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1.
Cardiology ; 149(3): 228-236, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38359813

RESUMO

INTRODUCTION: Although several guidelines recommend that patients with heart failure with reduced ejection fraction (HFrEF) be treated with angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEIs/ARBs) or angiotensin receptor-neprilysin inhibitors (ARNIs), beta-blockers, mineralocorticoid receptor antagonists (MRAs), and sodium-glucose cotransporter-2 inhibitor (SGLT2i), there are still several gaps in their prescription and dosage in Colombia. This study aimed to describe the use patterns of HFrEF treatments in the Colombian Heart Failure Registry (RECOLFACA). METHODS: Patients with HFrEF enrolled in RECOLFACA during 2017-2019 were included. Heart failure (HF) medication prescription and daily dose were assessed using absolute numbers and proportions. Therapeutic schemes of patients treated by internal medicine specialists were compared with those treated by cardiologists. RESULTS: Out of 2,528 patients in the registry, 1,384 (54.7%) had HFrEF. Among those individuals, 88.9% were prescribed beta-blockers, 72.3% with ACEI/ARBs, 67.9% with MRAs, and 13.1% with ARNIs. Moreover, less than a third of the total patients reached the target doses recommended by the European HF guidelines. No significant differences in the therapeutic schemes or target doses were observed between patients treated by internal medicine specialists or cardiologists. CONCLUSION: Prescription rates and target dose achievement are suboptimal in Colombia. Nevertheless, RECOLFACA had one of the highest prescription rates of beta-blockers and MRAs compared to some of the most recent HF registries. However, ARNIs remain underprescribed. Continuous registry updates can improve the identification of patients suitable for ARNI and SGLT2i therapy to promote their use in clinical practice.


Assuntos
Antagonistas Adrenérgicos beta , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Fidelidade a Diretrizes , Insuficiência Cardíaca , Sistema de Registros , Volume Sistólico , Humanos , Insuficiência Cardíaca/tratamento farmacológico , Masculino , Feminino , Colômbia , Fidelidade a Diretrizes/estatística & dados numéricos , Idoso , Pessoa de Meia-Idade , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Antagonistas Adrenérgicos beta/uso terapêutico , Antagonistas de Receptores de Angiotensina/uso terapêutico , Guias de Prática Clínica como Assunto , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico
2.
Australas J Dermatol ; 65(3): 272-275, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38544290

RESUMO

Cartilage hypoplasia syndrome is a primary immunodeficiency disease characterized by short stature, hypoplastic hair and a variable degree of immunodeficiency. Noninfectious cutaneous granulomas represent an uncommon yet well-recognized manifestation within the spectrum of primary immunodeficiency diseases. However, cutaneous granulomas as a manifestation of cartilage-hair hypoplasia syndrome, are extremely rare. We present a case of a middle-aged man with cartilage hypoplasia syndrome featuring cutaneous granulomas, manifesting as chronic, extensive and deep cutaneous ulcers. The patient was treated with anti-TNF-alpha adalimumab with partial improvement. Our case underscores the broad spectrum of clinical manifestations associated with cartilage hypoplasia syndrome and adds new evidence to the potential therapeutic efficacy of anti-TNF-alpha drugs in its treatment.


Assuntos
Adalimumab , Granuloma , Cabelo , Osteocondrodisplasias , Doenças da Imunodeficiência Primária , Úlcera Cutânea , Humanos , Masculino , Cabelo/anormalidades , Doenças da Imunodeficiência Primária/complicações , Doenças da Imunodeficiência Primária/diagnóstico , Adalimumab/uso terapêutico , Úlcera Cutânea/etiologia , Úlcera Cutânea/tratamento farmacológico , Granuloma/tratamento farmacológico , Osteocondrodisplasias/complicações , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/congênito , Doença de Hirschsprung/complicações , Doença de Hirschsprung/diagnóstico , Pessoa de Meia-Idade , Hipotricose/diagnóstico
3.
Molecules ; 28(15)2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37570822

RESUMO

In this work, some micro-samples belonging to the open-air rock art site of Cueva de la Vieja (Alpera, Albacete, Spain) were analysed. These samples were collected after and before a desalination treatment was carried out, with the aim of removing a whitish layer of concretion that affected the painted panel. The diagnostic study was performed to study the conservation state of the panel, and to then confirm the effectiveness of the treatment. Micro energy dispersive X-ray fluorescence spectrometry, Raman spectroscopy, and X-ray diffraction were employed for the characterization of the degradation product as well as that of the mineral substrate and pigments. The micro-samples analysis demonstrated that the painted layer was settled on a dolomitic limestone with silicon aggregates and aluminosilicates as well as iron oxides. The whitish crust was composed by sulfate compounds such as gypsum (CaSO4·2H2O) with a minor amount of epsomite (MgSO4·7H2O). An extensive phenomenon of biological activity has been demonstrated since then in almost all of the samples that have been analysed, and the presence of calcium oxalates monohydrate (CaC2O4·H2O) and dehydrate (CaC2O4·2H2O) were found. The presence of both calcium oxalates probably favoured the conservation of the pictographs. In addition, some carotenoids pigments, scytonemin (C36H20N2O4), and astaxanthin (C40H52O4) were characterized both by Raman spectroscopy and by X-ray diffraction. Hematite was found as a pigment voluntarily used for the painting of the panels used in a mixture with hydroxyapatite and amorphous carbon. The results of the analyses of the samples taken after the cleaning treatment confirmed a substantial decrease in sulphate formation on the panel surface.

4.
Molecules ; 27(11)2022 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-35684544

RESUMO

In this work, micro-Raman spectroscopy and micro-energy-dispersive X-ray fluorescence spectroscopy (µ-EDXRF) were applied on microsamples taken from the Plaiko Zubixe footbridge (1927) located in Ondarroa (Basque Country, Spain) in order to investigate the original paint coating and make an evaluation of the conservation state before its restoration. Elemental and molecular images were acquired for the study of the compounds distribution. Some modern pigments such as phthalocyanine blue and green pigments, minium, calcium carbonate, Prussian blue, and hematite were identified. Barium sulfate and titanium dioxide were recognized as opacifier agents. Thanks to the study of the stratigraphies, it has been possible to determine the original paint layer, which includes lead white, ultramarine blue, carbon black, and barium sulfate. In addition, colorimetric analyses made it possible to know the CIELab values of the original layer in order to reproduce the original colour during the planned restoration work. The massive presence of chlorine detected by µ-EDXRF and the corrosion products of the rust layer, in particular akaganeite and hematite, highlighted the atmospheric impact in the conservation of the bridge because they were due to the effect of both marine aerosol and to the presence of acidic components in the environment coming from anthropogenic activity. This work demonstrated the usefulness of a scientific approach for the study of industrial archaeology heritage with the aim to contribute to its conservation and restoration.

5.
Anal Chem ; 93(48): 15870-15877, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34817160

RESUMO

It is widely known that the vivid hue of red cinnabar can darken or turn black. Many authors have studied this transformation, but only a few in the context of the archeological site of Pompeii. In this work, the co-occurrence of different degradation patterns associated with Pompeian cinnabar-containing fresco paintings (alone or in combination with red/yellow ocher pigments) exposed to different types of environments (pre- and post-79 AD atmosphere) is reported. Results obtained from the in situ and laboratory multianalytical methodology revealed the existence of diverse transformation products in the Pompeian cinnabar, consistent with the impact of the environment. The effect of hydrogen sulfide and sulfur dioxide emitted during the 79 AD eruption on the cinnabar transformation was also evaluated by comparing the experimental evidence found on paintings exposed and not exposed to the post-79 AD atmosphere. Our results highlight that not all the darkened areas on the Pompeian cinnabar paintings are related to the transformation of the pigment itself, as clear evidence of darkening associated with the presence of manganese and iron oxide formation (rock varnish) on fragments buried before the 79 AD eruption has also been found.


Assuntos
Compostos de Mercúrio , Pinturas , Sepultamento , Erupções Vulcânicas
6.
Sensors (Basel) ; 21(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203186

RESUMO

In this work, decorative wallpapers (19th century) from an historical palace located in Oiartzun (Basque Country, Spain) were analyzed before their restoration. Micro-energy dispersive X-ray fluorescence spectroscopy, Raman spectroscopy, and attenuated total reflectance infrared spectroscopy were used to investigate the elemental and molecular composition of pigments, the presence of binders, and the state of conservation of the paper support. The aim of the investigation was trying to understand the possible degradation pathways and identify the raw materials in order to choose the best restoration protocol according to the original aspect of wallpapers. As stated from both the elemental distribution and the identification of mineral phases by Raman spectroscopy, the most used pigment was lead chromate. It was mixed with other pigments such as ultramarine blue, zinc chromate, hematite, and atacamite among others to obtain different shades and they were applied mixed with an animal glue. Brass, identified thanks to elemental micro-EDXRF maps, was employed as a shiny decorative element. In addition, a partial degradation of cellulose was detected due to its natural ageing, the acidic nature of lignin, and to a phenomenon of humidity of the walls. Probably the deposition of black particulate matter was the cause of the darkening of the painting surfaces.


Assuntos
Pintura , Pinturas , Animais , Corantes , Espanha , Análise Espectral Raman
7.
Molecules ; 26(10)2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-34066114

RESUMO

The environmental weathering and the formation of efflorescences on the brick walls are studied at the "Casa di Diana" Mithraeum at Ostia Antica archaeological site. Previous studies on subsoil, bedrock, hydrological systems and environmental conditions, and new ion chromatography analysis combined with ECOS-RUNSALT and Medusa-Hydra thermodynamic modelling software, had allowed us to identify the subsoil contamination related to soluble salts. The atmospheric acidic gases, CO2 and SO2, are determined as the main salt weathering species. A dry deposition after a subsequent hydration action from the shallow freshwater aquifer that reaches up to 1 m on the walls is identified as the mechanism of salt formation. An evaluation of potential sources such as the nearby Fiumicino airport, CO2-rich gases inputs from fumaroles and CO2 inputs was also debated. The risk level of contamination the surfaces of the materials should be considered mildly/very polluted with a medium/high risk of hygroscopic moisture due to the high concentration of sulphates.

8.
Angew Chem Int Ed Engl ; 60(6): 3028-3036, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33064357

RESUMO

Pyroclastic strata have always been thought to protect the archaeological remains of the Vesuvian area (Italy), hence allowing their conservation throughout the centuries. In this work, we demonstrate that they constitute a potential threat for the conservation state of the mural paintings of Pompeii. The ions that could be leached from them and the ion-rich groundwater coming from the volcanic soil/rocks may contribute to salt crystallisation. Thermodynamic modelling not only allowed to predict which salts can precipitate from such leaching events but also assisted the identification of additional sources of sulfates and alkali metals to explain the formation of the sulfates identified in efflorescences from the mural paintings of Pompeii. For the future, fluorine, mainly related to a volcanic origin, can be proposed as a marker to monitor the extent of the impact in the mural paintings of Pompeii in situ.

9.
Anal Bioanal Chem ; 412(29): 8155-8166, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32979075

RESUMO

In this work, an innovative non-destructive monitoring methodology based on the analysis over time of open-air rock art sites is presented. This approach is based on the combination of in situ spectroscopic and chemometric studies to diagnose and monitor the state of conservation of rock art sites. Data acquired over a period of time by non-invasive analytical techniques such as portable Raman spectrometry (RS) and handheld energy-dispersive X-ray fluorescence (HH-EDXRF) spectrometry are compared to detect physicochemical changes that could affect the rock painting integrity. To demonstrate the applicability of the proposed procedure, three analysis campaigns (between 2013 and 2016) were carried out, analyzing Levantine rock pictographs preserved in the rock shelter of Solana de las Covachas VI (Albacete, Spain; see Electronic Supplementary Material (ESM) Fig. S1). The analyzed areas showed different types of active weathering processes such as gypsum and calcium oxalate formation, giving rise to conservation issues such as painting fading, surface loss, microbial colonizations, and formation of crusts. Results evidence that the proposed methodology can be very useful to monitor chemical changes in the surface of the walls where the rock art is located, thus obtaining crucial information for its preservation and management.

10.
Anal Bioanal Chem ; 411(28): 7585-7593, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31701206

RESUMO

Most of the wall paintings from Pompeii are decorated with red and yellow colors but the thermal impact of 79 AD Mount Vesuvius eruption promoted the partial transformation of some yellow-painted areas into red. The aim of this research is to develop a quantitative Raman imaging methodology to relate the transformation percentage of yellow ochre (goethite, α-FeOOH) into red color (hematite, α-Fe2O3) depending on the temperature, in order to apply it and estimate the temperature at which the pyroclastic flow impacted the walls of Pompeii. To model the thermal impact that took place in the year 79 AD, nine wall painting fragments recovered in the archeological site of Pompeii and which include yellow ochre pigment were subjected to thermal ageing experiments (exposition to temperatures from 200 to 400 °C every 25 °C). Before the experiments, elemental information of the fragments was obtained by micro-energy dispersive X-ray fluorescence (µ-ED-XRF). The fragments were characterized before and after the exposition using Raman microscopy to monitor the transformation degree from yellow to red. The quantitative Raman imaging methodology was developed and validated using synthetic pellets of goethite and hematite standards. The results showed almost no transformation (0.5% ± 0.4) at 200 °C. However, at 225 °C, some color transformation (26.9% ± 2.8) was observed. The most remarkable color change was detected at temperatures between 250 °C (transformation of 46.7% ± 1.7) and 275 °C (transformation of 101.1% ± 1.2). At this last temperature, the transformation is totally completed since from 275 to 400 °C the transformation percentage remained constant.

11.
Anal Bioanal Chem ; 411(29): 7869-7877, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31701208

RESUMO

Libyan Desert Glasses (LDGs) and Darwin Glasses (DGs) are impact glasses produced by the impact of an extraterrestrial body into the Earth million years ago. LDGs were formed in the Libyan Desert (Africa) and DGs in Tasmania (Australia). From their formation, they have suffered terrestrial weathering processes due to their interaction with the environment. This is the first work that has evaluated their weathering processes according to their composition, the surrounding environment, and the climate. An innovative methodology based on the leaching of organic and inorganic ions and chemical modeling simulations was employed. Inductively coupled plasma-mass spectrometry (ICP-MS), ionic chromatography (IC), and solid-phase microextraction (SPME), and head space (HS) injections coupled to gas chromatography and mass spectrometry (GC-MS) detection were used. As a result, soluble organic compounds such as oxalates, n-hexadecanoic acid, and 4-chlorobenzalacetone were detected. The inorganic ions suffered a similar process, going inside the body of glasses and precipitating the corresponding salts when water evaporated. As these compounds are polar, they were probably transported by infiltration waters from outside the glasses, remaining inside in the pores, cavities, or cracks of the glasses during thousands of years. In the case of the DGs, it could be observed that under the oxidizing conditions of the terrestrial atmosphere, sulfides present in some samples transformed into sulfates. Finally, this methodology could be applied in other extraterrestrial materials discovered in deserts, ice fields, or in locations with great living activity like those of Tasmania.

12.
Anal Chem ; 90(9): 5795-5802, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29641899

RESUMO

Wavelength dispersive X-ray fluorescence (WD-XRF) spectrometry has been widely used for elemental quantification of mortars and cements. In this kind of instrument, samples are usually prepared as pellets or fused beads and the whole volume of sample is measured at once. In this work, the usefulness of a dual energy dispersive X-ray fluorescence spectrometer (ED-XRF), working at two lateral resolutions (1 mm and 25 µm) for macro and microanalysis respectively, to develop quantitative methods for the elemental characterization of mortars and concretes is demonstrated. A crucial step before developing any quantitative method with this kind of spectrometers is to verify the homogeneity of the standards at these two lateral resolutions. This new ED-XRF quantitative method also demonstrated the importance of matrix effects in the accuracy of the results being necessary to use Certified Reference Materials as standards. The results obtained with the ED-XRF quantitative method were compared with the ones obtained with two WD-XRF quantitative methods employing two different sample preparation strategies (pellets and fused beads). The selected ED-XRF and both WD-XRF quantitative methods were applied to the analysis of real mortars. The accuracy of the ED-XRF results turn out to be similar to the one achieved by WD-XRF, except for the lightest elements (Na and Mg). The results described in this work proved that µ-ED-XRF spectrometers can be used not only for acquiring high resolution elemental map distributions, but also to perform accurate quantitative studies avoiding the use of more sophisticated WD-XRF systems or the acid extraction/alkaline fusion required as destructive pretreatment in Inductively coupled plasma mass spectrometry based procedures.

13.
Anal Bioanal Chem ; 410(25): 6609-6617, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30039380

RESUMO

Impact glasses are rich silica melted formed at high temperature and pressure by the impact of an extraterrestrial body on Earth. Here, Libyan Desert glasses (LDGs) and Darwin glasses (DGs) were studied. Two non-destructive analytical techniques were used to detect and characterize organic compounds present in their inclusions: Raman spectroscopy and scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy (SEM-EDS). Phytoliths, humboldtine, palmitic acid, myristic acid, oleic acid, 4-methyl phthalic acid, and S-H stretching vibrations of amino acids were identified. The presence of these particular organic compounds in such materials has not been reported so far, providing information about (a) the ancient matter of the area where the impact glasses were formed, (b) organic matter belonging to the extraterrestrial body which impacted on the Earth, or (c) even to current plant or bacterial life, which could indicate an active interaction of the LDG and DG with the surrounding environment. Moreover, the identification of fullerene allowed us to know a pressure (15 GPa) and temperatures (670 K or 1800-1900 K) at which samples could be subjected.

14.
Anal Bioanal Chem ; 410(28): 7477-7488, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30218122

RESUMO

The application of a non-destructive analytical procedure to characterise the mineral phases in meteorites is a key issue in order to preserve this type of scarce materials. In the present work, the Elephant Moraine 83227 meteorite, found in Antarctica in 1983 and originated from 4 Vesta asteroid, was analysed by micro-Raman spectroscopy, micro-energy-dispersive X-ray fluorescence and the structural and chemical analyser (Raman spectroscopy coupled with scanning electron microscopy-energy-dispersive spectroscopy) working in both point-by-point and image modes. The combination of all these techniques allows the extraction of, at the same time, elemental, molecular and structural data of the studied microscopic area of the meteorite. The most relevant results of the Elephant Moraine 83227 were the finding of tridymite for the first time in a 4 Vesta meteorite, along with quartz, which means that the meteorite suffered high temperatures at a certain point. Moreover, both feldspar and pyroxene were found as the main mineral phases in the sample. Ilmenite, apatite, chromite and elemental sulphur were also detected as secondary minerals. Finally, calcite was found as a weathering product, which was probably formed in terrestrial weathering processes of the pyroxene present in the sample. Besides, Raman spectroscopy provided information about the conditions that the meteorite experienced; the displacements in some feldspar Raman bands were used to estimate the temperature and pressure conditions to which the Elephant Moraine 83227 was subjected, because we obtained both low and high formation temperature feldspar.

17.
Pol J Microbiol ; 67(1): 11-18, 2018 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-30015420

RESUMO

The aim of this study was to develop a non-invasive diagnostic test for the detection of Helicobacter pylori in stool samples from digestive symptomatic patients, using a new protocol of nested-qPCR. A total of 143 patients were invited to participate in the study. A gastric biopsy of each patient was collected for Rapid Urease Testing (RUT) and histology by Giemsa stain. A fecal sample for nested-qPCR analysis was also obtained. DNA was extracted from the fecal samples, and conventional PCR followed by qPCR of the ureC gene of H. pylori was carried out. We evaluated the presence of H. pylori, in 103 females and 40 males, mean (± SD) age of 56.5 ± 14.18. The sensitivity of RUT to detect the infection was 67.0% (95% C.I.: 57.2 - 75.8) and specificity was 92.3% (95% C.I.: 76.5 - 99.1). Histology by Giemsa stain, commonly used as a reference for H. pylori detection, showed a sensitivity of 98.6% (95% C.I.: 92.5 - 100.0) and a specificity of 89.7% (95% C.I.: 72.7 - 97.8). In contrast, detection of H. pylori infection in stools by nested-qPCR showed a sensitivity of 100% (95% C.I.: 94.9 - 100.0) and a specificity of 83.9% (95% C.I.: 66.3 - 94.6). Our test, based in nested-qPCR is a better diagnostic alternative than conventional RUT, and is similar to histology by Giemsa stain in the detection of H. pylori, by which the test could be used for non-invasive diagnosis in clinical practice.


Assuntos
Proteínas de Bactérias/genética , Fezes/microbiologia , Infecções por Helicobacter/diagnóstico , Helicobacter pylori/isolamento & purificação , Adulto , Idoso , Feminino , Helicobacter pylori/genética , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
18.
Rev Med Chil ; 146(5): 596-602, 2018 May.
Artigo em Espanhol | MEDLINE | ID: mdl-30148923

RESUMO

BACKGROUND: Helicobacter pylori is the most significant pathogen associated with gastric diseases, including gastric cancer. Infected patients with strains that are CagA-positive generally have worse outcomes than those infected with CagA-negative strains. Patients infected with CagA-positive strains have a higher risk for developing gastric cancer. AIM: To determine the prevalence of CagA-positive H. pylori strains in fecal samples of patients from the Coquimbo Region of Chile, using a non-invasive, nested-qPCR method. MATERIAL AND METHODS: We evaluated 160 patients with gastrointestinal symptoms subjected to an upper gastrointestinal endoscopy. DNA was extracted from fecal samples and tested for the presence of H. pylori using nested-qPCR for the ureC gene, and subsequently compared with the results of histology-Giemsa stain from the patients' endoscopic biopsies. When H. pylori was found, the presence of CagA-positive strains was determined via nested-qPCR. RESULTS: The histology-Giemsa stain was positive for H. pylori infection in 123 patients (76.9%), while the analysis of fecal samples detected H. pylori in 129 patients (80.6%). The sensitivity and specificity of nested-qPCR to detect the bacterium was 96.7 and 73.0% respectively. Among patients with the infection, 25% had CagA-positive strains. CONCLUSIONS: In this sample of patients, there is a low prevalence of CagA-positive H. pylori strains.


Assuntos
Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , DNA Bacteriano/análise , Fezes/microbiologia , Infecções por Helicobacter/diagnóstico , Helicobacter pylori/genética , Gastropatias/microbiologia , Antígenos de Bactérias/isolamento & purificação , Proteínas de Bactérias/isolamento & purificação , Endoscopia do Sistema Digestório , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Gastropatias/diagnóstico
19.
Anal Chem ; 89(7): 4246-4254, 2017 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-28281350

RESUMO

Energy dispersive X-ray fluorescence spectrometry (ED-XRF) is widely used in art and cultural heritage for direct measurements and elemental quantification of solid samples. However, in the literature there are not works dealing with the quantitative application of ED-XRF to liquid extracts coming from samples belonging to cultural heritage. In this work, a novel methodology based on the use of ED-XRF spectrometry after thin film deposition on special sample retainers and a subsequent evaporation was developed to quantify light elements (Z ≤ 20) in aqueous extracts and heavy elements (Z > 20) in acid extracts, coming from materials and degradation products belonging to built heritage (mortars, black crusts, and calcium carbonate formations). For this purpose, special sample retainers were used instead of more common adsorbent filter papers. Three different ED-XRF calibration methodologies were designed as elemental quantification tools and "green chemistry" alternatives to conventional techniques. On the one hand, the developed external ED-XRF calibration methodology for elements with Z ≤ 20 was proposed as an alternative to ion chromatography to obtain information about the degradation processes that the building materials suffered. On the other hand, the external ED-XRF calibration for elements with Z > 20 in acid extracts was optimized as a faster and cleaner quantification alternative to inductively coupled plasma mass spectrometry (ICPMS). Finally, with the aim to reduce the matrix effect and to improve the quantitative results for elements with Z > 20 in acid extracts, a novel ED-XRF calibration methodology based on standard additions was successfully designed and applied to real samples belonging to built heritage.

20.
Anal Bioanal Chem ; 409(8): 2221-2228, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28084510

RESUMO

The study and characterization of old artifacts such as pigments requires the use of techniques that need a small amount of sample to perform the analysis because of the high value of these samples. In recent years, organic molecules such as anthraquinone dyes have been identified by surface-enhanced Raman spectroscopy (SERS). However, different sample treatments must be applied to isolate the organic dye from the mordant, which produces great fluorescence in the Raman measurements. In this work, optimization of sample treatment for the SERS analysis of anthraquinone dyes was performed. Sample mass, the organic solvent, and its volume were optimized and different slide materials and excitation lasers were compared to choose the best conditions for the identification of the dyes. The optimization of sample treatment resulted in 5 mg of sample as the optimum amount. Further, two consecutive extractions with 0.5 mL of ethyl acetate was the best option for the extraction of the dye. A quartz slide was used instead of a glass slide to reduce background signal, and an excitation laser of 532 nm offers better results than one of 785 nm. The optimized method was applied to the characterization of the dyes used in Pompeian pink and purple lake pigments. Alizarin and purpurin anthraquinone dyes, obtained from madder lake, were identified as the organic colorants. The SERS results were confirmed by those obtained by means of UV-visible spectroscopy. Graphical Abstract ᅟ.

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