Bioaccumulation of metals by bivalves from the Limski Kanal (North Adriatic Sea). III. Copper distribution between Mytilus galloprovincialis (Lmk.) and ambient water.

Copper accumulation was studied in native mussels, Mytilus galloprovincialis, Lmk., from the Limski Kanal, North West Yugoslavia (Peninsula Istria), from June 1979 to June 1980. The distribution of copper between different body parts of the mussels is correlated with the concentrations of the different physico-chemical forms of copper in the ambient seawater. Free and labile complexes of dissolved Cu were electrochemically determined in a sample at a natural pH of approximately 8, "total" dissolved Cu was determined in acidified samples (pH 2), and Cu after acid decomposition of the suspended particulate matter was collected on 0.45 micron Millipore filters. The copper content correlates with the weight of the organs and with enhanced gametogenetic activity in the mussels. The copper concentrations in the total soft part and in the various organs are highly correlated with the dissolved "ionic" copper content of the ambient water. The particulate matter in the water column influences copper accumulation and its distribution within organs of the mussel. This conclusion arises because the concentration of copper in the mussels is highly correlated with the quantity of particulate material. The copper concentration varies very significantly with condition factors of the foot. Therefore, as the foot can be easily dissected, we propose this organ as a "sentinel" part of the mussel's body for "mussel watch", in the global monitoring program for copper surveillance.

Application of differential pulse anodic stripping voltammetry to the determination of heavy metals in environmental samples.

A reliable procedure for the determination of the trace metals Cd, Cu, Ni, Pb and Zn in liquid and solid environmental samples by an advanced voltammetric method has been developed. A convenient method of sample pretreatment is wet digestion in a HNO3/HClO4 mixture. The simultaneous voltammetric determination of Cd, Cu, Pb and Zn is made at pH 2 by differential pulse anodic stripping voltammetry (DPASV); the simultaneous determination of Ni and Co at pH 9 after adsorptive accumulation of the respective complex with dimethylglyoxime at the electrode is made by adsorption differential pulse voltammetry (ADPV). The particular advantages of the voltametric approach in food control for heavy metals are high sensitivity, good precision and accuracy, the possibilities for the simultaneous determination of groups of metals and low cost instrumentation.

Levels of heavy metals in the tidal Elbe and its estuary and the heavy metal input into the sea.

Surface water samples were collected during missions in 1977, 1978, 1980 and 1983 at different sampling stations along the tidal Elbe, from river km 632 downstream from Hamburg to the outer end of the estuary. Special care was taken to minimize contamination during sampling, handling and analysis. Within the tidal Elbe five distinct zones of substantial anthropogenic heavy metal pollution inputs can be detected. An attempt is made to define anthropogenic background levels, which are extremely low for the dissolved trace metals Cd and Pb; 35 and 65 ng/kg, respectively. The level of dissolved Cu is 2200 ng/kg. Total baseline levels of Cd, Pb and Cu are, respectively, 120, 2500 and 4200 ng/kg. In the five river zones affected by anthropogenic trace metal inputs, distinctly larger maximum levels can occur. They decrease to the background values after mixing with the main water body. More elevated levels caused by re-suspension in the mixing zone with maximum turbidity can be assumed. Nickel and Co data are from one mission only. The order of magnitude of the trace metal input from the Elbe into the sea is evaluated.

[Voltammetric determination of heavy metals in meat and the internal organs of slaughter cattle]. / Die voltammetrische Bestimmung von Schwermetallen in Fleisch und inneren Organen von Schlachtrindern.

The most important uptake of heavy metal by man occurs through ingestion. Therefore heavy metal analysis of food becomes of great importance. The whole analytical procedure including sampling, transport, drying, homogenisation, digestion and measurement for the determination of Zn, Cd, Pb, Cu, Ni, and Co in meat is described with due consideration given to the requirements for trace and ultratrace analysis. The particular advantages of the voltammetric approach for heavy metal determinations in meat and meat products are generally featured by this study. A standard deviation of 3-5% RSD in the microgram/g-range and 5-10%-RSD in the ng/g-range was obtained. In order to check the accuracy of the results, mixtures of sample and standard reference material were analysed. While the Cd-content in meat is in the range of 1 ng/g (wet weight) it increases in organs, such as liver (100-500 ng/g wet weight) and kidney (600-2000 ng/g wet weight). Pb shows a similar behaviour. The levels of these elements were found to be below the maximum allowable limits set by the "Bundesgesundheitsamt", with the exception of Cd in the kidneys. There is a statistical significant correlation between the Cd and Pb contents in liver and kidney. In liver the Cu content was especially high, because there are Cu-containing enzymes in this organ. Vitamin B12 is a Co containing complex in the liver. Therefore the Co values in liver are clearly higher than those in muscle meat.

The distribution of zinc in human erythrocytes.

Gel permeation chromatography was used to fractionate zinc-bound constituents in haemolysates of human blood samples. The zinc content of the fractions was determined by electrothermal atomic absorption spectrometry. The zinc-containing enzyme, carbonic anhydrase, was identified by isoelectric focusing. A fraction of more than 0.9 of the zinc eluted from the column was bound to the carbonic anhydrase fraction. The fraction of zinc associated with unbound carbonic anhydrase was 0.786 of the total, and the remainder was found in a carbonic anhydrase-CO-haemoglobin complex.

Observations with Thalassiosira rotula (Meunier) on the toxicity and accumulation of cadmium and nickel.

Cadmium and nickel toxicity thresholds based on generation time, maximum cell density, and chain length as toxicity indicators were evaluated from batch cultures of the marine diatom Thalassiosira rotula in nutrient-enriched seawater as substrate. Nickel toxicity is about an order of magnitude or more higher than cadmium toxicity. The toxicity thresholds decrease with increasing illumination and are not significantly affected by 10 mumol/liter EDTA. From the metal accumulation determined by voltammetry average maximum uptakes of 90 micrograms Ni/g DW and 600 micrograms Cd/g DW were determined.

Comparative studies on the distribution of heavy metals in the oceans and coastal waters.

Results of our investigations during the last five years are summarized. The concentrations of Cd, Pb and Cu have been determined in coastal areas of the Western Mediterranean and the North Sea, reflecting the influence of the pollution sources along the shore line. Deep sea water and surface water sample from the Pacific, Atlantic, Mediterranean and Arctic Sea have been analyzed for Cd, Pb, Cu and at some stations also additionally for Ni, Co. It is demonstrated that concentration levels of surface and deep sea waters may differ significantly in diverse oceans. The same is valid to a greater extent for coastal waters affected particularly by anthropogenic input that can be dispersed by tidal currents. Applying reliable sampling methods and the voltammetric determination procedure in particular suitable for heavy metals at the trace level, significant contributions to a consistent data basis for the distribution of heavy metals in the sea could be achieved.

A new electrochemical approach for the in vitro investigation of damage in native DNA by small gamma-radiation doses.

Voltammetry provides a new method to assess gamma-radiation damage to native DNA in vitro after low doses of irradiation. Using single sweep voltammetry at a stationary mercury electrode a substantial labilization of the double helical conformation of gamma-irradiated DNA was found. Up to 40 Gy a linear dose-effect relationship exists reflected for the number of strand breaks and the number of destabilized base pairs. A considerable difference in the frequency of formation of the two kinds of radiation damage is seen in the ratio of their G-values. Base pair labilization occurs depending on aeration conditions 200 to 300 times more frequently than the formation of a single strand break.

A rapid high-performance analytical procedure with simultaneous voltammetric determination of toxic trace metals in urine.

For the monitoring of toxic trace metals in urine a new high-performance trace analytical procedure with simultaneous voltammetric determination is presented. Particular emphasis has been placed on minimizing contamination by reducing the urine sample volume to 1 ml and consequently limiting the needed amount of HNO(3)/HClO(4) and the duration (<20 min) of the wet digestion stage. The procedure consists of three stages. First 20 urine samples (1 ml each) are simultaneously freeze-dried overnight. They then require only a short wet digestion (HClO(4)/HNO(3) 2:1, 20 min, 210 degrees ). They are then adjusted to pH 4.5 with acetate buffer and the trace metals are determined simultaneously by differential pulse anodic-stripping voltammetry at the mercury film electrode, the quartz digestion vessel being used as the voltammetric cell. If precipitates occur in the acidified samples, their trace metal content can be determined in the same manner, avoiding the low results commonly obtained by other methods. The procedure has high sensitivity with fair to good precision, covers a determination range from the sub-mug/l. to the medium mug/l. level and lends itself to automation. It is cheaper and more accurate than atomic absorption. Thus the procedure provides important potentialities for surveillance of occupationally exposed persons as well as for extended ecotoxicological baseline studies in man and cattle.

Toxic trace metals in food. II. A comparative study of the levels of toxic trace metals in wine by differential pulse anodic stripping voltammetry and electrothermal atomic absorption spectrometry.

A new high-performance analytical procedure for the determination of the toxic trace metals cadmium, lead and copper in wines by differential pulse anodic-stripping voltammetry (DPASV) subsequent to UV irradiation of the sample is compared with the hitherto more common application of electrothermal atomic absorption spectrometry (AAS). In this manner also mutually the accuracy attainable with both alternatives has been established. The particularly favourable potentialities of the new voltammetric approach for toxic metal control of wines are demonstrated by the investigation of a typical selection of 36 wines from recent vintages and common vine types of the German and some European wine cultivating regions.

Polarography and voltammetry in studies of toxic metals in man and his environment.

A brief introduction on sources, occurrence and fate of some toxic trace metals found in the natural environment is followed by a discussion of general methodological aspects from the trace chemical viewpoint. The versatile, significant and specific potentialities of advanced polarographic and voltammetric methods are compared with relevant non-electrochemical alternatives. They are subsequently demonstrated by a survey on representative applications, results and findings on problems from all types of environmental compartments and food chains to man, with emphasis on the toxic trace metals Cu, Cd, Hg, Pb, and also in certain matrices for Zn, As, Se, Tl and Bi. A final section is devoted to the particular potentialities of the electrochemical approach for speciation studies in natural waters at realistic trace levels of the dissolved toxic metals, e.g. Zn, Cd and Pb.

Toxic trace metals in food. I. A new voltammetric procedure for toxic trace metal control of wines.

A new highly sensitive and particularly reliable analytical procedure for the precise determination of the most relevant toxic trace metals cadmium, lead and copper in wine is presented. It consists of a simple and convenient sample pretreatment by UV irradiation (1,5 h, 500-W-Hg-lamp) to release the toxic trace metals bound by organic substances and subsequent voltammetry (DPASV) of cadmium and lead simultaneously at a mercury film electrode (MFE) formed in situ on a vitreous carbon carrier and of copper on a gold electrode. Particular emphasis has been placed on the efficient exclusion of interference due to contamination. Only special wines, with more than 10% of sugar, require substitution of UV irradiation by a wet digestion also described. The procedure may be easily expanded to include the determination of mercury and zinc.