L. Lepri

Organic pollutants in sea-surface microlayer and aerosol in the coastal environment of Leghorn—(Tyrrhenian Sea)

Abstract The levels of dissolved and particle-associated n -alkanes, alkylbenzenes, phthalates, PAHs, anionic surfactants and surfactant fluorescent organic matter (SFOM) were measured in sea-surface microlayer (SML) and sub-surface water (SSL) samples collected in the Leghorn marine environment in September and October 1999. Nine stations, located in the Leghorn harbour and at increasing distances from the Port, were sampled three times on the same day. At all the stations, SML concentrations of the selected organic compounds were significantly higher than SSL values and the enrichment factors (EF=SML concentration/SSL concentration) were greater in the particulate phase than in the dissolved phase. SML concentrations varied greatly among the sampling sites, the highest levels ( n -alkanes 3674 μg/l, phthalates 177 μg/l, total PAHs 226 μg/l) being found in the particulate phase in the Leghorn harbour. To improve the knowledge on pollutant exchanges between sea-surface waters and atmosphere, the validity of spray drop adsorption model (SDAM) was verified for SFOM, surface-active agents, such as phthalates, and compounds which can interact with SFOM, such as n -alkanes and PAHs.

Polyphenol levels and free radical scavenging activities of four apple cultivars from integrated and organic farming in different italian areas.

This paper investigates the influence of cultivar (Annurca, Golden Delicious, Red Chief, and Stayman Neepling), rural practice (integrated and organic), and growing region (different Italian regions) on polyphenol composition and antiradical activity of the pulp and skin of apples, as presented to the consumer at the market. Antiradical activity of fruit was strongly related with the total polyphenolic content, determined both by the spectrophotometric Folin-Ciocalteu method ( R (2) = 0.90; P < 0.01) and by HPLC ( R (2) = 0.85; P < 0.01). Considering the edible portion of the fruit, polyphenolics contribute toward explaining approximately 90% of the overall antiradical activity, thus highlighting their important role in human health protection. Therefore, the data indirectly indicated that ascorbic acid and other antiradical molecules differing from polyphenols play a much less important role in explaining the health-protecting properties of apples. Cultivar effect was by far the most important, and Annurca and Golden Delicious were respectively the best and the worst apples from the point of view of the health-protecting attributes.

The use of levoglucosan for tracing biomass burning in PM2.5 samples in Tuscany (Italy)

Levoglucosan was present in all samples and its concentrations showed a pronounced annual cycle with maximum levels in the cold season. The annual percentage of ratios of levoglucosan to OC ranged from 0.04 to 9.75% evidencing a major contribution of biomass burning to the aerosol OC during the winter. In the urban-background site, OC was strongly correlated with EC in winter, suggesting that the major fraction of OC was generated as primary particles along with EC. A background levoglucosan component showed that biomass burning was continuously taking place in all the investigated sites. The biomass burning contribution to the Tuscany aerosol was made up of a background component and an additional component during winter probably due to wood burning for domestic heating.

The mechanism of ion exchange with algenic acid

Abstract The exchange mechanism which determines the retention capacity of alginic acid has been investigated. Chromatographic, pH, and viscosity measurements, performed with several metal ions, have permitted us to show that ion exchange is not the only mechanism but that the influence of the two vicinal hydroxyl groups on the retention capacity of alginic acid is also important.

Organochlorine pesticide air-water exchange and bioconcentration in krill in the Ross Sea.

Mean hexachlorobenzene (HCB) and hexachlorocyclohexane (HCH) concentrations, measured in seawater and air samples, confirmed the decline in levels of these compounds in Antarctic air and water. However, low alpha/gamma-HCH ratios in air at the beginning of the sampling period suggest a predominance of fresh lindane entering the Antarctic atmosphere during the Austral spring probably due to current use in the Southern Hemisphere. Water-air fugacity ratios demonstrate the potential for HCH gas deposition to coastal Antarctic seas, while the water-air fugacity ratios for HCB imply that volatilization does not account for the observed decrease of HCB in surface seawater. HCH concentrations found in krill samples were correlated with seawater concentrations indicative of bioconcentration of HCHs from seawater.

Soap thin-layer chromatography of some primary aliphatic amines

Abstract The chromatographic characteristics of nine primary aliphatic amines have been studied using soap thin-layer chromatography. The influence of the type of detergent and its concentration, of the organic solvent and of the acid concentration on the chromatographic behaviour of these amines was investigated. Many separations that cannot be effected with either ion-exchange or reversed-phase chromatography have been effected.

Concentration, separation and determination of hydrocarbons in sea water

Abstract A method for determining the hydrocarbons dissolved in sea water, including their concentration and separation into homogeneous classes, is described. Extraction with organic solvents, determination of the optimum volumes for n-hexane and carbon tetrachloride and concentration procedures for the extracts were investigated. Separation of hydrocarbons from polar compounds and their fractionation into five classes (aliphatic, monoaromatic and polynuclear with 2, 3–4 and 5–6 rings) were achieved using adsorption chromatography on a two-step microcolumn of silica gel and aluminium oxide. The overall recovery efficiency of the procedures and the detection limits of several hydrocarbons in 11 of sea water are reported.

Effect of pasteurization and storage on some components of pooled human milk

Pooled human milk was subjected to Holder pasteurization and storage at -20 degrees C up to 90 days and examined for its content of fat and L-lactate and for lipid composition. This treatment reduced fats by 6% and L-lactate by at least 7%. In addition, pasteurization and storage induced triglyceride hydrolysis. The absolute amount of free fatty acids (FFAs) which was 0.5% after collection, doubled after pasteurization and rose even more after storage. Different FFA compositions were found by several authors using the same analytical method even for milk samples subjected to the same treatment. More detailed information on procedures must be given to explain the different results.

Alginic acid, a new thin layer material : Part I

Abstract Alginic acid is proposed as a new stationary phase for TLC. The effects of the distance moved by the solvent front, temperature, hydrogen ion concentration of the eluents and the thickness of the layers on the R F values of some common elements have been extensively investigated. Characteristic R F values of some common elements are reported. The chromatographic properties of alginic acid and carboxymethylcellulose were compared.

Distribution and mass balance of hexavalent and trivalent chromium in a subsurface, horizontal flow (SF-h) constructed wetland operating as post-treatment of textile wastewater for water reuse.

In this study, during a two-year period, we investigated the fate of hexavalent and trivalent chromium in a full-scale subsurface horizontal flow constructed wetland planted with Phragmites australis. The reed bed operated as post-treatment of the effluent wastewater from an activated sludge plant serving the textile industrial district and the city of Prato (Italy). Chromium speciation was performed in influent and effluent wastewater and in water-suspended solids, at different depths and distances from the inlet; plants were also analyzed for total chromium along the same longitudinal profile. Removals of hexavalent and trivalent chromium equal to 72% and 26%, respectively were achieved. The mean hexavalent chromium outlet concentration was 1.6 ± 0.9 μg l(-1) and complied with the Italian legal limits for water reuse. Chromium in water-suspended solids was in the trivalent form, thus indicating that its removal from wastewater was obtained by the reduction of hexavalent chromium to the trivalent form, followed by accumulation of the latter inside the reed bed. Chromium in water-suspended solids was significantly affected by the distance from the inlet. Chromium concentrations in the different plant organs followed the same trend of suspended solids along the longitudinal profile and were much lower than those found in the solid material, evidencing a low metal accumulation in P. australis.