Search results for "Cadmi"
showing 10 items of 442 documents
Inhibitoren der Korrosion 25(1) - Über die Rolle der Kationen in Neutralsalzen bei der Korrosion von Eisenwerkstoffen in Gegenwart von Sauerstoff
1979
Die Geschwindigkeit des Sauerstoffverbrauchs bei der Korrosion von jeweils 500 mg DAB6-Eisenpulver wird in Abhangigkeit von der Art des Kations in Neutralsalzen (Chloriden) unter Standardbedingungen bestimmt. In Gegenwart von Alkali-, Quartaren Ammonium, Quartaren Phosphonium-und Erdalkalichloriden ist die Geschwindigkeit des Sauerstoffverbrauches vergleichbar gros. Mit Zink-, Cadmium-, Nickel-und Kobaltchloriden wird aber im Bereich von pH5 bis pH7 eine uberraschend grose Verzogerung der Sauerstoffaufnahme beobachtet. Es handelt sich mit hoher Wahrscheinlichkeit um eine Blockade der kathodischen Bezirke in der Eisengrenzflache durch Abscheidung der schwerloslichen basischen Hydroxyde von Z…
Effect of cadmium pre-exposure in cadmium accumulation by brine shrimp Artemia: Involvement of low-molecular-weight cadmium-binding ligands
1993
Abstract Cadmium is a ubiquitous non-essential element that possesses high toxicity and is easily accumulated from the environment by aquatic organisms. It is known that pre-exposure to cadmium increases the resistance of animals to a subsequent exposure. In this work, we report studies of the effect of pre-exposure to cadmium on the accumulation of this metal from seawater by brine shrimp Artemia, as well as the involvement of low-molecular-weight cadmium-binding ligands in this process. During the pre-exposure experiments, animals were kept in seawater containing 20 mg/litre Cd for 24 h and then transferred to clean seawater for 48 h. Afterwards, pre-exposed and control animals were expos…
Literature survey of on-line elemental speciation in aqueous solutions.
2001
The literature about the on-line speciation in water has been comprehensively studied. Critical examination of this subject reveals that a great deal of work has been performed in this area for inorganic metal species and some organic compounds. The topic studied mainly includes the speciation of chromium, selenium, copper, arsenic, lead, cadmium, mercury, iron, aluminium, nickel, tin, antimony, phosphorus, nitrogen and others. The present literature survey includes also comments about the possibilities and problems of speciation as a function of analytical steps, general strategies involved and methods proposed in the literature for each element or a series of elements.
Comparison of ultrasound-assisted extraction, microwave-assisted acid leaching and reflux for the determination of arsenic, cadmium and copper in con…
2002
Extraction methods for the determination of arsenic, cadmium, and copper in contaminated soil samples by Zeeman effect electrothermal atomic absorption spectrometry have been compared. The determination of cadmium and copper in ultrasound-assisted aqua regia extracts of contaminated soil SRMs by ETAAS, using a mixture of NH4H2PO4 and Mg(NO3)2, for cadmium, and a mixture of Pd and Mg(NO3)2, for copper, as a matrix modifier, was carried out with high accuracy and precision (RSD < 5.1%). The analysis of SRM 2711 failed to obtain the certified concentrations of Cd and Cu by microwave and reflux methods, respectively. The determination of arsenic was performed successfully in low chloride concen…
Determination of Cd, Co, Cu, Fe, Pb, Mn, Ni and Zn in diets: Development of a method
1991
A method useful for the determination of cadmium, cobalt, copper, iron, lead, manganese, nickel and zinc in diets is described. Organic matter is destroyed applying a wet procedure, and element content is measured by flame atomic absorption spectroscopy (FAAS) in the case of copper, iron, manganese, nickel and zinc, and by graphite furnace (GF-AAS) in the case of cadmium, cobalt and lead. The matrix interference study is carried out. Values found for linearity, detection and quantitation limits as well as accuracy show that the described method is useful to determine the elements taken into account at usual levels in diets.
Determination of selenium, zinc and cadmium in antidandruff shampoos by atomic spectrometry after microwave assisted sample digestion
2000
Microwave assisted pre-treatments for atomic spectrometric determination (inductive coupled plasma-optical emission spectrometry, ICP-OES or flame atomic absorption spectrometry, FAAS) of metallic elements, usually present in antidandruff shampoos, are proposed. They are based on the digestion of the sample with HNO(3) into a closed reactor, which is irradiated at 800 W for a few minutes. Selenium was determined by ICP-OES. The limit of detection was 0.11 mg l(-1); the relative standard deviation (R.S.D.) for the selenium content in the samples was in the 0.6-3.6% range. The results obtained were in agreement with the label contents and the recovery of the proposed method was in the 100-106…
Defective copper transport in the copt5 mutant affects cadmium tolerance.
2014
Cadmium toxicity interferes with essential metal homeostasis, which is a problem for both plant nutrition and the consumption of healthy food by humans. Copper uptake is performed by the members of the Arabidopsis high affinity copper transporter (COPT) family. One of the members, COPT5, is involved in copper recycling from the vacuole toward the cytosolic compartment. We show herein that copt5 mutants are more sensitive to cadmium stress than wild-type plants, as indicated by reduced growth. Exacerbated cadmium toxicity in copt5 mutants is due specifically to altered copper traffic through the COPT5 transporter. Three different processes which have been shown to affect cadmium tolerance ar…
Effect of cadmium exposure on zinc levels in the brine shrimp Artemia parthenogenetica
1999
Zinc and cadmium have been reported as metabolic antagonists, such that high zinc intake afford animals some protection against the potentially toxic effects of cadmium exposure. There is considerable evidence to support a role of metallothioneins (MTs) in regulating or controlling the intracellular availability of essential metals and the non-essential metal. The effect of 24-h cadmium pre-exposure (10 mg Cd/l) on zinc concentrations in the brine shrimp Artemia parthenogenetica exposed to zinc (5 mg Zn/l) was studied. The zinc content of shrimps was not altered by cadmium. The homeostatic mechanism for zinc regulation appears not to be disturbed by cadmium exposure in shrimps kept in natur…
Evaluation of Antimony, Cadmium and Lead Levels in Vegetables, Drinking and Raw Water from Different Agricultural Areas
1990
Abstract Lead and cadmium levels in edible vegetables and antimony, lead and cadmium in drinking and raw waters from three agricultural areas exposed to different levels of environmental pollution (1-high industrial pollution, 2-high urban pollution, 3-standard low industrial and urban pollution) are determined. The organic matter is destroyed by repeated attack with nitric acid. Cadmium and lead are determined by graphite furnace atomic absorption spectrometry (GFAAS) and antimony by hydride generation atomic absorption spectrometry (HGAAS). When the results obtained for three different areas are compared, differences between cadmium and lead contents in vegetables are observed. Waters are…
Quantification of cadmium-induced metallothionein in crustaceans by the silver-saturation method
1995
Metallothionein (MT) has been proposed as a specific biochemical probe for metal exposure of aquatic organisms. It is recognized that its usefulness as a monitoring tool depends on the full understanding of its function and on the possibility of measuring its concentration in tissues. Therefore the study of MT in crustaceans is interesting from two different points of view: the need to understand mechanisms associated with the toxicology of metals, and the potential use of this protein for monitoring metal-contamined environments. Several methods have been developed for quantitative measurements of MT in biological samples. Immunochemical and electrochemical procedures are reliable techniqu…