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Kim ST, Conklin SD, Redan BW, Ho KK. Determination of the Nutrient and Toxic Element Content of Wild-Collected and Cultivated Seaweeds from Hawai'i. ACS Food Sci Technol 2024; 4:595-605. [PMID: 38528908 PMCID: PMC10961648 DOI: 10.1021/acsfoodscitech.3c00476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
For centuries, Hawaiians have gathered seaweed for food, medicine, and ceremonial purposes. Seaweed contains nutrients, but some varieties can accumulate toxic elements. We measured target macrominerals (Na, Mg, P, K, Ca), microminerals (B, V, Mn, Co, Cu, Zn, Mo), and nonessential/toxic elements (As, Sr, Cd, Sn, Hg, Pb, and U) in a sample of wild-collected and cultivated seaweeds from Hawai'i. The samples consisted of brown (Sargassum aquifolium, Sargassum echinocarpum), red (Gracilaria parvispora, Halymenia formosa, Halymenia hawaiiana), and green (Ulva ohnoi) seaweed. Elemental composition was determined by inductively coupled plasma (ICP)-atomic emission spectroscopy and ICP-mass spectrometry (MS). Speciation of As was conducted by using liquid chromatography-ICP-MS. S. echinocarpum per 80 g serving was high in Ca (~37% daily value [DV]), U. ohnoi was high in Mg (~40%DV), H. formosa was high in Fe (~40%DV), and G. parvispora was high in Mn (~128%DV). In this study, the highest amounts of toxic elements were observed in S. aquifolium and S. echinocarpum (27.6 mg inorganic As/kg fdw), G. parvispora (43.3 mg Pb/kg fdw) and H. formosa (46.6 mg Pb/kg fdw). These results indicate that although seaweeds from Hawai'i contain a variety of nutrients, some species can accumulate high amounts of toxic elements.
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Affiliation(s)
- Samuel T. Kim
- Department of Human Nutrition, Food and Animal Sciences, University of Hawai‘i at Mānoa, Honolulu, HI, 96822, United States
| | - Sean D. Conklin
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD, 20740, United States
| | - Benjamin W. Redan
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Food Safety, Bedford Park, IL, 60501, United States
| | - Kacie K.H.Y. Ho
- Department of Human Nutrition, Food and Animal Sciences, University of Hawai‘i at Mānoa, Honolulu, HI, 96822, United States
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Todorov TI, Wolle MM, Conklin SD. Distribution of 26 major and trace elements in edible seaweeds from the US market. Chemosphere 2022; 294:133651. [PMID: 35065179 DOI: 10.1016/j.chemosphere.2022.133651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
In this study we present an elemental profile of 46 edible seaweed samples purchased in the United States. The seaweeds were grouped in 13 subgroups/species based on DNA barcoding analysis. The seaweeds were decomposed by microwave accelerated acid digestion followed by quantification of 26 elements by ICP-MS. Elements were grouped into macronutrient (Na, K, Ca, S, Mg and P), essential (Fe, Zn, Mn, V, Cu, Cr, Ni, Mo and Se), non-essential including toxic elements (Sr, Ba, Th, Sn and Sb As, Cd, Pb, U, W and Hg). The highest levels were found for Na and the lowest were for Hg. The elemental profiles depended on the taxonomy of the species and several elements (Fe, Ba, Cr, Pb, W and Th) also exhibited high intraspecies variations, likely due to geographic origin or food processing conditions. Higher Cd and Pb accumulation was observed in wakame, hijiki and nori, with Cd as high 4.05 mg/kg and Pb as high as 2.85 mg/kg in kombu. A study of correlation between the elements using Pearson's coefficients revealed multiple pairs of highly correlated elements in seaweed, as well as triple and quintuple correlations of certain elements.
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Affiliation(s)
- Todor I Todorov
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 5001 Campus Dr, College Park, MD, 20740, USA.
| | - Mesay M Wolle
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 5001 Campus Dr, College Park, MD, 20740, USA
| | - Sean D Conklin
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 5001 Campus Dr, College Park, MD, 20740, USA
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Handy SM, Ott BM, Hunter ES, Zhang S, Erickson DL, Wolle MM, Conklin SD, Lane CE. Suitability of DNA Sequencing Tools for Identifying Edible Seaweeds Sold in the United States. J Agric Food Chem 2020; 68:15516-15525. [PMID: 33334103 DOI: 10.1021/acs.jafc.0c03734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Seaweeds have been consumed by billions of people around the world and are increasingly popular in United States (US) diets. Some seaweed species have been associated with adverse health effects-such as heavy metal toxicity-and higher priced seaweeds may be more prone to adulteration. Knowing which species of seaweeds are being marketed in the US is important for protecting human health and preventing economic adulteration. Therefore, the United States Food and Drug Administration is developing new DNA-based species identification tools to complement established chemical methods for verifying the accurate labeling of products. Here, seaweed products available in the United States were surveyed using a tiered approach to evaluate a variety of DNA extraction techniques followed by traditional DNA barcoding via Sanger sequencing; if needed, genome skimming of total extracted nuclear DNA via next-generation sequencing was performed. This two-tiered approach of DNA barcoding and genome skimming could identify most seaweed samples (41/46), even those in blends (2/2, 1 out of 3 labeled species in each). Only two commercial samples appeared to be mislabeled or to contain unintended algal species. Five samples, labeled as "hijiki" or "arame", could not be confirmed by these DNA-based identification methods.
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Affiliation(s)
- Sara M Handy
- Center for Food Safety and Applied Nutrition, Office of Regulatory Science, U.S. Food and Drug Administration, College Park 20740, Maryland, United States
| | - Brittany M Ott
- Center for Food Safety and Applied Nutrition, Office of Regulatory Science, U.S. Food and Drug Administration, College Park 20740, Maryland, United States
- Joint Institute for Food Safety and Applied Nutrition, University of Maryland, College Park 20742, Maryland, United States
| | - Elizabeth Sage Hunter
- Department of Biological Sciences, University of Rhode Island, Kingston 02881, Rhode Island, United States
| | - Shu Zhang
- DNA4 Technologies LLC, Baltimore 21227, Maryland, United States
| | - David L Erickson
- Joint Institute for Food Safety and Applied Nutrition, University of Maryland, College Park 20742, Maryland, United States
- DNA4 Technologies LLC, Baltimore 21227, Maryland, United States
| | - Mesay Mulugeta Wolle
- Center for Food Safety and Applied Nutrition, Office of Regulatory Science, U.S. Food and Drug Administration, College Park 20740, Maryland, United States
| | - Sean D Conklin
- Center for Food Safety and Applied Nutrition, Office of Regulatory Science, U.S. Food and Drug Administration, College Park 20740, Maryland, United States
| | - Christopher E Lane
- Department of Biological Sciences, University of Rhode Island, Kingston 02881, Rhode Island, United States
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Wolle MM, Stadig S, Conklin SD. Market Basket Survey of Arsenic Species in the Top Ten Most Consumed Seafoods in the United States. J Agric Food Chem 2019; 67:8253-8267. [PMID: 31294564 DOI: 10.1021/acs.jafc.9b02314] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The study focused on the determination of arsenic species in the top ten most consumed seafoods in the United States. Fifty-four samples were collected from local supermarkets, and their species identities were confirmed by DNA barcoding. The total arsenic in the samples varied greatly in the range of 8-22200 ng/g (wet mass). Speciation analysis based on extraction of water-soluble and nonpolar arsenic showed that inorganic arsenic (iAs) was found only in clams and crabs, while arsenobetaine (AsB) predominates in most samples. Among the other arsenicals, trimethylarsoniopropionate (TMAP) was found in most matrices with higher concentrations in crabs, and arsenosugars existed in most clams and crabs. Nonpolar arsenic accounted for 1-46% of the total arsenic in the samples. The accuracy of the analytical results was evaluated using standard reference materials and spike recovery tests. The survey showed that the iAs concentrations in America's most consumed seafood products are much lower than the tolerable intake set by the Joint FAO/WHO Expert Committee, even at the highest levels found in this study.
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Affiliation(s)
- Mesay Mulugeta Wolle
- Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition , U.S. Food and Drug Administration , 5001 Campus Drive , College Park , Maryland 20740 , United States
| | - Sarah Stadig
- Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition , U.S. Food and Drug Administration , 5001 Campus Drive , College Park , Maryland 20740 , United States
| | - Sean D Conklin
- Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition , U.S. Food and Drug Administration , 5001 Campus Drive , College Park , Maryland 20740 , United States
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Wolle MM, Conklin SD, Wittenberg J. Matrix-induced transformation of arsenic species in seafoods. Anal Chim Acta 2019; 1060:53-63. [DOI: 10.1016/j.aca.2019.02.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/11/2019] [Accepted: 02/18/2019] [Indexed: 02/08/2023]
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Tanabe CK, Hopfer H, Ebeler SE, Nelson J, Conklin SD, Kubachka KM, Wilson RA. Matrix Extension and Multilaboratory Validation of Arsenic Speciation Method EAM §4.10 to Include Wine. J Agric Food Chem 2017; 65:4193-4199. [PMID: 28457128 DOI: 10.1021/acs.jafc.7b00855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A multilaboratory validation (MLV) was performed to extend the U.S. Food and Drug Administration's (FDA) analytical method Elemental Analysis Manual (EAM) §4.10, High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometric Determination of Four Arsenic Species in Fruit Juice, to include wine. Several method modifications were examined to optimize the method for the analysis of dimethylarsinic acid, monomethylarsonic acid, arsenate (AsV), and arsenite (AsIII) in various wine matrices with a range of ethanol concentrations by liquid chromatography-inductively coupled plasma-mass spectrometry. The optimized method was used for the analysis of five wines of different classifications (red, white, sparkling, rosé, and fortified) by three laboratories. Additionally, the samples were fortified in duplicate at levels of approximately 5, 10, and 30 μg kg-1 and analyzed by each participating laboratory. The combined average fortification recoveries of dimethylarsinic acid, monomethylarsonic acid, and inorganic arsenic (iAs the sum of AsV and AsIII) in these samples were 101, 100, and 100%, respectively. To further demonstrate the method, 46 additional wine samples were analyzed. The total As levels of all the wines analyzed in this study were between 1.0 and 38.2 μg kg-1. The overall average mass balance based on the sum of the species recovered from the chromatographic separation compared to the total As measured was 89% with a range of 51-135%. In the 51 analyzed samples, iAs accounted for an average of 91% of the sum of the species with a range of 37-100%.
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Affiliation(s)
- Courtney K Tanabe
- Department of Viticulture & Enology, University of California , Davis, California 95616, United States
- Food Safety & Measurement Facility, University of California , Davis, California 95616, United States
| | - Helene Hopfer
- Department of Food Science, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Susan E Ebeler
- Department of Viticulture & Enology, University of California , Davis, California 95616, United States
- Food Safety & Measurement Facility, University of California , Davis, California 95616, United States
| | - Jenny Nelson
- Department of Viticulture & Enology, University of California , Davis, California 95616, United States
- Food Safety & Measurement Facility, University of California , Davis, California 95616, United States
- Agilent Technologies, Inc. , 5301 Stevens Creek Blvd., Santa Clara, California 95051, United States
| | - Sean D Conklin
- Center for Food Safety and Applied Nutrition, U.S. FDA , College Park, Maryland 20866, United States
| | - Kevin M Kubachka
- Forensic Chemistry Center, U.S. FDA , Cincinnati, Ohio 45237, United States
| | - Robert A Wilson
- Forensic Chemistry Center, U.S. FDA , Cincinnati, Ohio 45237, United States
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Gray PJ, Conklin SD, Todorov TI, Kasko SM. Cooking rice in excess water reduces both arsenic and enriched vitamins in the cooked grain. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2015; 33:78-85. [PMID: 26515534 DOI: 10.1080/19440049.2015.1103906] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This paper reports the effects of rinsing rice and cooking it in variable amounts of water on total arsenic, inorganic arsenic, iron, cadmium, manganese, folate, thiamin and niacin in the cooked grain. We prepared multiple rice varietals both rinsed and unrinsed and with varying amounts of cooking water. Rinsing rice before cooking has a minimal effect on the arsenic (As) content of the cooked grain, but washes enriched iron, folate, thiamin and niacin from polished and parboiled rice. Cooking rice in excess water efficiently reduces the amount of As in the cooked grain. Excess water cooking reduces average inorganic As by 40% from long grain polished, 60% from parboiled and 50% from brown rice. Iron, folate, niacin and thiamin are reduced by 50-70% for enriched polished and parboiled rice, but significantly less so for brown rice, which is not enriched.
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Affiliation(s)
- Patrick J Gray
- a Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition , US Food and Drug Administration (USFDA) , College Park , MD , USA
| | - Sean D Conklin
- a Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition , US Food and Drug Administration (USFDA) , College Park , MD , USA
| | - Todor I Todorov
- a Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition , US Food and Drug Administration (USFDA) , College Park , MD , USA
| | - Sasha M Kasko
- a Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition , US Food and Drug Administration (USFDA) , College Park , MD , USA
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Conklin SD, Shockey N, Kubachka K, Howard KD, Carson MC. Development of an ion chromatography-inductively coupled plasma-mass spectrometry method to determine inorganic arsenic in liver from chickens treated with roxarsone. J Agric Food Chem 2012; 60:9394-9404. [PMID: 22897610 DOI: 10.1021/jf302366a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Roxarsone, (4-hydroxy-3-nitrophenyl)arsonic acid, is an arsenic-containing compound that has been approved as a feed additive for poultry and swine since the 1940s; however, little information is available regarding residual arsenic species present in edible tissues. We developed a novel method for the extraction and quantification of arsenic species in chicken liver. A strongly basic solution solubilized the liver, and ultrafiltration removed macromolecules and particulate material. Ion chromatography separated the species [arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, (4-hydroxy-3-aminophenyl)arsonic acid, (4-hydroxy-3-acetaminophenyl)arsonic acid, and roxarsone] in the extracts, which were then detected by inductively coupled plasma-mass spectrometry. The extraction oxidized most arsenite to arsenate. For fortification concentrations at 2 μg kg(-1) and above, recoveries ranged from 70 to 120%, with relative standard deviations from 7 to 34%. We detected roxarsone, its 3-amino and 3-acetamido metabolites, inorganic arsenic, and additional unknown arsenic species in livers from roxarsone-treated chickens. Both the originating laboratory and a second laboratory validated the method.
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Affiliation(s)
- Sean D Conklin
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, United States Food and Drug Administration, College Park, Maryland 20740, United States
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Conklin SD, Chen PE. Quantification of four arsenic species in fruit juices by ion-chromatography–inductively coupled plasma–mass spectrometry. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2012; 29:1272-9. [DOI: 10.1080/19440049.2012.687775] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Edison SE, Conklin SD, Kaval N, Cheruzel LE, Krause JA, Seliskar CJ, Heineman WR, Buchanan RM, Baldwin MJ. Spectroscopic characterization of a Ni-organic radical intermediate in the aerobic oxidation of methanol catalyzed by a Ni(II)(polyoximate) complex. Inorganica Chim Acta 2008. [DOI: 10.1016/j.ica.2007.05.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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11
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Hughes MF, Devesa V, Adair BM, Conklin SD, Creed JT, Styblo M, Kenyon EM, Thomas DJ. Tissue dosimetry, metabolism and excretion of pentavalent and trivalent dimethylated arsenic in mice after oral administration. Toxicol Appl Pharmacol 2007; 227:26-35. [PMID: 18036629 DOI: 10.1016/j.taap.2007.10.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 10/05/2007] [Accepted: 10/15/2007] [Indexed: 12/01/2022]
Abstract
Dimethylarsinic acid (DMA(V)) is a rat bladder carcinogen and the major urinary metabolite of administered inorganic arsenic in most mammals. This study examined the disposition of pentavalent and trivalent dimethylated arsenic in mice after acute oral administration. Adult female mice were administered [(14)C]-DMA(V) (0.6 or 60 mg As/kg) and sacrificed serially over 24 h. Tissues and excreta were collected for analysis of radioactivity. Other mice were administered unlabeled DMA(V) (0.6 or 60 mg As/kg) or dimethylarsinous acid (DMA(III)) (0.6 mg As/kg) and sacrificed at 2 or 24 h. Tissues (2 h) and urine (24 h) were collected and analyzed for arsenicals. Absorption, distribution and excretion of [(14)C]-DMA(V) were rapid, as radioactivity was detected in tissues and urine at 0.25 h. For low dose DMA(V) mice, there was a greater fractional absorption of DMA(V) and significantly greater tissue concentrations of radioactivity at several time points. Radioactivity distributed greatest to the liver (1-2% of dose) and declined to less than 0.05% in all tissues examined at 24 h. Urinary excretion of radioactivity was significantly greater in the 0.6 mg As/kg DMA(V) group. Conversely, fecal excretion of radioactivity was significantly greater in the high dose group. Urinary metabolites of DMA(V) included DMA(III), trimethylarsine oxide (TMAO), dimethylthioarsinic acid and trimethylarsine sulfide. Urinary metabolites of DMA(III) included TMAO, dimethylthioarsinic acid and trimethylarsine sulfide. DMA(V) was also excreted by DMA(III)-treated mice, showing its sensitivity to oxidation. TMAO was detected in tissues of the high dose DMA(V) group. The low acute toxicity of DMA(V) in the mouse appears to be due in part to its minimal retention and rapid elimination.
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Affiliation(s)
- Michael F Hughes
- US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, USA.
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Adair BM, Moore T, Conklin SD, Creed JT, Wolf DC, Thomas DJ. Tissue distribution and urinary excretion of dimethylated arsenic and its metabolites in dimethylarsinic acid- or arsenate-treated rats. Toxicol Appl Pharmacol 2007; 222:235-42. [PMID: 17559899 DOI: 10.1016/j.taap.2007.04.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 04/27/2007] [Accepted: 04/27/2007] [Indexed: 11/20/2022]
Abstract
Adult female Fisher 344 rats received drinking water containing 0, 4, 40, 100, or 200 parts per million of dimethylarsinic acid or 100 parts per million of arsenate for 14 days. Urine was collected during the last 24 h of exposure. Tissues were then taken for analysis of dimethylated and trimethylated arsenicals; urines were analyzed for these arsenicals and their thiolated derivatives. In dimethylarsinic acid-treated rats, highest concentrations of dimethylated arsenic were found in blood. In lung, liver, and kidney, concentrations of dimethylated arsenic exceeded those of trimethylated species; in urinary bladder and urine, trimethylated arsenic predominated. Dimethylthioarsinic acid and trimethylarsine sulfide were present in urine of dimethylarsinic acid-treated rats. Concentrations of dimethylated arsenicals were similar in most tissues of dimethylarsinic acid- and arsenate-treated rats, including urinary bladder which is the target for dimethylarsinic acid-induced carcinogenesis in the rat. Mean concentration of dimethylated arsenic was significantly higher (P<0.05) in urine of dimethylarsinic acid-treated rats than in arsenate-treated rats, suggesting a difference between treatment groups in the flux of dimethylated arsenic through urinary bladder. Concentrations of trimethylated arsenic concentrations were consistently higher in dimethylarsinic acid-treated rats than in arsenate-treated rats; these differences were significant (P<0.05) in liver, urinary bladder, and urine. Concentrations of dimethylthioarsinic acid and trimethylarsine sulfide were higher in urine from dimethylarsinic acid-treated rats than from arsenate-treated rats. Dimethylarsinic acid is extensively metabolized in the rat, yielding significant concentrations of trimethylated species and of thiolated derivatives. One or more of these metabolites could be the species causing alterations of cellular function that lead to tumors in the urinary bladder.
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Affiliation(s)
- Blakely M Adair
- Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 109 Alexander Drive, Research Triangle Park, NC 27709, USA
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Conklin SD, Ackerman AH, Fricke MW, Creed PA, Creed JT, Kohan MC, Herbin-Davis K, Thomas DJ. In vitro biotransformation of an arsenosugar by mouse anaerobic cecal microflora and cecal tissue as examined using IC-ICP-MS and LC-ESI-MS/MS. Analyst 2006; 131:648-55. [PMID: 16633578 DOI: 10.1039/b516275k] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This investigation examined chemical and microbiological transformations of an arsenosugar by mouse cecum. To mimic the low oxygen environment in the mammalian gastrointestinal tract, reaction mixtures were incubated under anaerobic conditions. An arsenosugar extracted from ribbon kelp, 3-[5'-deoxy-5-(dimethylarsinoyl)-beta-ribofuranosyloxy]-2-hydroxypropanesulfonic acid, As392, was added to reaction mixtures that contained either cecal microflora or cecal tissue homogenate. These reaction mixtures were incubated at 0 or 37 degrees C for up to 48 hours to monitor biotransformation of the arsenosugar. Analysis of the reaction mixtures by IC-ICP-MS and LC-ESI-MS/MS indicated that the arsenosugar was converted primarily (95%) to its sulfur analog in less than 1 h at 37 degrees C. Conversion of As392 to its sulfur analog was much slower at 0 degrees C (21% conversion after 48 h). In reaction mixtures with cecal tissue homogenate, conversion of As392 to its sulfur analog was slower (77% conversion after 48 h at 37 degrees C). A good mass balance was found in all reaction mixtures between the amount of arsenosugar added and the sum of all detected arsenic-containing products. LC-ESI-MS/MS spectra of the sulfur-containing arsenosugar formed in all reaction mixtures containing cecal microflora compared well with those of a synthetic standard. These results suggest that the anaerobic microflora of the gastrointestinal tract can rapidly convert ingested arsenosugars to sulfur analogs. This biotransformation may affect the subsequent absorption, metabolism, and disposition of arsenic present in arsenosugars.
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Affiliation(s)
- Sean D Conklin
- US EPA, ORD, NERL, Microbiological and Chemical Exposure Assessment Research Division, Cincinnati, OH 45268, USA
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Maghasi AT, Conklin SD, Shtoyko T, Piruska A, Richardson JN, Seliskar CJ, Heineman WR. Spectroelectrochemical sensing based on attenuated total internal reflectance stripping voltammetry. 2. Determination of mercury and lead. Anal Chem 2004; 76:1458-65. [PMID: 14987104 DOI: 10.1021/ac034830h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Detection of lead and mercury by attenuated total internal reflectance spectroscopy coupled to stripping voltammetry is demonstrated. Changes in attenuation of light passing through an indium tin oxide optically transparent electrode (ITO-OTE) accompany the electrodeposition and stripping of lead and mercury on the electrode surface. The change in absorbance during stripping of electrodeposited metal constitutes the analytical response that enables detection over a range of 2.5 x 10(-7)-5 x 10(-5) and 5 x 10(-8)-5 x 10(-5) M for mercury and lead, respectively. The spectroelectrochemical responses of mercury and lead on the ITO surface are characterized and optimized with respect to solution conditions, the potential excitation signals used for deposition and stripping, and wavelength for detection. The deposited metals were examined by environmental scanning electron miscroscopy, and the electrodeposition pattern of lead and mercury was found to influence the optical response.
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Affiliation(s)
- Anne T Maghasi
- Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, USA
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Zudans I, Paddock JR, Kuramitz H, Maghasi AT, Wansapura CM, Conklin SD, Kaval N, Shtoyko T, Monk DJ, Bryan SA, Hubler TL, Richardson JN, Seliskar CJ, Heineman WR. Electrochemical and optical evaluation of noble metal– and carbon–ITO hybrid optically transparent electrodes. J Electroanal Chem (Lausanne) 2004. [DOI: 10.1016/j.jelechem.2003.10.025] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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