1,721,017 research outputs found
A simple approach for the determination of heavy metals in airborne particulate matter (PM10) by Laser Ablation-Inductively Coupled Plasma Mass Spectrometry
No full textThe coupling of Laser Ablation (LA) with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is applied for the qualitative and quantitative determination of element in many areas of analytical chemistry (Di Franco et al., 2011; Giannossa et al., 2015). The aim of this work is the development of a method for the determination of heavy metals suspended by LA-ICP-MS in airborne inhalable particulate matter, sampled with an impactor high volume air sampler on quartz fiber filters.
The easy, rapid, non-destructive method is proposed as a rapid screening procedure for this peculiar environmental specimen. The un-necessity of a preparative/extracting or diluting step and the absence of the stressing conditions generally included in that step (temperature, microwave power, strong acids) dramatically reduces the probability of interferences or underestimating errors (Rauch et al., 2001; Wang et al., 1999). On the other hand, a major statistical study is needed in planning instrumental conditions and data collecting, in order to ensure valuable and reproducible numerical data. We propose a cross-calibration procedure which uses the results obtained on some of the specimens of the sample batch, analysed after acidic digestion and interpolated on a aqueous standard solution calibration curve, as reference points for the direct quantification of the remaining samples, analysed under laser ablation. Real samples from a traffic city site and a rural site, taken as blank, were analysed and compared with acidic digestion analysis. The method was proved to be affordable, reliable and rapid to set. The method is also low environmental impact as it does not involve the use of harmful chemical
An innovative derivatisation GC/MS procedure for the identification of proteins in the Paint Microsample
No full textThe secret of the artisans of Salento: diagnostic investigations applied to the study of the finishing techniques of the baroque buildings of Lecce (Puglia, Italy)
No full textThe city of Lecce (Puglia, Italy) known internationally thank s to the local stone handicraft and to the precious historical and artistic monuments, owes its title of "Cradle of the Baroque" to two types of rock: pietra leccese and carparo. These two rocks belong to the group of miocenic limestone and of quaternary limestone, respectively. The formation of soil of Puglia dates to the quaternary and tertiary periods and soil is characterized by limestone with chemical and physical characteristics very different from each other and with satisfactory colors. Thanks to their quality pietra leccese and carparo were the materials mostly used by local artisans for the construction of buildings located in Salento peninsula (Puglia-Southern Italy) since ancient times. The complex baroque architecture of the city of Lecce was also produced: significant examples are the pinnacles, the decorations, the capitals, the statues that decorate the facades of the baroque buildings of the city of Lecce. In these buildings, public or private, laic or religious, the bricks of the facades sometimes were left untreated, more often were finished with inorganics or organics for aesthetic, hygienic or protective purposes. Knowledge of the finish materials applied on the facades of these buildings is important to plan a correct restoration and to preserve the cultural heritage and the tourism of the city. However, there are several difficulties such as the scarcity of written sources, since the finishing techniques used in the past were jealously preserved by artisans, and, mainly for organics, the phenomena of alteration and degradation that inhibit the identification of the techniques employed. A multidisciplinary research, which involved the study of the few written and oral sources, has allowed the identification of some organic products, which possibly were applied by the artisans of Salento on the surface of the buildings constructed between the 1600 and 1900 centuries: among these products, there are also natural materials whose usage was not hyphotesized before on cultural stone heritage. In the present work laboratory specimens of pietra leccese and carparo, treated according to the already known and knewly discovered recipes and subjected to natural and artificial aging, have been studied, through the use of optical, colorimetric, spectroscopic and chromatographic techniques; the employed analytical methods were of great help to the identification of molecular markers, characteristic of the various organic substances, and to the characterization of methods, used in the past on the facades of baroque buildings of Lecce, revealing some secrets of the ancient artisans of Salento
The Roman wall paintings at Pompeii: archaeometrical investigation of preparatory drawings (sinopie) and pigments
No full textSpectroscopic studies of medieval wall paintings of Salento (Puglia, Italy): characterisation of pigment and techniques
No full textA multidisciplinary approach to study the skin of baroque buildings in Salento (Puglia, Italy)
No full textPuglia (Italy) has always occupied a prominent place in the field of production and use of stone materials, because it is rich of limestone with good chemical, physical and mechanical characteristics and with satisfactory colors. As a result these stones have been widely used in recent and past construction in Salento (Puglia-Southern Italy); both carparo and pietra leccese (the names of the most important among these lithotypes) are known since ancient times and have been valued in the art achieving an international appraisal thanks to local handicraft. Over the centuries these stones have produced the complex and well known architecture of Lecce spanning from Romanique to Baroque.
The skin of these buildings is an interesting topic because different conservation states can be acknowledged and art historians generally considered a different surface finish the main cause [Casciaro personal communication?]. Unfortunately only the geologist De Giorgi [3] in one of his book, reports that San Nicolò and Cataldo church (a Romanique church) was treated with encaustics, but PyGCMS analyses carried out on a few samples collected before restoration do not agree with this report [tesi? Poster nostro?]. Also workers protected both materials and techniques, making quite difficult today to identify the ancient product and procedures.
A recent research reports that between the sixteenth century and the eighteenth century the facades were often left untreated whereas in other periods finishing techniques were applied for aesthetic, hygienic, protective or conservative purposes [1], however no material knowledge is reviewed.
The study of literary, historical and oral sources has led to a list of organic products that could have been applied on the building surfaces as waterproof agent: among them, walnut oil, ovine or bovine milk, leaf of the prickly pear, wax, and bulb of the “Drimia maritima” plant [2]. Following this research, a collaborative project started in which all the organic products acknowledged in the different sources have been applied on laboratory samples. These “finished” samples have been aged naturally and artificially and studied by different analytical tools to identify potential biomarkers characteristic of the finishes. For this purpose, a multidisciplinary approach including optical, spectroscopic and chromatographic techniques was carried out and the relevant results will be presented and discussed in the present poster.
[1] D. G. De Pascalis, L'arte di fabbricare e i fabbricatori, Nardò, Besa, 2001.
[2] G. Siciliano, Tecniche di finitura dell’architettura in pietra a Lecce e provincia, tesi di laurea in “Storia delle tecniche artistiche”, Università degli Studi di Lecce, a.a. 2004-2005.
[4] M. R. Derrick, D. Stulik, J. M. Landry, Infrared spectroscopy in conservation science. Scientific tools for conservation, Los Angeles, The Getty Conservation Institute, 1999
Characterization of surface finishes on ancient historical buildings: an integrated analytical approach to estabilish the secrets of artisans in Salento (Southern Italy)
No full textNew evidences on efficacy of boronic acid-based derivatization method to identify sugars in plant material by gas chromatography-mass spectrometry
No full textThis work presents an analytical procedure based on gas chromatography-mass spectrometry which allows the determination of aldoses (glucose, mannose, galactose, arabinose, xylose, fucose, rhamnose) and chetoses (fructose) in plant material. One peak for each target carbohydrate was obtained by using an efficient derivatization employing methylboronic acid and acetic anhydride sequentially, whereas the baseline separation of the analytes was accomplished using an ionic liquid capillary column. First, the proposed method was optimized and validated. Successively, it was applied to identify the carbohydrates present in plant material. Finally, the procedure was successfully applied to samples from a XVII century painting, thus highlighting the occurrence of starch glue and fruit tree gum as polysaccharide materials
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