taxa in feces along with arsenic exposure. Function predicting analysis indicated that arsenic exposure might also significantly increase differential metabolic pathways and would disturb carbohydrates, lipid, and amino acids metabolism of gut bacteria. ConclusionsThe results demonstrate that subchronic arsenic exposure via food significantly changes the gut microbiome, and the toxicity of arsenic in food, especially in staples, should be comprehensively evaluated in terms of the disturbance of microbiome, and feces might be the main pathway through which arsenic from food exposure is excreted and bio-transformed, providing a new insight into the investigation of bio-detoxification for arseniasis.

The Bioaccumulation and Tissue Distribution of Arsenic Species in Tilapia.

Arsenic is a public concern due to its widespread occurrence and carcinogenicity. Consumption of arsenic-contaminated fish is an important exposure pathway for human health. This study focused on understanding how exposure to arsenic-contaminated fish is informative to human health risk assessment. While the bioaccumulation and tissue distributions of total arsenic concentration in fish are commonly reported, there are limited studies related to the time-course of arsenic species in various tissues. Using the Tilapia as a case, this study aimed to investigate the bioaccumulation and tissue distributions (liver, gastrointestinal (GI), muscle, and gill) of arsenic species in freshwater fish via diet-borne inorganic arsenic exposure. In particular, the Tilapia were exposed to arsenic (III) and As(V) for 32 days. The accumulation of arsenic in all tissues linearly increased with time in the first 10 days’ exposure, while the arsenic levels remained stable in the following 20 days’ exposure. The accumulation of arsenic in tissue followed the sequence of intestine > liver > gill > muscle. Meanwhile, more than 90% of arsenic was converted into organic form in liver, gill, and muscle, while organic arsenic contributed about 30–80% to the total arsenic in the GI. The percentage of organic form in muscle is the highest, followed by gill, liver, and intestine, and arsenobetaine is the main form of organic arsenic. While the exposure profiles of As(III) and As(V) are quite similar, the absorption rate of As(V) is relatively higher than that of As(III). Information provided here can be instrumental for exposure assessment and risk management for arsenic in aquatic environment.

Occurrence, toxicity, and speciation analysis of arsenic in edible mushrooms

Owing to the strong concentration and biotransformation of arsenic, the influence of some edible mushrooms on human health has attracted widespread attention. The toxicity of arsenic greatly depends on its species, so the speciation analysis of arsenic is of critical importance. The aim of the present review is to highlight recent advances in arsenic speciation analysis in edible mushrooms. We summarized the contents and distribution of arsenic species in some edible mushrooms, the methods of sample preparation, and the techniques for their identification and quantification. Stability of the arsenic species during sample pretreatment and storage is also briefly discussed.

Study of the accumulation and distribution of arsenic species and association with arsenic toxicity in rats after 30 days of oral realgar administration.

Because the toxicity and efficacy of arsenic is closely related to its chemical species, we conducted examinations of arsenic species accumulation and distribution in the rat body after one-time and 30-day realgar administration and then elucidated the probable roles of different arsenic species in the short-term toxicity of realgar. According to ICH M3 guidelines for non-clinical repeated dose toxicity studies and OECD Test guideline TG407 "Repeated Dose 28-Day oral Toxicity Study in Rodents, the doses of realgar set were 10.6 mg/kg, 40.5 mg/kg and 170 mg/kg. Rats were orally administered with realgar for one-tme and 30 days, respectively. Thereafter, biological samples (plasma, urine, liver, kidney, and brain) were obtained from rats and analyzed using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) to determine realgar metabolism, arsenic species accumulation and distribution. Additionally, the toxicity of realgar in rats was evaluated. The absorption, distribution and elimination half-life of total arsenic species in realgar were 3.33 hs, 16.08 hs and 24.65 hs, respectively. After 30 days of oral administration of realgar in rats, no significant drug-related toxicity occurred in the rats. Dimethylarsenic acid (DMA) is the most abundant arsenic species. The DMA contents of the liver and kidney of the high-dose realgar group were approximately 40-fold and 50-fold higher than those in the corresponding tissues of the control group, respectively. The arsenic species (III) was mainly detected in the liver and its content was about 40-fold higher than that of the control group. MMA was mainly detected in rat kidney, and the MMA content of the realgar treatment group was more than 2000 times higher than that of the control group. Arsenic is rapidly absorbed and distributed over the liver, kidneys and brain, and the distribution and elimination of arsenic in the blood is slow. The realgar doses corresponded to human equivalent doses (HED) of 1.7, 6.4 and 27.2 mg/kg, respectively. Considering that humans are 10 times more sensitive than animals, the realgar dose is equivalent to 0.17, 0.64 and 2.7 mg/kg HED. It can be considered that if patients take no more than 2.7 mg/kg realgar for 2 weeks, there will be no adverse reactions.

Determination of arsenic species distribution in extra virgin olive oils from arsenic-endemic areas by dimensional chromatography and atomic spectroscopy

Arsenic species were determined in extra virgin olive oils (EVOOs) by two dimension chromatography and atomic spectroscopy: inductively coupled plasma mass spectrometry (ICP MS) and electrothermal atomic absorption spectrometry (ETAAS). A first approach determined total As concentration in EVOOs samples by microwave assisted digestion and ICP MS from 2.01 to 152μgkg−1. EVOOs with elevated As concentration were selected for protein extraction. In a first dimension, by size exclusion chromatography (SEC) coupled to ICP MS, a fraction of 66kDa was identified and collected for analysis. Free and proteic As were separated by molecular weight cut off filters. Proteic and free arsenic concentrations determined by ETAAS range from 0.56–4.44 and 0.67-3.89μgkg−1 of As respectively. Finally in a second dimension, by anion exchange chromatography (AEC) coupled to ICP MS, dimethylarsenate and arsenite were determined in proteic fraction of EVOOs in concentrations of 1.68–2.86 and 0.53–0.55μgkg−1 respectively.

Determination of Inorganic Arsenic in a Wide Range of Food Matrices using Hydride Generation - Atomic Absorption Spectrometry.

The European Food Safety Authority (EFSA) underlined in its Scientific Opinion on Arsenic in Food that in order to support a sound exposure assessment to inorganic arsenic through diet, information about distribution of arsenic species in various food types must be generated. A method, previously validated in a collaborative trial, has been applied to determine inorganic arsenic in a wide variety of food matrices, covering grains, mushrooms and food of marine origin (31 samples in total). The method is based on detection by flow injection-hydride generation-atomic absorption spectrometry of the iAs selectively extracted into chloroform after digestion of the proteins with concentrated HCl. The method is characterized by a limit of quantification of 10 µg/kg dry weight, which allowed quantification of inorganic arsenic in a large amount of food matrices. Information is provided about performance scores given to results obtained with this method and which were reported by different laboratories in several proficiency tests. The percentage of satisfactory results obtained with the discussed method is higher than that of the results obtained with other analytical approaches.