481 research outputs found
Development of advanced analytical methods for the determination of emerging pollutants in environmental waters
No full textThis thesis work was focused on the analytical determination of emerging
pollutants in environmental water matrix, concerning preparative step and
analysis using Gas Chromatography coupled with Mass Spectrometry (GCMS).
The emerging pollutants are so defined because they have been
recognized only recently as pollutants and regulatory and monitoring plans
are not yet implemented at Italian and European level. Pharmaceuticals
and Personal Care Products (PPCPs) are considered emerging
contaminants, they describe a large class of chemical contaminants that
can originate from human usage and excretions and veterinary
applications. There are a large number of different substances used as
medicines, during and after treatment, humans and animals excrete a
combination of intact and metabolised pharmaceuticals, many of which are
generally soluble in water and have been discharged to the aquatic
environment with little evaluation of possible risks or consequences to
humans and environment. In addition, the chemicals that are components
of personal care products (PCPs) number in the thousands, the world’s
people consume enormous quantities of skin care products, dental care
products, soaps, sunscreen agents, and hair styling products. PCPs
continuously enter the wastewater after their regular use during showering
or bathing. Recent studies indicate the potential widespread occurrence on
low-level concentrations (ng-μg/L) of PPCPs in the aquatic environment.
Therefore, there’s critical need for efficient and reliable analytical methods
to address the occurrence concentrations, and fate of the PPCPs in
environment. GC-MS has been the basic tool for environmental analyses of
various organic pollutants and it has been the approach of this study choice
because of its superior separation and identification capabilities.
The activity has been concentrated on the development of sample
preparation procedures that could be fast, cost-effective and environmentfriendly
for the analysis of PPCPs. It’s known that sample pre-treatment
causes an analysis bottleneck that typically accounts for over 60% of the total analysis time. The work was focused on evaluation and optimization of
different extraction techniques for treatment of water matrix.
There are fundamentally two kinds of approach for parameters
optimization. One Factor At Time (OFAT) method involves the testing of
factors, or causes, one at a time instead of all factors are changed at once.
Even more people, prominent text books and academic papers currently
favour design of experiments (DOE) approach; it’s a statistically
multivariate method for screening and/or optimization of different factors at
the same time (multiple factors are changed at once). It shows several
relevant advantages over OFAT approach: it requires less runs for the
same (sometimes more) precision in effect estimation, it can estimate
interactions and it provides a knowledge (and optimal settings of factors) in
the whole experimental domain, where OFAT can miss them. For these
reasons this approach was chosen for several published works, using in
particular Central Composite Design (CCD) or Box-Behnken Design (BBD).
Two different extraction procedure have been studied: Solid Phase
Extraction (SPE) and Solid Phase Micro Extraction (SPME). The first
technique was evaluated in order to optimize extraction step of 25 PCPs,
including fragrances, PAHs, antioxidants, UV-filters, plasticizers, and
pesticides, from water, using OFAT approach. The optimized parameters
were different: SPE sorbent, type and volume of eluent, elution rate, and
evaporation procedure. The better recovery yield considering the totality of
PCPs were found extracting with a Strata-X SPE cartridge, using a volume
of 15 mL of Ethyl Acetate as solvent, operating with slow flow rate, and
evaporating at 40°C of temperature. Under these con ditions the procedure
achieves a recovery higher than 70% for most PCPs investigated (with
LOD ranged from 5 to 10 pg injected on GC), this result makes the
developed method suitable for comprehensive chemical profiling of PCPs in
various aqueous matrices. It is clear that higher recovery values can be
achieved only for selected PCPs using specific target-compound methods.
That it was done for method optimization for determination of two synthetic
phenolic antioxidants and their five main metabolites in water. This is the first published method dedicated solely to the determination of this
chemical class in water samples. The methodology was developed using
SPE approach with derivatization before GC-MS analysis. Extraction on 10
mg Oasis HLB cartridges provides a satisfactory enrichment factor for
environmental samples avoiding the need of solvent evaporation and
reducing SPE costs and organic solvent wastes. After extraction, polar
metabolites are derivatized with MTBSTFA to produce stable, less polar
analytes that are determined by GC-MS at low levels. The usage of two
surrogate internal standards results in a method providing good accuracy,
with relative recoveries between 80 and 110%, and limits of detection (2-44
ng/L). The application of the method to wastewater and river samples
showed BHT and BHT-Q as the compounds in higher concentrations in
wastewater (up to 800 ng/L) and the metabolites BHT-CHO and BHTCOOH
as the most resistant to water treatment, being at the 10-100 ng/L in
sewage and river samples. In this work the optimization was done with an
experimental design approach, using a Box-Behnken design (BBD). This
work was developed in collaboration with University of Santiago de
Compostela (E).
SPME technique was investigated in order to extract a mixture of several
PCPs, evaluating extraction time and temperature and desorption time and
temperature. A simple SPME method has been developed for the
simultaneous GC-MS determination of 23 PCPs (i.e. antioxidants, PAHs,
UV-filters, pesticides, fragrances, plasticizers, that display log Kow values >
3.2) at trace levels in water. An Inscribed Central Composite (CCI) design
approach was employed for investigate extraction temperature and time,
and desorption temperature and time. A direct immersion mode was used
for extraction from a fixed sample volume. The optimum SPME operating
conditions have been defined as: extraction time of 90 min at a temperature
of 80°C, desorption time of 11 min at 260°C. Under these conditions the
procedure provides low detection limits (<= ppb) and satisfactory
reproducibility (RSD%<=1%) for most of the PCPs investigated.
The analysis was then extended to more polar compounds, for a total of 21
PPCPs that display a range of log Kow between 1.2 and 6.4 (i.e. antiseptic,
antinflammatory drugs, estrogens, UV-filters) with the necessity of
derivatize the compounds before GC analysis. A on-fiber after extraction
approach was chosen for SPME derivatization, using silylation agent. The
derivatization can be performed in only 30.5 minutes with a very small
consumption of silylation reagent and without need of high temperature.
Under the optimized conditions of extraction, derivatization and desorption,
the procedure provides low detection limits (<= 1 ppb for the non polar
analytes and <=35 ppb for the derivatized ones) and satisfactory
reproducibility (RSD% <=10% or 20%) for most of the PPCPs investigated.
The PhD project, in his totality, was a logic progressive work, expanding the
study in term of kind of analytes studied, extraction techniques and
optimization approach. A preliminary and careful study was carried out in
order to properly understand the current situation and the possible research
developments of interest. The study was initially focused on less polar
analytes (PCPs), then extending to more polar ones (PPCPs). It was firstly
took in consideration the SPE technique, going to more innovative and
preferable on several points of view SPME. The expanded range (in
particular polarity range) of analytes makes necessary a derivatization step
before GC-MS analysis, for these reason the subsequent step was the
optimization of a method that includes SPME-derivatization. Also
considering the optimization approach, the work started using OFAT
optimization, this approach was left after the first work for the more
accurate and precise DOE.
These works led to development of multiresidual analytical method suitable
for the comprehensive analysis of this kind of pollutants in water matrix.
These methodologies may be the basis of water monitoring for temporal
and spatial changes
BFB-EMG NELLA MODIFICAZIONE DEL COMPORTAMENTO MOTORIO IN SOGGETTI EMIPLEGICI ADULTI STABILIZZATI: FOLLOW-UP AD UN ANNO
No full textThe aim of the study was the evaluation of the BFB-EMG effectiveness in a group of 15 adult patients affected by hemiplegia in a steady state one year after the end of the BFB-EMG training directed to increase the dorsiflexion of the ankle. Data obtained demonstrate that some of the induced modifications of motor behavior persist after the treatment. The authors have divided the patients into 4 groups according to the response to the treatment: F.B. indifferent, F.B. sensitive, weak learning, and stable learning, giving a cognitive interpretation to the results
LA RIABILITAZIONE DELLA PERIARTRITE DELLA SPALLA. CONSIDERAZIONI PRELIMINARI SULL'APPROCCIO MESOTERAPICO AL TRATTAMENTO
No full textThe clinical evolution of two groups of patients subjected to three fortnightly sessions of mesotherapy combined with an intense kinesitherapyprogram versus a control group arouses new interest in this therapeutic technique and the utility of a more thorough study of the criteria of application
Electromyographic biofeedback for modification of motor behavior in stabilized adult hemiplegics (controlled study)
No full textThe increase of the dorsal flexion of the ankle and the control of the inversion of the foot have been evaluated in a clinical study conducted in a group of adult chronic patients affected from hemiplegia. The patients were provided with visual and auditive feedback of the electrical activity of the muscles peronaeus longus and extensor communis. Data obtained demonstrate that by EMG feedback the expected increase in the dorsal flexion of the ankle and the control of the inversion of the foot together with an improvement in walking and stair climbing has been obtained
Il biofeedback nel trattamento delle bronopneumopatie croniche ostruttive (BPCO) [Biofeedback in treatment of chronic obstructive bronchopneumopathies]
No full text--
An hypothesis of work for a 'rehabilitating environment' in the light of a new method of cortical facilitation
No full textThe authors present a new conception of rehabilitation, based on cortex functions (motion language), in the light of which every other method could be reviewed and modified. Out of this conception is born the hypothesis of a 'rehabilitation environment' the most dynamic, mutable and as stimulating as possible (conception of architectual trace and a fountain of images and perceptions), this being an instrument of the rehabilitation and a needed complement of the method itself
Growth of Staphylococcus aureus and enterotoxin production in fresh egg pasta
No full textThis study investigated the growth of enterotoxin-producing Staphylococcus aureus and time–temperature combinations necessary for enterotoxin production in artificially and naturally contaminated fresh egg pasta. Egg pasta (35 ± 1 g) inoculated with three strains of enterotoxin-producing S. aureus at two different concentrations (103 CFU/g and 10 CFU/g) were incubated at 20 °C, 30 °C and 37 °C for 34 h. Industrial samples were S. aureus was naturally present at a concentration of 2.5 x 102 CFU/g were incubated under the same conditions. Enterotoxin was produced in all samples inoculated with the three strains of S. aureus incubated at 20 °C for 24 h or 30 °C for 10 h. No enterotoxin was produced in the naturally contaminated samples, even if the S. aureus concentration reached 106–107 CFU/g by the end of the experiment (34 h) indicating that the Staphylococci isolated in the production line were not enterotoxin-producing strains. Practical application: This research focused on the growth and enterotoxin production of Staphylococcus aureus naturally present on fresh egg pasta produced in an industrial line or artificially inoculated with three different strains of this bacterium. Our results confirmed that the staphylococci, naturally contaminating the fresh egg pasta during the production, were not enterotoxin-producing. However, the results obtained using enterotoxin producing strains show that this kind of product can support the development of theses bacteria and enterotoxin production. Therefore, these results should be useful to fresh pasta manufacturers and aid them in setting up their control measures in the Hazard Analysis and Critical Control Point in order to manage the microbial safety of the fresh egg pasta products
Analisi di contaminanti emergenti nelle acque: messa a punto di un metodo multiresiduo tramite GC-MS
No full textI componenti chimici presenti nei prodotti per la cura e l’igiene personali (PCPs, Personal Care Products) includono un’ampia e diversificata gamma di sostanze chimiche, fra cui: tensioattivi (benzeni alchilici), profumi (nitro muschi e muschi policiclici), filtri UV (benzofenone, ottocrilene), antibatterici (triclosan, triclocarban), conservanti (parabeni) [1,2].
Nonostante la loro presenza nell’ambiente sia riconducibile all’entrata in commercio, solo negli ultimi decenni sono stati riconosciuti come agenti inquinanti. A tutt’oggi non sono ancora previste, a livello nazionale ed europeo, nessun tipo di regolamentazione e monitoraggio.
I PCPs vengono smaltiti nei reflui urbani quotidianamente in quantità molto elevate, sono inquinanti che persistono nell’ambiente grazie al loro continuo rilascio; hanno, si può dire, una “pseudo-persistenza”, con significative conseguenze [3]. Tra le principali problematiche relative a questi composti , oltre naturalmente agli effetti tossicologici e lo studio di tecniche di abbattimento, vi è la necessità di definire metodiche analitiche di monitoraggio adeguate. Un singolo metodo di analisi per differenti classi di composti ha diversi vantaggi, in quanto riduce i tempi di analisi, il numero di campioni da prelevare e i costi.
Il presente progetto di ricerca riguarda la messa a punto di un metodo multiresiduo GC-MS per l'analisi simultanea di PCPs appartenenti a classi diverse, da applicare allo studio di campioni reali complessi. Il campione liquido è purificato e preconcentrato usando estrazione in fase solida (SPE) prima dell’analisi GC-MS.
Dopo un preliminare studio bibliografico [4], sono state esaminate e confrontate differenti condizioni di estrazione: la composizione della cartuccia, il tipo ed il volume del solvente utilizzato per eluire gli analiti da questa; al fine di sviluppare una procedura di preparazione del campione adeguata.
Sono state valutate cartucce SPE C-18 (Restek) e STRATA-X (Phenomenex, funzionalizzata con styrene divinylbenzene N-vinylpyrrolidone terpolymer), quest’ultima con caratteristiche sia lipofile che idrofile. Come solventi di eluizione sono stati considerati: Metanolo, Diclorometano, Acetato di Etile e miscele dei tre.
Sono state studiate, inoltre, le condizioni operative di analisi tramite GC, per separare il maggior numero di componenti possibili nel campione.
Il metodo è stato testato su 30 composti target.
1. R. Kanda, P. Griffin, A.J. Huw, J. Fothergill, J. Environ. Monit., 5 (2003) 823-830.
2. Y. Yoon, P. Westerfoff, S.A. Snyder, E.C. Wert, J. Membr. Sci., 270 (2006) 88-100.
3. C.G. Daughton, A. Ternes, Environmental Health Perspectives, 107 (1999) Suppl. 6.
4. M.C. Pietrogrande, G. Basaglia, Trends in Analytical Chemistry, in pres
Imparare dal manicomio: parco Basaglia come laboratorio di progetto
No full textNel lavorare sul parco Basaglia all’interno di un corso universitario, si è ritenuto che progettare la sua restituzione alla città richiedesse, oltre all’individuazione necessaria di usi, materie e forme compatibili, soprattutto di ricostruirne la lezione. La restituzione così intesa comporta un’attività quasi rabdomantica di rintracciare le correnti di vita sommerse in questo luogo silente per riattingere al giacimento di pensiero critico che rappresenta. Il tema dell’identità e delle sue implicazioni spaziali, conduce, in architettura, a una riflessione sul limite e sulla sua ambivalenza, di cui il parco è un esempio emblematico
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