Adriana Rizzo - Academia.edu (original) (raw)

Papers by Adriana Rizzo

Portable Spectroscopy and Spectrometry, 2021

Journal of Combinatorial Chemistry, 2000

A scheme combining the preparation of building blocks in solution followed by solid-phase combina... more A scheme combining the preparation of building blocks in solution followed by solid-phase combinatorial chemistry has been developed to side-chain diversify 5-(hydroxymethyl)oxazole scaffold (1) into aryl ethers, thioethers, sulfones, sulfonamides, and carboxamides. Protected heterocyclic scaffolds 2 were linked to the solid phase and N-terminal derivatized using active ester chemistry, providing chemset 4{1-4,1-4}. The free side-chain hydroxyl of 4 was smoothly converted to aryl ethers 6 under Mitsunobu conditions, with a broad range of substituted phenols. Alternatively, quantitative conversion of hydroxyl to bromide followed by displacement with alkyl and aryl thiols gave thioethers 8. Thioethers were optionally oxidized to sulfones 9. Bromide displacement by azide, followed by reduction to amine and acylation with a range of carboxylic acids and sulfonyl chlorides gave carboxamides 11 and sulfonamides 13, respectively. Crude purity at typically >90% was observed for each of the five modifications detailed. A series of 20 compounds, exemplifying each modification, was reprepared, purified, and fully characterized.

Proceedings of the International Conference LACONA XI, 2017

This research seeks to optimize Nd:YAG laser cleaning parameters for the removal of corrosion pro... more This research seeks to optimize Nd:YAG laser cleaning parameters for the removal of corrosion products on historic iron alloy surfaces. This article presents the treatment of a 19th-century, European scale armor jazeran in the collection of the Arms and Armor Department at The Metropolitan Museum of Art. Laser cleaning was coupled with traditional mechanical cleaning techniques to increase the time efficiency of treatment while best preserving the composite material construction of the artifact and the aesthetic expectations of treatment. Laser cleaning using an 8 ns, Q-switched, Nd:YAG laser at 532 nm was found more effective at corrosion removal and less damaging to the underlying metal surface than laser cleaning at 1064 nm. Wavelength-dependent absorption and scattering effects on the laser cleaning of the corroded iron alloy surfaces were investigated. The composition, morphology, and stratigraphy of the corrosion layers were characterized and the effects of laser cleaning of these corrosion layers at 1064 nm and 532 nm were examined using stereomicroscopy, scanning electron microscopy-energy dispersive spectroscopy and back-scattered and secondary electron imaging, Raman spectroscopy, Fourier transform-infrared spectroscopy, and thermally assisted hydrolysis and methylation-gas chromatography-mass spectrometry. It was found that the success of the 532 nm laser cleaning is consistent with the green laser's more resonant energy absorption and decreased scattering length as compared to 1064 nm. These data were used to optimize the optical parameters of the laser energy interaction with the corrosion products to develop more effective and safer laser cleaning profiles for the removal of ferrous corrosion layers on the historic iron alloy surface.

Heritage Science

The availability and popularity of portable non-invasive instrumentation for the study of paintin... more The availability and popularity of portable non-invasive instrumentation for the study of paintings has increased due to a shift away from using micro-invasive techniques. Fourier transform infrared spectroscopy (FTIR) is a successful and established technique for the characterisation of organic materials in varnish coatings and paint films. In addition, portable FTIR (pFTIR) spectrometers allow for non-invasive in situ analyses. This overcomes the disadvantages associated with micro-sampling and reproducibility issues encountered in analysis at a specific spot, as pFTIR enables examination of the whole painting. However, the practical applications and capabilities of pFTIR as a suitable screening method for the chemical characterization of varnish coatings in painting collections require systematic evaluation. This study involves a selection of three paintings from the collection of 57 works by Edvard Munch belonging to The National Museum of Art in Norway. Its focus is the identif...

Journal of Raman Spectroscopy

Antiquity

The Paracas culture of Late Formative Period south coastal Peru (c. 900-100 BC) is renowned for i... more The Paracas culture of Late Formative Period south coastal Peru (c. 900-100 BC) is renowned for its elaborate and colourful ceramics-particularly those decorated using the post-fire painting technique. The materials and the methods used to achieve post-fire painting, however, remain elusive. To investigate the evolution of, and regional variation in, this technology, the authors deploy a range of techniques to analyse a sample of Paracas ceramics curated in museum collections. The results indicate diachronic and regional variations in the paint binders and colourants used by the Paracas potters, which correlate with changes in vessel form and iconography over time.

Environmental Science and Pollution Research, 2016

The research complements the complex study carried out to understand the source of brown discolou... more The research complements the complex study carried out to understand the source of brown discolourations of ten marble statues in the Church of Orsanmichele in Florence, Italy. Originally located in exterior niches, the statues were restored to reverse the extensive alterations they had undergone throughout the centuries. One of the major alterations was the application of a dark brown patina that dated just after 1789. After the statues were placed indoors, brownish discolourations started to appear on their surfaces. Cross sections were examined using FTIR mapping and immunological methods. In parallel, the pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) data already obtained from the statues&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; scrapings were compared with data from aged casein films applied to microscope glass slides and aged milk-treated marble. All the statues had been treated with milk-based substances before the time the bronze patina was applied. The values of temperature and illumination of the room were important factors in the ageing of organic substances and in the formation of calcium oxalates. It is likely that products of thermo-oxidation and photo-oxidation of the oils together with the oxalates caused the darkening. The marble samples corresponded to a Lunense provenance.

Journal of The American Institute for Conservation

&amp;amp;amp;amp;amp;amp;amp;quot;Many materials used in museums for construction of disp... more &amp;amp;amp;amp;amp;amp;amp;quot;Many materials used in museums for construction of display cases or storage facilities can emit volatile compounds in a process called off-gassing. These compounds can cause detrimental changes to certain materials constituting art objects. Therefore, before using a new material, especially in a closed environment such as a display case or a storage box, it is important to ensure that the material does not emit potentially damaging volatile compounds.&amp;amp;amp;amp;amp;amp;amp;quot;

Journal of the Chemical Society, Perkin Transactions 1, 2000

ChemInform, 2001

A New Route to Hydrophobic Amino Acids Using Copper-Promoted Reactions of Serine-Derived Organozi... more A New Route to Hydrophobic Amino Acids Using Copper-Promoted Reactions of Serine-Derived Organozinc Reagents.-In continuation of earlier works, 6 novel hydrophobic amino acid derivatives such as (VII) and (VIII) are synthesized. The key step in this approach is the Cu-catalyzed reaction of the serine-derived zinc reagent (I) with different allyl electrophiles.-(DEBOVES,

Heritage Science, 2015

Introduction: The paper describes the complex investigations carried out to understand the source... more Introduction: The paper describes the complex investigations carried out to understand the sources of the brown chromatic changes that have occurred on ten marble statues dated back to the first half of the 15th century and now located in the Church of Orsanmichele in Florence, Italy. When the statues were removed from the outdoor niches for restoration in the 1980s, they appeared covered with a dark brown patina (called 'bronzatura') that dated to interventions occurred just after 1789. Archival documents confirmed that they had been carried out to make the marble statues look like bronzes. Because of the removal of the dark patina carried out by the Opificio delle Pietre Dure in the 1990s, the marble almost regained its distinguishing clear tonality even if darker areas remained. After the statues were placed indoors at the end of restoration, brownish discolorations started to appear on their surfaces. Results: Research began by using various non-invasive analyses (photographs under ultraviolet illumination, fluorescence lifetime imaging, x-ray fluorescence). The results of UV fluorescence tests and FLIM showed that the fluorescence emission's distribution map does not have distinctive and homogeneous characteristics in relation to the areas with the discoloration. Therefore, it is not a superficial film, but rather a phenomenon affecting the marble structure. Then we performed invasive analyses on samples from some statues. The results of optical microscopy, ATR-FTIR and Raman spectroscopy on cross sections, pyrolysis-gas chromatography/mass spectrometry on powdered samples from the surfaces and/or the bulk of the marble allowed the identification of the various substances involved in the chromatic alteration. Most important was the detection of weddellite and gypsum on the surface and within the marble. This finding, combined with the presence of lipids inside the stone, suggests that mineralization of treatments have occurred, causing discolorations. Conclusions: Even though the study focuses on the statues from Orsanmichele, their issue nevertheless should not be considered specific to them. Marble discolorations are a widespread phenomenon whose complete understanding needs a complex series of analyses and only the combination of non-invasive and invasive analyses can fulfill this goal.

Studies in Conservation, 2014

Journal of Raman Spectroscopy, 2014

ABSTRACT The natural sepia pigment is based on eumelanin, the most prevalent type of melanin, and... more ABSTRACT The natural sepia pigment is based on eumelanin, the most prevalent type of melanin, and can be obtained from the ink sac of different members of the Cephalopoda class, such as cuttlefish and squid. The main components of natural sepia are indole derivatives, but pigments prepared following historical recipes are generally more heterogeneous as they may also contain proteins, polysaccharides, and lipids. Sepia is difficult to identify in works of art owing to its heterogeneity, insolubility in most organic solvents, interference by the binding media, and its poorly defined spectroscopic properties. In the present study, three commercial natural sepia pigments, along with a sample extracted from cuttlefish following a historical recipe in an artists' manual, a relatively more pure commercial melanin, and a synthetic eumelanin obtained by the oxidation of dopamine were characterized by normal Raman and surface-enhanced Raman scattering (SERS), complemented by Fourier transform infrared, pyrolysis–gas chromatography–mass spectrometry, and X-ray fluorescence, in order to obtain vibrational signatures for the identification of the pigment in works of art. Pyrolysis–gas chromatography–mass spectrometry and X-ray fluorescence analysis showed that the pigment composition is strongly influenced by the extraction procedure used. Lipids were identified in the chromatograms of all the natural samples analyzed, and the majority of these also showed the presence of cholesterol derivatives. Additional components resulting from the decomposition of polysaccharides were found to be present in the sepia extracted from cuttlefish in our laboratories. Normal Raman and SERS were also used to study two sepia inks applied on paper and subjected to accelerated aging. In the SERS measurements, a hydroxylamine-reduced silver colloid was used as this substrate is suitable for the identification of other natural heterogeneous black-brown pigments. The SERS methodology developed was applied to identify sepia in Waiting for Aaron, a drawing by the 19th century artist Robert Frederick Blum. Copyright © 2014 John Wiley & Sons, Ltd.

MRS Proceedings, 2014

A combination of FTIR, normal Raman, SERS, Py-GC/MS and XRF was used to analyze commercial bistre... more A combination of FTIR, normal Raman, SERS, Py-GC/MS and XRF was used to analyze commercial bistre samples to determine specific biomarkers that will allow for a rapid identification of the pigment in works of art. The results of the XRF analysis showed that potassium, calcium and iron are the main elements present. Characteristic bands belonging to phenolic components of lignin were observed in the FTIR spectra. The SERS analysis provided a fingerprint that may originate in the polymerization of the phenolic components catalyzed by the presence of the nanostructured silver surface under alkaline conditions. The Py-GC/MS analysis revealed the presence of lignin and cellulose biomarkers and a series of polycyclic aromatic hydrocarbons. The similarities observed between the commercial samples studied suggest that both originate in the same raw material, hardwood. The results demonstrate the potential of the multi-technique approach used for the characterization of this complex black-br...

Studies in Conservation, 2010

ABSTRACT Among the highlights of the Islamic art collection at The Metropolitan Museum of Art is ... more ABSTRACT Among the highlights of the Islamic art collection at The Metropolitan Museum of Art is the earliest surviving reception room from Damascus (AH 1119 /AD 1707), known as the Nur al-Din Room. The wooden paneling and ceilings of this interior are embellished with gesso relief decoration, called 'ajami, which is gilded, tin-leafed, glazed and painted to create a complex interplay of reflective or matte and intensely colored surfaces. As in many such rooms, the current appearance no longer reflects the original aesthetic, largely due to later varnishes that have darkened. This paper presents the results of a thorough study of the Room's materials and manufacturing techniques. The investigation, combined with research into its history and the study of Ottoman interiors in their original settings, enables a more accurate reinstallation and presentation of the room in the newly renovated galleries for Islamic art.

Journal of the American Institute for Conservation, 2009

Analytical and Bioanalytical Chemistry, 2011

Aloe plants have been widely documented in artists' treatises dating from the sixteenth to the ni... more Aloe plants have been widely documented in artists' treatises dating from the sixteenth to the nineteenth century as a source of colorant to achieve lustrous golden glazes on tin-and silver-foiled objects and warm-toned finishes on musical instruments, such as violins. Aloe extracts contain characteristic anthraquinone and phenolic components which impart a distinctive orange tone and fluorescence to mixtures containing them. Because of the low concentration of colorant in the coatings and its probable degradation by high temperature during manufacture, the identification of aloe in heated oil-resin mixtures represents an analytical challenge. For this reason, the possible presence of aloe in glazes and coatings has been largely overlooked. This paper describes various analytical approaches to the identification of aloe in historic samples, from comparison with results obtained from reference standards and mock-up samples. Complementary analytical techniques including thermally assisted hydrolysis and methylation-gas chromatography-mass spectrometry, highperformance liquid chromatography, laser desorption-mass spectrometry, matrix-assisted laser desorption-ionizationmass spectrometry and surface-enhanced Raman scattering were used. Different chemical markers were identified by the individual methods and the advantages and limitations of each technique for the identification of aloe in oil-resin varnishes are discussed.

Analytical and Bioanalytical Chemistry, 2008

As a non-invasive or micro-invasive technique attenuated total reflectance Fourier transform infr... more As a non-invasive or micro-invasive technique attenuated total reflectance Fourier transform infrared spectroscopic (ATR-FTIR) microscopy is a valuable tool for the analysis of materials in works of art. An application for which it has received growing interest is in the analysis of paint cross-sections. However, FTIR microscope configurations, objectives&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; geometries and low spatial resolutions, and issues of sample preparation have often hampered the characterization of individual layers or features in cross-sections. With the use of case studies, it is demonstrated here that an ATR-FTIR microscope featuring a crystal of optimized geometry and a viewing capability feature allows characterization of individual layers, or areas within layers, of 10 microm thickness or less in single measurements. Of particular value is a remote aperturing feature which allows the analysis of selected areas within the contact footprint of the ATR crystal. Since the technique is non-destructive, the same area can be analyzed by complementary microscopic techniques such as Raman spectroscopy and scanning electron microscopy with energy-dispersive spectroscopy. Pyrolysis gas chromatography-mass spectrometry was also used in some cases to corroborate the spectroscopic data. The analyses presented provided data which were important in informing art historical interpretation and conservation of the artworks examined.