摘要:

AbstractAnalytical methods for arsine, silane and dichlorosilane by adsorption sampling and elemental analysis with graphite furnace AA were studied to establish convenient methods for atmospheric contamination surveys. This study included the following five items: (1) primary selection of adsorbents applicable to adsorption sampling; (2) examination of the adsorption capacities of the adsorbents for the gases; (3) improvement of the adsorbents by chemical modification; (4) desorption of the gases adsorbed on the adsorbents with solvents; and (5) quantitative analysis of arsenic and silicon in the solutions.Experimental results showed that active carbon made from synthetic thermosetting resin beads contained no aresenic and little silicon as impurities. This active carbon by itself was proved to adsorb arsine and dichlorosilane, but not silane. Impregnation with sodium hydroxide of the active carbon improved the adsorption capacity for all three gases. Refined silica gel, free from arsenic contamination, did not adsorb arsine by itself but potassium permanganate impregnation produced an adsorption capacity for arsine.The adsorbed arsine on the active carbon was desorbed into a hot dilute nitric acid solution with high efficiency (over 90%), but arsine adsorbed on sodium hydroxide impregnated active carbon or on potassium permanganate impregnated silica gel was dissolved into various solutions only at lower efficiencies. Silane adsorbed on sodium hydroxide‐impregnated active carbon was desorbed with hot water with an efficiency higher than 90%. Dichlorosilane adsorbed on the active carbon with or without sodium hydroxide impregnation was desorbed with a nitric acid solution with efficiency of 85%. The lower determination limit for arsine able to discriminate from background interference of arsenie was 0.005 ppm, and those for silane and dichlorosilane were each 0.05 ppm for 3‐dm3air samp

ISSN:0268-2605    

DOI:10.1002/aoc.590050202

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractA Puget Sound sediment core has been quantitatively analyzed for organic silicon content, as derived from post‐1945 release of poly(organo)‐siloxanes (silicones). The sedimentary silicone data record and preserve at depth, a smeared event horizon, or first appearance of silicone in the sediment column. Core samples older than 50 years showed no detectable silicone as measured by a new procedure utilizing inductively coupled plasma (ICP) emission spectroscopy after solvent extraction to collect the silicone from gram‐sized sediment core sa

ISSN:0268-2605    

DOI:10.1002/aoc.590050203

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe methylation of heavy‐metal compounds (e.g. mercury, lead, tin) in the environment has great significance owing to the much higher toxicity of their methyl derivatives in comparison with inorganic metal species.In this paper abiological methylation of inorganic tin is described. Ethanol, acetic acid and propionic acid abiologically methylated inorganic tin, and the highest yield of methyltin was observed in the reaction between inorganic tin(II) and ethanol. Furthermore, environmental factors for the methylation, such as pH, temperature, added ethanol, concentration of sodium chloride and photoirradiation, were investigated in this reaction. Methyltin production increased at low pH, and decreased at higher concentrations of sodium chloride. Photoirradiation accelerated the reaction rate, and a shorter wavelength showed a higher rate. Inorganic tin(II) was converted rapidly into monomethyltin, and gradually transformed into dimethyltin and trimethyltin with the course tim

ISSN:0268-2605    

DOI:10.1002/aoc.590050204

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe LC50values of a series of 29 organotin compounds were determined for the red killifish (Oryzias latipes) according to an OECD test guideline. Their toxicities varied from 10−1to 10−5mmol dm−3in five orders of magnitude. In this paper a quantitative structure‐activity relationship (QSAR) study of these organotin compounds was carried out using physicochemical and topological parameters as independent variables. These parameters were found not to be good descriptors for estimating the LC50values. However, when the term index Value (IV), which is created as a new parameter and is defined by the number of phenyl or alkyl groups attached to the tin atom, was used, excellent regression equations to predict the toxicities of organotin compounds were obtained and a multiparametric relationship including IV, Information Index (IWDand Mean Information Index (IWD)) showed the best corr

ISSN:0268-2605    

DOI:10.1002/aoc.590050205

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractTributyltin (TBT) from marine antifouling paints has been shown to have a major impact on the oyster industry in eastern Australia. Current research projects are examining the impact of TBT on Australian estuaries, assessing the response of sensitive biota to recently imposed bans and determining whether a continuing use of TBT on large vessels is an environmental concern.

ISSN:0268-2605    

DOI:10.1002/aoc.590050206

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe utility of29Si NMR spectroscopy has been demonstrated on sediment‐like materials in the quantitative and qualitative determination of polyorganosiloxanes (silicones) in selected environmental samples. This technique is highly selective for polydimethylsiloxanes (PDMS) and is non‐destructive to the sample. Also, specific identification of polyorganosiloxanes in sediment is possible, in contrast to previous methods which provided only quantitative information while consuming the sample. The detection limit for a 9 h experiment is approximately 45

ISSN:0268-2605    

DOI:10.1002/aoc.590050207

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractTotal digestion of estuarine water samples by dry ashing shows that a significant fraction of dissolved arsenic does not form hydrides with sodium tetrahydroborane (NaBH4) and is therefore not detected by the normal hydride generation‐atomic absorption analytical technique. It is also refractory to alkaline digestion with sodium hydroxide. Sequential ultrafiltration suggests a molecular weight below 210 for this new arsenic fraction. The magnitude and molecular weight of this fraction may open new perspectives on the biogeochemical cycling of arsenic. Ecological reasons can explain the discrepancy between these findings and previous researc

ISSN:0268-2605    

DOI:10.1002/aoc.590050208

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractOrganic arsenic compounds (trialkylarsines) present in natural gas were extracted by 10 cm3of concentrated nitric acid from 1 dm3of gas kept at ambient pressure and temperature. The flask containing the gas and the acid was shaken for 1 h on a platform shaker set at the highest speed. The resulting solution was mixed with concentrated sulfuric acid and heated to convert all arsenic compounds to arsenate. Total arsenic was determined in the mineralized solutions by hydride generation. The arsenic concentrations in natural gas samples from a number of wells in several gas fields were in the range 0.01–63 μ As dm−3. Replicate determinations of arsenic in a gas sample with an arsenic concentration of 5.9 μ dm−3had a relative standard deviation of 1.7%. Because of the high blank values, the lowest arsenic concentration that could be reliably determined was 5 ng As dm−3gas. Analysis of nonmineralized extracts by hydride generation identified trimethylarsine as the major arsenic compound in natural gas. Low‐temperature gas chromatography‐mass spectrometry showed more directly than the hydride generation technique, that trimethylarsine accounts for 55–80% of the total arsenic in several gas samples. Dimethylethylarsine, methyldiethylarsine, and triethylarsine were also identified, in concentrations decreasing with increasing molecular mass

ISSN:0268-2605    

DOI:10.1002/aoc.590050209

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe release of mono‐and di‐butyltin species (MBT and DBT) in water after leaching of five different poly(vinyl chloride) (PVC) materials was investigated under mild conditions over a period of one month in batch reactor systems. Results showed that inorganic tin, MBT and DBT compound were released from the material tested under experimental static leaching conditions. The total amount of inorganic tin and organotin compounds observed upon leaching varied considerably from one PVC material to anot

ISSN:0268-2605    

DOI:10.1002/aoc.590050210

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe effect of triorganotin compounds, R3SnX, on the growth of three wild strains ofCeratocystis ulmi (C. ulmi)fungus, two aggressive and one non‐aggressive strains, was evaluated in shake culture. In all cases, the triphenyltins were the more effective organotins for the inhibition ofC. ulmi in vitro. The anionic group, X, did not have a significant role in the inhibition, suggesting that the species involved in the inhibition is the triphenyltin moiety (Ph3Sn+) or the hydrated triphenyltin moiety (Ph3Sn(H2O)+2). It is further suggested that the triphenyltin species Ph3SnOH and Ph3SnOAc are the preferred compounds for the control of Dutch elm disease. The tolerance of aggressive isolates to fungitoxins appears to depend more on the nature of the fungicide than on the type of fungu

ISSN:0268-2605    

DOI:10.1002/aoc.590050211

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY