R. Capelli

Evaluation of different derivatization methods for the multi-element detection of Hg, Pb and Sn compounds by gas chromatography-microwave induced plasma-atomic emission spectrometry in environmental samples

A multi-element, element-specific detector for gas chromatography (GC) based on atomic emission spectroscopy (AES) with a microwave induced plasma (MIP) source was tested on some environmental samples. As derivatization procedure, direct aqueous phase ethylation and chelation/extraction followed by Grignard reaction were tested on the following ions: methylmercury, ethylmercury, phenylmercury, mercury(II), trimethyllead, dimethyllead, lead(II), trimethyltin, dimethyltin, triethyltin, tripropyltin, tributyltin, dibutyltin, butyltin, and tin(IV). For mercury species a direct aqueous phase phenylation was successfully tested. The different methods of derivatization are compared, and the performance (sensitivity, linearity) of the GC-MIP-AES system is discussed. Some examples of application to environmental samples (biological tissues) are given.

Study of trace elements in organs and tissues of striped dolphins (Stenella coeruleoalba) found dead along the Ligurian coasts (Italy)

Abstract Concentrations of copper, iron, manganese, zinc, selenium and mercury (total and organic) were measured in muscle tissue, brain, heart, lung, kidney, spleen, and liver of 18 dead striped dolphins ( Stenella coeruleoalba ) found stranded on the beaches of the Ligurian Sea. Distribution of the trace elements among the tissues and bioaccumulation are discussed. High levels of mercury were observed in all tissues analysed, with concentrations reaching 260 μg g −1 dry weight (dry wt.) in the muscle, 448 μg g −1 dry wt. in the lung, 1316 μg g −1 dry wt. in the spleen, and 2993 μg g −1 dry wt. in the liver. Mercury present in the organic form was, on average, approximately 30% of the total for all tissues with the exception of the heart, which showed higher values (mean 63%), and liver, where organic mercury was very low (mean 12%). In muscle tissue the organic mercury fraction decreased with increasing total mercury concentration. The liver accumulated trace elements to a greater extent than the other organs studied, with the exception of iron. Principal component analysis (PCA) revealed a grouping of the specimens on the basis of their estimated age. A strong positive correlation between the concentration of inorganic mercury and selenium was found for all the tissues analysed. In the liver the selenium to inorganic mercury molar ratio was very close to 1, confirming results of previous authors.

Microcolumn preconcentration and gas chromatography-microwave induced plasma-atomic emission spectrometry (GC-MIP-AES) for mercury speciation in waters

A novel method for the direct determination of mercury species at the ng l−1 level in natural waters is described. Methyl-, ethyl- and inorganic mercury are preconcentrated on a sulphhydryl cotton microcolumn incorporated in a flow injection system. Retained mercury species are then eluted with hydrochloric acid solution (3 mol/l) and subjected to phenylation before determination by gas chromatography-microwave induced plasma-atomic emission spectrometry. Limits of detection for mercury species are 10 ng l−1 for methyl- and ethyl-mercury and 16 ng l−1 for inorganic mercury based on processing 200 ml of sample. Application of the methodology to waters of the Manchester Ship Canal revealed elevated levels of methylmercury and inorganic mercury.

Heavy metals in mussels (Mytilus galloprovincialis) from the gulf of la spezia and from the promontory of Portofino, Italy

In different samples of Mytilus galloprovincialis Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb and Zn were determined by AAS. The mussels were taken from 11 sites in the Port of La Spezia. Typical concentration ranges (μ/g dry weight) were as follows: Cd, 2.0–6.8; Co, 0.8–3.2; Cr, 5.8–19.5; Cu, 6.9–33.7; Hg, 0.15–0.38; Mn, 11.8–37.8; Ni, 1.3–10.9; Pb, 13.9–44.6 and Zn, 203–379. Other samples were collected at 4 sites on the Promontory of Portofino and the following values were obtained: Cd, 0.8–1.1; Co, 2.6–2.9; Cu, 3.3–4.2; Hg, 0.09–0.15; Mn, 6.3–9.1; Ni, 1.2–2.4; Zn, 120–140.

Biomonitoring of Trace Metals by Different species of Lichens (Parmelia) in North-West Italy

The concentrations of Cd, Cu, Mn, Ni, Pb, V, and Zn were measured in four different species of lichens (Parmelia caperata, P. pastillifera, P. saxatilis, P. sulcata) sampled in North-West Italy, in order to obtain maps showing metal distribution and the degree of deviation from background (natural) conditions. Significant differences among the species were found for Zn, Mn, Pb and V, suggesting that the combined use of mixed species in biomonitoring surveys can affect the interpretation of results. Results obtained for Parmelia caperata samples have been compared with background (natural) levels, and maps showing the distribution of each metal expressed as deviation from background levels have been obtained. Overall such maps show a medium to high alteration degree in the study area.

The presence of mercury (total and organic) and selenium in human placentae.

The concentrations of mercury (total and organic) and selenium in samples of human placentae obtained after normal births from 22 women living in Genova (Italy), were determined by atomic absorption spectrometry. The concentration of total mercury was between less than 0.005 and 0.230 microgram Hg/g dry weight, and the average value was 0.076 microgram Hg/g dry weight. For the same samples, the average percentage of organic mercury as mercury was 65%, with a maximum of 95%. Smaller variations were observed for selenium, i.e. concentrations ranging between 0.38 and 1.03 microgram Se/g dry weight, with an average value of 0.77 microgram Se/g dry weight. The ratio between wet weight and dry weight was determined for each sample and the average value found was 6.32. The placental selenium concentration did not correlate with total and organic mercury content, which is in accordance with the results of other researchers.

A four-year study on the distribution of some heavy metals in five marine organisms of the ligurian sea

Abstract This paper presents the results obtained during a four-year study of heavy metal distribution in certain organisms of the Ligurian Sea. The species which we have considered (mussels, mullet, shrimp and anchovies) were systematically sampled from December 1976 to December 1980, and were taken from the area between Punta del Mesco (east of Genoa) and Savona (west of Genoa). The metals (Hg, Cd, Cu, Mn, Pb and Zn) were determined using atomic absorption spectrometry of the solutions obtained by mineralizing the samples with HNO3 at 90% in decomposition flasks fitted with a reflux condenser. The values obtained depend upon the place and year of sampling and are compared to values found by other authors for the same organisms in the other Italian seas.

Total mercury, organic mercury, copper, manganese, selenium, and zinc in Sarda sarda from the Gulf of Genoa

The total mercury content of the Atlantic bonito (Sarda sarda) increases with increasing size of the specimen, as shown by other authors for other marine organisms (Renzoni et al., 1973; Buffoni et al., 1982; Bernhard and Andreae, 1984; Thibaud, 1986). Organic mercury content also increases with the size of the specimen, whereas inorganic mercury remains constant, which is in agreement with the prediction made on another species of Sgombridae (Bernhard, 1985). This kind of mercury partitioning has not, to our knowledge, been reported for other species of fish. It is interesting to note that the mercury concentration in the gonads also increases with the size of the specimen. A very small difference between the total mercury content of white and dark muscle was observed, while for selenium, zinc, copper, and manganese the concentrations are lower in white muscle than in dark muscle.

Total and organic mercury in North Atlantic fin whales: distribution pattern and biological related changes

Abstract Total and organic mercury concentrations were determined in muscle, liver and kidney of thirty-six fin whales ( Balaenoptera physalus ) of the Northeast Atlantic. Age, sex and length relationships for both forms of metal were examined. Tissue concentrations were lower than those of toothed whales and seals. A slight increase with age was observed for total mercury concentrations in muscle and liver and organic mercury concentrations in liver, which suggests a low rate of excretion for the metal, even at low concentrations. No differences between sexes were found regarding mercury concentrations, nor to their accumulation pattern.

PCBs and chlorinated pesticides in organisms from the Ligurian Sea

The concentrations of BHCs, DDTs and PCBs have been determined in samples of Engraulis encrasicholus, Mytilus galloprovincialis, Nephrops norvegicus, Mullus barbatus, Euthymnus alletteratus and Sarda sarda, collected in different stations of the Ligurian Sea. Increasing levels of contamination were found in the order: Nephrops, Mytilus and Engraulis, Mullus and Euthymnus, Sarda. A comparison with the data available in the literature relevant to Mytilus samples collected in Genoa in 1973–1974 showed a notable decrease in the concentration of chlorinated residues.