Bestimmung von Quecksilber, Blei und Cadmium in Rhein- und Mainfischen mittels flammenloser Atomabsorption

Zusammenfassung Von 1976 bis 1982 wurden 854 Rheinfische und 1983 43 Mainfische auf Quecksilber, von 1980 bis 1982 212 Rheinfische und 1983 43 Mainfische auf Blei und Cadmium untersucht. Die Analytik dieser Elemente, wobei besonderes Gewicht auf dem Aufschluß liegt, wird vorgestellt. Die Ergebnisse belegen, daß die Quecksilberbelastung der Rheinfische im Laufe der Jahre abgenommen hat, was sich auch in der Zahl der Höchstwertüberschreitungen niederschlägt. Bei Blei und Cadmium ist in den drei Untersuchungsjahren kein Trend zu erkennen. Die Kontamination liegt auf jeden Fall wesentlich höher als in unbelasteten Gewässern. Cadmium und Blei scheinen im Stromverlauf in der Konzentration zuzunehmen, wie aus dem Vergleich mit Untersuchungsergebnissen aus dem Hoch- und Oberrhein hervorgeht. Überschreitungen der BGA-Richtwerte werden festgestellt.

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Determination of mercury lead and cadmium residues in fish from the rhine and main by flameless atomicabsorption

Summary From 1976 until 1982 854 fishes from the Rhine and in 1983 43 fishes from the Main-river were analysed for mercury, from 1980 until 1982 212 fishes from the Rhine and in 1983 43 fishes from the Mainriver were analysed for lead and cadmium. The analytical behaviour of these elements with special emphasis on the digestion is described. The results demonstrate that the contamination of the fishes from the Rhine by mercury has decreased within the period. This becomes also evident by the decreasing number of samples which exceed the tolerances. For lead and cadmium no trend can be deduced from the results. The contamination, however is appreciably higher than in unpolluted waters. Cadmium and lead seem to increase in concentration during the course of the river as demonstrated by a comparison of results from different stretches of this river. BGA-guide values (Federal Office of Health) were exceeded in some samples.

     

Arsen,Blei und Cadmium in haushaltsüblich hergestellten Obst- und Gemüsekonserven aus früheren Jahrzehnten

Levels of arsenic, lead and cadmium in climbing beans of harvest years 1913 to 1986, home-sterilized in glass jars, were determined by atomic absorption spectrometry. Concentrations of arsenic showed a decreasing trend from 1913 (highest value) to 1955, all levels being above 5μg kg^-1, whereas after 1955 only levels below 5 μg kg^-1 were found. Presumably the formerly allowed arsenic containing pesticides are responsible for this. No clearly increasing or decreasing trend in the concentrations of lead and cadmium were observed.     

Arsen,Blei und Cadmium in haushaltsüblich hergestellten Obst- und Gemüsekonserven aus früheren Jahrzehnten

Levels of arsenic, lead and cadmium in cherries of harvest years 1911 to 1986, home-sterilized in glass jars, were determined by atomic absorption spectrometry. Concentrations of arsenic showed a decreasing trend during that period, presumably reflecting the discontinuation of the use of arsenic-containing pesticides. Unexpectedly, some of the older samples also contained more lead or more cadmium than more recent samples.     

Cadmium in Pilzen

Zusammenfassung Der Cadmiumgehalt von 402 Arten (1049 Proben) wildgewachsener Pilze lag zwischen < 0,1 and 120 mg/kg Trockengewicht, entsprechend < 0,01 and 10,8 mg/kg Frischpilz. Cadmiumarme Proben ilberwogen: 68% enthielten < 2 mg/kg Trockengewicht, 86,5% < 5 mg/kg Trockengewicht, entsprechend ca. < 0,2 and < 0,5 mg/kg Frischpilz. Der Cadmiumgehalt war eindeutig species- and auch gattungsabhängig. Proben mit mehr als 10 mg/kg Trockengewicht kamen bei 41 Arten vor, darunter 9Tricholomataceae, 10Agaricaceae, 11Cortinariaceae, 3Amanita-und 4Russula-Arten. Proben mit mehr als 50 mg/kg Trockengewicht kamen vor beiAgaricus augustus, A. perrarus, A. silvicola, A. macrosporus, A. maleolens undInocybe bongardii. Im einzelnen Fruchtkörper war der Cadmiumgehalt am niedersten im Stiel, am höchsten in den Lamellen bzw. der Röhrenschicht. Lamellen enthielten maximal 5mal so viel Cadmium wie das Hutfleisch. Bei cadmiumreichen Pilzen bestand eine erhebliche Anreicherung gegenüber dem Boden.

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Cadmium in mushrooms

Summary The cadmium content of 402 species of wild mushrooms was determined by flameless atomic absorption spectroscopy. Altogether 1049 samples, grown mainly, in southern Germany, were tested. The cadmium content was between < 0,1 and 120 mg/kg dry weight, equivalent to < 0,01 and 10,8 mg/kg fresh weight. Samples with low cadmium content were predominant: 68% of the samples contained < 2 mg/kg dry weight, 86.5% contained < 5 mg/kg dry weight, equivalent to about < 0,2 and < 0,5 mg/kg fresh weight, respectively. The cadmium content was clearly species-dependent, and to a lesser extent genus-dependent. Samples containing more than 10 mg/kg dry weight occured in 41 species, among these were 9Tricholomataceae, 10Agaricaceae, 11Cortinariaceae, 3Amanitas and 4Russula species. Samples containing more than 50 mg/kg dry weight were found inAgaricus augustus, A perrarus, A. silvicola, A. macrosporus, A. maleolens, andInocybe bongardii. In single fruiting-bodies the lowest cadmium content was found in the stem, whereas the highest content was found in the gills and tubes. Cadmium content of the gills was at most five times the amount present in the cup. In cadmium-rich mushrooms a marked concentration as compared with the cadmium content of the soil had occured.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft

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Unter technischer Mitarbeit von Rosemarie Nützel und Ulrike Dill     

Cadmium in roadside grapes

The concentration of cadmium in unwashed wine grapes and leaves is considered as a function of the distance from the suspected source, an isolated straight road. Cadmium levels were determined by a.a.s. with electrothermal atomisation in a graphite furnace. The grape and leaf samples display an asymptotic decrease in cadmium concentration (c) according to the distance (d) from the edge of the road. The observed data can be fitted with the exponential function c=A+B exp (-Cd), the parameters being estimated by least-squares non-linear regression. The simple model allows the determination of the cadmium level at d→∞ (A) and at d=0 (A+B). The results obtained indicate that the effect of the presence of the road is not detectable beyond a distance of 50 m.     

含镉稻米的分布及治理技术概述

镉是一种重要的重金属污染物,可经土壤、粉尘和农作物进入食物链. 稻米易于富集土壤和环境中的镉,给消费者健康带来潜在风险. 我国土壤中的镉含量存在地域不均一性,个别地区由于地质原因或工业、采矿污染,土壤镉含量偏高,导致当地生产的稻米镉超标. 为应对稻米镉污染问题,目前已开展了土壤修复治理、水稻品种改良和稻米降镉加工利用等方面的研究. 总结了中国土壤和稻米镉污染现状,分析了影响稻米富集镉的主要因素,概述了国内外稻米镉污染治理的新方法,为开展镉污染稻米治理及利用提供建议.     

烟草镉低积累材料根系镉吸收动力学特征

为揭示烟草Cd低积累材料根系Cd吸收特性,本研究采用水培试验,以烟草Cd低积累材料RG11、CF986为研究对象,高积累材料Yuyan5为对照,探讨烟草Cd低积累材料根系Cd吸收动力学特征。结果表明：（1）随培养液Cd浓度升高,两类烟草材料生物量均显著降低（p ≤ 0.05）,但RG11、CF986地上部和地下部生物量降幅低于Yuyan5;同时两类烟草材料Cd含量均显著增加（p ≤ 0.05）,但RG11、CF986地上部和地下部Cd含量显著低于Yuyan5（p ≤ 0.05）。（2）随Cd处理时间延长,两类烟草材料根系Cd吸收总量呈上升趋势,拟合得到的RG11、CF986直线斜率值小于Yuyan5,为Yuyan5的68.6%和80.0%。相同时间Cd处理下,RG11、CF986根系Cd吸收总量比Yuyan5低8.6%~27.7%。（3）两类烟草材料根系Cd吸收速率随Cd处理浓度的增加而升高。RG11、CF986根系最大吸收速率为Yuyan5的33.4%和48.5%,真实吸收能力比Yuyan5低51.3%和7.9%,直线斜率是Yuyan5的1.3和1.4倍。与高积累材料相比,烟草Cd低积累材料根系Cd吸收能力更弱,根系质外体对Cd的吸附能力更强。     

Cadmium accumulation in Agaricusblazei Murrill

BACKGROUND: Agaricus blazei Murrill has become a popular food source of high nutritional and medicinal value in many Asian countries. However, there are growing health concerns on cadmium (Cd) accumulation by A. blazei. Experiments were conducted to investigate Cd accumulation patterns in A. blazei and to identify key factors contributing to Cd accumulation. RESULTS: Cd concentrations in the substrates and subsequent fruit bodies declined rapidly after the first, second and third harvest wave. A quick rinse of the fruit bodies in water reduced the Cd concentration by 27–54% depending on the strain. The Cd concentration in the fruit bodies decreased as the fruit body yield m^?2 or fruit body number m^?2 increased, while it increased as the substrate Cd content or fruit body size increased. Cd accumulation was positively associated with phosphorus (P) uptake. CONCLUSION: The results suggests that, in the A. blazei‐growing region studied, Cd and P concentrations in the substrates and casing soil should be reduced in order to effectively minimise Cd accumulation in the fruit bodies. It is also necessary to improve fruit body yield by increasing the number of medium‐sized fruit bodies. Overgrowth of individual fruit bodies stimulates Cd accumulation in A. blazei. Copyright © 2008 Society of Chemical Industry     

Cadmium levels in peanut products.

Samples of peanut products such as peanut butter, raw, roasted and crushed peanuts from various commercial producers and obtained from local markets in Brisbane contained generally low levels of cadmium with mean values ranging from 0.013 to 0.031 mg/kg. These values were lower than the maximum permitted concentration for cadmium in peanuts in Australia, which is currently set at 0.05 mg/kg. Pre-digestion of samples using a microwave digestion system was found to be very effective in reducing digestion time prior to dry ashing for the analysis of cadmium.