Vegetables collected in the cultivated Andean area of northern Chile: total and inorganic arsenic contents in raw vegetables.

High levels of arsenic are found in the soil and water of the Second Region in Chile as a result of natural causes. Total and inorganic arsenic contents were analyzed in the edible part of 16 agricultural products (roots, stems, leaves, inflorescences, and fruits) grown in this area. The total arsenic contents varied in the range 0.008-0.604 microg g(-1) of wet weight (ww), below the maximum level allowed by Chilean legislation (1 microg(-1) of ww). Inorganic arsenic contents (range = 0.008-0.613 microg(-1) of ww) represented between 28 and 114% of total arsenic. The concentrations of total and inorganic arsenic found in edible roots and leaves were higher than those found in fruit. The highest concentrations were found in a sample of spinach. High quantities of this vegetable would have to be consumed (250 g/day) to reach the Provisional Tolerable Weekly Intake for inorganic arsenic. The vegetable group may make a considerable contribution to the total intake of inorganic arsenic.     

Survey of total and inorganic arsenic content in blue mussels (Mytilus edulis L.) from Norwegian fiords: revelation of unusual high levels of inorganic arsenic

The present study reports the findings of unusual high levels of inorganic arsenic in samples of blue mussels (Mytilus edulis L.). A total of 175 pooled samples of blue mussels from various locations along the Norwegian coastline were analyzed for their content of total arsenic and inorganic arsenic. Total arsenic was determined using inductively coupled plasma mass spectrometry (ICPMS) following microwave-assisted acidic digestion of the samples. Inorganic arsenic was determined using an anion-exchange HPLC-ICPMS method following microwave-assisted alkaline solubilization of the samples. For the majority of the samples (78%) the concentration of total arsenic was below 3 mg kg(-1) wet weight (ww) and inorganic arsenic constituted <9% of the total arsenic (i.e., <0.25 mg kg(-1) ww). However, in some samples higher concentrations of total arsenic were found (up to 13.8 mg kg(-1) ww) and the inorganic arsenic content constituted up to 42% of the total arsenic (up to 5.8 mg kg(-1) ww). These are among the highest inorganic arsenic concentrations reported so far for marine animals. The findings of samples with concentrations of inorganic arsenic above 0.53 mg kg(-1) ww were restricted to sampling sites from two counties, Sogn and Fjordane and Hordaland, whereas samples from the rest of the country showed lower inorganic arsenic concentrations. Consumption of a meal containing 200 g of the blue mussels with the highest content of inorganic arsenic would for a 70 kg person lead to a 10% excess of the provisional tolerable weekly intake (PTWI) value for inorganic arsenic of 15 microg kg(-1) of body weight week(-1).     

Effects of raw materials,ingredients, and production lines on arsenic and copper concentrations in confectionery products

The Spaniard legislation sets up maximum levels for total arsenic (As) and copper (Cu) in confectionery products at 0.1 and 5.0 microg g(-)(1), respectively. Concentrations of these two trace elements were determined in four confectionery products: chewing gum, two licorice items, and soft candy. The effects of raw materials quality and production lines were studied. Arsenic and copper were quantified by atomic absorption spectrometry with hydride generation and slotted-tube atom trap tubes, respectively. Their levels were, in general, below the maximum limits establish by the Spaniard legislation; however, the As concentration in the licorice sticks was above this maximum limit (0.11 +/- 0.01 microg g(-)(1)). Statistics proved that quality of raw materials and the production lines both significantly affected As and Cu concentrations in the final products. The licorice extract and molasses were found as the common source for As and Cu pollution. The As concentration in the licorice extract was 0.503 +/- 0.01 microg g(-)(1), and could represent a serious hazard to human health if it is used in high proportions.     

Source of arsenic in licorice confectionery products

Spanish legislation sets a maximum level for total arsenic (As) in confectionery products at 0.1 microg g(-)(1). The U.S. Food and Drug Administration limitations for glycyrrhizic acid in hard and soft candies are 160 and 31 mg g(-)(1), respectively. Arsenic and glycyrrhizic acid were determined in 22 different confectionery products: 9 throat pearls, 4 hard candies, and 9 soft candies. Arsenic and glycyrrhizic acid were quantified by atomic absorption spectrometry with hydride generation and high-performance liquid chromatography, respectively. Levels of glycyrrhizic acid were always below the maximum limits established by the U.S. FDA; however, the As concentration in seven of nine throat pearls (0.55 +/- 0.15 microg g(-)(1)) were above the Spanish maximum limit. A clear empirical relationship between the arsenic and glycyrrhizic acid concentrations was observed (R (2) = 0.9357), implying that to avoid high levels of potentially toxic arsenic in licorice confections high-quality licorice extract should be used.     

Survey of inorganic arsenic in marine animals and marine certified reference materials by anion exchange high-performance liquid chromatography-inductively coupled plasma mass spectrometry

A method for the determination of inorganic arsenic in seafood samples using high-performance liquid chromatography-inductively coupled plasma mass spectrometry is described. The principle of the method relied on microwave-assisted alkaline dissolution of the sample, which at the same time oxidized arsenite [As(III)] to arsenate [As(V)], whereby inorganic arsenic could be determined as the single species As(V). Anion exchange chromatography using isocratic elution with aqueous ammonium carbonate as the mobile phase was used for the separation of As(V) from other coextracted organoarsenic compounds, including arsenobetaine. The stability of organoarsenic compounds during the sample pretreatment was investigated, and no degradation/conversion to inorganic arsenic was detected. The method was employed for the determination of inorganic arsenic in a variety of seafood samples including fish, crustaceans, bivalves, and marine mammals as well as a range of marine certified reference materials, and the results were compared to values published in the literature. For fish and marine mammals, the results were in most cases below the limit of detection. For other sample types, inorganic arsenic concentrations up to 0.060 mg kg(-)(1) were found. In all samples, the inorganic arsenic content constituted less than 1% of the total arsenic content.     

Organoarsenical species contents in fresh and processed seafood products

A study was carried out to determine organic species of arsenic in the main varieties of seafood consumed in the Basque country (Spain). The concentrations of arsenobetaine (AB), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), arsenocholine (AC), and tetramethylarsonium ion (TMA(+)) in 64 samples corresponding to different food items are presented. The study provides information about a possible distribution pattern of organoarsenical species in seafood products. AB was detected in all of the samples [0.3-104.1 microg g(-1) dry weight (dw)]. DMA was detected in all of the samples except squid and salted cod (0.027-1.757 microg g(-1) dw). MMA was detected only in certain fatty fish (0.004-0.028 microg g(-1) dw) and bivalves (0.031-0.047 microg g(-1) dw). AC was only present in some samples of lean fish (0.014-0.089 microg g(-1) dw), and TMA(+) was detected only in anchovy (0.039-0.169 microg g(-1) dw) and crustaceans (0.044-0.966 microg g(-1) dw).     

Arsenic in cooked seafood products: study on the effect of cooking on total and inorganic arsenic contents

Total and inorganic arsenic contents were analyzed in cooked seafood products consumed in Spain during the period July 1997-June 1998: hake, meagrim, small hake, anchovy, Atlantic horse mackerel, sardine, bivalves, crustaceans, squid, and salted cod. Various cooking treatments were used (grilling, roasting, baking, stewing, boiling, steaming, and microwaving). The results obtained were compared statistically with those found previously in the same products raw, and they showed that after cooking there was a significant increase in the concentration of total arsenic for salted cod and bivalves, and in the concentration of inorganic arsenic for bivalves and squid. The mean content of inorganic arsenic was significantly higher in bivalves than in any other type of seafood. For the Spanish population, the mean intake of total arsenic estimated on the basis of the results obtained in this study is 245 microg/day. The intake of inorganic arsenic (2.3 microg/day) represents 1.7% of the World Health Organization provisional tolerable weekly intake (PTWI), leaving an ample safety margin for this population, which has a very high consumption of seafood.     

Cooking decreases observed perfluorinated compound concentrations in fish

Dietary intake is a major route of exposure to perfluorinated compounds (PFCs). Although fish and seafood contribute significantly to total dietary exposure to these compounds, there is uncertainty with respect to the effect of cooking on PFC concentrations in these foods. Eighteen fish species purchased from markets in Toronto, Mississauga, and Ottawa, Canada were analyzed for perfluorooctanesulfonamide (PFOSAs)-based fluorochemicals and perfluorinated acids (PFAs) in raw and cooked (baked, boiled, fried) samples. Of 17 analytes, perfluorooctanesulfonic acid (PFOS) was detected most frequently; concentrations ranged from 0.21 to 1.68 ng/g ww in raw and cooked samples. PFOSAs were detected only in scallops at concentrations ranging from 0.20 ng/g ww to 0.76 ng/g ww. Total concentrations of PFAs in samples were 0.21 to 9.20 ng/g ww, respectively, consistent with previous studies. All cooking methods reduced PFA concentrations. Baking appeared to be the most effective cooking method; after baking samples for 15 min at 163 C (325 degrees F), PFAs were not detected in any of the samples. The margin of exposures (MOE) between the toxicological points of reference and the dietary intake of perfluorocarboxylates (PFCAs) and PFOS in fish and seafood muscle tissue were greater than 4 orders of magnitude. This indicates that reducing consumption of fish muscle tissue is not warranted on the basis of PFC exposure concerns at the reported levels of contamination, even for high fish consuming populations.     

Heavy metal, total arsenic, and inorganic arsenic contents of algae food products

The total arsenic, inorganic arsenic, lead, cadmium, and mercury contents of 18 algae food products currently on sale in Spain were determined. The suitability of the analytical methodologies for this type of matrix was confirmed by evaluating their analytical characteristics. The concentration ranges found for each contaminant, expressed in milligrams per kilogram of dry weight, were as follows: total arsenic, 2.3-141; inorganic arsenic, 0.15-88; lead, < 0.05-1.33; cadmium, 0.03-1.9; and mercury, 0.004-0.04. There is currently no legislation in Spain regarding contaminants in algae food products, but some of the samples analyzed revealed Cd and inorganic As levels higher than those permitted by legislation in other countries. Given the high concentrations of inorganic As found in Hizikia fusiforme, a daily consumption of 1.7 g of the product would reach the Provisional Tolerable Weekly Intake recommended by the WHO for an average body weight of 68 kg. A more comprehensive study of the contents and toxicological implications of the inorganic As present in the algae food products currently sold in Spain may be necessary, which might then be the basis for the introduction of specific sales restrictions.     

Daily intake of arsenic, cadmium, mercury, and lead by consumption of edible marine species

The daily intake of arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) through the consumption of 14 edible marine species by the general population of Catalonia, Spain, was estimated. Health risks derived from this intake were also assessed. In March-April 2005, samples of sardine, tuna, anchovy, mackerel, swordfish, salmon, hake, red mullet, sole, cuttlefish, squid, clam, mussel, and shrimp were randomly acquired in six cities of Catalonia. Concentrations of As, Cd, Hg, and Pb were determined by ICP-MS. On the basis of recent fish and seafood consumption data, the daily intake of these elements was calculated for eight age/sex groups of the population. The highest As concentrations were found in red mullet, 16.6 microg/g of fresh weight, whereas clam and mussel (0.14 and 0.13 microg/g of fresh weight, respectively) were the species with the highest Cd levels. In turn, swordfish (1.93 microg/g of fresh weight) and mussel and salmon (0.15 and 0.10 microg/g of fresh weight) showed the highest concentrations of Hg and Pb, respectively. The highest metal intake through fish and seafood consumption corresponded to As (217.7 microg/day), Cd (1.34 microg/day), and Pb (2.48 microg/day) for male seniors, whereas that of Hg was observed in male adults (9.89 microg/day). The daily intake through fish and seafood consumption of these elements was compared with the provisional tolerable weekly intakes (PTWI). The intakes of As, Cd, Pb, and total Hg by the population of Catalonia were below the respective PTWI values. However, the estimated intake of methylmercury for boys, 1.96 microg/kg/week, was over the PTWI.     

Arsenic speciation in farmed Hungarian freshwater fish

Arsenic speciation analysis was carried out on freshwater farmed fish collected from an area with elevated groundwater arsenic concentrations in Hungary as well as from outside of the area (control samples). The arsenic species were determined by high-performance liquid chromatography-inductively coupled plasma mass spectrometry on methanol extracts of the muscle tissue from the fish. Catfish (Claries gariepinus) were raised in geothermal water where the average total arsenic concentrations were 167 (contaminated sites) and 15.1 ng As mL(-1) (control); they were all fed an artificial diet containing 2880 microg As kg(-1) total arsenic, mostly present as arsenobetaine. In the catfish, the accumulated total arsenic (2510-4720 microg As kg(-1)) was found mostly in the form of arsenobetaine suggesting that uptake of arsenic was dominated by their diet. Carp (Cyprinus carpio) were cultured in surface lakes with no significant arsenic pollution and had total arsenic concentrations ranging from 62 to 363 microg As kg(-1). The arsenic species found in the carp extracts differed markedly from those in the catfish in that no arsenobetaine was detected. Most samples of carp from the investigated sites contained low concentrations of As(III) (arsenite), As(V) (arsenate), MA (methylarsonate), and DMA (dimethylarsinate), and no other compounds were detected. The four individuals from the control site, however, all contained appreciable levels of oxo-arsenosugar-glycerol and oxo-arsenosugar-phosphate. Indeed, the oxo-arsenosugar-phosphate dominated the speciation pattern for these carp contributing about 75% of the sum of species. The contrast between these two freshwater aquaculture species regarding total arsenic and arsenic species has relevant toxicological aspects in terms of food safety.     

Determination of chlorate and chlorite and mutagenicity of seafood treated with aqueous chlorine dioxide.

The use of chlorine dioxide (ClO(2)) as a potential substitute for aqueous chlorine to improve the quality of seafood products has not been approved by regulatory agencies due to health concerns related to the production of chlorite (ClO(2)(-)) and chlorate (ClO(3)(-)) as well as possible mutagenic/carcinogenic reaction products. Cubes of Atlantic salmon (Salmo salar) and red grouper (Epinephelus morio) were treated with 20 or 200 ppm aqueous chlorine or ClO(2) solutions for 5 min, and extracts of the treated fish cubes and test solutions were checked for mutagenicity using the Ames Salmonella/microsome assay. No mutagenic activity was detected in the treated fish samples or test solutions with ClO(2). Only the sample treated with 200 ppm chlorine showed weak mutagenic activity toward S. typhimurium TA 100. No chlorite residue was detected in sea scallops, mahi-mahi, or shrimp treated with ClO(2) at 3.9-34.9 ppm. However, low levels of chlorate residues were detected in some of the treated samples. In most cases, the increase in chlorate in treated seafood was time- and dose-related.     

Arsenic Concentrations in Water,Soil, Milk and Forage in Comarca Lagunera,Mexico

Arsenic levels were determined in seventy three samples of well water, and in fifty samples of soil, forage and cow's milk collected at the most important dairy farms of the Comarca Lagunera located in Coahuila and Durango, Mexico, region naturally rich in As. The total inorganic arsenic concentration in well water ranged from 7 to 740 μg L-1 and about ninety percent of the total arsenic was found as As(V). The agricultural soil texture of the sampled area was sandy clay loam type with total arsenic levels up to 30 μg g-1, however, the extractable arsenic was not higher than 12% of the total and it was higher in the 0–30 cm depth horizon. In alfalfa, the most important crop, the total aresenic ranged from 0.24 to 3.16 μg g-1, with 40% of it accumulated at the root level. Significant correlations (p=0.05) were obtained between arsenic (III), (V) and total inorganic arsenic in groundwater with arsenic in soil (0–30 cm depth), and with arsenic in alfalfa (leaves and roots). It was also found a good correlation between extractable arsenic in soil with As concentrations in alfalfa (roots). Arsenic concentrations found in milk ranged from <0.9 to 27.4 ng g-1. The cow's milk biotransfer factor for arsenic was up to 6 × 10-4, applying a pharmacokinetic approach. It was associated with the exposure not only to food but also to water arsenic.     

SPME-GC-pyrolysis-AFS determination of methylmercury in marine fish products by alkaline sample preparation and aqueous phase phenylation derivatization

Characterization of a cost-efficient analytical method based on alkaline sample digestion with KOH and NaOH, followed by aqueous phase phenylation derivatization with NaBPh4 and solid phase microextraction (SPME) for the determination of methylmercury in typical fish-containing food samples commercially available in Hungary, is reported. The sample preparation procedure along with the applied SPME-GC-pyrolysis-AFS system was validated by measuring certified reference materials (CRM) BCR-464, TORT-2, and a candidate CRM BCR 710. To carry out an estimation of average Hungarian methylmercury exposures via marine fish and/or fish-containing food consumption, 16 commercially available products and 3 pooled representative seafood samples of-according to a previous European survey--the three most consumed fish species in Hungary, herring, sardines, and hake, were analyzed. Methylmercury concentrations of the analyzed samples were in the range 0.016-0.137 microg of MeHg g(-1) dry weight as Hg.     

Lead contamination in Portuguese red wines from the Douro region: from the vineyard to the final product

To quantify lead contamination in wines and to try to identify major lead sources, two winemaking processes were followed during one annual cycle of wine production. Two vineyards from the Douro Portuguese region and two types of wine, one red table wine, which has been produced in a very modern winery, and one red fortified wine (similar to Port), which has been produced by a traditional vinification process, were selected for this study. Aerosols from the vineyards atmosphere, vineyard soil, vine leaves, grapes, and samples from the intermediary and final wine product were collected. Suitable pretreatments, namely, high-pressure microwave assisted digestion (soil, leaves, and grapes) and UV-irradiation (grape juices and samples from the different steps of the vinification processes), were used. The samples were analyzed in terms of lead total concentration and respective isotope ratios by using inductively coupled plasma mass spectrometry and atomic absorption spectrophotometry with electrothermal atomization. It was observed that the major sources of lead were in the vinification system, the more traditional one introducing more lead than the modern one. For the fortified wine, the lead concentration increased from 4.7 microg L(-1), in the grape juice, to 17.2 microg L(-1), in the final product, while for the table wine the increase was from 4.1 to 13.1 microg L(-)(1). Therefore, only about 1/4 (fortified wine) and 1/3 (table wine) of the lead total content of the final products came from soil and atmospheric deposition. Therefore, it is expected that marked reductions of the lead content in the wines would occur if the sources of lead were removed from the tubes and containers used in the vinification system, particularly by using welding alloys and small fittings free of lead. The lead levels in the vine leaves (global mean of 0.43 microg g(dry leave)(-1)) and grapes (global mean of 35 ng g(dry grape)(-1)) were similar in both vineyards.     

Presence of organoarsenicals used in cotton production in agricultural water and soil of the southern United States

Arsenicals have been used extensively in agriculture in the United States as insecticides and herbicides. Mono- and disodium methylarsonate and dimethylarsinic acid are organoarsenicals used to control weeds in cotton fields and as defoliation agents applied prior to cotton harvesting. Because the toxicity of most organoarsenicals is less than that of inorganic arsenic species, the introduction of these compounds into the environment might seem benign. However, biotic and abiotic degradation reactions can produce more problematic inorganic forms of arsenic, such as arsenite [As(III)] and arsenate [As(V)]. This study investigates the occurrences of these compounds in samples of soil and associated surface and groundwaters. Preliminary results show that surface water samples from cotton-producing areas have elevated concentrations of methylarsenic species (>10 microg of As/L) compared to background areas (<1 microg of As/L). Species transformations also occur between surface waters and adjacent soils and groundwaters, which also contain elevated arsenic. The data indicate that point sources of arsenic related to agriculture might be responsible for increased arsenic concentrations in local irrigation wells, although the elevated concentrations did not exceed the new (2002) arsenic maximum contaminant level of 10 microg/L in any of the wells sampled thus far.     

Bioaccumulation of PCDD/Fs and Co-PCBs in Lower-Trophic-Level Organisms in Sendai Bay,Japan

In Sendai Bay, Japan, the total PCDD, PCDF, and Co-PCB (dioxins) concentrations in phytoplankton were equivalent to 150, 12, and 51 pg/g wet weight (ww), respectively. The average concentrations in seaweed were 3, 0.095, and 2.1 pg/g ww, respectively. The total concentrations in phytoplankton were much higher than those in seaweed, even though both groups are algae. The concentrations in zooplankton were 11, 1.1, and 110 pg/g ww, respectively. The total PCDD/F concentrations in zooplankton (primary consumers and lower-trophic-level invertebrates) were lower than in phytoplankton (primary producers), but the total Co-PCB concentration in zooplankton was higher than that in phytoplankton. The concentrations in mysids (secondary consumers and higher-trophic-level invertebrates) were 190, 18, and 290 pg/g ww, respectively. The average concentrations in shrimp (secondary consumers and higher-trophic-level invertebrates) were 120, 17, and 410 pg/g ww, respectively. The concentrations in higher-tropic-level invertebrates were higher than those in lower-trophic-level invertebrates. The average concentrations in sand lance were 4.5, 1.7, and 550 pg/g ww, respectively. The total PCDD concentration in sand lance was lower than that in zooplankton (prey of sand lance), but the total Co-PCB concentration in sand lance was higher than that in zooplankton. The bioaccumulation of PCDD congeners in sand lance differed from that of Co-PCB congeners. The bioaccumulation of PCDD/Fs from lower- to higher-trophic-level invertebrates through the food web differed from that from lower-trophic-level invertebrates to fish.     

Trace metals concentrations in marine organisms from the coastal areas of Bahrain,Arabian Gulf

A total of 162 fish and shellfish samples representing important species have been collected from different coastal areas of Bahrain in the Arabian Gulf, and analyzed for lead, cadmium, mercury, and arsenic using electrothermal atomic absorption spectrophotometric method. The dverall mean levels for Pb, Cd, Hg and As in fish samples were 0.132, 0.032, 0.084 and 1.7 µg g^?1 wet weight, respectively, whereas for shellfish they were 0.149, 0.045, 0.042 and 3.61 µg g^?1 wet weight. These values indicate higher levels of metals in shellfish when compared with fish, except for mercury, and reveal that generally the levels of metals in these organisms are lower than existing guidelines, except for arsenic. The provisional tolerable weekly intake of Pb, Cd, Hg and As through fish was estimated to be 0.7, 0.17, 0.45 and 9 µg kg^?1 bodyweight per week, respectively. Our results did not reveal a clear pattern regarding variations of metals concentration between areas and species.     

11种四省市售淡水鱼肌肉中重金属含量特征与污染状况评价

为明确我国湖北、广东、河南和黑龙江四省市售淡水鱼肌肉中重金属含量现状,本研究于2021年9月至10月在四省11个市县(区)采集11种淡水鱼,共计133份样本,采用微波消解-电感耦合等离子体质谱(ICP-MS)法检测淡水鱼肌肉中铬(Cr)、铜(Cu)、砷(As)、镉(Cd)、汞(Hg)和铅(Pb)6种元素含量,依据《GB 2762-2017食品安全国家标准食品中污染物限量》对重金属污染状况进行评价。结果表明,所测样品中Cr、Cu、Cd、Hg和Pb 5种重金属元素均未超标;淡水鲈鱼和乌鳢中As含量均大于0.1 mg·kg^-1,其含量分别为0.182～0.738 mg·kg^-1和0.180～0.628 mg·kg^-1,且较其他淡水鱼类具有蓄积显著性差异(P<0.05)。对总砷含量高于0.1 mg·kg^-1的样品,进一步采用液相色谱-原子荧光光谱(LC-AFS)法对其无机砷含量进行检测,结果均为未检出,表明其无机砷含量在总砷含量中占比非常低。采用单因子污染指数法和内梅罗综合污染指数法评价所检淡水鱼中6...     

Speciation of arsenic in different types of nuts by ion chromatography-inductively coupled plasma mass spectrometry

In this work the quantitative determination and analytical speciation of arsenic were undertaken in different types of nuts, randomly purchased from local markets. The hardness of the whole nuts and high lipid content made the preparation of this material difficult for analysis. The lack of sample homogeneity caused irreproducible results. To improve the precision of analysis, arsenic was determined separately in nut oil and in the defatted sample. The lipids were extracted from the ground sample with the two portions of a mixture of chloroform and methanol (2:1). The defatted material was dried and ground again, yielding a fine powder. The nut oil was obtained by combining the two organic extracts and by evaporating the solvents. The two nut fractions were microwave digested, and total arsenic was determined by inductively coupled plasma mass spectrometry (ICP-MS). The results obtained for oils from different types of nuts showed element concentration in the range 2.9-16.9 ng g(-)(1). Lower levels of arsenic were found in defatted material (<0.1 ng g(-)(1) with the exception of Brazil nuts purchased with and without shells, 3.0 and 2.8 ng g(-)(1) respectively). For speciation analysis of arsenic in nut oils, elemental species were extracted from 2 g of oil with 12 mL of chloroform/methanol (2:1) and 8 mL of deionized water. The aqueous layer, containing polar arsenic species, was evaporated and the residue dissolved and analyzed by ion chromatography-ICP-MS. The anion exchange chromatography enabled separation of As(III), dimethylarsinic acid (DMAs(V)), monomethylarsonic acid (MMAs(V)), and As(V) within 8 min. Several types of nuts were analyzed, including walnuts, Brazil nuts, almonds, cashews, pine nuts, peanuts, pistachio nuts, and sunflower seeds. The recovery for the speciation procedure was in the range 72.7-90.6%. The primary species found in the oil extracts were As(III) and As(V). The arsenic concentration levels in these two species were 0.7-12.7 and 0.5-4.3 ng g(-)(1), respectively. The contribution of As in DMAs(V) ranged from 0.1 +/- 0.1 ng g(-)(1) in walnuts to 1.3 +/- 0.3 ng g(-)(1) in pine nuts. MMAs(V) was not detected in almonds, peanuts, pine nuts, sunflower seeds, or walnuts, and the highest concentration was found in pistachio nuts (0.5 +/- 0.2 ng g(-)(1)).