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  • 1
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    German Medical Science GMS Publishing House; Düsseldorf
    In:  31. Jahrestagung der Deutschsprachigen Arbeitsgemeinschaft für Verbrennungsbehandlung (DAV 2013); 20130116-20130119; Mayrhofen, Österreich; DOC13dav15 /20130219/
    Publication Date: 2013-02-20
    Keywords: ddc: 610
    Language: German
    Type: conferenceObject
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  • 2
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    facet.materialart.
    German Medical Science GMS Publishing House; Düsseldorf
    In:  Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017); 20171024-20171027; Berlin; DOCPO13-799 /20171023/
    Publication Date: 2017-10-23
    Keywords: Silber ; Megaprothese ; ddc: 610
    Language: German
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  • 3
    facet.materialart.
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    German Medical Science GMS Publishing House; Düsseldorf
    In:  31. Jahrestagung der Deutschsprachigen Arbeitsgemeinschaft für Verbrennungsbehandlung (DAV 2013); 20130116-20130119; Mayrhofen, Österreich; DOC13dav08 /20130219/
    Publication Date: 2013-02-20
    Keywords: ddc: 610
    Language: German
    Type: conferenceObject
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  • 4
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Common shrimp, Crangon crangon (L.), were exposed to inorganic arsenic (arsenate), trimethylarsine oxide, or arsenobetaine in sea water (100 μg As l−1) or in food (1 mg As g−1 wet wt) for up to 24 d, followed by 16 d depuration in clean sea water with undosed food, in order to determine the efficiency of uptake and retention of the compounds. Accumulation of arsenic in the tail muscle, gills, midgut gland, exoskeleton, and remaining tissues was found to depend on the chemical form of the arsenic and the route of exposure. No arsenic was accumulated by C. crangon exposed to arsenate or trimethylarsine oxide in sea water. Shrimps exposed to waterborne arsenobetaine initially accumulated a small amount of arsenic in their tail muscle and gills. After 16 d, C. crangon fed arsenate, trimethylarsine oxide, or arsenobetaine had accumulated arsenic in their tail muscle to levels ∼2-, 2-, or 40-times, respectively, that of the control group. A roughly linear rate of accumulation was shown by shrimps fed trimethylarsine oxide or arsenobetaine, but C. crangon fed arsenate accumulated arsenic for 16 d, then lost arsenic such that their concentration on Day 24 was not significantly different from that of the control group. Patterns of arsenic accumulation in the gills of shrimps fed the compounds were similar to those seen in the tail muscle. On a whole animal basis, C. crangon retained ∼1.2% of the arsenate, 1.6% of the trimethylarsine oxide, and 42% of the arsenobetaine consumed over the first 16 d of exposure, with roughly half present in the tail muscle in each case. Data obtained support the view that the direct uptake of arsenobetaine from sea water does not make a significant contribution to the relatively high concentrations of this compound in marine crustaceans, and that food is the primary source. Naturally occurring arsenic compounds in C. crangon and possible transformations of the administered arsenic compounds were examined by high performance liquid chromatography using an inductively coupled plasma mass spectrometer as the arsenic-specific detector. Control C. crangon contained arsenobetaine as the major arsenic compound (>95% of total arsenic); tetramethylarsonium ion (0.7%) and an unknown arsenic compound (1.7%) were also present as minor constituents. Shrimp ingesting arsenobetaine accumulated it unchanged. Shrimp ingesting arsenate did not form methylated arsenic compounds; they appeared to contain their accumulated arsenic as unchanged arsenate only, although the possibility that some of the arsenic was reduced to arsenite could not be excluded. C. crangon ingesting trimethylarsine oxide biotransformed the compound predominantly to dimethylarsinate.
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  • 5
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract 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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  • 6
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract When mercury is quantified by ICP-MS under routine conditions (external calibration) in reference materials, which require mineralization with nitric acid, the experimental concentrations are almost always unacceptably low in comparison to certified values. Sorption of mercury on the Teflon surfaces of the digestion vessels, changes in the viscosity of the aspirated solutions, in the efficiency of the nebulization, in the aerosol transport, and memory effects cannot be responsible for the low results. The intensity of a mercury signal is strongly dependent on the concentration of nitric acid (and other mineral acids) in the measured solutions. Correct results for mercury in the SRM GBW-90101 (Chinese human hair; 2.16 ± 0.21 mg Hg/kg certified) can only be obtained, when the solutions, with which the external calibration curves were established, have exactly the same nitric acid concentration as the aspirated digests (2.03 ± 0.01 mg Hg/kg; n = 5), when mercury is determined by the standard addition method (2.10 ± 0.01 mg Hg/kg; n = 5), or when the experimental mercury concentration obtained at a nitric acid concentration in the digest, different from the concentration in the external calibration solutions, is corrected mathematically based on a pre-established function [Hg2+] = f [HNO3]. The concentrations found by this mathematically based correction 2.04 ± 0.01 mg Hg/kg (n = 5) is in good agreement with the values obtained by acid matched calibration or by the standard addition method. For practical work with large numbers of samples the mathematical correction appears to be the method of choice. For occasional mercury determinations, the standard addition method seems to be the most practicable.
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  • 7
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A microwave procedure for the digestion of the NIST 1634b reference material “residual fuel oil” in closed pressurized vessels was developed in an attempt to facilitate routine analysis and obtain reproducible conditions or comparable results. The influence of sample size, reagent composition and volume, microwave power, and duration of heating on the digestion procedure was studied. Pressure and temperature inside the reaction vessels were monitored to determine the progression of the reaction and to develop optimal conditions. A nine-step heating program requiring 36.5 min with microwave power not exceeding 450 W in the pulsed mode was found suitable for the digestion of ∼ 250 mg fuel oil with a mixture of nitric acid (5.0 mL) and hydrogen peroxide (2.0 mL). The reproducibility of microwave power was determined in terms of the relative standard deviations (n = 3) for temperature (2.7%) and pressure (4.9%) data. The vapor pressures obtained with 5.0 mL Milli-Q water (heated) in an 80-mL digestion vessel showed good agreement with literature data. The excess acid in the resulting digests was removed by evaporation and the concentrations of 24 elements (Ag, Al, As, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mo, Ni, Pb, Sb, Sn, Sr, Ti, Tl, V, U, and Zn) were determined in the diluted digests by inductively coupled plasma mass spectrometry (ICP-MS). The experimental results were in good agreement with the certified and recommended concentrations for eight elements (Al, As, Co, Cr, Ni, Pb, V, Zn) in solutions obtained after one digestion step. An additional digestion step, consisting of intermediate cooling and venting stages, was required for the accurate determination of Fe. No agreement was reached for Ca and Ba even after two-step digestion. The proposed method of digestion provided precise results with relative standard deviations generally less than 5% for most of the elements determined.
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  • 8
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The retention behavior of four naturally occurring dimethylarsinoylribosides with –CH2-CHOH-CH2X (X = OH, HO3POCH2CHOHCH2OH, SO3H, OSO3H) as aglycones, of arsenous acid, arsenic acid, methylarsonic acid, and dimethylarsinic acid was investigated on a Hamilton PRP-X100 anion-exchange column with aqueous solutions of ammonium dihydrogen phosphate (20 mmol/L) in the pH range of 3.8–9.0 as mobile phase. A HP 4500 inductively coupled plasma mass spectrometer (ICP-MS) served as arsenic-specific detector. The influence of pH, temperature, and the concentration of methanol in the mobile phase on the retention times of these arsenic compounds was explored. An aqueous 20 mM ammonium dihydrogen phosphate solution at pH 5.6 at a column temperature of 40 °C was considered optimal as it allowed ¶the separation of seven of the arsenic compounds within 16 min. Only arsenous acid and the ribose with the glycerol aglycone have overlapping signals with both migrating almost with the solvent front. At a concentration of 0.50 ng As mL–1 the relative standard deviations (n = 3) of the signal areas of the eight arsenic compounds was in the range from 3.5 to 8.1%. The linear calibration curves (peak areas) from 0.5 to 10 ng/mL had correlation coefficients ¶> 0.997. Extracts obtained from the brown algae Fucus spiralis and Halidrys siliquosa were chromatographed under the optimized conditions. Both species contained the sulfate riboside as the major arsenic compound (∼55% of total extractable arsenic) together with the sulfonate- and phosphate riboside. Arsenic acid was a significant constituent of Halidrys siliquosa (∼6.5%), but was not detected in Fucus spiralis.
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  • 9
    ISSN: 0268-2605
    Keywords: arsenic species ; mushrooms ; methylarsonic acid ; dimethylarsinic acid ; tetramethylarsonium ion ; arsenobetaine ; arsenite ; arsenate ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Arsenic species in arsenic accumulating mush- rooms (Sarcosphaera coronaria, Laccaria amethystina, Sarcodon imbricatum, Entoloma lividum, Agaricus haemorrhoidaius, Agaricus placomyces, Lycoperdon perlatum) were determined. HPLC/ICP MS and ion-exchange chromatogra- phy-instrumental neutron activation analysis (NAA) combinations were used. The remarkable accumulator Sarcosphaera coronaria (up to 2000 mg As kg-1 dry wt) contained only methylarsonic acid, Entoloma lividum only arsenite and arsenate. In Laccaria amethystina dimethylarsinic acid was the major arsenic compound. Sarcodon imbricatum and the two Agaricus sp. were found to contain arsenobetaine as the major arsenic species, a form which had previously been found only in marine biota. Its identification was confirmed by electron impact MS.
    Additional Material: 5 Ill.
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  • 10
    ISSN: 0268-2605
    Keywords: Chlorella sp. ; biomethylation ; arsenic ; HPLC-ICP-MS ; cadmium ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The growth of Chlorella Böhm, Chlorella kessleri and Chlorella 108 in media containing sodium arsenate at 200 or 2000 mg As dm-3 was investigated. The cell densities in the stationary phases were 40% higher for Chlorella Böhm (5.6×105 cells cm-3) and Chlorella kessleri (4.5×105 cells cm-3) grown in the 2000 mg As dm-3 arsenate media compared with the arsenic-free media. The growth of Chlorella 108 was depressed by arsenate. Dimethylarsinic acid (at concentrations never exceeding 1.2 mg As dm-3) and arsenite (≲0.2 mg As dm-3) were detected in the growth medium. The cells harvested during the stationary phase had 2400 mg arsenic associated with 1 kg dry mass. A water/methanol (80:20) mixture extracted all the arsenic from the cells. Most of the arsenic (99%) was arsenate. Arsenite, methylarsonic acid and dimethylarsinic acid accounted for the remaining arsenic. Cadmium in the arsenic-containing growth media (50 μg to 100 mg dm-3) reduced the yield of algal cells and induced the formation of an unidentified arsenic compound in Chlorella Böhm. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 7 Ill.
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