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Monomethylarsonic Acid (monomethylarsonic + acid)
Selected AbstractsDose-dependent uptake, elimination, and toxicity of monosodium methanearsonate in adult zebra finches (Taeniopygia guttata)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2008Courtney A. Albert Abstract Monosodium methanearsonate (MSMA), an arsenic-based pesticide, has been used for the past 10 years in attempts to suppress mountain pine beetle (Dendroctonus ponderosae) outbreaks in British Columbia, Canada. Previous studies have shown that cavity nesting forest birds such as woodpeckers forage and breed in MSMA treated pine stands. Here we examined the effects of MSMA in the laboratory using the zebra finch (Taeniopygia guttata), with the objective to examine tissue distribution and sublethal toxic effects in a model avian species. Zebra finches were exposed to this pesticide at doses similar to those found in bark beetle samples from MSMA stands of trees treated in the southern interior of British Columbia (8, 24, and 72 ,g/g/d and a control group). Results showed high excretion (>90%) of arsenic in all dose groups, as well as dose-dependent trends in accumulation of arsenic in the blood (p < 0.001) and specific tissues. Monomethylarsonic acid, MMA (V), was the predominant form of arsenic in the blood plasma. Dimethylarsinic acid was the major form of arsenic found in the liver (83%) and kidney (61%) tissues. The brain tissue contained primarily the MMA (V) form (57%). Significant weight loss occurred in the two highest dose groups (p < 0.05). Birds in the highest dose group lost up to 15% of initial body mass. [source] Speciation of arsenic compounds in fish and oyster tissues by capillary electrophoresis-inductively coupled plasma-mass spectrometryELECTROPHORESIS, Issue 7-8 2005Ching-Fen Yeh Abstract A capillary electrophoresis-inductively coupled plasma-mass spectrometric (CE-ICP-MS) method for the speciation of six arsenic compounds, namely arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid, dimethylarsinic acid, arsenobetaine and arsenocholine is described. The separation has been achieved on a 70,cm length×75,µm,ID fused-silica capillary. The electrophoretic buffer used was 15,mM Tris (pH,9.0) containing 15,mM sodium dodecyl sulfate (SDS), while the applied voltage was set at +22,kV. The arsenic species in biological tissues were extracted into 80%,v/v methanol-water mixture, put in a closed centrifuge tube and kept in a water bath, using microwaves at 80°C for 3,min. The extraction efficiencies of individual arsenic species added to the sample at 0.5,µg As/g level were between 96% and 107%, except for As(III), for which it was 89% and 77% for oyster and fish samples, respectively. The detection limits of the species studied were in the range 0.3,0.5,ng As/mL. The procedure has been applied for the speciation analysis of two reference materials, namely dogfish muscle tissue (NRCC DORM-2) and oyster tissue (NIST SRM 1566a), and two real-world samples. [source] Trace determination of arsenic species by capillary electrophoresis with direct UV detection using sensitivity enhancement by counter- or co-electroosmotic flow stacking and a high-sensitivity cellELECTROPHORESIS, Issue 12-13 2003Baoguo Sun Abstract Stacking techniques used independently and also with a high-sensitivity cell (HSC) were employed to optimise sensitivity and detection limits in the direct photometric detection of the following eight arsenic species by capillary zone electrophoresis (CZE): arsenite, arsenate, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), 4-hydroxy-3-nitrophenylarsonic acid (Roxarsone), p -aminophenylarsonic acid (p -ASA), 4-nitrophenylarsonic acid (4-NPAA), and phenylarsonic acid (PAA) (target analytes). The stacking mechanisms, optimised stacking and separation conditions, and concentration sensitivity enhancement factors were discussed and compared for (i) normal stacking mode (NSM, sometimes also referred to as field-amplified stacking) in an uncoated fused-silica capillary in the counter-electroosmotic flow (EOF) mode, (ii) large-volume sample stacking (LVSS) with polarity switching, and (iii) the less often applied stacking method of co-EOF NSM stacking with EOF reversal using a poly(diallydimethylammonium chloride) (PDDAC)-coated capillary. The optimal injection volumes were 7.4, 60 and 17.2% of the total capillary volume, for the above three methods, respectively. LVSS with polarity switching gave the lowest limit of detection (LOD). The use of the HSC further reduced the LOD of each target analytes by a factor of 5,8 times. By combining LVSS and HSC, LODs of the target analytes could be reduced by a factor of 218,311, to 5.61, 9.15, 11.1, and 17.1 ,g/L for As(III), DMA, MMA, and As(V), respectively. The method was demonstrated to be applicable to the determination of the target analytes in tap water and lake water, with recoveries in the range of 89.4,103.3%. [source] Uptake and transport of roxarsone and its metabolites in water spinach as affected by phosphate supplyENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2010Lixian Yao Abstract Roxarsone (ROX) is widely used as a feed additive in intensive animal production. While an animal is fed with ROX, the As compounds in the manure primarily occur as ROX and its metabolites, including arsenate (As[V]), arsenite (As[III]), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Animal manure is commonly land applied with phosphorous fertilizers in China. A pot experiment was conducted to investigate the phytoavailability of ROX, As(V), As(III), MMA, and DMA in water spinach (Ipomoea aquatica), with the soil amended with 0, 0.25, 0.50, 1.0, and 2.0,g PO4/kg, respectively, plus 2% (w/w manure/soil) chicken manure (CM) bearing ROX and its metabolites. The results indicate that this species of water spinach cannot accumulate ROX and MMA at detectable levels, but As(V), As(III), and DMA were present in all plant samples. Increased phosphorous decreased the shoot As(V) and As(III) in water spinach but did not affect the root As(V). The shoot DMA and root As(III) and DMA were decreased/increased and then increased/decreased by elevated phosphorous. The total phosphorous content (P) in plant tissue did not correlate with the total As or the three As species in tissues. Arsenate, As(III), and DMA were more easily accumulated in the roots, and phosphate considerably inhibited their upward transport. Dimethylarsinic acid had higher transport efficiency than As(V) and As(III), but As(III) was dominant in tissues. Conclusively, phosphate had multiple effects on the accumulation and transport of ROX metabolites, which depended on their levels. However, proper utilization of phosphate fertilizer can decrease the accumulation of ROX metabolites in water spinach when treated with CM containing ROX and its metabolites. Environ. Toxicol. Chem. 2010;29:947,951. © 2009 SETAC [source] A simple and fast detection technique for arsenic speciation based on high-efficiency photooxidation and gas-phase chemiluminescence detectionLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 5 2009Junhai Xue Abstract High-efficiency photooxidation (HEPO) and gas phase chemiluminescence detection (CL) combined with high-performance liquid chromatography (HPLC) and hydride generation were developed for speciation of As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). After chromatography separation, the arsenic species were passed through HEPO which performed efficient photooxidation and converted MMA and DMA to As(V) in several seconds. Then the reaction of ozone and arsine upon hydride generation produced a CL signal as the analytical parameter. The total analytical process was completed within 10 min. The effects of operational parameters such as the concentrations of hydrochloric acid and NaBH4 solution, carrier gas flow and air gas flow for ozone generation were investigated. Detection limits were 3.7, 10.3, 10.2 and 10.0 µg/L for As(III), As(V), MMA and DMA, respectively. The recoveries of the four arsenic species in human urine sample ranged from 87 to 94%. Copyright © 2009 John Wiley & Sons, Ltd. [source] Accumulation of arsenic by Traustochytrium sp.APPLIED ORGANOMETALLIC CHEMISTRY, Issue 8 2002CHN-1 from Seto Inland Sea Abstract The accumulation of arsenic by Traustochytrium sp. CHN-1 (Labyrinthulids) was examined by using a medium [2% (w/v) glucose, 0.1% (w/v) yeast extract, 0.1% (w/v) peptone in a half salt concentration of sea water] containing arsenic as As(V), As(III). Traustochytrium sp. CHN-1 was grown in 1/2 sea water medium [2% (w/v) glucose, 0.1% (w/v) yeast extract, 0.1% (w/v) peptone] containing an arsenate (As(V)) at up to 1000,mg dm,3 and arsenite (As(III)) at up to 50,mg dm3. The cells died even at [As(III)]-100,mg dm,3. These results suggested that the order of growth inhibition of Traustochytrium sp. CHN-1 by arsenic was As(III),>,As(V). The biomass of Traustochytrium sp. CHN-1 decreased with an increase of the surrounding arsenic concentration. On the other hand, the arsenic concentration in cells increased with an increase of the surrounding arsenic concentration. Arsenic compounds were extracted with methanol/water (1:1) from a freeze-dried sample of Traustochytrium sp. CHN-1. The extracts were analyzed by high-performance liquid chromatography, with an inductively coupled plasma mass spectrometer serving as an arsenic-specific detector. Arsenite, arsenate, monomethylarsonic acid (MMAA), dimethylarsinic acid (DMAA) and arsenosugar were identified in Traustochytrium sp. CHN-1. The order of arsenic species in Traustochytrium sp. CHN-1 was As(V),>,DMAA,>,As(III),>,MMAA,>,arsenosugar at [As]-10,mg dm,3 in the medium. Detoxification of arsenic by cells was probably achieved by methylation. Copyright © 2002 John Wiley & Sons, Ltd. [source] Biologically mediated mobilization of arsenic from granular ferric hydroxide in anaerobic columns fed landfill leachateBIOTECHNOLOGY & BIOENGINEERING, Issue 6 2008Irail Cortinas Abstract To gain insight on the fate of arsenic (As) from drinking water treatment residuals in landfills, the mobilization of arsenate adsorbed onto granular ferric hydroxide (GFH) was studied in continuous anaerobic columns fed with a synthetic landfill leachate. The release of As was compared in biologically active and abiotic columns. More than 150 days of incubation were required before noteworthy As release occurred. After 400 days of operation, 19% of the As was mobilized as identified species in the biologically active column, which was 25.5-fold greater than that of the abiotic column. Fine colloids accounted for up to 81% of the As released. Arsenite was the predominant species identified in filtered (0.45 µm) effluent samples. Dimethylarsinic acid and monomethylarsonic acid were also observed as metabolites. During column operation, approximately 30% of the iron (hydr)oxide mass was lost and most of the mass loss was attributed to changes in iron mineralogy that could be demonstrated in a batch bioassay. The results indicate that As-laden GFH residuals from drinking water treatment are subject to mobilization in municipal landfills and that biologically mediated changes in the iron mineralogy may play an important role in the mobilization mechanism. Biotechnol. Bioeng. 2008;101: 1205,1213. © 2008 Wiley Periodicals, Inc. [source] | |||||||||||||