Molecules

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18 pages, 3499 KiB

Open AccessArticle

Analytical Characterization of the Intercalation of Neutral Molecules into Saponite

by Valentina Toson, Diego Antonioli, Enrico Boccaleri, Marco Milanesio, Valentina Gianotti and Eleonora Conterosito

Molecules 2022, 27(10), 3048; https://doi.org/10.3390/molecules27103048 - 10 May 2022

Cited by 1 | Viewed by 1641

Abstract

Organo-modified layered materials characterization poses challenges due to their complexity and how other aspects such as contamination, preparation methods and degree of intercalation influence the properties of these materials. Consequently, a deep understanding of their interlayer organization is of utmost importance to optimize [...] Read more.

Organo-modified layered materials characterization poses challenges due to their complexity and how other aspects such as contamination, preparation methods and degree of intercalation influence the properties of these materials. Consequently, a deep understanding of their interlayer organization is of utmost importance to optimize their applications. These materials can in fact improve the stability of photoactive molecules through intercalation, avoiding the quenching of their emission at the solid state, to facilitate their use in sensors or other devices. Two synthetic methods for the preparation of saponites with a cationic surfactant (CTABr) and a neutral chromophore (Fluorene) were tested and the obtained products were initially characterized with several complementary techniques (XRPD, SEM, TGA, IR, UV-Vis, Fluorescence and Raman spectroscopy), but a clear understanding of the organization of the guest molecules in the material could not be obtained by these techniques alone. This information was obtained only by thermogravimetry coupled with gas chromatography and mass spectroscopy (TGA-GC-MS) which allowed identifying the species present in the sample and the kind of interaction with the host by distinguishing between intercalated and adsorbed on the surface. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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12 pages, 1692 KiB

Open AccessArticle

Gas Chromatography Combustion Isotope Ratio Mass Spectrometry to Detect Differences in Four Compartments of Simmental Cows Fed on C3 and C4 Diets

by Silvia Pianezze, Mirco Corazzin, Luana Bontempo, Angela Sepulcri, Elena Saccà, Matteo Perini and Edi Piasentier

Molecules 2022, 27(7), 2310; https://doi.org/10.3390/molecules27072310 - 2 Apr 2022

Cited by 1 | Viewed by 1872

Abstract

Fatty acids (FAs) metabolism in animals represents an important field of study since they influence the quality and the properties of the meat. The aim of this study is to assess the possibility to discriminate the diets of cows in different animal compartments [...] Read more.

Fatty acids (FAs) metabolism in animals represents an important field of study since they influence the quality and the properties of the meat. The aim of this study is to assess the possibility to discriminate the diets of cows in different animal compartments and to study the fate of dietary FAs in the bovine organism, using carbon isotopic ratios. Five FAs, both essential (linoleic and linolenic) and non-essential (palmitic, stearic, and oleic) in four compartments (feed, rumen, liver, meat) of animals fed two different diets (based on either C3 or C4 plants) were considered. For all compartments, the carbon isotopic ratio (δ¹³C) of all FAs (with few exceptions) resulted significantly lower in cows fed on C3 than C4 plants, figuring as a powerful tool to discriminate between different diets. Moreover, chemical reactions taking place in each animal compartment result in fraction processes affecting the δ¹³C values. The δ¹³C_FAs tendentially increase from feed to meat in group C3. On the other hand, the δ¹³C_FAs generally increase from rumen to liver in group C4, while δ¹³C_FAs of rumen and meat are mostly not statistically different. Different trends in the δ¹³C_FAs of the two groups suggested different FAs fates depending on the diet. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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15 pages, 3752 KiB

Open AccessArticle

Quantitative Compositional Analyses of Calcareous Rocks for Lime Industry Using LIBS

by Juri Agresti, Carlo Indelicato, Matteo Perotti, Roberto Moreschi, Iacopo Osticioli, Ilaria Cacciari, Andrea Azelio Mencaglia and Salvatore Siano

Molecules 2022, 27(6), 1813; https://doi.org/10.3390/molecules27061813 - 10 Mar 2022

Cited by 10 | Viewed by 2498

Abstract

Here, the potential of laser-induced breakdown spectroscopy (LIBS) in grading calcareous rocks for the lime industry was investigated. In particular, we developed a system equipped with non-intensified detectors operating in scanning mode, defined a suitable data acquisition protocol, and implemented quantitative data processing [...] Read more.

Here, the potential of laser-induced breakdown spectroscopy (LIBS) in grading calcareous rocks for the lime industry was investigated. In particular, we developed a system equipped with non-intensified detectors operating in scanning mode, defined a suitable data acquisition protocol, and implemented quantitative data processing using both partial least squares regression (PLS-R) and a multilayer perceptron (MLP) neural network. Tests were carried out on 32 samples collected in various limestone quarries, which were preliminarily analyzed using traditional laboratory X-ray fluorescence (XRF); then, they were divided into two groups for calibration and validation. Particular attention was dedicated to the development of LIBS methodology providing a reliable basis for precise material grading. The congruence of the results achieved demonstrates the capability of the present approach to precisely quantify major and minor geochemical components of calcareous rocks, thus disclosing a concrete application perspective within the lime industry production chain. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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12 pages, 6318 KiB

Open AccessArticle

Evaluating the Conservation State of Naturally Aged Paper with Raman and Luminescence Spectral Mapping: Toward a Non-Destructive Diagnostic Protocol

by Sabina Botti, Francesca Bonfigli, Valentina Nigro, Alessandro Rufoloni and Angelo Vannozzi

Molecules 2022, 27(5), 1712; https://doi.org/10.3390/molecules27051712 - 5 Mar 2022

Cited by 7 | Viewed by 2165

Abstract

Micro-Raman and luminescence spectroscopy were combined with morphological analysis to study the conservation state of differently degraded paper samples, dated from 1873 to 2021. The aim of the work reported in this paper was to obtain ageing markers based on variations of Raman [...] Read more.

Micro-Raman and luminescence spectroscopy were combined with morphological analysis to study the conservation state of differently degraded paper samples, dated from 1873 to 2021. The aim of the work reported in this paper was to obtain ageing markers based on variations of Raman and fluorescence spectral features. Raman and luminescence spectra were acquired by scanning non-printed areas of books, and Raman and fluorescence maps were built by contrasting spectral parameters point by point, obtaining a micron-scale space resolved imaging of the degradation pattern. Complementary information on paper morphology and surface compactness were obtained by high-resolution scanning electron and atomic force microscopy. The proposed non-destructive procedure is particularly interesting for precious and ancient samples to analyze their degradation processes and to evaluate the performance and effectiveness of restoration treatments. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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17 pages, 2792 KiB

Open AccessArticle

Intracluster Sulphur Dioxide Oxidation by Sodium Chlorite Anions: A Mass Spectrometric Study

by Chiara Salvitti, Federico Pepi, Anna Troiani and Giulia de Petris

Molecules 2021, 26(23), 7114; https://doi.org/10.3390/molecules26237114 - 24 Nov 2021

Cited by 4 | Viewed by 1895

Abstract

The reactivity of [NaL·ClO₂]⁻ cluster anions (L = ClO_x⁻; x = 0–3) with sulphur dioxide has been investigated in the gas phase by ion–molecule reaction experiments (IMR) performed in an in-house modified Ion Trap mass spectrometer (IT-MS). [...] Read more.

The reactivity of [NaL·ClO₂]⁻ cluster anions (L = ClO_x⁻; x = 0–3) with sulphur dioxide has been investigated in the gas phase by ion–molecule reaction experiments (IMR) performed in an in-house modified Ion Trap mass spectrometer (IT-MS). The kinetic analysis revealed that SO₂ is efficiently oxidised by oxygen-atom (OAT), oxygen-ion (OIT) and double oxygen transfer (DOT) reactions. The main difference from the previously investigated free reactive ClO₂⁻ is the occurrence of intracluster OIT and DOT processes, which are mediated by the different ligands of the chlorite anion. This gas-phase study highlights the importance of studying the intrinsic properties of simple reacting species, with the aim of elucidating the elementary steps of complex processes occurring in solution, such as the oxidation of sulphur dioxide. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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20 pages, 3339 KiB

Open AccessArticle

Longitudinal Bottom-Up Proteomics of Serum, Serum Extracellular Vesicles, and Cerebrospinal Fluid Reveals Candidate Biomarkers for Early Detection of Glioblastoma in a Murine Model

by Francesco Greco, Federica Anastasi, Luca Fidia Pardini, Marialaura Dilillo, Eleonora Vannini, Laura Baroncelli, Matteo Caleo and Liam A. McDonnell

Molecules 2021, 26(19), 5992; https://doi.org/10.3390/molecules26195992 - 2 Oct 2021

Cited by 12 | Viewed by 3222

Abstract

Glioblastoma Multiforme (GBM) is a brain tumor with a poor prognosis and low survival rates. GBM is diagnosed at an advanced stage, so little information is available on the early stage of the disease and few improvements have been made for earlier diagnosis. [...] Read more.

Glioblastoma Multiforme (GBM) is a brain tumor with a poor prognosis and low survival rates. GBM is diagnosed at an advanced stage, so little information is available on the early stage of the disease and few improvements have been made for earlier diagnosis. Longitudinal murine models are a promising platform for biomarker discovery as they allow access to the early stages of the disease. Nevertheless, their use in proteomics has been limited owing to the low sample amount that can be collected at each longitudinal time point. Here we used optimized microproteomics workflows to investigate longitudinal changes in the protein profile of serum, serum small extracellular vesicles (sEVs), and cerebrospinal fluid (CSF) in a GBM murine model. Baseline, pre-symptomatic, and symptomatic tumor stages were determined using non-invasive motor tests. Forty-four proteins displayed significant differences in signal intensities during GBM progression. Dysregulated proteins are involved in cell motility, cell growth, and angiogenesis. Most of the dysregulated proteins already exhibited a difference from baseline at the pre-symptomatic stage of the disease, suggesting that early effects of GBM might be detectable before symptom onset. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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12 pages, 2117 KiB

Open AccessArticle

Analysis of Cannabinoids and Metabolites in Dried Urine Spots (DUS)

by Matteo Moretti, Francesca Freni, Claudia Carelli, Carlo Previderé, Pierangela Grignani, Claudia Vignali, Maria Cobo-Golpe and Luca Morini

Molecules 2021, 26(17), 5334; https://doi.org/10.3390/molecules26175334 - 2 Sep 2021

Cited by 8 | Viewed by 3445

Abstract

Dried urine spots (DUS) represent a potential alternative sample storage for forensic toxicological analysis. The aim of the current study was to develop and validate a liquid chromatographic tandem mass spectrometric procedure for the detection and quantitative determination of cannabinoids and metabolites in [...] Read more.

Dried urine spots (DUS) represent a potential alternative sample storage for forensic toxicological analysis. The aim of the current study was to develop and validate a liquid chromatographic tandem mass spectrometric procedure for the detection and quantitative determination of cannabinoids and metabolites in DUS. A two-step extraction was performed on DUS and urine samples. An LC-MS/MS system was operated in multiple reaction monitoring and positive polarization mode. The method was checked for sensitivity, specificity, linearity, accuracy, precision, recovery, matrix effects and carryover. The method was applied to 70 urine samples collected from healthy volunteers and drug addicts undergoing withdrawal treatment. The method was successfully developed for DUS. LODs lower than 2.0 ng/mL were obtained for all the monitored substances. All the validation parameters fulfilled the acceptance criteria either for DUS or urine. Among the real samples, 45 cases provided positive results for at least one compound. A good quali-quantitative agreement was obtained between DUS and urine. A good stability of THC, THCCOOH and THCCOOH-gluc was observed after a 24 h storage, in contrast to previously published results. DUS seems to provide a good alternative storage condition for urine that should be checked for the presence of cannabinoids and metabolites. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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9 pages, 686 KiB

Open AccessArticle

Development of an Accurate Mass Retention Time Database for Untargeted Metabolomic Analysis and Its Application to Plasma and Urine Pediatric Samples

by Chiara Lavarello, Sebastiano Barco, Martina Bartolucci, Isabella Panfoli, Emanuele Magi, Gino Tripodi, Andrea Petretto and Giuliana Cangemi

Molecules 2021, 26(14), 4256; https://doi.org/10.3390/molecules26144256 - 13 Jul 2021

Cited by 8 | Viewed by 3530

Abstract

Liquid-chromatography coupled to high resolution mass spectrometry (LC-HRMS) is currently the method of choice for untargeted metabolomic analysis. The availability of established protocols to achieve a high confidence identification of metabolites is crucial. The aim of this work is to describe the workflow [...] Read more.

Liquid-chromatography coupled to high resolution mass spectrometry (LC-HRMS) is currently the method of choice for untargeted metabolomic analysis. The availability of established protocols to achieve a high confidence identification of metabolites is crucial. The aim of this work is to describe the workflow that we have applied to build an Accurate Mass Retention Time (AMRT) database using a commercial metabolite library of standards. LC-HRMS analysis was carried out using a Vanquish Horizon UHPLC system coupled to a Q-Exactive Plus Hybrid Quadrupole-Orbitrap Mass Spectrometer (Thermo Fisher Scientific, Milan, Italy). The fragmentation spectra, obtained with 12 collision energies, were acquired for each metabolite, in both polarities, through flow injection analysis. Several chromatographic conditions were tested to obtain a protocol that yielded stable retention times. The adopted chromatographic protocol included a gradient separation using a reversed phase (Waters Acquity BEH C18) and a HILIC (Waters Acquity BEH Amide) column. An AMRT database of 518 compounds was obtained and tested on real plasma and urine samples analyzed in data-dependent acquisition mode. Our AMRT library allowed a level 1 identification, according to the Metabolomics Standards Initiative, of 132 and 124 metabolites in human pediatric plasma and urine samples, respectively. This library represents a starting point for future metabolomic studies in pediatric settings. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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14 pages, 2259 KiB

Open AccessArticle

Urinary Metabolomics Study of Patients with Bicuspid Aortic Valve Disease

by Massimo Chessa, Mario Panebianco, Sara Corbu, Milena Lussu, Angelica Dessì, Roberta Pintus, Flaminia Cesare Marincola and Vassilios Fanos

Molecules 2021, 26(14), 4220; https://doi.org/10.3390/molecules26144220 - 12 Jul 2021

Cited by 4 | Viewed by 2634

Abstract

Bicuspid aortic valve (BAV) is the most common congenital heart defect responsible for valvular and aortic complications in affected patients. Causes and mechanisms of this pathology are still elusive and thus the lack of early detection biomarkers leads to challenges in its diagnosis [...] Read more.

Bicuspid aortic valve (BAV) is the most common congenital heart defect responsible for valvular and aortic complications in affected patients. Causes and mechanisms of this pathology are still elusive and thus the lack of early detection biomarkers leads to challenges in its diagnosis and prevention of associated cardiovascular anomalies. The aim of this study was to explore the potential use of urine Nuclear Magnetic Resonance (NMR) metabolomics to evaluate a molecular fingerprint of BAV. Both multivariate and univariate statistical analyses were performed to compare the urinary metabolome of 20 patients with BAV with that of 24 matched controls. Orthogonal partial least squared discriminant analysis (OPLS-DA) showed statistically significant discrimination between cases and controls, suggesting seven metabolites (3-hydroxybutyrate, alanine, betaine, creatine, glycine, hippurate, and taurine) as potential biomarkers. Among these, glycine, hippurate and taurine individually displayed medium sensitivity and specificity by receiver operating characteristic (ROC) analysis. Pathway analysis indicated two metabolic pathways likely perturbed in BAV subjects. Possible contributions of gut microbiota activity and energy imbalance are also discussed. These results constitute encouraging preliminary findings in favor of the use of urine-based metabolomics for early diagnosis of BAV. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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19 pages, 5180 KiB

Open AccessArticle

Discrimination of Genetically Very Close Accessions of Sweet Orange (Citrus sinensis L. Osbeck) by Laser-Induced Breakdown Spectroscopy (LIBS)

by Aida B. Magalhães, Giorgio S. Senesi, Anielle Ranulfi, Thiago Massaiti, Bruno S. Marangoni, Marina Nery da Silva, Paulino R. Villas Boas, Ednaldo Ferreira, Valdenice M. Novelli, Mariângela Cristofani-Yaly and Débora M. B. P. Milori

Molecules 2021, 26(11), 3092; https://doi.org/10.3390/molecules26113092 - 21 May 2021

Cited by 6 | Viewed by 3253

Abstract

The correct recognition of sweet orange (Citrus sinensis L. Osbeck) variety accessions at the nursery stage of growth is a challenge for the productive sector as they do not show any difference in phenotype traits. Furthermore, there is no DNA marker able [...] Read more.

The correct recognition of sweet orange (Citrus sinensis L. Osbeck) variety accessions at the nursery stage of growth is a challenge for the productive sector as they do not show any difference in phenotype traits. Furthermore, there is no DNA marker able to distinguish orange accessions within a variety due to their narrow genetic trace. As different combinations of canopy and rootstock affect the uptake of elements from soil, each accession features a typical elemental concentration in the leaves. Thus, the main aim of this work was to analyze two sets of ten different accessions of very close genetic characters of three varieties of fresh citrus leaves at the nursery stage of growth by measuring the differences in elemental concentration by laser-induced breakdown spectroscopy (LIBS). The accessions were discriminated by both principal component analysis (PCA) and a classifier based on the combination of classification via regression (CVR) and partial least square regression (PLSR) models, which used the elemental concentrations measured by LIBS as input data. A correct classification of 95.1% and 80.96% was achieved, respectively, for set 1 and set 2. These results showed that LIBS is a valuable technique to discriminate among citrus accessions, which can be applied in the productive sector as an excellent cost–benefit tool in citrus breeding programs. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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11 pages, 2267 KiB

Open AccessArticle

A Friendly Complexing Agent for Spectrophotometric Determination of Total Iron

by Valeria M. Nurchi, Rosita Cappai, Nadia Spano and Gavino Sanna

Molecules 2021, 26(11), 3071; https://doi.org/10.3390/molecules26113071 - 21 May 2021

Cited by 16 | Viewed by 4130

Abstract

Iron, one of the most common metals in the environment, plays a fundamental role in many biological as well as biogeochemical processes, which determine its availability in different oxidation states. Its relevance in environmental and industrial chemistry, human physiology, and many other fields [...] Read more.

Iron, one of the most common metals in the environment, plays a fundamental role in many biological as well as biogeochemical processes, which determine its availability in different oxidation states. Its relevance in environmental and industrial chemistry, human physiology, and many other fields has made it necessary to develop and optimize analysis techniques for accurate determination. Spectrophotometric methods are the most frequently applied in the analytical determination of iron in real samples. Taking advantage of the fact that desferrioxamine B, a trihydroxamic acid used since the 1970s in chelation therapy for iron overload treatment, forms a single stable 1:1 complex with iron in whichever oxidation state it can be found, a smart spectrophotometric method for the analytical determination of iron concentration was developed. In particular, the full compliance with the Lambert-Beer law, the range of iron concentration, the influence of pH, and the interference of other metal ions have been taken into account. The proposed method was validated in terms of LoD, LoQ, linearity, precision, and trueness, and has been applied for total iron determination in natural water certified material and in biological reference materials such as control human urine and control serum. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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15 pages, 1950 KiB

Open AccessArticle

Combined Experimental and Multivariate Model Approaches for Glycoalkaloid Quantification in Tomatoes

by Gabriella Tamasi, Alessio Pardini, Riccardo Croce, Marco Consumi, Gemma Leone, Claudia Bonechi, Claudio Rossi and Agnese Magnani

Molecules 2021, 26(11), 3068; https://doi.org/10.3390/molecules26113068 - 21 May 2021

Cited by 10 | Viewed by 2363

Abstract

The intake of tomato glycoalkaloids can exert beneficial effects on human health. For this reason, methods for a rapid quantification of these compounds are required. Most of the methods for α-tomatine and dehydrotomatine quantification are based on chromatographic techniques. However, these techniques require [...] Read more.

The intake of tomato glycoalkaloids can exert beneficial effects on human health. For this reason, methods for a rapid quantification of these compounds are required. Most of the methods for α-tomatine and dehydrotomatine quantification are based on chromatographic techniques. However, these techniques require complex and time-consuming sample pre-treatments. In this work, HPLC-ESI-QqQ-MS/MS was used as reference method. Subsequently, multiple linear regression (MLR) and partial least squares regression (PLSR) were employed to create two calibration models for the prediction of the tomatine content from thermogravimetric (TGA) and attenuated total reflectance (ATR) infrared spectroscopy (IR) analyses. These two fast techniques were proven to be suitable and effective in alkaloid quantification (R² = 0.998 and 0.840, respectively), achieving low errors (0.11 and 0.27%, respectively) with the reference technique. Full article

(This article belongs to the Special Issue Analytical Chemistry in Italy)

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