ORCID Profile
0000-0002-9136-3215
Current Organisation
The University of Canberra
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Biochemistry And Cell Biology Not Elsewhere Classified | Global Change Biology | Chemical Oceanography | Oceanography
Climate change | Physical and chemical conditions | Oceanic processes (excl. climate related) |
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/MF08256
Abstract: Although over 50 arsenic species have been identified in marine organisms, the biochemical pathways by which these species are formed are not known. In this paper, we present an overview of bioconversions of arsenic species that occur in marine food chains based on studies conducted by our laboratory as well as the work of others. Phytoplankton and macroalgae only contain dimethylarsenoribosides or simple methylated arsenic compounds such as dimethylarsenate and dimethylarsenoethanol. Marine animals contain mostly arsenobetaine and a range of other arsenic species that may be precursors of arsenobetaine formation. The formation of arsenobetaine in marine animals from dimethylarsenoribosides may occur through a two-stage conversion pathway: arsenoriboside or trimethylarsonioriboside degradation to arsenocholine followed by quantitative oxidation to arsenobetaine. The minor arsenic species found in marine organisms are sulfur analogues of compounds found in the S-adenosylmethionine-methionine salvage and the dimethylsulfoniopropionate metabolic pathway of animals. A key intermediate in these pathways would be arsenomethionine, which could possibly be formed from dimethylarsinite, dimethylarsenoribosides or an arsenic-containing analogue of S-adenosylmethionine. Examining arsenic species in whole ecosystems has the advantage of using the pattern of arsenic species found to postulate the biochemical pathways of their formation.
Publisher: American Physical Society (APS)
Date: 21-08-2008
Publisher: Wiley
Date: 23-05-2007
DOI: 10.1002/AOC.1229
Publisher: American Physical Society (APS)
Date: 23-07-2008
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/EN05061
Abstract: Environmental Context. The pathways by which arsenic is accumulated and transferred in aquatic ecosystems are relatively unknown. Examination of whole marine ecosystems rather than in idual organisms provides greater insights into the biogeochemical cycling of arsenic. Saltmarshes with low ecological ersity are an important terrestrial–marine interface about which little is known regarding arsenic concentrations and species distribution. This study examines the cycling of arsenic within Australian saltmarsh ecosystems to further understand its distribution and trophic transfer. Abstract. This paper reports the distribution of total arsenic and arsenic species in saltmarsh ecosystems located in south-east Australia. We also investigated the relationship between arsenic, iron, and phosphorus concentrations in saltmarsh halophytes and associated sediment. Total mean arsenic concentrations in saltmarsh plants, S. quinqueflora and S. australis, for leaves ranged from 0.03 ± 0.05 to 0.67 ± 0.48 μg g−1 and 0.03 ± 0.02 to 0.08 ± 0.06 μg g−1, respectively, and for roots ranged from 2 ± 2 to 6 ± 12 μg g−1 and 0.39 ± 0.20 to 0.57 ± 1.06 μg g−1 respectively. Removal of iron plaque from the roots reduced the arsenic concentration variability to 0.40–0.79 µg g−1 and 0.95–1.05 µg g−1 for S. quinqueflora and S. australis roots respectively. Significant differences were found between locations for total arsenic concentrations in plant tissues and these differences could be partially attributed to differences in sediment arsenic concentrations between locations. For S. quinqueflora but not S. australis there was a strong correlation between arsenic and iron concentrations in the leaf and root tissues. A significant negative relationship between arsenic and phosphorus concentrations was found for S. quinqueflora leaves but not roots. Total mean arsenic concentrations in salt marsh animal tissues (7 ± 2–21 ± 13 µg g−1) were consistent with those found for other marine animals. The concentration of total arsenic in gastropods and hipods could be partially explained by the concentration of total arsenic in the dominant saltmarsh plant S. quinqueflora. Of the extractable arsenic, saltmarsh plants were dominated by arsenic(iii), arsenic(v) (66–99%), and glycerol arsenoribose (17–35%). Arsenobetaine was the dominant extractable arsenic species in the gastropods Salinator soilda (84%) and Ophicardelus ornatus (89%) and the crab Neosarmatium meinerti (89%). Amphipods contained mainly arsenobetaine (44%) with some phosphate arsenoribose (23%). Glycerol trimethyl arsonioribose was found in both gastropods (0.7–0.8%) and the visceral mass of N. meinerti (0.1%). These results show that arsenic uptake into plants from uncontaminated saltmarsh environments maybe dependent on plant iron uptake and inhibited by high phosphorus concentrations. Arsenic in saltmarsh plants is mainly present as inorganic arsenic, but arsenic in animals that eat plant detritus is present as organo arsenic species, primarily arsenobetaine and arsenosugars. The presence of glycerol trimethyl arsonioribose poses the question of whether trimethylated arsonioriboses are transitory intermediates in the formation of arsenobetaine.
Publisher: Elsevier BV
Date: 09-2016
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.FORSCIINT.2015.03.029
Abstract: Laser-induced breakdown spectroscopy (LIBS) is an emerging atomic emission based solid s ling technique that has many potential forensic applications. In this study, the analytical performance of LIBS, as well as that of inductively coupled plasma mass spectrometry (ICP-MS), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray microfluorescence (μXRF), was evaluated for the ability to conduct elemental analyses on Cannabis plant material, with a specific investigation of the possible links between hydroponic nutrients and elemental profiles from associated plant material. No such study has been previously published in the literature. Good correlation among the four techniques was observed when the concentrations or peak areas of the elements of interest were monitored. For Cannabis s les collected at the same growth time, the elemental profiles could be related to the use of particular commercial nutrients. In addition, the study demonstrated that ICP-MS, LA-ICP-MS and LIBS are suitable techniques for the comparison of Cannabis s les from different sources, with high discriminating powers being achieved. On the other hand, μXRF method was not suitable for the discrimination of Cannabis s les originating from different growth nutrients.
Publisher: Frontiers Media SA
Date: 04-11-2014
Publisher: Elsevier BV
Date: 2017
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7JA00391A
Abstract: A variety of approaches for measuring the content and speciation of Sb in environmental matrices are discussed.
Publisher: Elsevier BV
Date: 08-2014
DOI: 10.1016/J.FORSCIINT.2014.04.040
Abstract: A commercially available laser-induced breakdown spectroscopy (LIBS) instrument was evaluated for the determination of elemental composition of twenty Australian window glass s les, consisting of 14 laminated s les and 6 non-laminated s les (or not otherwise specified) collected from broken windows at crime scenes. In this study, the LIBS figures of merit were assessed in terms of accuracy, limits of detection and precision using three standard reference materials (NIST 610, 612, and 1831). The discrimination potential of LIBS was compared to that obtained using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), X-ray microfluorescence spectroscopy (μXRF) and scanning electron microscopy energy dispersive X-ray spectrometry (SEM-EDX) for the analysis of architectural window glass s les collected from crime scenes in the Canberra region, Australia. Pairwise comparisons were performed using a three-sigma rule, two-way ANOVA and Tukey's HSD test at 95% confidence limit in order to investigate the discrimination power for window glass analysis. The results show that the elemental analysis of glass by LIBS provides a discrimination power greater than 97% (>98% when combined with refractive index data), which was comparable to the discrimination powers obtained by LA-ICP-MS and μXRF. These results indicate that LIBS is a feasible alternative to the more expensive LA-ICP-MS and μXRF options for the routine forensic analysis of window glass s les.
Publisher: Elsevier BV
Date: 07-2018
Publisher: American Physical Society (APS)
Date: 12-03-2008
Publisher: Elsevier BV
Date: 11-2012
Publisher: Wiley
Date: 23-05-2007
DOI: 10.1002/AOC.1231
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.JES.2016.08.007
Abstract: Arsenic metabolism in living organisms is dependent on the ability of different arsenic species to traverse biological membranes. Simple diffusion provides an alternative influx and efflux route to mediated transport mechanisms that can increase the amount of arsenic available for metabolism in cells. Using octanol-water and liposome-water partition coefficients, the ability of arsenous acid, arsenate, methylarsonate, dimethylarsinate, thio-methylarsonate, thio-dimethylarsinic acid, arsenotriglutathione and monomethylarsonic diglutathione to diffuse through the lipid bilayer of cell membranes was investigated. Molecular modelling of arsenic species was used to explain the results. All arsenic species with the exception of arsenate, methylarsonate and thio-methylarsonate were able to diffuse through the lipid bilayer of liposomes, with liposome-water partition coefficients between 0.04 and 0.13. Trivalent arsenic species and thio-pentavalent arsenic species showed higher partition coefficients, suggesting that they can easily traverse cell membranes by passive simple diffusion. Given the higher toxicity of these species compared to oxo-pentavalent arsenic species, this study provides evidence supporting the risk associated with human exposure to trivalent and thio-arsenic species.
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.FOODCHEM.2016.05.163
Abstract: Humans are exposed to organic arsenic species through their diet and therefore, are susceptible to arsenic toxicity. Investigating the transformations occurring in the gastrointestinal tract will influence which arsenic species to focus on when studying metabolism in cells. Using a physiologically based extraction test, the bioaccessibility of arsenic species was determined after the simulated gastrointestinal digestion of rice, seaweed and fish. Pure standards of the major arsenic species present in these foodstuffs (arsenic glutathione complexes, arsenosugars and short chain fatty acids) were also evaluated to assess the effect of the food matrix on bioaccessibility and transformation. Approximately 80% of arsenic is released from these foodstuffs, potentially becoming available. Hydrolysis and demethylation of arsenic glutathione complexes and arsenosugars standards was observed, but no transformations occurred to arsenosugars present in seaweed. Demethylation of MA and DMA from rice occurs increasing the amount of inorganic arsenic species available for metabolism.
Publisher: Elsevier BV
Date: 07-2011
DOI: 10.1016/J.TALANTA.2011.03.022
Abstract: A procedure for the extraction and determination of methyl mercury and mercury (II) in fish muscle tissues and sediment s les is presented. The procedure involves extraction with 5% (v/v) 2-mercaptoethanol, separation and determination of mercury species by HPLC-ICPMS using a Perkin-Elmer 3 μm C8 (33 mm×3 mm) column and a mobile phase 3 containing 0.5% (v/v) 2-mercaptoethanol and 5% (v/v) CH(3)OH (pH 5.5) at a flow rate 1.5 ml min(-1) and a temperature of 25°C. Calibration curves for methyl mercury (I) and mercury (II) standards were linear in the range of 0-100 μgl(-1) (r(2)=0.9990 and r(2)=0.9995 respectively). The lowest measurable mercury was 0.4 μgl(-1) which corresponds to 0.01 μgg(-1) in fish tissues and sediments. Methyl mercury concentrations measured in biological certified reference materials, NRCC DORM - 2 Dogfish muscle (4.4±0.8 μgg(-1)), NRCC Dolt - 3 Dogfish liver (1.55±0.09 μgg(-1)), NIST RM 50 Albacore Tuna (0.89±0.08 μgg(-1)) and IRMM IMEP-20 Tuna fish (3.6±0.6 μgg(-1)) were in agreement with the certified value (4.47±0.32μgg(-1), 1.59±0.12 μgg(-1), 0.87±0.03 μgg(-1), 4.24±0.27 μgg(-1) respectively). For the sediment reference material ERM CC 580, a methyl mercury concentration of 0.070±0.002 μgg(-1) was measured which corresponds to an extraction efficiency of 92±3% of certified values (0.076±0.04 μgg(-1)) but within the range of published values (0.040-0.084 μgg(-1) mean±s.d.: 0.073±0.05 μgg(-1), n=40) for this material. The extraction procedure for the fish tissues was also compared against an enzymatic extraction using Protease type XIV that has been previously published and similar results were obtained. The use of HPLC-HGAAS with a Phenomenox 5 μm Luna C18 (250 mm×4.6 mm) column and a mobile phase containing 0.06 moll(-1) ammonium acetate (Merck Pty Limited, Australia) in 5% (v/v) methanol and 0.1% (w/v) l-cysteine at 25°C was evaluated as a complementary alternative to HPLC-ICPMS for the measurement of mercury species in fish tissues. The lowest measurable mercury concentration was 2 μgl(-1) and this corresponds to 0.1 μgg(-1) in fish tissues. Analysis of enzymatic extracts analysed by HPLC-HGAAS and HPLC-ICPMS gave equivalent results.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6JA00442C
Abstract: The use of sub-critical water and hydrogen peroxide provides a fast, clean and efficient means of extracting arsenic from rice.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5JA00155B
Abstract: The importance of measuring arsenic (As) species has been appreciated for a long time mainly because of the wide spread knowledge of arsenic's toxicity and its use as a poison.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.AQUATOX.2017.02.014
Abstract: This study describes the transcriptomic response of the Australian endemic freshwater gastropod Isidorella newcombi exposed to 80±1μg/L of copper for 3days. Analysis of copper tissue concentration, lysosomal membrane destabilisation and RNA-seq were conducted. Copper tissue concentrations confirmed that copper was bioaccumulated by the snails. Increased lysosomal membrane destabilisation in the copper-exposed snails indicated that the snails were stressed as a result of the exposure. Both copper tissue concentrations and lysosomal destabilisation were significantly greater in snails exposed to copper. In order to interpret the RNA-seq data from an ecotoxicological perspective an integrated biological response model was developed that grouped transcriptomic responses into those associated with copper transport and storage, survival mechanisms and cell death. A conceptual model of expected transcriptomic changes resulting from the copper exposure was developed as a basis to assess transcriptomic responses. Transcriptomic changes were evident at all the three levels of the integrated biological response model. Despite lacking statistical significance, increased expression of the gene encoding copper transporting ATPase provided an indication of increased internal transport of copper. Increased expression of genes associated with endocytosis are associated with increased transport of copper to the lysosome for storage in a detoxified form. Survival mechanisms included metabolic depression and processes associated with cellular repair and recycling. There was transcriptomic evidence of increased cell death by apoptosis in the copper-exposed organisms. Increased apoptosis is supported by the increase in lysosomal membrane destabilisation in the copper-exposed snails. Transcriptomic changes relating to apoptosis, phagocytosis, protein degradation and the lysosome were evident and these processes can be linked to the degradation of post-apoptotic debris. The study identified contaminant specific transcriptomic markers as well as markers of general stress. From an ecotoxicological perspective, the use of a framework to group transcriptomic responses into those associated with copper transport, survival and cell death assisted with the complex process of interpretation of RNA-seq data. The broad adoption of such a framework in ecotoxicology studies would assist in comparison between studies and the identification of reliable transcriptomic markers of contaminant exposure and response.
Publisher: American Physical Society (APS)
Date: 15-02-2008
Publisher: American Physical Society (APS)
Date: 08-01-2008
Publisher: American Physical Society (APS)
Date: 14-07-2008
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/EN06026
Abstract: Environmental Context. The pathways by which arsenic is accumulated, biotransformed and transferred in aquatic ecosystems are relatively unknown. Examination of whole marine ecosystems rather than in idual organisms provides greater insights into the biogeochemical cycling of arsenic. Rocky intertidal zones, which have a high abundance of organisms but low ecological ersity, are an important marine habitat. This study examines the cycling of arsenic within intertidal ecosystems to further understand its distribution and transfer. Abstract. The present study reports total arsenic and arsenic species in a short rocky intertidal marine food chain in NSW, Australia. Total mean arsenic concentrations increased up the food chain in the following order: 4 ± 2 µg g–1 in attached rock microalgae, 31 ± 14 µg g–1 in Bembicium nanum Lamarck, 45 ± 14 µg g–1 in Cellana tramoserica Sowerby, 58 ± 14 µg g–1 in Nerita atramentosa Reeve, 75 ± 15 µg g–1 in Austrocochlea constrica Lamarck (a herbivore) and 476 ± 285 µg g–1 in the carnivore Morula marginalba Blainville. Significant differences in arsenic concentrations of B. nanum, N. atramentosa and M. marginalba were found among locations and may be related to food availability, spawning or differences in age and/or size classes of in iduals. Significant differences in arsenic concentrations were also found within locations among species, and increased in the order: rock microalgae B. nanum C. tramoserica N. atramentosa A. constricta M. marginalba. Although small differences in total arsenic concentrations were found among locations for some gastropod species, arsenic species proportions were very consistent within gastropod species across locations. The majority of arsenic in Homosira banksii (macroalgae) was oxo-arsenoribosides, with thio-arsenoribosides making up ~10% of the total methanol–water extractable arsenic. The rock microalgae contained arsenobetaine (AB) (59 ± 5%) and arsenoribosides (36 ± 15%). The AB content of the herbivores B. nanum, N. atramentosa and A. constricta ranged from 71 to 95%, and that of the carnivore M. marginalba was 98%. Most gastropods contained thio-arsenosugars (up to 13 ± 3% of total extractable arsenic), with C. tramoserica containing higher proportions of thio-phosphate arsenoriboside (7 ± 2%) and lower proportions of AB (69 ± 4%). Glycerol trimethylarsonioribosides (1.4 ± 0.1%) were also found in most of the herbivorous gastropods. Oxo-dimethylarsinoylethanol (oxo-DMAE) was found in N. atramentosa ( %).
Publisher: Royal Society of Chemistry (RSC)
Date: 2008
DOI: 10.1039/B715465H
Abstract: This paper describes the measurement of total antimony and antimony species in "real world" mine contaminated sediments using ICPMS and HPLC-ICPMS. Low and high temperature microwave extraction procedures (90 degrees C and 150 degrees C, respectively) using a range of nitric-hydrochloric acid combinations were examined as to their efficacy to extract antimony from six mine contaminated soils and a certified reference material. The use of the higher temperature with nitric-hydrochloric acid (1:2 (v/v)) was suitable to release antimony from sediments and the certified reference material, NIST 2710 Montana soil. Antimony concentrations obtained using this acid mixture were similar to those obtained using a more aggressive extraction with nitric, hydrochloric, perchloric and hydrofluoric acid mixture. A 25 mM citric acid solution at 90 degrees C for 15 min extracted 47-78% of antimony from soils. A Hamilton PRP X-100 anion exchange column with 20 mM EDTA mobile phase, pH 4.5, flow rate 1.5 mL min(-1) and column temperature of 50 degrees C was used to separate antimony species. Column recoveries ranged from 78-104%. The predominant form of antimony was Sb(5+). Little conversion of Sb(5+) occurred (<5%) during extraction, however, significant conversion of Sb(3+) occurred (approximately 36%). The extraction of antimony species with citric acid should be useful in the determination of inorganic antimony available to plants, as plants commonly excrete carboxylic acids, including citric acid, into their rhizospheres to mobilise trace elements for nutritional purposes.
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 2008
Publisher: Oxford University Press (OUP)
Date: 26-02-2015
DOI: 10.1039/C5MT00025D
Abstract: Three month old Thunbergia alata were exposed for 13 days to 10 μM selenite to determine the biotransformation of selenite in their roots. Selenium in formic acid extracts (80 ± 3%) was present as selenopeptides with Se–S bonds and selenium–PC complexes (selenocysteinyl-2-3-dihydroxypropionyl-glutathione, seleno-phytochelatin2, seleno-di-glutathione). An analytical method using HPLC-ICPMS to detect and quantify elemental selenium in roots of T. alata plants using sodium sulfite to quantitatively transform elemental selenium to selenosulfate was also developed. Elemental selenium was determined as 18 ± 4% of the total selenium in the roots which was equivalent to the selenium not extracted using formic acid extraction. The results are in an agreement with the XAS measurements of the exposed roots which showed no occurrence of selenite or selenate but a mixture of selenocysteine and elemental selenium.
Publisher: Royal Society of Chemistry (RSC)
Date: 2005
DOI: 10.1039/B509202G
Abstract: This paper describes our experiences with undertaking measurements of total antimony and antimony speciation in algae, plant and animal tissues. Digestion with nitric acid alone is suitable to release antimony from animal tissues. When organisms have high silica contents, e.g. some plants and algae, the addition of tetrafluorboric acid is required to dissolve silica as some antimony is retained by silica in extracts. Antimony in digested extracts is present as Sb5+ and hydride generation procedures can be used to determine total antimony concentrations, as total antimony in extracts will not be under estimated. Relatively non-aggressive solvents such as water, dilute nitric acid, sodium hydroxide and enzymes remove highly variable amounts of antimony (2-84%) from algae, plant and animal tissues. Addition of Sb3+ and Sb5+ to NIST CRM 1572 Citrus Leaves, pre- and post-extraction with water showed that Sb3+ is oxidised to Sb5+ while Sb5+ is redistributed amongst binding sites giving rise to artefacts. DOLT-2 and algae extracts indicated the presence of only inorganic antimony. A moss s le had inorganic antimony and a number of unknown antimony species in extracts. Future studies should explore the nature of the binding of antimony in tissues as solvents commonly used to extract metals and metalloids from algae, plant and animal tissues are not appropriate.
Publisher: Elsevier BV
Date: 15-02-2007
DOI: 10.1016/J.TALANTA.2006.04.027
Abstract: This paper describes the use of dilute nitric acid for the extraction and quantification of arsenic species. A number of extractants (e.g. water, 1.5M orthophosphoric acid, methanol-water and dilute nitric acid) were tested for the extraction of arsenic from marine biological s les, such as plants that have proved difficult to quantitatively extract. Dilute 2% (v/v) nitric acid was found to give the highest recoveries of arsenic overall and was chosen for further optimisation. The optimal extraction conditions for arsenic were 2% (v/v) HNO(3), 6 min(-1), 90 degrees C. Arsenic species were found to be stable under the optimised conditions with the exception of the arsenoriboses which degraded to a product eluting at the same retention time as glycerol arsenoribose. Good agreement was found between the 2% (v/v) HNO(3) extraction and the methanol-water extraction for the certified reference material DORM-2 (AB 17.1 and 16.2microg g(-1), respectively, and TETRA 0.27 and 0.25microg g(-1), respectively), which were in close agreement with the certified concentrations of AB 16.4+/-1.1microg g(-1) and TETRA 0.248+/-0.054microg g(-1). To preserve the integrity of arsenic species, a sequential extraction technique was developed where the previously methanol-water extracted pellet was further extracted with 2% (v/v) HNO(3) under the optimised conditions. Increases in arsenic recoveries between 13% and 36% were found and speciation of this faction revealed that only inorganic and simple methylated species were extracted.
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/EN14069
Abstract: Environmental context Arsenic biotransformation processes play a key role in the cycling of arsenic in aquatic systems. We show that a freshwater cyanobacterium can convert inorganic arsenic into arsenolipids, and the conversion efficiency depends on the arsenic concentration. The role of these novel arsenic compounds remains to be elucidated. Abstract Although methylated arsenic and arsenosugars have been verified in various freshwater organisms, lipid-soluble arsenic compounds have not been identified. Here, we report investigations with the model organism cyanobacterium Synechocystis sp. PCC 6803 wild type and ΔarsM (arsenic(III) S-adenosylmethionine methyltransferase) mutant strain, which lacks the enzymes for arsenic methylation cultured in various concentrations of arsenate (AsV). Although Synechocystis accumulated higher arsenic concentrations at the higher exposure levels, the bioaccumulation factor decreased with increasing AsV. The accumulated arsenic in the cells was partitioned into water-soluble and lipid-soluble fractions lipid-soluble arsenic was found in Synechocystis wild type cells (3–35% of the total depending on the level of arsenic exposure), but was not detected in Synechocystis ΔarsM mutant strain showing that ArsM was required for arsenolipid biosynthesis. The arsenolipids present in Synechocystis sp. PCC 6803 were analysed by high performance liquid chromatography–inductively coupled plasma–mass spectrometry, high performance liquid chromatography–electrospray mass spectrometry, and high resolution tandem mass spectrometry. The two major arsenolipids were characterised as arsenosugar phospholipids based on their assigned molecular formulas C47H88O14AsP and C47H90O14AsP, and tandem mass spectrometric data demonstrated the presence of the phosphate arsenosugar and acylated glycerol groups.
Publisher: American Physical Society (APS)
Date: 10-07-2008
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/EN07063
Abstract: Environmental context. The present study examines arsenic species in kelp and associated grazing animals of an Ecklonia radiata food chain. The study focusses on the changes in proportions of arsenoribosides obtained from E. radiata and mechanisms are proposed to explain the transformations of arsenoribosides observed in the organisms that graze on it. Abstract. Total arsenic and arsenic species in the tissues of three growth stages of the macroalgae Ecklonia radiata and within organisms that feed on it are reported. Arsenic concentrations in E. radiata tissues varied from 40 to 153 μg g–1. Growth stage did not influence arsenic concentrations or arsenic species. E. radiata contained glycerol arsenoriboside (1–8.5%), phosphate arsenoriboside (10–22%) and sulfonate arsenoriboside (73–91%). Arsenic concentrations varied significantly among animal species and between tissues (5–123 μg g–1). Animals contained variable quantities of arsenobetaine (14–83%). Haliotis rubra tissues contained high concentrations of glycerol trimethylarsonioriboside (0.7–22%) and the fish Odax cyanomelas contained large quantities of phosphate arsenoriboside (25–64%) with little arsenobetaine (1.5–15%). Arsenoribosides consumed from macroalgae are substantially converted or differentially accumulated as glycerol and phosphate arsenoribosides in animal tissues. In all animals, phosphate arsenoriboside would appear to be conserved or synthesised de novo. In gastropods, glycerol trimethylarsonioriboside and thio arsenic species are formed in the digestive system. Thus, the intermediate arsenic species that form a plausible pathway for the formation of arsenobetaine from dimethylarsenoribosides are present.
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.JES.2016.06.003
Abstract: Arsenobetaine (AB) and thio-arsenoribosides were measured in common macroalgae species (8 phaeophyta, 4 rhodophyta and 2 chlorphyta), along the Australian south east coast line. As well, arsenic species profiles were measured for two common marine herbivores, the sea urchin Centrostephanus rodgersii and the fish Odax cyanomelas that graze on these macroalgae to understand if trophic transfer of these species would account for their presence in marine herbivores. AB was found in seven of the fourteen macroalgae species investigated but does not contributed significantly to any of the macroalgae arsenic content (0.01-1.2μg/g). AB was found in only two of the brown macroalgae and all the red and green macroalgae (with the exception of Corallina officinalis). Thio-arsenic species were found sporadically, but not in high concentrations in any of the macroalgae investigated. AB present in macroalgae is likely to be associated with epiphytic organisms while thio-arsenoribosides are likely to be produced by decaying parts of damaged macroalgae. A laboratory feeding experiment in which the herbivorous gastropod, Austrocochlea constricta, was fed macroalgae containing thio-arsenoribosides for a 24hr period every three days showed that these are readily accumulated over a short period. Thio-arsenoribosides in herbivores are therefore probably obtained through trophic transfer. Some AB is also obtained through trophic transfer however, the presence of trimethylated arsonioribosides, a hypothesized precursor of AB formation in herbivores, suggests that some AB is produced within herbivores from the transformation of arsenoribosides accumulated from their diet.
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/EN08097
Abstract: Environmental context. Concern over the presence of antimony (Sb) in the environment because of chemical similarities with arsenic (As) has prompted a need to better understand its environmental behaviour and risks. The present study investigates the bioaccumulation and uptake of antimony in a highly contaminated stream near the Hillgrove antimony–gold mine in NSW, Australia, and reports high Sb (and As) concentrations in many components of the ecosystem consisting of three trophic levels, but limited uptake into aboveground parts of riparian vegetation. The data suggest that Sb can transfer into upper trophic levels of a creek ecosystem, but that direct exposure of creek fauna to creek sediment and soil, water and aquatic autotrophs are more important metalloid uptake routes than exposure via riparian vegetation. Abstract. Bioaccumulation and uptake of antimony (Sb) were investigated in a highly contaminated stream, Bakers Creek, running adjacent to mining and processing of Sb–As ores at Hillgrove Mine, NSW, Australia. Comparisons with arsenic (As) were included owing to its co-occurrence at high concentrations. Mean metalloid creek rhizome sediment concentrations were 777 ± 115 μg g–1 Sb and 60 ± 6 μg g–1 As, with water concentrations at 381 ± 23 μg L–1 Sb and 46 ± 2 μg L–1 As. Antimony and As were significantly elevated in aquatic autotrophs (96–212 μg g–1 Sb and 32–245 μg g–1 As) but Sb had a lower uptake efficiency. Both metalloids were elevated in all macroinvertebrates s led (94–316 μg g–1 Sb and 1.8–62 μg g–1 As) except Sb in gastropods. Metalloids were detected in upper trophic levels although biomagnification was not evident. Metalloid transfer to riparian vegetation leaves from roots and rhizome soil was low but rhizome soil to leaf As concentration ratios were up to 2–3 times greater than Sb concentration ratios. Direct exposure to the rhizosphere sediments and soils, water ingestion and consumption of aquatic autotrophs appear to be the major routes of Sb and As uptake for the fauna of Bakers Creek.
Publisher: American Physical Society (APS)
Date: 26-06-2008
Publisher: American Chemical Society (ACS)
Date: 13-05-2013
DOI: 10.1021/ES304299V
Abstract: The measurement of As species in rice is normally accomplished by extraction followed by HPLC-ICPMS analysis. This method, however, has not been comprehensively validated by comparing these speciation results with XANES, which does not require s le extraction, due to the challenge of conducting XANES analysis at very low As concentrations. In this study As speciation data using nitric acid extraction/HPLC-ICPMS and XANES are compared to verify the efficacy of using 2% v/v nitric acid extraction and HPLC-ICPMS to measure inorganic As, DMA, and MA in reference rice materials and common rice varieties obtainable in Australia. Total As and As species (As(III), As(V), DMA, and MA) concentrations measured in 8 reference materials were in agreement with published values. XANES analysis was performed on 5 s les having total As concentrations ranging from 0.198 to 0.335 μg g(-1). XANES results gave similar proportions of total As(III), As(V), and DMA to HPLC-ICPMS. XANES was able to distinguish two forms of As(III): As(III) and As(III)GSH. Total As concentrations in rice s les varied from 0.006 to 0.45 μg g(-1) As (n = 47) with a mean ± std of 0.127 ± 0.112 μg g(-1) As with most As present as inorganic species (63 ± 26%). DMA was found in nearly all the rice s les with the majority of s les containing concentrations below 0.05 μg g(-1) As while MA concentrations were negligible (<0.003 μg g(-1) As). Six rice varieties produced in Australia, China, and Spain all had elevated DMA concentrations (0.170-0.399 μg g(-1) As) that were correlated with total As concentrations (r(2) = 0.7518). In conclusion, comparison of As speciation by HPLC-ICPMS and XANES showed that similar As species were detected indicating the appropriateness of using 2% v/v nitric acid for extraction of rice prior to speciation. Common rice varieties obtainable in Australia generally have low As concentrations with most As present as inorganic As.
Publisher: American Physical Society (APS)
Date: 10-11-2008
Publisher: Elsevier BV
Date: 05-2016
Publisher: American Physical Society (APS)
Date: 12-09-2008
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/EN05027
Abstract: Environmental Context. In well-oxygenated water and sediments, nearly all arsenic is present as arsenate (AsO43−). As arsenate is a phosphate (PO43−) analogue, organisms living in arsenate-rich environments must acquire the nutrient phosphorus yet avoid arsenic toxicity. Organisms take in and transform arsenic compounds by many means. Three major modes of arsenic biotransformation have been found to occur in the environment—redox transformation between arsenate and arsenite (AsO2−), the reduction and methylation of arsenic, and the biosynthesis of organoarsenic compounds such as arsenobetaine. These biotransformations lead to biogeochemical cycling of arsenic compounds and bioconcentration of arsenic in aquatic organisms and thence into the food web. Abstract. The paper reports the whole-tissue total arsenic concentrations and water-soluble arsenic species in eight common coastal Australian polychaete species. Laboratory experiments showed the period of depuration did not significantly alter the whole-tissue total arsenic concentrations in the two estuarine polychaete species tested. Significant differences were found between the whole-tissue total arsenic concentrations of the eight polychaete species (mean arsenic concentrations ranged from 18 to 101 µg g−1 dry mass). Total arsenic concentrations in polychaete species, grouped on the basis of a combination of their feeding guild and habitat type, were also significantly different with a significant interaction between these factors indicating that both factors simultaneously influence arsenic concentration in polychaetes. A large number of polychaete species contained similar arsenic species with high proportions of arsenobetaine (AB 57–88%) and relatively low proportions of As3+, As5+, methyarsonic acid, dimethylarsinic acid, arsenocholine, trimethylarsoniopropionate, and tetramethylarsonium ion (not detected to 12%). All polychaete species contained arsenoribosides (5–30%). This study identified two Australian polychaete species with particularly unusual whole-tissue water-soluble arsenic species proportions: Australonuphis parateres contained a very high proportion of trimethylarsoniopropionate (~33%), while Notomastus estuarius had a very low proportion of arsenobetaine (9%) and high proportions of As3+ (~30%), As5+ (~8%), arsenoribosides (30%), and an unknown anionic arsenic species (~4%). Most polychaetes accumulate arsenobetaine, except deposit feeders inhabiting estuarine mud habitats. Thus most polychaetes, which are prey for higher organisms, are a source of arsenobetaine in benthic food webs. Deposit feeders inhabiting estuarine muddy substrates contain appreciable quantities of inorganic arsenic and arsenoribosides that may be metabolized to different end products in higher organisms.
Location: Australia
Start Date: 2009
End Date: 2009
Funder: Australian Synchrotron
View Funded ActivityStart Date: 2009
End Date: 2009
Funder: Office for Learning and Teaching
View Funded ActivityStart Date: 2010
End Date: 2013
Funder: NSW Environmental Trust
View Funded ActivityStart Date: 2006
End Date: 2009
Funder: Royal Australian Chemical Institute
View Funded ActivityStart Date: 2008
End Date: 2010
Funder: The Hermon Slade Foundation
View Funded ActivityStart Date: 2009
End Date: 12-2011
Amount: $700,000.00
Funder: Australian Research Council
View Funded Activity