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Kazuo Shiomi - One of the best experts on this subject based on the ideXlab platform.
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Water-Soluble and Lipid-Soluble Arsenic Compounds in Japanese Flying Squid Todarodes pacificus
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Tran Dang Ninh, Yuji Nagashima, Kazuo ShiomiAbstract:Water-soluble and lipid-soluble Arsenic Compounds in Japanese flying squid Todarodes pacificus were analyzed. Regardless of the tissues, the major water-soluble Arsenic compound was identified as arsenobetaine by LC/ESI-MS analysis, as reported for a number of marine animals. Lipid-soluble Arsenic Compounds were found at relatively high levels in liver and testis. LC/ESI-MS analysis of water-soluble Arsenic Compounds released from liver phospholipids by either chemical hydrolysis or phospholipase D hydrolysis demonstrated that the major arsenolipids are dimethylarsinic acid (DMA)-containing glycerophospholipid (phosphatidyldimethylarsinic acid) and DMA-containing sphingomyelin where the choline moiety of sphingomyelin is replaced by DMA. This is the first work to report the presence of DMA-containing phospholipids in marine invertebrates. Keywords: Arsenic; arsenolipids; LC/ESI-MS; lipid-soluble Arsenic Compounds; squid; Todarodes pacificus; water-soluble Arsenic Compounds
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Water-Soluble and Lipid-Soluble Arsenic Compounds in Japanese Flying Squid Todarodes pacificus
Journal of agricultural and food chemistry, 2007Co-Authors: Tran Dang Ninh, Yuji Nagashima, Kazuo ShiomiAbstract:Water-soluble and lipid-soluble Arsenic Compounds in Japanese flying squid Todarodes pacificus were analyzed. Regardless of the tissues, the major water-soluble Arsenic compound was identified as arsenobetaine by LC/ESI-MS analysis, as reported for a number of marine animals. Lipid-soluble Arsenic Compounds were found at relatively high levels in liver and testis. LC/ESI-MS analysis of water-soluble Arsenic Compounds released from liver phospholipids by either chemical hydrolysis or phospholipase D hydrolysis demonstrated that the major arsenolipids are dimethylarsinic acid (DMA)-containing glycerophospholipid (phosphatidyldimethylarsinic acid) and DMA-containing sphingomyelin where the choline moiety of sphingomyelin is replaced by DMA. This is the first work to report the presence of DMA-containing phospholipids in marine invertebrates.
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Quantification of seven Arsenic Compounds in seafood products by liquid chromatography/electrospray ionization-single quadrupole mass spectrometry (LC/ESI-MS).
Food additives and contaminants, 2006Co-Authors: Tran Dang Ninh, Yuji Nagashima, Kazuo ShiomiAbstract:A liquid chromatography/electrospray ionization-single quadrupole mass spectrometry (LC/ESI-MS) method was developed to quantify seven Arsenic Compounds: arsenate (As(V)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AB), trimethylarsine oxide (TMAO), arsenocholine (AC) and tetramethylarsonium ion (TEMA), widely found in seafood. The Arsenicals separated by anion- or cation-exchange LC were all readily identified under the optimized ESI-MS conditions. Linear calibration curves constructed by plotting the peak area counts of molecular ions against the Arsenic concentrations were obtained for all seven Arsenic Compounds. The limits of quantification (S/N = 10) were 800, 600, 50, 10, 5, 5 and 5 ng ml−1 for As(V), MMA, DMA, AB, TMAO, AC and TEMA, respectively. The LC/ESI-MS method was found to be useful to quantify Arsenic Compounds in seafood by model experiments using the mid-gut gland and muscle of a shellfish (Buccinid whelks). Spiking experiments verified the accuracy of the m...
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Purification and comparison of water-soluble Arsenic Compounds in a flatfish Limanda herzensteini, sea squirt Halocynthia roretzi, and sea cucumber Stichopus japonicus
Comparative Biochemistry and Physiology Part C: Comparative Pharmacology, 2004Co-Authors: Kazuo Shiomi, Akira Shinagawa, Hideaki Yamanaka, Masanori Azuma, Takeaki KikuchiAbstract:Abstract 1. The water-soluble Arsenic Compounds were purified frorn a flatfish Limanda herzensteini , sea squirt Halocynthia roretzi , and sea cucumber Stichopus japonicus . 2. In the cases of flatfish and sea cucumber the major Arsenic compound was judged to be arsenobetaine. 3. The sea squirt contained one acidic and two basic Arsenic Compounds differing from arsenobetaine.
Tran Dang Ninh - One of the best experts on this subject based on the ideXlab platform.
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Water-Soluble and Lipid-Soluble Arsenic Compounds in Japanese Flying Squid Todarodes pacificus
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Tran Dang Ninh, Yuji Nagashima, Kazuo ShiomiAbstract:Water-soluble and lipid-soluble Arsenic Compounds in Japanese flying squid Todarodes pacificus were analyzed. Regardless of the tissues, the major water-soluble Arsenic compound was identified as arsenobetaine by LC/ESI-MS analysis, as reported for a number of marine animals. Lipid-soluble Arsenic Compounds were found at relatively high levels in liver and testis. LC/ESI-MS analysis of water-soluble Arsenic Compounds released from liver phospholipids by either chemical hydrolysis or phospholipase D hydrolysis demonstrated that the major arsenolipids are dimethylarsinic acid (DMA)-containing glycerophospholipid (phosphatidyldimethylarsinic acid) and DMA-containing sphingomyelin where the choline moiety of sphingomyelin is replaced by DMA. This is the first work to report the presence of DMA-containing phospholipids in marine invertebrates. Keywords: Arsenic; arsenolipids; LC/ESI-MS; lipid-soluble Arsenic Compounds; squid; Todarodes pacificus; water-soluble Arsenic Compounds
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Water-Soluble and Lipid-Soluble Arsenic Compounds in Japanese Flying Squid Todarodes pacificus
Journal of agricultural and food chemistry, 2007Co-Authors: Tran Dang Ninh, Yuji Nagashima, Kazuo ShiomiAbstract:Water-soluble and lipid-soluble Arsenic Compounds in Japanese flying squid Todarodes pacificus were analyzed. Regardless of the tissues, the major water-soluble Arsenic compound was identified as arsenobetaine by LC/ESI-MS analysis, as reported for a number of marine animals. Lipid-soluble Arsenic Compounds were found at relatively high levels in liver and testis. LC/ESI-MS analysis of water-soluble Arsenic Compounds released from liver phospholipids by either chemical hydrolysis or phospholipase D hydrolysis demonstrated that the major arsenolipids are dimethylarsinic acid (DMA)-containing glycerophospholipid (phosphatidyldimethylarsinic acid) and DMA-containing sphingomyelin where the choline moiety of sphingomyelin is replaced by DMA. This is the first work to report the presence of DMA-containing phospholipids in marine invertebrates.
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Quantification of seven Arsenic Compounds in seafood products by liquid chromatography/electrospray ionization-single quadrupole mass spectrometry (LC/ESI-MS).
Food additives and contaminants, 2006Co-Authors: Tran Dang Ninh, Yuji Nagashima, Kazuo ShiomiAbstract:A liquid chromatography/electrospray ionization-single quadrupole mass spectrometry (LC/ESI-MS) method was developed to quantify seven Arsenic Compounds: arsenate (As(V)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AB), trimethylarsine oxide (TMAO), arsenocholine (AC) and tetramethylarsonium ion (TEMA), widely found in seafood. The Arsenicals separated by anion- or cation-exchange LC were all readily identified under the optimized ESI-MS conditions. Linear calibration curves constructed by plotting the peak area counts of molecular ions against the Arsenic concentrations were obtained for all seven Arsenic Compounds. The limits of quantification (S/N = 10) were 800, 600, 50, 10, 5, 5 and 5 ng ml−1 for As(V), MMA, DMA, AB, TMAO, AC and TEMA, respectively. The LC/ESI-MS method was found to be useful to quantify Arsenic Compounds in seafood by model experiments using the mid-gut gland and muscle of a shellfish (Buccinid whelks). Spiking experiments verified the accuracy of the m...
Walter Goessler - One of the best experts on this subject based on the ideXlab platform.
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Arsenic Compounds in tropical marine ecosystems: similarities between mangrove forest and coral reef
Environmental Chemistry, 2009Co-Authors: Somkiat Khokiattiwong, Walter Goessler, Narumol Kornkanitnan, Sabine Kokarnig, Kevin A. FrancesconiAbstract:Environmental context. Despite the widespread occurrence of arsenobetaine in marine animals the origin of this Arsenic compound remains unknown. A current hypothesis is that arsenobetaine is formed from more complex Arsenic Compounds found in marine algae. To test this hypothesis, we examined the Arsenic Compounds in a mangrove ecosystem where algae play a limited role in primary productivity. Abstract. Marine algae are known to bioaccumulate Arsenic and transform it into arsenosugars, which are thought to be precursors of the major Arsenic compound, arsenobetaine, found in marine animals. Marine ecosystems based on mangrove forests have high nutrient input from mangrove leaves, and thus provide a unique opportunity to study the cycling of Arsenic in a marine system where algae are not the dominant food source. Two mangrove forests in Phuket, Thailand were selected as sampling sites for this study. For comparison, samples were also collected from two coral reef sites at and near Phuket. The samples collected included mangrove leaves, corals, algae, molluscs, fish and crustaceans. Arsenic contents in the samples and in aqueous extracts of the samples were determined by hydride generation atomic absorption spectrometry following a dry-ashing mineralisation procedure, and Arsenic species were determined in the aqueous extracts by HPLC-MS (mainly ICPMS). Mangrove leaves contained only low concentrations of total Arsenic (0.10–0.73 mg kg–1 dry mass) and the aqueous extracts thereof contained inorganic Arsenic species, methylarsonate and dimethylarsinate, but arsenosugars were not detected. The total mean Arsenic contents (3.2–86 mg kg–1 dry mass) of the animals from the mangrove ecosystem, however, were typical of those found in animal samples from other marine ecosystems. Similarly the Arsenic Compounds present were typical of those in animals from other marine ecosystems comprising mainly arsenobetaine with smaller quantities of other common Arsenicals including arsenosugars, arsenocholine, tetramethylarsonium ion, trimethylarsine oxide and dimethylarsinate. A trimethylated arsenosugar, which is not commonly reported in marine organisms, was a significant Arsenical (6–8% of total As) in some gastropod species from the mangrove ecosystem. The coral samples contained mainly arsenosugars and arsenobetaine, and the other animals collected from the coral ecosystem contained essentially the same pattern of Arsenicals found for the mangrove animals. The data suggest that food chains based on algae are not necessary for animals to accumulate large concentrations of arsenobetaine.
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Comparison of mild extraction procedures for determination of plant-available Arsenic Compounds in soil
Analytical and Bioanalytical Chemistry, 2005Co-Authors: Jiřina Szakova, Walter Goessler, Pavel Tlustos, Daniela Pavlíková, Jiří Balík, Claudia SchlagenhaufenAbstract:In this work three mild extraction agents for determination of plant-available fractions of elements in soil were evaluated for Arsenic speciation in soil samples. Pepper (Capsicum annum, L.) var. California Wonder was cultivated in pots, and aqueous solutions of arsenite, arsenate, methylarsonic acid, and dimethylarsinic acid, at a concentration of 15 mg As kg−1 soil, were added at the beginning of the experiment. Control pots (untreated) were also included. Deionized water, 0.01 mol L−1 CaCl2, and 0.05 mol L−1 (NH4)2SO4 were used to extract the plant-available fraction of the Arsenic Compounds in soil samples collected during the vegetation period of the plants. Whereas in control samples the extractable Arsenic fraction did not exceed 1% of total Arsenic content, soil amendment by Arsenic Compounds resulted in extraction of larger amounts, which varied between 1.4 and 8.1% of total Arsenic content, depending on soil treatment and on the extracting agent applied. Among Arsenic Compounds determined by HPLC–ICPMS arsenate was predominant, followed by small amounts of arsenite, methylarsonic acid, and dimethylarsinic acid, depending on the individual soil treatment. In all the experiments in which methylarsonic acid was added to the soil methylarsonous acid was detected in the extracts, suggesting that the soil bacteria are capable of reducing methylarsonic acid before a further methylation occurs. No significant differences were observed between analytical data obtained by using different extraction procedures.
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Comparison of mild extraction procedures for determination of Arsenic Compounds in different parts of pepper plants (Capsicum annum, L.)
Applied Organometallic Chemistry, 2005Co-Authors: Jiřina Szakova, Walter Goessler, Pavel Tlustos, Daniela Pavlíková, Jiří BalíkAbstract:Eight extraction agents (water, methanol–water mixtures in various ratios, methanol, a 20 mmol l−1 ammonium phosphate buffer, and a methanol–phosphate buffer) were tested for the extraction of Arsenic Compounds from fruits, stems + leaves, and roots of pepper plants grown on soil containing 17.2 mg kg−1 of total Arsenic. The Arsenic Compounds in the extracts were determined using high-performance liquid chromatography–hydride generation inductively coupled plasma mass spectrometry. Whereas pure water was the most effective extraction agent for fruits (87 ± 3.3% extraction yield) and roots (96 ± 0.6% extraction yield), the 20 mM ammonium phosphate buffer at pH 6 extracted about 50% of the Arsenic from stems + leaves. Decreasing extractability of the Arsenic Compounds was observed with increasing methanol concentrations for all parts of the pepper plant. In pepper fruits, Arsenic(III), Arsenic(V), and dimethylarsinic acid (DMA) were present (25%, 37%, and 39% respectively of the extractable Arsenic). Arsenic(V) was the major compound in stems + leaves and roots (63% and 53% respectively), followed by Arsenic(III) representing 33% and 42% respectively, and small amounts (not exceeding 5%) of DMA and methylarsonic acid were also detected. Hence, for a quantitative extraction of Arsenic Compounds from different plant tissues the extractant has to be optimized individually. Copyright © 2005 John Wiley & Sons, Ltd.
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Arsenic Compounds in leaves and roots of radish grown in soil treated by arsenite, arsenate and dimethylarsinic acid†
Applied Organometallic Chemistry, 2002Co-Authors: Pavel Tlustos, Walter Goessler, Jiřina Szakova, Josef BalíkAbstract:The effect of arsenite [Arsenic(III)], arsenate [Arsenic(V)] and dimethylarsinic acid (DMA) on the growth of radish and the concentration of Arsenic Compounds in the roots and leaves of radish were investigated. Radish was grown in pots on Luvisols individually amended with Arsenic concentrations of 20 mg kg -1 in the form of Arsenic(III), Arsenic(V), and DMA. In untreated soil, arsenate was the dominant Arsenic compound; arsenite and DMA were also present. Arsenic(III) added to the soil was oxidized to Arsenic(V), so that no differences between Arsenic(III) and Arsenic(V) soil treatments were observed. On DMA treatment, this compound remained in soil in high concentration in soluble and plant-available states, and the sum of Arsenic(III), Arsenic(V) and methylarsonic acid (MA) reached only 30% of water-extractable Arsenic content. A low portion of soil Arsenic added as DMA was immobilized, via adsorption, compared with inorganic Compounds. Arsenic(III) was the dominant compound in radish roots planted in the untreated soil, whereas in leaves most of the Arsenic present was Arsenic(V). DMA was also detected in both plant tissues. A similar distribution of Arsenic Compounds was also found on Arsenic(III) and Arsenic(V) treatments. On DMA treatment, this compound showed high stability and the DMA concentration exceeded the sum of the remaining Arsenic Compounds [Arsenic(III), Arsenic(V) and MA] in both roots and leaves of radish.
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Determination of Arsenic Compounds in Earthworms
Environmental Science & Technology, 1998Co-Authors: Anita Geiszinger, Walter Goessler, Kevin A. Francesconi, Doris Kuehnelt, Walter KosmusAbstract:Earthworms and soil collected from six sites in Styria, Austria, were investigated for total Arsenic concentrations by ICP-MS and for Arsenic Compounds by HPLC−ICP-MS. Total Arsenic concentrations ranged from 3.2 to 17.9 mg/kg dry weight in the worms and from 5.0 to 79.7 mg/kg dry weight in the soil samples. There was no strict correlation between the total Arsenic concentrations in the worms and soil. Arsenic Compounds were extracted from soil and a freeze-dried earthworm sample with a methanol/water mixture (9:1, v/v). The extracts were evaporated to dryness, redissolved in water, and chromatographed on an anion- and a cation-exchange column. Arsenic Compounds were identified by comparison of the retention times with known standards. Only traces of Arsenic acid could be extracted from the soil with the methanol/water (9:1, v/v) mixture. The major Arsenic Compounds detected in the extracts of the earthworms were arsenous acid and Arsenic acid. Arsenobetaine was present as a minor constituent, and traces ...
Kurt J. Irgolic - One of the best experts on this subject based on the ideXlab platform.
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Arsenic Compounds in a marine food chain
Fresenius Journal of Analytical Chemistry, 1997Co-Authors: Walter Goessler, Kurt J. Irgolic, Doris Kuehnelt, William A. Maher, Claudia SchlagenhaufenAbstract:A three-organism food chain within a rock pool at Rosedale, NSW, Australia, was investigated with respect to Arsenic Compounds by high performance liquid chromatography – hydraulic high pressure nebulization – inductively coupled plasma mass spectrometry (HPLC-HHPN-ICP-MS). Total Arsenic concentration was determined in the seaweed Hormosira banksii (27.2 μg/g dry mass), in the gastropod Austrocochlea constricta (74.4 μg/g dry mass), which consumes the seaweed, and in the gastropod Morula marginalba (233 μg/g dry mass), which eats Austrocochlea constricta. The major Arsenic Compounds in the seaweed were (2′R)-dimethyl[1-O-(2′,3′-dihydroxypropyl)-5-deoxy-β-d-ribofuranos-5-yl]arsine oxide and an unidentified compound. The herbivorous gastropod Austrocochlea constricta transformed most of the Arsenic taken up with the seaweed to arsenobetaine. Traces of arsenite, arsenate, dimethylarsinic acid, arsenocholine, the tetramethylarsonium cation, and several unknown Arsenic Compounds were detected. Arsenobetaine accounted for 95% of the Arsenic in the carnivorous gastropod Morula marginalba. In Morula marginalba the concentration of arsenocholine was higher, and the concentrations of the minor Arsenic Compounds lower than in the herbivorous gastropod Austrocochlea constricta.
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Arsenic Compounds in Higher Fungi
Applied Organometallic Chemistry, 1997Co-Authors: Zdenka Šlejkovec, Anthony Robert Byrne, Walter Goessler, Tjakko Stijve, Kurt J. IrgolicAbstract:In 50 mushroom species (56 samples) from Slovenia, Switzerland, Brazil, Sweden, The Netherlands and USA, total Arsenic was determined by radiochemical neutron activation analysis (RNAA). Arsenic concentrations ranged from 0.1 to 30 μg g−1 (dry mass). Arsenic Compounds were determined in methanol extracts from the mushrooms by HPLC–ICP–MS. The aim of the study was not only to quantify Arsenic Compounds in mushrooms but also to uncover trends relating the methylating ability of a mushroom to its taxonomic or evolutionary status. The main Arsenic compound found in many mushrooms (various puffballs, Agaricales and Aphyllophorales) was arsenobetaine. Arsenate [As(V)] was the main Arsenic species in Laccaria fraterna and Entoloma rhodopolium and arsenite [As(III)] in Tricholoma sulphureum. A mixture of arsenite and arsenate was present in Amanita caesarea. Dimethylarsinic acid (DMA) and methylarsonic acid were present in many mushrooms, but generally as minor components. In Laccaria laccata, Leucocoprinus badhamii and Volvariella volvacea, DMA was the major metabolite. Arsenocholine (AC) and the tetramethylarsonium ion were present in a few species, generally at low concentrations, except for Sparassis crispa, in which AC was the main compound. Tri- methylarsine oxide was not found in any of the mushrooms. In some species small amounts of unknown Compounds were also present. The possible taxonomic significance of the metabolite patterns and the predominance of arsenobetaine in more advanced fungal types are discussed. © 1997 John Wiley & Sons, Ltd.
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Determination of Arsenic Compounds in human urine by HPLC-ICP-MS
Arsenic, 1997Co-Authors: Walter Goessler, Doris Kuehnelt, Kurt J. IrgolicAbstract:Humans are unavoidably exposed to the Arsenic Compounds present in drinking water, in food items, and sometimes in respirable particles. Normally, the daily dose of total Arsenic in the range of 10 to 50μg appears to be no threat to human health. However, in geographically limited regions Taiwan, India, Argentina, Chile) the concentrations of Arsenic in drinking water and perhaps in food are elevated leading to excessive intake of Arsenic and to Arsenic-related health problems. Humans are exposed to inorganic Arsenic Compounds (arsenite, arsenate) and organic Arsenic Compounds methylarsonic acid, dimethylarsinic acid, arsenobetaine, Arsenic-containing riboses, arsenolipids). These Compounds are processed in the body quite differently. Arsenate might be reduced to arsenite, arsenite might be methylated to methylarsonic acid, and methylarsonic acid reduced and then methylated to dimethylarsinic acid. All of these Compounds can be eliminated in the urine. Non-eliminated, trivalent Compounds, such as arsenite and methylated Compounds with trivalent Arsenic, can interfere with biochemically important processes through reactions with thiol groups present, for instance, in enzymes. Information about the nature and the concentration of Arsenic Compounds excreted in the urine can be used to deduce exposure, gain insight into the chemical transformations of the Arsenic Compounds in the body, and estimate the methylating capacity of exposed persons.
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Arsenic Compounds in terrestrial organisms II : Arsenocholine in the mushroom Amanita muscaria
Applied Organometallic Chemistry, 1997Co-Authors: Doris Kuehnelt, Walter Goessler, Kurt J. IrgolicAbstract:Arsenic Compounds were identified and quantified in the mushroom Amanita muscaria, collected close to a facility that had roasted Arsenic ores. The powdered dried mushrooms were extracted with methanol/water (9:1), the extracts were concentrated and the concentrates were dissolved in water. The resulting solutions were chromatographed on anion-exchange, cation-exchange and reversed- phase columns. Arsenic was detected on-line with an ICP–MS detector equipped with a hydraulic high-pressure nebulizer. Arsenite, arsenate, dimethylarsinic acid and the tetramethylarsonium cation were minor Arsenic Compounds (∼2% each of the total 22 mg kg−1 dry mass), and arsenobetaine, arsenocholine (∼15% each) and several unidentified Arsenic Compounds (∼60%) were the major Arsenic Compounds in Amanita muscaria. The presence of arsenocholine (detected for the first time in a terrestrial sample) was ascertained by matching retention times in the anion-exchange, cation- exchange and reversed-phase chromatograms with the retention time of synthetic arsenocholine bromide and chromatographing extracts spiked with arsenocholine bromide. © 1997 John Wiley & Sons, Ltd.
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Can Humans Metabolize Arsenic Compounds to Arsenobetaine
Applied Organometallic Chemistry, 1997Co-Authors: Walter Goessler, Doris Kuehnelt, Claudia Schlagenhaufen, Herbert Greschonig, Kurt J. IrgolicAbstract:Arsenic Compounds were determined in 21 urine samples collected from a male volunteer. The volunteer was exposed to Arsenic through either consumption of codfish or inhalation of small amounts of (CH3)3As present in the laboratory air. The Arsenic Compounds in the urine were separated and quantified with an HPLC–ICP–MS system equipped with a hydraulic high-pressure nebulizer. This method has a determination limit of 0.5 μg As dm−3 urine. To eliminate the influence of the density of the urine, creatinine was determined and all concentrations of Arsenic Compounds were expressed in μg As g−1 creatinine. The concentrations of arsenite, arsenate and methylarsonic acid in the urine were not influenced by the consumption of seafood. Exposure to trimethylarsine doubled the concentration of arsenate and increased the concentration of methylarsonic acid drastically (0.5 to 5 μg As g−1 creatinine). The concentration of dimethylarsinic acid was elevated after the first consumption of fish (2.8 to 4.3 μg As g−1 creatinine), after the second consumption of fish (4.9 to 26.5 μg As g−1 creatinine) and after exposure to trimethyl- arsine (2.9 to 9.6 μg As g−1 creatinine). As expected, the concentration of arsenobetaine in the urine increased 30- to 50-fold after the first consumption of codfish. Surprisingly, the concentration of arsenobetaine also increased after exposure to trimethylarsine, from a background of approximately 1 μg As g−1 creatinine up to 33.1 μg As g−1 creatinine. Arsenobetaine was detected in all the urine samples investigated. The arsenobetaine in the urine not ascribable to consumed seafood could come from food items of terrestrial origin that—unknown to us—contain arsenobetaine. The possibility that the human body is capable of metabolizing trimethyl- arsine to arsenobetaine must be considered. © 1997 by John Wiley & Sons, Ltd.
Kevin A. Francesconi - One of the best experts on this subject based on the ideXlab platform.
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Arsenic Compounds in tropical marine ecosystems: similarities between mangrove forest and coral reef
Environmental Chemistry, 2009Co-Authors: Somkiat Khokiattiwong, Walter Goessler, Narumol Kornkanitnan, Sabine Kokarnig, Kevin A. FrancesconiAbstract:Environmental context. Despite the widespread occurrence of arsenobetaine in marine animals the origin of this Arsenic compound remains unknown. A current hypothesis is that arsenobetaine is formed from more complex Arsenic Compounds found in marine algae. To test this hypothesis, we examined the Arsenic Compounds in a mangrove ecosystem where algae play a limited role in primary productivity. Abstract. Marine algae are known to bioaccumulate Arsenic and transform it into arsenosugars, which are thought to be precursors of the major Arsenic compound, arsenobetaine, found in marine animals. Marine ecosystems based on mangrove forests have high nutrient input from mangrove leaves, and thus provide a unique opportunity to study the cycling of Arsenic in a marine system where algae are not the dominant food source. Two mangrove forests in Phuket, Thailand were selected as sampling sites for this study. For comparison, samples were also collected from two coral reef sites at and near Phuket. The samples collected included mangrove leaves, corals, algae, molluscs, fish and crustaceans. Arsenic contents in the samples and in aqueous extracts of the samples were determined by hydride generation atomic absorption spectrometry following a dry-ashing mineralisation procedure, and Arsenic species were determined in the aqueous extracts by HPLC-MS (mainly ICPMS). Mangrove leaves contained only low concentrations of total Arsenic (0.10–0.73 mg kg–1 dry mass) and the aqueous extracts thereof contained inorganic Arsenic species, methylarsonate and dimethylarsinate, but arsenosugars were not detected. The total mean Arsenic contents (3.2–86 mg kg–1 dry mass) of the animals from the mangrove ecosystem, however, were typical of those found in animal samples from other marine ecosystems. Similarly the Arsenic Compounds present were typical of those in animals from other marine ecosystems comprising mainly arsenobetaine with smaller quantities of other common Arsenicals including arsenosugars, arsenocholine, tetramethylarsonium ion, trimethylarsine oxide and dimethylarsinate. A trimethylated arsenosugar, which is not commonly reported in marine organisms, was a significant Arsenical (6–8% of total As) in some gastropod species from the mangrove ecosystem. The coral samples contained mainly arsenosugars and arsenobetaine, and the other animals collected from the coral ecosystem contained essentially the same pattern of Arsenicals found for the mangrove animals. The data suggest that food chains based on algae are not necessary for animals to accumulate large concentrations of arsenobetaine.
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Applications of liquid chromatography–electrospray ionization-single quadrupole mass spectrometry for determining Arsenic Compounds in biological samples†
Applied Organometallic Chemistry, 2002Co-Authors: Kevin A. FrancesconiAbstract:Recent work on the determination of Arsenic Compounds in biological samples using liquid chromatography-electrospray ionization-single quadrupole mass spectrometry is reviewed. Specific examples include the quantification of arsenosugars in algae, confirmation of novel Arsenic metabolites from marine microbes and in human urine, and the structural elucidation of two new Arsenic Compounds in marine animals.
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Determination of Arsenic Compounds in Earthworms
Environmental Science & Technology, 1998Co-Authors: Anita Geiszinger, Walter Goessler, Kevin A. Francesconi, Doris Kuehnelt, Walter KosmusAbstract:Earthworms and soil collected from six sites in Styria, Austria, were investigated for total Arsenic concentrations by ICP-MS and for Arsenic Compounds by HPLC−ICP-MS. Total Arsenic concentrations ranged from 3.2 to 17.9 mg/kg dry weight in the worms and from 5.0 to 79.7 mg/kg dry weight in the soil samples. There was no strict correlation between the total Arsenic concentrations in the worms and soil. Arsenic Compounds were extracted from soil and a freeze-dried earthworm sample with a methanol/water mixture (9:1, v/v). The extracts were evaporated to dryness, redissolved in water, and chromatographed on an anion- and a cation-exchange column. Arsenic Compounds were identified by comparison of the retention times with known standards. Only traces of Arsenic acid could be extracted from the soil with the methanol/water (9:1, v/v) mixture. The major Arsenic Compounds detected in the extracts of the earthworms were arsenous acid and Arsenic acid. Arsenobetaine was present as a minor constituent, and traces ...
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Metabolism of Arsenic Compounds by the blue mussel mytilus edulis after accumulation from seawater spiked with Arsenic Compounds
Applied Organometallic Chemistry, 1995Co-Authors: Jürgen Gailer, K. J. Lrgolic, Kevin A. Francesconi, John S. EdmondsxsAbstract:Blue mussels (Mytilus edulis) were exposed to 100 μg As dm -3 in the form of arsenite, arsenate, methylarsonic acid, dimethylarsinic acid, arsenobetaine, arsenocholine, trimethylarsine oxide, tetramethylarsonium iodide or dimethyl(2-hydroxyethyl)arsine oxide in seawater for 10 days. The seawater was renewed and spiked with the Arsenic Compounds daily. Analyses of water samples taken 24 h after spiking showed that arsenobetaine and arsenocholine had been converted to trimethylarsine oxide, whereas trimethylarsine oxide and tetramethylarsonium iodide were unchanged. Arsenobetaine was accumulated by mussels most efficiently, followed in efficiency by arsenocholine and tetramethylarsonium iodide. None of the other Arsenic Compounds was significantly accumulated by the mussels. Extraction of mussel tissues with methanol revealed that control mussels contained arsenobetaine, a dimethyl-(5-ribosyl)arsine oxide and an additional Arsenic compound, possibly dimethylarsinic acid. Mussels exposed to arsenobetaine contained almost all their experimentally accumulated Arsenic as arsenobetaine, and mussels exposed to tetramethylarsonium iodide contained it as the tetramethylarsonium compound. Mussels exposed to arsenocholine had arsenobetaine as the major Arsenic compound and glycerylphosphorylarsenocholine as a minor Arsenic compound in their tissues. The results show that arsenobetaine and arsenocholine are efficiently accumulated from seawater by blue mussels and that in both cases the accumulated Arsenic is present in the tissues as arsenobetaine. Consequently arsenobetaine and/ or arsenocholine present at very low concentrations in seawater may be responsible for the presence of arsenobetaine in M. edulis and probably also among other marine animals. The quantity of arsenobetaine accumulated by the mussels decreases with increasing concentrations of betaine. HPLC-ICP-MS was found to be very powerful for the investigation of the metabolism of Arsenic Compounds in biological systems.