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The mobility of Cu, Pb and Zn in harbour sediments was investigated using single, sequential and kinetic extraction techniques. Each type of extraction provides different information on the mobility of these elements in the environment. The single HCl extraction assesses general mobility, the sequential extraction assesses geochemical partitioning and kinetic extraction allows quickly and slowly mobilized elements to be identified. Kinetic extraction also allows the influence of extraction duration to be assessed. The results presented in this paper highlight the complementary information provided by different types of mobility study.

(H. Hamdoun). Ab s t r a c tFor a full assessment of the environmental risk posed by dredged sediments not only the anthropogenic enrichment of contaminants, but also their mobility and biological impact should be considered. This study reports on the enrichment factor (EF), mobility, and Adverse Effect Index (AEI) of metals and metalloids in nine dredged sediments. Significant enrichment of As, Cd, Pb and Zn with respect to background values is detected, and calculated AEI values for these elements suggest that it is possible that a corresponding biological effect may be observed. Correlation coefficients also reveal a link between mobility in HCl and enrichment for Cd, Cr, Ni, Pb and Zn, however As and Cu do not display such a link, possibly suggesting that the source of contamination for these elements is less recent. Mobility and enrichment are two parameters which are often studied separately; however this paper shows that in some cases strong correlations occur.

The chemical compositions of the essential oils of Pituranthos chloranthus harvested at the vegetative, flower budding, flowering and fruiting stages from three distinct geographical areas of Tunisia were investigated using GC-FID and GC-MS. One hundred and fifty compounds were identified in which α-pinene, β-pinene, α-phellandrene, β-myrcene, β-phellandrene, pcymene, 8-methyldecanal, exo-2-hydroxycineole acetate and carvacrol could reach more than 10% of the total amount. However, this composition varied with respect to both the geographical area and the season. A clear discrimination of samples could be achieved by submitting the results to PLS discriminant analysis. p-Cymenene was only detected at the floral budding stage (February), whereas high amounts of exo-2-hydroxycineole and exo-2-hydroxycineole acetate were specific for the flowering period (April). Carvacrol was showed to be characteristic mainly of the fruiting period (August), whereas the vegetative state (November) could be distinguished from the others by the presence of αand β-pinene. Limonene, camphene, geraniol and β-damascenone were likely to be specific for the essential oils of this species collected from the different regions of Tunisia.

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The Aspergilli of the series Versicolores include several airborne species to which we are exposed daily. Most of them synthesise sterigmatocystin, a mycotoxin precursor of aflatoxins recognised as potentially carcinogenic for humans (group 2B) by the International Agency for Research on Cancer. Our objective was to study the potential role of these moulds in the synthesis of extrolites of the aflatoxin biosynthetic pathway. A total of 124 isolates belonging to the eight species of the series Versicolores collected in French bioaerosols were studied: Aspergillus amoenus (n=1), Aspergillus creber (n=45), Aspergillus fructus (n=2), Aspergillus jensenii (n=39), Aspergillus protuberus (n=6), Aspergillus puulaauensis (n=5), Aspergillus sydowii (n=14) and Aspergillus tabacinus (n=2). All these isolates and a reference strain of each species were extracted using ethyl acetate acidified with 1% (v/v) acetic acid. In each extract, we screened for the following extrolites of the aflatoxin biosynthetic pathway by UPLC-HRMS: norsolorinic acid, versicolorin A, 6-demethylsterigmatocystin, sterigmatocystin, 8-O-methylsterigmatocystin, 5-methoxysterigmatocystin and aflatoxins B1, B2, G1 and G2. All extrolites, except aflatoxins, were found variably among species. Sterigmatocystin was found in extracts of all eight Versicolores species, including A. sydowii and A. tabacinus whose ability to synthesise sterigmatocystin was questioned or unknown, respectively.

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