Biomethylation of Heavy Metals in Soil and Terrestrial Invertebrates

It is known for a long time that calcified tissues secreted by aquatic or terrestrial invertebrates – such as mollusc shells – have the ability to concentrate large amounts of pollutants, in particular heavy metals. In the present paper, we have found an extremely rapid and easy procedure to qualitatively detect the putative presence of heavy metals in shells, without having to use sophisticated techniques such as Wavelength Dispersive Spectroscopy, atomic adsorption spectroscopy or ICP-MS. Our method rests on the capacity of the silver enhancement chemicals that are traditionally used in immunogold localization experiments to increase the size of heavy metal nanoparticles, whatever the chemical element. It goes as follows: freshly broken pieces of shells that are suspected to contain traces of heavy metals are simply incubated 15 minutes in few drops of a silver enhancement solution (British Biocell International), and, after short rinsing and drying, the shell fragments are directly observed with a tabletop Scanning Electron Microscope, under back scattered electron (BSE) mode without any further preparation. Heavy metals nanoparticles are detected as bright spots. Our method is extremely fast (about half an hour in total), and may be used as a quick check for pre-selecting series of calcified samples prior to the quantitative analysis of their heavy metal content.

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Bioaccumulation of heavy metals in terrestrial invertebrates

Environmental Pollution ◽

10.1016/s0269-7491(00)00179-2 ◽

2001 ◽

Vol 113 (3) ◽

pp. 385-393 ◽

Cited By ~ 175

Author(s):

A Heikens ◽

W.J.G.M Peijnenburg ◽

A.J Hendriks

Keyword(s):

Heavy Metals ◽

Terrestrial Invertebrates

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Terrestrial Invertebrates as a Bioindicators of Heavy Metals Pollution

Baghdad Science Journal ◽

10.21123/bsj.12.1.72-79 ◽

2015 ◽

Vol 12 (1) ◽

pp. 72-79

Author(s):

Baghdad Science Journal

Keyword(s):

Heavy Metals ◽

Terrestrial Invertebrates ◽

Metals Pollution ◽

Heavy Metals Pollution

Bioaccumulation of heavy metals in the terrestrial invertebrates in Al-Jadriyia district Baghdad- Iraq were investigated. Forth terrestrial invertebrates snails, slug, isopods, and diplopods , were selected for this study. The results showed that all invertebrate groups have the ability in accumulate considerable amounts of heavy metals. Higher levels of zinc and copper were observed in the isopods specimens, it's about ( 60.50±0.58 ) and ( 96.00±0.58 ) ppm respectively , while higher levels of lead were observed in the diplopods specimens ,it's about ( 23.00±1.15 ) ppm ,but the higher levels of both iron and cadmium were observed in snail specimens , it's about ( 590.00±1.15 ) and ( 9.50±1.15 ) ppm respectively .but the higher level between all heavy metals concentration in soil specimens were recorded in iron , zinc , lead, copper, and cadmium, it's about ( 8000.00±1.73 ) , ( 33.00±1.73 ) , ( 30.00±1.15 ) , ( 20.00±0.58 ) , and ( 10.00±1.73 ) ppm respectively .The correlation values show that most significant in some metals , while they show that non significant between in other metals .

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Sampling and analysis of the air-water interface with SEM and EDS of microlayers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157000 ◽

1989 ◽

Vol 47 ◽

pp. 1004-1005

Author(s):

Randall W. Smith ◽

John Dash

Keyword(s):

Heavy Metals ◽

Surface Microlayer ◽

Surface Films ◽

Water Interface ◽

Physical Processes ◽

Infrared Spectroscopic Analysis ◽

Eds Analysis ◽

Air Water Interface ◽

Significant Area ◽

Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

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