Biomedical subjects

H Emons

Publications and source records attributed to H Emons.

26 records · Page 2Linked to original sources

PubMed1997

Mussels and algae as bioindicators for long-term tendencies of element pollution in marine ecosystems.

Results of more than ten years of experience in the determination of metals in mussels and algae collected in the North Sea and the Baltic Sea are presented. The various elements determined here are Hg, As, Se, Cd, Pb, Cu, Na, K, S, P, Zn, Mn, Fe, Sr, Ca, Ba, Mg, Tl, Ni, Co using techniques such as cold vapor AAS, INAA, hydride generation AAS, electrothermal AAS, ICP-AES, IDMS and stripping voltammetry. The results indicate the occurrence of three groups of elements with respect to long-term tendencies of their concentrations. In the first group, the concentrations in both mussels and algae varied in the same manner; in the second group no change was observed in either matrix while in the third group, the concentrations of elements changed in an opposite manner.

Animals↗

PubMed1997

Eel-pout (Zoarces viviparus L.) as a marine bioindicator.

Several elements and metal species were analyzed in eel-pout or viviparous blenny (Zoarces viviparus). The analytical data demonstrate that fish muscle is a suitable bioindicator for mercury (Hg) and arsenic (As). About 90% of the total Hg content is present in the fish muscle in the form of methyl mercury. Due to higher concentration levels, the liver is more useful for monitoring Pb and TI. No biomagnification of some trace elements, such as Cd, Ni or Co, were observed in eel-pout. More information is necessary to decide about the use of eel-pout for long-time monitoring programs.

Aging↗

PubMed1997

Environmental monitoring and banking of marine pollutants by using common mussels.

Since 1985 the common mussel Mytulis edulis has been collected, characterized and stored within the framework of the German Environmental Specimen Bank program. Selected results about the determination of various pollutants such as heavy metals, polycyclic aromatic hydrocarbons and chlorinated hydrocarbons are presented. Particular emphasis is given to the comparison of seasonal variations with respect to different environmental contaminants and their correlations depending on sampling location and time.

Animals↗

PubMed1997

Wet deposition in Germany: long-term trends and the contribution of heavy metals.

As part of the program of the German Environmental Specimen Bank (ESB), precipitation is sampled on a weekly basis from eight sites in different ecosystems throughout Germany. The samples are analyzed for Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3-, and SO4(2-) using ion chromatography with conductometrie detection Mn, Co, Ni, Cu, Zn, Cd, Pb, and Tl are determined by ICP-MS. In addition, pH and conductivity of the samples are measured. In this paper, the weekly and annual deposition in 1994 is compared for the different sampling sites and with literature data.

Biological Specimen Banks↗

PubMed1996

Environmental specimen banking - Aspects of metal determination and distribution.

Analytical investigations of metals within the present program of the German Environmental Specimen Bank (ESB) are briefly introduced. The focus is directed to challenges and opportunities which are provided by an ESB for analytical chemistry. Several aspects of instrumental approaches for environmental analysis, bioindication, speciation, data evaluation and quality assurance are discussed. Illustrative examples of ESB results are presented concerning metal concentrations in biological material, comparison of ecosystems and long-term tendencies.

Journal Article↗

PubMed1990

Voltammetric behaviour of immunoglobulin G at stationary mercury electrodes.

A.c. voltammetric measurements have shown that bovine and human immunoglobulin G are adsorbed at a mercury electrode over a broad potential range and at open circuit. A current signal at ca. -0.55 V was identified as being due to an interfacial process connected with reversible protein re-orientations in the adsorption layer and, possibly, with fast faradaic reactions of both adsorbed redox states of the immunoglobulin.

Animals↗

PubMed1990

Influence of bovine immunoglobulin G on faradaic reactions at electrodes.

The effect of bovine immunoglobulin G (IgG), adsorbed on different electrode materials, on faradaic reactions of hexacyanoferrate(III)-hexacyanoferrate(II), hydroquinone-benzoquinone, nicotinamide adenine dinucleotide, reduced from (NADH), and phenol is described and discussed. The reactions are partially inhibited by IgG, but the current and peak potentials reach protein-independent values for higher concentrations of IgG. The hydroquinone-benzoquinone couple can be used for detection purposes at IgG-covered electrodes in electrochemical immunoassays.

Biosensing Techniques↗

PubMedDate not supplied

The potential of rhizosphere microbes isolated from a constructed wetland to biomethylate selenium.

The potential of rhizosphere microbes isolated from common reed [Phragmites australis (Cav.) Trin. ex Steud] plants grown in a subsurface-flow constructed wetland to biomethylate selenate or selenite was studied in liquid cultures under controlled conditions. Total mean percentages of volatilized Se from half-strength Hoagland culture solutions (low C content) supplemented with selenate or selenite and inoculated with cultured rhizosphere microbes after 15 d of incubation were 7.9 and 49.1%, respectively. There was a relative best fit (r = 0.87) between total number of rhizosphere and cultured microbes and the percentage of volatilized Se in Hoagland solution after 15 d of incubation. However, when the same microbes were cultured in tryptic soybean broth (TSB) medium (high C content), the percentages of volatilized Se from selenate and selenite were 1.3 and 1.9%, respectively. The volatilization percentages of Se from selenate or selenite in culture solutions inoculated with rhizosphere suspension instead of cultured rhizosphere microbes were very low (1.2-3.0%) in both cultivation media. In all experiments, selenite was volatilized significantly (p < 0.05) in higher amounts by cultured rhizosphere microbes after 15 d of incubation compared with selenate. Dissolved biomethylated dimethylselenide (DMSe) in water samples taken from the subsurface-flow bed was determined by purging with helium. The DMSe in water samples was indirectly detected up to 2.4 microg Se L(-1), which indicates that part of the produced DMSe was dissolved in the matrix before being released into the atmosphere. Our results show that rhizosphere microbes isolated from common reed plants have a high potential of Se biomethylation and volatilization from selenate and selenite.

Bacteria↗