Annali di chimica最新文献

Cotton yarn was dyed in Turkey red using madder through a special method. Amount of the dyestuffs bound to mordanted cotton fibre and the oiling numbers of the cotton yarn was investigated by using TLC (thin layer chromatography) and spectrophotometry. Sn(II) in the bright red cotton yarn was analysed by X-ray diffraction method.

The present paper reviews examples of the application of a portable - in house developed- XRF spectrometer for the analysis of museum metal artefacts in Greece. Specific topics are addressed, in particular, to which extent the qualitative or quantitative XRF analyses reveal important information about the raw materials and manufacture techniques used for gold, silver and bronze alloys in antiquity. The analytical information that it is gained by means of the XRF measurements is further assessed in comparison with the existing archaeometallurgical knowledge.

Four archaeological samples, unearthed from Qana in Yemen were analysed by analytical technique, currently applied in the field of petroleum geochemistry, and by gas chromatography coupled with a mass spectrometer (GC-MS). Sample no 1286 comes from a burned warehouse and samples no 964, 963 and 962 from the central sanctuary. These specimens were probably exposed to a heating source. In each case olibanum resin was identified according to the presence of their chemical markers corresponding to α-, β-boswellic and lupeolic acids (3α-hydroxy-olean-12-en-24-oic, 3α-hydroxy-urs-12-en-24-oic and 3α-hydroxy-lup-20(29)en-24-oic acids) and their respective O-acetyled derivatives (3α- O-acetyl -olean-12-en-24-oic, 3α-O-acetyl-urs-12-en-24-oic and 3-O-acetyl-lup-20(29)-en-24-oic acids). Concerning the thermal degradation state of samples, the GC-MS results are in agreement with the geochemical ones. Sample no 1286 and 964 correspond to ageing incense which has not undergone any heating action and are consequently relatively well preserved. Lastly, samples no 963 and 962 are thermally degraded resins and their gross composition data permits to conclude that sample no 963 is only partially burnt while sample no 962 has been much more degraded.

Recent developments in microscopy and image processing have made digital measurements on high-resolution images of fibrous materials possible. This helps to gain a better understanding of the structure and other properties of the material at micro level. In this paper SEM image segmentation based on mathematical morphology is proposed. In fact, paper models images (Whatman, Murillo, Watercolor, Newsprint paper) selected in the context of the Euro Mediterranean PaperTech Project have different distributions of fibers and fillers, caused by the presence of SiAl and CaCO₃ particles. It is a microscopy challenge to make filler particles in the sheet distinguishable from the other components of the paper surface. This objectif is reached here by using switable strutural elements and mathematical morphology operators.

We report a GC-MS method for the simultaneous analysis of proteins oil, and diterpenoid resins found in cultural objects. The method was initially designed for protein analysis of protenaceous paints and adhesives and involves acid hydrolysis as the first step. The amino acids in the protein hydrolysates, thus obtained, are treated with propan-1-ol/ hydrogen chloride and then pentafluoropropionic anhydride. The procedure was found also to yield the propyl esters of fatty acids derived from lipids and diterpenoid acids derived from natural resins, and thus allows the choice of a single method for the analysis of artists media which contain either oil s or proteins or mixtures of both proteins and oils or even resins. Thus natural mixtures such as egg yolk and also mixtures made by the artist such as animal glue / seed oil emulsions can be analysed. Coupled with FTIR analysis of paints and the staining of cross sections, to indicate layer structure the method can help to elucidate the paints and adhesives used by artists.

The applicability of an Energy Dispersive X-ray Diffractometer to some technical questions in the field of Cultural Heritage is presented. This diffractometer, equipped with a white source, has been utilized for the structural and elemental analysis of some items having different nature. Given its design, the instrument allows to collect data from samples as big as a book or a little more. Samples, without collection of any portion and without any preliminary preparation, have been placed in the instrument and spectra have been collected in a wide energy range that contains X-ray fluorescence and diffraction features. In all cases, data acquired in air and in a non destructive way were reliable and their collection was fast. Fluorescence and X-ray diffraction information, when possible, have been compared with those obtained by XRF micro-analysis and by an Angle Dispersive X-ray Diffractometer equipped with a Cu X-ray source. By using the last two techniques, data have been collected from small areas of the samples.

Vibrational spectroscopy is applied on samples obtained from the excavation area of the medieval Monastery (10^th century) of Karaach-Teke in Bulgaria. The results of the corresponding study, reveal the type of materials used for the creation of the wall-paintings and give evidence of Byzantine influence, a fact that further supports the well known impact of Byzantium on the technology and thematic-aesthetic features of iconography in Bulgaria during this era. In addition, the complementarity of FTIR and μ-Raman spectroscopies in the identification of pigments is indicated.