1,721,211 research outputs found
Lab-scale monitoring of electrokinetic remediation of contaminated sediments
No full textThe management of dredged sediment is commonly recognized as a complex procedure in industrialized countries, where sediments are often contaminated by metals and organic contaminants due to the presence of a number of point and diffuse contamination sources. Due to the huge amounts of sediments to be dredged due for either maintenance or environmental dredging purposes, management options different from landfilling are claimed. Among the available treatment options, Electrokinetic Remediation (EKR) appears to be particularly suitable due to a number of potential advantages, including the capability of treating finely graded and low-permeability matrices such as sediments, and the ability of removing organic and inorganic contaminants. In order to improve the remediation process, enhancing agents such acids, chelating agents, surfactants can be added in the electrode compartments. However, due to the complexity of both the sediment matrix and the contaminants nature, despite the interest demonstrated by the scientific sector in EK, the uncertainties in process yields and control still hinder its full-scale application. This work was aimed at studying EKR for metal removal from contaminated sediment samples from three Italian harbors. The lab-scale EKR tests were performed using different types of acids, namely acetic, nitric and hydrochloric aci
A direct screening procedure for diuretics in human urine by liquid chromatography-tandem mass spectrometry with information dependent acquisition
No full textBackground: Diuretics are a class of compounds largely used for either therapeutic (edemas, hypertension, etc.) or illegal (doping) purposes. Probably owing to the substantial variety of their chemical structures, which makes them hardly extractable from a biological matrix in a single procedure, a quite short list of screening methods can be retrieved in the literature.
Methods: This work presents a screening procedure for 24 diuretics based on the direct injection of urine (after 50 folds dilution) in a LC-ESI-MS/MS system (Applied Biosytems 4000 QTrap). Two information dependent acquisitions (IDA), one in positive, one in negative ionization, allowed the acquisition of one selected reaction monitoring transition for each compound, which, when a significant peak was found, triggered the acquisition of the enhanced product ion (EPI) spectrum.
Results and conclusions: EPI spectra were stored in a library and the procedure was able to recognize by library matching various diuretics in real positive samples. The limits of detection were comprised between 0.002 and 0.25 mg/l and ion suppression was not found to significantly influence the analysis
Il sito inquinato di Lunghezza a Roma sulla tratta Roma - Napoli: un esempio di soluzione ad una discarica abusiva - Gli studi dell’Università di Roma “La Sapienza”
No full textGas-solid carbonation kinetics of Air Pollution Control residues for CO2 storage
No full textGas-solid carbonation of Air Pollution Control (APC) residues is a CO2 Capture and Storage (CCS) technology, where highly reactive Mg- or Ca-bearing materials adsorb CO2 and form stable Mg- or Ca-carbonates. The carbonation kinetics of this reaction have been studied at different temperatures, CO2 concentrations, and at atmospheric pressure in order to select the best operative conditions on the basis of CO2 stored and reaction time. The samples were initially heated up to the operative conditions under argon atmosphere and then carbonated under a CO2-argon atmosphere. All carbonation kinetics were characterized by a rapid chemically controlled reaction followed by a slower product layer diffusion-controlled process. Maximum conversions between 60% and 80% were achieved, depending on the operative temperature and CO2 concentration. Temperature did not notably affect the maximum conversion obtained in the experiments performed at temperatures equal or above 400 °C; the influence on the kinetics was masked by the change in initial composition due to dehydroxylation reaction and surface area while heating up to the operative temperature. A slight influence of CO2 concentration on the kinetics was observed, whereas no influence on the maximum conversion was noticed. The obtained results suggest that the flue gases with 10 vol.% CO2 concentration can be directly used to form stable carbonates, thus lumping capture and storage in a single step. The APC residues produced from the existing incineration plants would cover only 0.02-0.05% of the total CO2 European storage capacity required to comply with the Kyoto protocol objectives. Nevertheless, the proposed carbonation route could be applied to other residues, such as Cement Kiln Dust, Paper mill residues and Stainless Steel Desulphurization slags, characterized by a high content of free calcium oxides and hydroxides, thus increasing the impact of this process option. © 2008 Elsevier B.V. All rights reserved
Ethyl glucuronide in hair: sensitivity, specificity, and factors potentially influencing its performance
No full text
RAPID AND HIGHLY SELECTIVE GC/MS/MS DETECTION OF HEROIN AND ITS METABOLITES IN HAIR
No full textA direct treatment of methanol-washed hair with a silylating solution is proposed to extract heroin, O-6-monoacetylmorphine, morphine, acetylcodeine, and codeine, obtaining the simultaneous derivatization of the hydroxylated metabolites and reducing potential sample contamination. Analysis is performed by capillary gas chromatography-tandem mass spectrometry (GC/MS/MS) using multiple selected reaction monitoring. Owing to the selectivity and sensitivity of the GC/MS/MS analysis, and to the extremely simple treatment of the sample, the method fulfils the requirements of both clinical and forensic diagnosis of heroin use
Application of thermospray liquid Chromatography-Tandem Mass Spectrometry (HPLC/TSP/MS/MS) to the confirmatory analysis of heroin metabolites in biological fluids.
No full textIn tema di atrazina e simazina: Nota I - Comportamento nell'ambiente e contributo sperimentale all'analisi nelle acque.
No full textThe role of alcohol abuse in the etiology of heroin-related deaths. Evidence for pharmacokinetic interactions between heroin and alcohol
No full textIn order to evaluate pharmacokinetic interactions between heroin and alcohol and their role in the etiology of heroin-related deaths (HRD), the alcohol concentration in blood (BAC), the free (FM) and total morphine (TM) concentrations in blood (determined by DPC Coat-A-Count radioimmunoassay before and after enzymatic hydrolysis), and the TM concentration in urine and bile (DPC Coat-A-Count after enzymatic hydrolysis) in a population of 39 lethal cases included in the records of the Department of Legal Medicine and Public Health at the University of Pavia from the period January 1997-April 1998 were examined. The cause of death in each case was attributed to either heroin or associated heroin-ethanol intoxication. Cases were arbitrarily divided into two groups according to BAC (low-ethanol group, LE, BAC 1000 mg/L). The differences in the FM and TM concentrations in blood, bile, and urine and in the FM/TM ratios between the two . groups were statistically evaluated (Mann-Whitney U test). A similar statistical evaluation was carried out on data from a previously published study concerning the disposition of heroin and its metabolites (6-acetylmorphine and morphine) in blood and urine in 23 lethal cases attributed to either heroin or heroin and alcohol intoxication. The values of the following variables in the LE and HE groups were compared: FM, TM, and 6-acetylmorphine concentrations in blood (6-AM); the FM/ (FM + 6-AM) ratio; the FM/TM ratio; and the urinary concentrations of heroin, 6-acetylmorphine, and free morphine. Statistical analyses of data indicated that high BACs are associated with reduced hydrolysis of 6-AM to morphine (FM/[FM + 6-AM], p = 0.0022) and that a good inverse correlation exists between BAC and hydrolysis of 6-AM to morphine (r2 = 0.67). High BACs were also found to be associated with an increased FM/TM ratio and with reduced excretion of free and total morphine. These results suggest the hypothesis that pharmacokinetic interactions between heroin and alcohol do occur in individuals exposed to high doses of these substance
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