John S. Edmonds

Arsenic and Marine Organisms

Publisher Summary The chapter provides an overview of marine arsenic research and arsenic concentrations in the various marine compartments. General chemical and analytical characteristics of the arsenic compounds of significance in marine arsenic studies are mentioned in the chapter followed by an outline of their occurrence, distribution, and biotransformation in marine samples. Workers in the area have applied different scientific disciplines to advance various aspects of the problem over the years. For example, progress in biological and biochemical studies of the uptake of arsenic by algae was made following chemical studies identifying the natural arsenic constituents of algae. Subsequent chemical synthesis of the arsenic compounds enabled toxicological assessment and further biotransformation studies to be carried out. The presence of both arsenobetaine and arsenosugars in the one organism, particularly one from such an isolated and selfcontained environment, might be taken as support for the view that arsenosugars are serving as precursors to arsenobetaine.

Fish otolith reference material for quality assurance of chemical analyses

Abstract A certified reference material (CRM) for major, minor and trace element analysis was prepared from sagittal otolith of red emperor ( Lutjanus sebae ) at National Institute for Environmental Studies (NIES), Japan in collaboration with Western Australian Marine Research Laboratories (WAMRL), Australia. Otoliths (1.4 kg) were cleaned, pulverized, sieved to pass a 105-μm screen and homogenized, and 375 vials, each containing 3 g, were prepared. Certified value was determined for Na, Mg, K, Ca, Sr and Ba through a collaboration involving NIES and five other laboratories. The certified value (mean of the means reported from the collaborating laboratories plus or minus the 95% confidence interval) were 97.0±4.2 μmol/g (0.223±0.010%) for Na, 0.88±0.06 μmol/g (21±1 μg/g) for Mg, 7.21±0.20 μmol/g (282±8 μg/g) for K, 9.69±0.11 mmol/g (38.8±0.5%) for Ca, 26.9±0.5 μmol/g (0.236±0.005%) for Sr and 21.1±0.6 nmol/g (2.89±0.09 μg/g) for Ba. Reference values were given for Cu [12 nmol/g (0.74 μg/g)], Zn [7.2 nmol/g (0.47 μg/g)], Cd [0.025 nmol/g (0.0028 μg/g)] and Pb [0.11 nmol/g (0.023 μg/g)] based on definitive analyses at NIES. This CRM will be of practical value for the quality assurance of solution-based elemental analysis of fish otoliths and other marine aragonites.

Arsenic-Containing Long-Chain Fatty Acids in Cod-Liver Oil: A Result of Biosynthetic Infidelity?†

tioned between hexane and aqueous methanol, and the polar phase subjected to preparative chromatography with sizeexclusion and anion-exchange media to yield a fraction enriched in polar arsenolipids. Analysis of this fraction by HPLC–inductively coupled plasma mass spectrometry (ICPMS) revealed the presence of at least 15 arsenolipids (Figure 2). Further investigation of the fraction with HPLC– electrospray ionization MS (ESI-MS), under conditions that provided simultaneous detection of elemental arsenic and molecular masses, [3] showed that six of the major arsenicals (A–F in Figure 2) had the following molecular masses: A 334, B 362, C 390, D 418, E 388, and F 436. The mass spectral data for four of these compounds (A–D) were consistent with the presence of a homologous series of arsenic-containing saturated fatty acids of the type (CH3)2As(O)-(CH2)nCOOH (n = 12, 14, 16, and 18) with a dimethylarsinoyl group,

Accumulation of arsenic in yelloweye mullet (Aldrichetta forsteri) following oral administration of organoarsenic compounds and arsenate

Groups of yelloweye mullet (Aldrichetta forsteri) were maintained for several weeks on diets containing one of a range of organoarsenic compounds (arsenobetaine, arsenocholine, 2-dimethylarsinylethanol, 2-dimethylarsinylacetic acid, 2-dimethylarsinothioylethanol) or arsenate. Fish fed 2-dimethylarsinylethanol, 2-dimethylarsinylacetic acid or 2-dimethylarsinothioylethanol showed no increase in arsenic concentrations in their muscle tissue, while fish fed arsenate showed small increases. The two groups of fish which received either arsenobetaine or arsenocholine had greatly elevated arsenic concentrations in their muscle tissue resulting from an estimated approximately 40% retention of ingested arsenic. Examination of the form of arsenic accumulated by fish fed arsenocholine showed that most of the arsenic (89%) was accumulated as arsenobetaine.

Arsenic Transformations in Short Marine Food Chains studied by HPLC-ICP MS

The chemical forms of arsenic in some herbivorous or mainly herbivorous marine animals and, in some cases, the algae on which they feed were determined by HPLC-ICP MS. In most cases arsenobetaine was present in the animals as well as arsenosugars consumed directly from the algae. However in the case of copepods Gladioferens imparipes fed only on the diatom Chaetoceros concavicornis which had been grown in axenic culture, arseno-betaine was absent. Arsenobetaine was also absent from the muscle of the silver drummer Kyphosus sydneyanus, although trimethyl-arsine oxide was present. This is the first reported case of the absence of arsenobetaine in a marine teleost fish and may be related to its fermentative faculty for digesting the macroalgae that it consumes.

Arsenic-Containing Lipids Are Natural Constituents of Sashimi Tuna

Arsenic occurs naturally in many types of seafood as water- and fat-soluble organoarsenic compounds. Although water-soluble compounds have been well characterized, the fat-soluble compounds, so-called arsenolipids, have until recently remained unknown. We report that sashimi-grade tuna fish, with a total arsenic content of 5.9 microg of As/g dry mass, contains approximately equal quantities of water- and fat-soluble arsenic. The water-soluble arsenic comprised predominantly arsenobetaine (>95%) with a trace of dimethylarsinate. Two fat-soluble compounds, which together accounted for about 40% of the lipid-arsenic, were isolated and characterized. The first was identified as 1-dimethylarsinoylpentadecane [(CH(3))(2)As(O)(CH(2))(14)CH(3)] by comparison of HPLC/mass spectrometric data and accurate mass data with those of an authenticated synthesized standard. The second arsenolipid was postulated as 1-dimethylarsinoyl all-cis-4,7,10,13,16,19-docosahexane from mass spectrometric data and analogy with non-arsenic-containing lipids found in fish. The remaining fat-soluble arsenic consisted of less polar arsenolipids of currently unknown structure. This is the first identification of arsenolipids in commonly consumed seafood.

Methylated arsenic from marine fauna.

IT has long been known that certain species of marine animals contain arsenic in their tissues at concentrations up to 100 p.p.m. (ref. 1), and there is little doubt that this arsenic is naturally acquired and does not reflect environmental pollution. The toxicity of arsenic is dependent on its chemical environment and valency state2,3. Since the demonstration of the rapid and complete excretion by the human kidney of arsenic consumed in fish and shellfish1,4, it has been accepted that such arsenic is in an organic and nontoxic form5. Clearly full toxicological evaluation of the arsenic in marine animals awaits the elucidation of the precise chemical nature of that arsenic. We have found that mussels (Mytilus edulis planulatus Lamarck), western rock lobster (Panulirus longipes cygnus George), and stingray (Dasyatis thetidis Waite) contain dimethylated and trimethylated arsenic together with a small proportion of inorganic arsenic.

Degradation of 1,4-dioxane and cyclic ethers by an isolated fungus.

ABSTRACT By using 1,4-dioxane as the sole source of carbon, a 1,4-dioxane-degrading microorganism was isolated from soil. The fungus, termed strain A, was able to utilize 1,4-dioxane and many kinds of cyclic ethers as the sole source of carbon and was identified as Cordyceps sinensis from its 18S rRNA gene sequence. Ethylene glycol was identified as a degradation product of 1,4-dioxane by the use of deuterated 1,4-dioxane-d8 and gas chromatography-mass spectrometry analysis. A degradation pathway involving ethylene glycol, glycolic acid, and oxalic acid was proposed, followed by incorporation of the glycolic acid and/or oxalic acid via glyoxylic acid into the tricarboxylic acid cycle.

Arsenic lipids in the digestive gland of the western rock lobster Panulirus cygnus: an investigation by HPLC ICP-MS

The digestive gland of the western rock lobster, Panulirus cygnus, was shown to contain phosphatidylarsenocholine and a phosphatidyldimethylarsinylriboside by HPLC ICP-MS examination of lipid materials rendered water-soluble by hydrolysis. Water-soluble arsenic material in the digestive gland was chiefly arsenobetaine but the deacylated analogue of the phosphatidyldimethylarsinylriboside and an unidentified compound were also present.

Trace elements in the otoliths of yellow-eye mullet (Aldrichetta forsteri) as an aid to stock identification

Abstract Concentrations of trace elements in the sagittal otoliths of yellow-eye mullet from three (1986) and four (1988) locations along the coast of southwestern Australia, including two neighbouring estuaries, were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Canonical variate (discriminant) analyses of the elemental concentrations showed these to be specific to the location of capture of the fish, although, with the exception of Swan River samples, there was a considerable overlap of data points. There were substantial (and unexplained) differences in the potassium concentrations in samples taken in 1986 and 1988, but other aspects of the accumulation patterns appeared to persist through time. Populations of yellow-eye mullet in the Swan River might, therefore, be regarded as essentially separate for some fisheries management purposes, but the similarity in element accumulation patterns for the other locations suggested that further evidence would be required before they could be regarded as demographically isolated.