S. Chiavarini

Butyltins concentration levels and imposex occurrence in snails from the Sicilian coasts (Italy).

Two sampling campaigns have been carried out along the Sicilian coasts within the frame of a European project (Hic-TBT) financed by the LIFE programme. Snails and sediments have been sampled at 5 stations, characterised by very low (Ustica natural sea reserve), low (Ustica harbour), intermediate (Castellamare and Termini Imerese) and high shipping densities (Palermo). Biological and chemical analyses were carried out in order to evaluate the incidence of imposex occurring in snails, and the concentration levels of organotins in sediment and snail samples. Despite the low organotin concentration levels in sediment and snail samples, the results show that imposex is widespread around Sicily. In four locations almost all female snails were affected by imposex at advanced development stages, even in areas with a fairly low shipping density. Only in the natural sea reserve of Ustica Island imposex was relatively less severe. Finally a logarithmic correlation between TBT and imposex stages was observed.

Distribution of PCB congeners in aquatic ecosystems : A case study

Abstract Polychlorinated biphenyls (PCB) congeners were determined in water samples, sediments, and animal species in the frame of a survey of the River Arrone (Central Italy, near Rome) after a major contamination episode. Animal species were selected on the basis of their living and feeding habits and evaluated as candidate bioindicators of PCB pollution in this lotic ecosystem. Total PCB concentrations in water were found to be low (ng/L level), and in sediments, ranged from about 10 to 200 μg/kg dry weight, depending on the distance from the contamination source. PCB patterns in sediments showed a prevalence of higher chlorinated congeners over time. Concentrations in macroinvertebrates ( Calopteryx splendens and Anax imperator ) ranged from 60 to 400 μg/kg dry weight, showing significantly different species to species patterns. PCB concentrations were almost parallel in sediments for different sampling stations, while differences in patterns among species can be explained in terms of bioaccumulation/excretion mechanisms. Freshwater shrimps ( Palaemonetes antennarius ) were not found close to the contamination source, as a consequence of their extreme sensitivity to chemicals, and showed a peculiar pattern (almost exclusively determined by congeners 153, 138, and 180) probably originating from biodegradation mechanisms. Fish samples ( Rutilus erythrophthalmus ) showed the highest concentrations, as a combination of feeding habit, lipid content, and, probably, less effective biodegradation/excretion pathways. Congener patterns closely match those of Aroclor 1260, which originates from the contamination source. This study confirms that congener physical and chemical parameters, different degradation rates, feeding habits, and mobility of the analysed aquatic organisms, metabolism, and excretion mechanisms, are to be considered to explain the distinctive PCB patterns of different samples.

Influence of storage conditions on the determination of organotin in mussels

Abstract In order to check the possible occurrence of degradation of tributyltin and triphenyltin in mussel samples during their storage, a 1-year stability study was carried out. Analyses by gas chromatography with flame photometric detection and gas chromatography-mass spectrometry were performed on freeze-dried mussel samples stored under different conditions of temperature and light. The results showed that very good stability of butyl- and phenyltins can be achieved when samples are stored at −20°C in the dark. In contrast, samples stored at room temperature showed significant variations in organotin speciation, particularly in the presence of light.

Comparison of Derivatization Methods for the Determination of Butyl- and Phenyl-tin Compounds in Mussels by Gas Chromatography

Commission of the European Communities, DG XII, Standards, Measurements, and TestingProgramme, Rue de la Loi 200, 1049 Brussels, BelgiumTwo different derivatization methods, alkyla-tion with Grignard reagents, and ethylationwith sodium tetraethylborate, were comparedfor the determination of organotin com-pounds, viz. tributyltin, dibutyltin,monobutyltin, triphenyltin, diphenyltin andmonophenyltin, in mussel samples. Tempera-ture, reaction time and concentration ofGrignard reagents were optimized in theformer method; in the latter the effect of pH,concentration of sodium tetraethylborate andreaction time were studied. In the derivatiza-tion with Grignard reagents hexyl, pentyl,propyl, ethyl and methyl were used as alkylGrignard groups. A critical evaluation of thedifferent derivatization methods is presented.© 1997 by John Wiley & Sons, Ltd.

Monitoring of organotins in the La Spezia Gulf—II. Results of the 1990 sampling campaigns and concluding remarks

Abstract As part of a wider survey programme, in order to study the environmental fate of these compounds, organotins have been determined in water, sediment and mussel samples for 1 year. In a previous paper we presented two analytical methods for organotin determinations in water samples and some preliminary results. Here we present the results obtained from 1989 and 1990 sampling campaigns. Concentrations of butyl and phenyltin in water were found to be low.

Analytical Methods for the Determination of Organotins in the Marine Environment

Abstract Analytical procedures for the determination of organotin compounds in sea water, sediments and mussels have been adopted in our laboratory, intercomparison/certification exercises with other European laboratories giving satisfactory results. The characteristics of the different methodologies are discussed, the balance between practical and analytical aspects leading to the selection of the following procedures. For water samples two alternative extraction techniques are used: liquid/liquid extraction (0.3% tropolone in methylene chloride) or liquid/solid extraction (C18- or Carbopack B-loaded extraction tubes). Solid-phase extraction ensures good results and is more suitable in the field, avoiding high volumes of organic solvents and transport of fragile glassware. Extraction rubes can be easily stored, and problems with the transfer of whole samples to the laboratory, and storage and conservation problems are prevented. For sediments and mussels, sonication (0.05% tropolone in methanol) can be u...

Determination of Selenomethionine in Wheat Samples: Comparison of Gas Chromatography-Microwave-induced Plasma Atomic Emission Spectrometry, Gas Chromatography-Flame Photometric Detection and Gas Chromatography–Mass Spectrometry

A method is described for the selective determination of selenomethionine in wheat samples. The method is based on three steps prior to the determination: (1) hydrolysis of the proteins with tetramethylammonium hydroxide, (2) clean-up on an aluminium oxide column (acid form), (3) derivatization to convert selenomethionine into a compound suitable for GC. The derivatization reaction consists in esterification of the carboxylic acid group with propan-2-ol in 4 mol l -1 HCl medium and subsequent acylation of the amino group with heptafluorobutyric anhydride. The parameters affecting the efficiency of both reactions were optimized, as well as the esterification medium. Other esterification and acylation reagents were also tested. Three different detection techniques were evaluated using selenomethionine standard solutions: FPD, MIP-AES and MS. Electrothermal AAS was also tested, but proved to be unreliable. MS was selected as the best option.

Monitoring of organotins in La Spezia Gulf I. Analytical methods and preliminary results (Summer 1989)

Abstract As part of a general monitoring program, organotins are to be determined in water, sediments and mussels for 2 years in order to study the environmental fate of these compounds. In this paper, two analytical methods have been optimized, with particular attention paid to their suitability to field conditions, and tested on seawater samples. The first method is based on enrichment on graphitized carbon black, separation on silica-gel, and graphite furnace atomic absorption spectrophotometric detection. The second method is based on hydride generation with simultaneous liquid-liquid extraction and flame photometric gas chromatographic detection. The results of the first water sampling (August–September) are reported. Concentrations of tributyltin were found to be low ( −1 ) and the hypotheses of discontinuous emission and a seasonal minimum will be verified in the next sampling programmed for winter and spring.

Effects of glandular trichomes on the development of Phytophthora infestans infection in potato (S. tuberosum)

S. berthaulltii Hawkes, a wild potato species, possesses two types of glandular trichomes on its leaf surface: types A and B wich confer resistance to insects. Preliminary results indicated that the presence of glandular trichomes also confers resistance to Phytophthora infestans, the causal agent of late blight. In this paper we report the evaluation of trichome characteristics (density and exudate activities) performed on 8 lines of potato, including the control varieties Desirée and Tropicana, 5 hybrid lines derived from intercrosses and backcrosses between S. tuberosum and S. berthaultii and one accession of S. berthaultii. Whole plants of the 8 genotypes were inoculated with a spore suspension of Phytophthora infestans in order to evaluate their resistance to late blight. The resultant disease incidence correlated negatively with type A trichome density and with polyphenol-oxidase (PPO) activity of type A trichome glands. The removal of type B trichomes exudate by leaf dipping in ethanol did not influence the disease development after artificial inoculation of detached leaves. Type B trichome exudate was extracted and the fraction corresponding to Fatty Acids Sucrose Esters (FASE) was recovered after Thin Layer Chromatography and tested on the fungal mycelium in vitro. The FASE exhibited a slight inhibitory effect on mycelium growth. The results of the experiments are discussed, and several hypotheses regarding the possible role of types A and B trichomes are formulated.

Determination of PAH in atmospheric particulates in the area of the Italian base in Antarctica: Report on monitoring activities during the last three scientific expeditions☆

Concentrations of polycyclic aromatic hydrocarbons (PAH) in atmospheric particulates have been determined in the frame of the control activities for environmental protection during the VI (1990-1991), VII (1991-1992) and VIII (1992-1993) Italian expeditions in Antarctica. Samples were collected at the four cardinal points at about 200 m from the central area of the Italian scientific base. Data show low levels of the individual PAH (95% in the range 1-50 pg m(-3)) confirming the absence, up to now, of significant contamination from the base. These results could be used as a reference for the assessment of the air pollution due to combustion sources present in the base. Any possible variation in the bases activities in the future should be analysed and evaluated with respect to these findings.