Mauro Rotatori

Dioxins and furans formation in pilot incineration tests of sewage sludge spiked with organic chlorine

The factors affecting polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) formation were studied in sewage sludge incineration tests carried out on a demonstrative plant. The plant includes a circulating fluidised bed furnace (FBF) and a rotary kiln furnace (RKF), operating alternatively. During the tests sewage sludge was spiked with chlorinated hydrocarbons and the operating parameters of the afterburning chamber were varied. PCDD/F were sampled in each test before the bag filter, thus collecting the above contaminants before abatement systems. From the tests it appeared that PCDD/F were always produced in more abundance in the tests carried out by FBF than by RKF. The higher PCDD/F concentrations in the tests by FBF were reached when sewage sludge was spiked with a high dosage of a surrogate organic mixture of chlorinated hydrocarbons and when the afterburning chamber was used only as transit equipment with the burner off. The distribution of the different PCDD/F homologues was compared. P5CDFs were generally the prevalent fraction, with very few exceptions for the tests by RKF at high temperature of the afterburning chamber. As for FBF tests, it was found that the PCDD/F homologue profile depends on the afterburning chamber temperature.

Concentration and determination of polycyclic aromatic hydrocarbons in aqueous samples on graphitized carbon black

Abstract A method is proposed for the determination of six polycyclic hydrocarbons in water samples, using a short column packed with graphitized carbon black (GCB). The adsorbed compounds are eluted by passing through the column toluene-benzene-acetonitrile (5:2:3). In order to choose the optimal eluent, the partition coefficients in GCB-liquid systems were studied in a static arrangement; to optimize the size of the concentration columns breakthrough curves were plotted.

HPLC determination of benzydamine and its metabolite N-oxide in plasma following oral administration or topical application in man, using fluorimetric detection

A method for the extraction and quantification of benzydamine and its metabolite N-oxide by liquid chromatography with fluorescence detection in plasma samples is described. This method has adequate sensitivity, specificity and is reproducible. The use of the extraction column allowed a recovery of both benzydamine and its metabolite of over 97% to be obtained. The plasma levels of benzydamine and its metabolite N-oxide were studied after oral administration as sugar-coated tablets or topical application to the vaginal mucosa as a cream to 6 healthy volunteers. After topical application, the plasma concentrations of the unchanged drug and its metabolite are lower than those obtained following oral administration. These data further stress the concept that, whenever possible, topical use should be considered the treatment of choice since, along with a more selective therapy, the incidence of systemic side effects can be considerably reduced.

Concentration and isolation of organic acids on graphitized carbon black

Abstract The application of graphitized carbon black to the extraction of traces of organic acids has been studied. It is demostrated that the recovery of these substances cannot be carried out without considering the nature of these compounds and their molecular structure. The amount of adsorbent and the kind of eluent required were deduced respectively from the breakthrough values and from distribution ratios.

Polycyclic aromatic hydrocarbon emission profiles and removal efficiency by electrostatic precipitator and wetfine scrubber in an iron ore sintering plant.

Abstract A monitoring campaign of polychlorinated dibenzo-p-dioxins and dibenzofurans, polyaromatic hydrocarbons (PAHs), and polychlorinated biphenyl was carried out in an Italian iron ore sintering plant by sampling the combustion gases at the electrostatic precipitator (ESP) outlet, at the Wetfine scrubber (WS) outlet, and by collecting the ESP dust. Few data are available on these micropollutants produced in iron ore sintering plants, particularly from Italian plants. This study investigates the PAH emission profiles and the removal efficiency of ESPs and WS. PAHs were determined at the stack, ESP outlet flue gases, and in ESP dust to characterize the emission profiles and the performance of the ESP and the WS for reducing PAH emission. The 11 PAHs monitored are listed in the Italian legislative decree 152/2006. The mean total PAH sum concentration in the stack flue gases is 3.96 μg/N · m3, in ESP outlet flue gases is 9.73 μg/N · m3, and in ESP dust is 0.53 μg/g. Regarding the emission profiles, the most abundant compound is benzo(b)fluoranthene, which has a relative low BaP toxic equivalency factors (TEF) value, followed by dibenzo(a,l)pyrene, which has a very high BaP(TEF) value. The emission profiles in ESP dust and in the flue gases after the ESP show some changes, whereas the fingerprint in ESP and stack flue gases is very similar. The removal efficiency of the ESP and of WS on the total PAH concentration is 5.2 and 59.5%, respectively.

High-performance liquid chromatographic determination of norfloxacin in human tissues and plasma with fluorescence detection

A high-performance liquid chromatographic method with fluorimetric detection is described for the quantitative determination of norfloxacin in renal and prostatic tissues and in plasma. It consists of tissue pretreatment, purification by solid-state extraction and separation and quantification by high-performance liquid chromatography on a C8 reversed-phase column. Analytical recoveries ranged from 95.2 to 97.6%. Within-day and between-day precision were assessed by analysing serum containing 50 and 500 ng/ml norfloxacin. At each concentration, the within-day precision was less than or equal to 3.6% (coefficient of variation; n = 10) and the day-to-day precision was less than or equal to 5.3% (n = 10). The limit of detection was 1 ng/ml.