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1.
Molecules ; 28(2)2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36677918

RESUMO

Recently, there has been a growing interest in producing functional foods containing encapsulated probiotic bacteria due to their positive effects on human health. According to their perceived health benefits, probiotics have been incorporated into a range of dairy products, but the current major challenge is to market new, multicomponent probiotic foods and supplements. Nevertheless, only a few products containing encapsulated probiotic cells can be found as non-refrigerated products. In this work, spray drying technology was investigated in order to produce an innovative nutraceutical formulation based on lactic acid bacteria (LAB), and was able to ensure a good storage stability of probiotics (no less than 109 CFU/cps) in non-refrigerated conditions. Probiotic-loaded microparticles from spray drying experiments were produced under different conditions and compared by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and the enumeration of the number of viable cells in order to identify the formulation exhibiting the most promising characteristics. Results from the dissolution test revealed that the optimized formulation provides a suitable amount of living cells after digestion of microparticles stored for 12 months at room temperature and confirmed that the microencapsulation process by spray drying ensures a good protection of probiotics for nutraceutical purposes.


Assuntos
Probióticos , Secagem por Atomização , Humanos , Viabilidade Microbiana , Bactérias , Laticínios/microbiologia
2.
Molecules ; 27(11)2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35684458

RESUMO

Advances in on-line thermally induced evolved gas analysis (OLTI-EGA) have been systematically reported by our group to update their applications in several different fields and to provide useful starting references. The importance of an accurate interpretation of the thermally-induced reaction mechanism which involves the formation of gaseous species is necessary to obtain the characterization of the evolved products. In this review, applications of Evolved Gas Analysis (EGA) performed by on-line coupling heating devices to mass spectrometry (EGA-MS), are reported. Reported references clearly demonstrate that the characterization of the nature of volatile products released by a substance subjected to a controlled temperature program allows us to prove a supposed reaction or composition, either under isothermal or under heating conditions. Selected 2019, 2020, and 2021 references are collected and briefly described in this review.


Assuntos
Gases , Calefação , Gases/análise , Espectrometria de Massas
3.
Molecules ; 27(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36558054

RESUMO

The on-line thermally induced evolved gas analysis (OLTI-EGA) is widely applied in many different fields. Aimed to update the applications, our group has systematically collected and published examples of EGA characterizations. Following the recently published review on EGA-MS applications, this second part reviews the latest applications of Evolved Gas Analysis performed by on-line coupling heating devices to infrared spectrometers (EGA-FTIR). The selected 2019, 2020, 2021 and early 2022 references are collected and briefly described in this review; these are useful to help researchers to easily find applications that are sometimes difficult to locate.


Assuntos
Espectroscopia de Infravermelho com Transformada de Fourier
4.
Analyst ; 145(13): 4452-4456, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32478764

RESUMO

Systematic screening for congenital erythrocyte disorders is not a common practice, due to a lack in the accuracy of the methods and to the costs of the analyses. As a consequence, the diagnosis is usually made when a severe complication occurs. This study introduces an innovative method to perform the screening of a hereditary disease characterized by erythrocyte membrane defects such as hereditary spherocytosis (HS) and hereditary elliptocytosis (HE). Blood samples from healthy donors and patients affected by HS and HE were processed by thermogravimetric analysis (TGA) and the resulting curves were analyzed by chemometrics in order to develop a model of prediction. A novel test was developed and validated by chemometrics and results were found to be in accordance with the genetic diagnosis, confirming the prediction ability of the optimized model that uses few microliters of whole non pretreated blood to perform the diagnosis of HS/HE in less than one hour.


Assuntos
Análise Química do Sangue/métodos , Eliptocitose Hereditária/diagnóstico , Esferocitose Hereditária/diagnóstico , Termogravimetria/métodos , Adolescente , Adulto , Idoso , Análise Química do Sangue/estatística & dados numéricos , Criança , Pré-Escolar , Diagnóstico Diferencial , Análise Discriminante , Eliptocitose Hereditária/sangue , Feminino , Humanos , Lactente , Recém-Nascido , Análise dos Mínimos Quadrados , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Esferocitose Hereditária/sangue , Adulto Jovem
5.
Analyst ; 145(5): 1777-1782, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-31915770

RESUMO

In this work, the capabilities of a novel miniaturized and portable microNIR spectrometer were investigated in order to propose a practical and intelligible test allowing the rapid and easy screening of cannabinoids in veterinary feeds. In order to develop a predictive model that could identify and simultaneously quantify the residual amounts of cannabinoids, specimens from popular veterinary feeds were considered and spiked with increasing amounts of cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), and cannabigerol (CBG). Partial least squares discriminant analysis (PLS-DA) and partial least squares regression (PLSr) were applied for the simultaneous detection and quantification of cannabinoids. The results demonstrated that the microNIR/chemometric platform could statistically identify the presence of CBD, THC and CBG in the simulated samples containing cannabinoids from 0.001 to 0.01%w/w, with the accuracy and sensitivity of the official reference methods actually proposed. The method was checked against false positive and true positive responses, and the results proved to be those required for confirmatory analyses, permitting to provide a fast and accurate method for monitoring cannabinoids in veterinary feeds.


Assuntos
Ração Animal/análise , Canabinoides/análise , Dieta/veterinária , Miniaturização/instrumentação , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Bovinos , Espectrometria de Massas em Tandem
6.
Molecules ; 25(3)2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31991662

RESUMO

The interactions of epinephrine ((R)-(-)-3,4-dihydroxy-α-(methylaminomethyl)benzyl alcohol; Eph-) with different toxic cations (methylmercury(II): CH3Hg+; dimethyltin(IV): (CH3)2Sn2+; dioxouranium(VI): UO22+) were studied in NaClaq at different ionic strengths and at T = 298.15 K (T = 310.15 K for (CH3)2Sn2+). The enthalpy changes for the protonation of epinephrine and its complex formation with UO22+ were also determined using isoperibolic titration calorimetry: HHL = -39 ± 1 kJ mol-1, HH2L = -67 ± 1 kJ mol-1 (overall reaction), HML = -26 ± 4 kJ mol-1, and HM2L2(OH)2 = 39 ± 2 kJ mol-1. The results were that UO22+ complexation by Eph- was an entropy-driven process. The dependence on the ionic strength of protonation and the complex formation constants was modeled using the extended Debye-Hückel, specific ion interaction theory (SIT), and Pitzer approaches. The sequestering ability of adrenaline toward the investigated cations was evaluated using the calculation of pL0.5 parameters. The sequestering ability trend resulted in the following: UO22+ >> (CH3)2Sn2+ > CH3Hg+. For example, at I = 0.15 mol dm-3 and pH = 7.4 (pH = 9.5 for CH3Hg+), pL0.5 = 7.68, 5.64, and 2.40 for UO22+, (CH3)2Sn2+, and CH3Hg+, respectively. Here, the pH is with respect to ionic strength in terms of sequestration.


Assuntos
Epinefrina/química , Compostos de Metilmercúrio/química , Óxidos/química , Termodinâmica , Urânio/química
7.
Anal Chem ; 91(11): 7025-7031, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31059231

RESUMO

In this work, a novel multiway approach by spectroscopy and thermogravimetry associated with chemometrics is developed, providing a multiparametric characterization of vitreous humor as a function of the time since death. Estimation of the precise time since death was performed on hospital deaths occurred in casualty, by medico-legal and post mortem examination, with no metabolic disorders. Micro and macro elements in vitreous specimens were determined by ICP-OES and were found to be diagnostic in predicting the post mortem interval (PMI). The percentage of bulk and bound water provided by thermal analysis investigation was correlated to spectroscopic analysis, and chemometric tools were used to compare results and to develop a model of prediction of PMI. The study reveals a significant role of P, S, and Mg in addition to the potassium concentration in determining the death interval and permits increased accuracy with respect to conventional procedures and allows the investigation of PMI to be extended to 15 days.


Assuntos
Análise Espectral/métodos , Corpo Vítreo/química , Autopsia , Feminino , Humanos , Magnésio/análise , Masculino , Fósforo/análise , Potássio/análise , Reprodutibilidade dos Testes , Termogravimetria , Fatores de Tempo
8.
Anal Chem ; 91(10): 6435-6439, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31034204

RESUMO

A novel, entirely automated MicroNIR-chemometric platform was developed for the "lab-on-click" detection of illicit drugs in nonpretreated oral fluids, and a novel tool for the first-level test is proposed. Calibration of the method was achieved by collecting oral-fluid specimens from volunteers, and chemometric analysis was considered for the development of models for prediction for cocaine, amphetamine, and Δ9-tetrahydrocannabinol. In addition, a comprehensive model was optimized for the simultaneous prediction of positive-negative samples and the specific illicit drug used by abusers in a single "click". The detection ability of the method was checked for true-positive and false-positive outcomes, and results were validated by a GC-MS reference official method. The MicroNIR-chemometric platform provided the simultaneous prediction of the three most frequently abused addictive drugs with the sensitivity and accuracy of the confirmatory analyses, offering the advantages of rapidity and simplicity and demonstrating that it is a promising tool for supporting public-health surveillance.


Assuntos
Drogas Ilícitas/química , Saliva/química , Detecção do Abuso de Substâncias/instrumentação , Detecção do Abuso de Substâncias/métodos , Humanos , Testes Imediatos
9.
J Environ Manage ; 231: 1012-1020, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30602225

RESUMO

A big challenge for the civilization in energy saving/waste management can be "the regeneration of monomers from the waste plastics followed by their re-polymerization" using an ideal recycling method. Herein, we investigate the thermal depolymerization of poly(methyl methacrylate) (PMMA) using thermogravimetric analysis coupled with mass spectrometry (TGA-MS). In this process, the polymer chains were decomposed to methyl methacrylate (MMA) in high yield and the degradation species were thoroughly characterized. The obtained MMA contained traces of byproducts. Firstly, the byproducts were found to be nonpolymerizable, secondly, their presence interrupt the polymerization reaction, and thirdly, they reduce the quality of re-polymerized PMMA (r-PMMA). This study reclaims that besides the main byproduct (methyl isobutyrate), traces of methyl pyruvate and 2,3-butanedione were also formed during the thermal depolymerization of PMMA. The formed 2,3-butanedione was found to be responsible for the unpleasant smell in the recovered MMA that also found itself in the r-PMMA. Further, the generated byproducts were eliminated from the r-PMMA by a dissolution/re-precipitation method. The structural characterizations of the recycled and purified PMMA were carried out by Fourier-transform-infrared spectroscopy (FT-IR), Hydrogen-1 (1H)- and Carbon-13 (13C)-nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). The chemical properties of the r-PMMA and purified PMMA proved to be similar to that of the virgin commercial PMMA. This study can provide an effective and practical prototype for the recycling of waste PMMA scraps and thus reduction in pollution caused by the landfilling of waste PMMA scraps.


Assuntos
Polímeros , Polimetil Metacrilato , Varredura Diferencial de Calorimetria , Polimerização , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Molecules ; 24(16)2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31434223

RESUMO

Speciation studies are based on fundamental models that relate the properties of biomimetic coordination compounds to the stability of the complexes. In addition to the classic approach based on solution studies, solid state properties have been recently proposed as supporting tools to understand the bioavailability of the involved metal. A ten-year long systematic study of several different complexes of imidazole substituted ligands with transition metal ions led our group to the definition of a model based on experimental evidences. This model revealed to be a useful tool to predict the stability of such coordination complexes and is based on the induced behavior under thermal stress. Several different solid state complexes were characterized by Thermally Induced Evolved Gas Analysis by Mass Spectrometry (TI-EGA-MS). This hyphenated technique provides fundamental information to determine the solid state properties and to create a model that relates stability to coordination. In this research, the model resulting from our ten-year long systematic study of complexes of transition metal ions with imidazole substituted ligands is described. In view of a systematic addition of information, new complexes of Cu(II), Zn(II), or Cd(II) with 2-propyl-4,5-imidazoledicarboxylic acid were precipitated, characterized, and studied by means of Thermally Induced Evolved Gas Analysis performed by mass spectrometry (TI-EGA-MS). The hyphenated approach was applied to enrich the information related to thermally induced steps, to confirm the supposed decomposition mechanism, and to determine the thermal stability of the studied complexes. Results, again, allowed supporting the theory that only two main characteristic and common thermally induced decomposition behaviors join the imidazole substituted complexes studied by our group. These two behaviors could be considered as typical trends and the model allowed to predict coordination behavior and to provide speciation information.


Assuntos
Complexos de Coordenação/química , Imidazóis/química , Modelos Químicos , Cádmio/química , Cobre/química , Ligantes , Espectrometria de Massas , Temperatura , Zinco/química
11.
Anal Chem ; 90(7): 4288-4292, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29509004

RESUMO

Portable near-infrared spectroscopy (MicroNIR) coupled with chemometrics was investigated for the first time as a new tool for the on-site analysis of explosives on human hands. A novel, entirely on-site approach based on the use of a particular miniaturized NIR spectrometer was developed and validated in cooperation with the Scientific Investigation Department (Carabinieri RIS) of Rome. Spectra from 25 volunteers were acquired in the NIR region in reflectance mode, and a prediction model was optimized on the basis of chemometric tools. The results demonstrated the capability of the MicroNIR-Chemometrics approach to correctly identify explosives from hands and not be affected by the complexity and variability of the matrix. This study has shown that the MicroNIR-Chemometrics approach can be considered a useful, fast, nondestructive tool identifying the manipulation of explosives in real forensic cases.


Assuntos
Substâncias Explosivas/análise , Mãos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Espectroscopia de Luz Próxima ao Infravermelho
12.
Analyst ; 143(18): 4394-4399, 2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-30137067

RESUMO

Using a miniaturized near infrared spectrometer associated to chemometrics we developed a rapid and non destructive procedure to characterise paper and investigate its aging with the aim of solving dating problems. Two sets of paper were considered in this study (books and sheets) in order to ensure the results are not dependent of the storage conditions. The MicroNIR has the ability to distinguish paper according to the chemical composition of the surface as a function of the period of manufacturing. The optimized analytical platform is fast and simple, avoiding sample pre-treatment procedures. As a consequence, the approach may be considered as the optimal technology to carry out analysis of ancient paper or other similar materials for diagnostic or forensic purposes as it is entirely portable and non-destructive.

13.
J Proteome Res ; 13(6): 2856-66, 2014 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-24766658

RESUMO

A simple procedure is proposed for selective protein solubilization and trypsin digestion, followed by off-line liquid chromatography-matrix assisted laser desorption ionization mass spectrometry (LC-MALDI MS) analysis of Oenococcus oeni (O. oeni) bacterium. Peptides were identified from tryptic digests using sequencing by tandem mass spectrometry and database searches. Cytoplasmic and membrane related proteins (MRP) were identified in the O. oeni bacterium. MS/MS data analysis points out 13 peptides having one point mutation from 9 proteins. The major microheterogeneity was found for Zn-dependent alcohol dehydrogenase (Zn-ADH, Q04GE6) and 60 kDa chaperonin (GroEL, Q04E64) that are involved in methionine catabolism and post-translational protein folding, respectively. MS/MS data processing also leads to the identification of 34 unique phosphorylation sites from 19 phosphoproteins.


Assuntos
Proteínas de Bactérias/química , Oenococcus/metabolismo , Proteoma/química , Sequência de Aminoácidos , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Cromatografia Líquida de Alta Pressão , Dados de Sequência Molecular , Fosfoproteínas/isolamento & purificação , Fosfoproteínas/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Proteólise , Proteoma/isolamento & purificação , Proteoma/metabolismo , Proteômica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem , Tripsina/química , Vinho/microbiologia
14.
Animals (Basel) ; 14(6)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38539924

RESUMO

This study aimed to investigate the exposure of wild boars and swine from semi-extensive farms in the same area to essential and non-essential elements, measuring their concentration in liver and muscle. Furthermore, the study explored the influence of factors such as sex, age, and the sampling location on wild boars. Higher liver element concentrations were observed in both wild boars and swine. Geographical comparisons revealed minor differences. Young wild boars showed significantly higher Cu, Se, Cd, and Cr levels, while older subjects exhibited elevated Mn levels, reflecting age-related element absorption variations. No significant sex-based variations were noted. Comparing wild boars to swine, wild boars had more non-essential elements due to their foraging behavior and a larger home range. Conversely, swine exhibited a greater prevalence of essential elements, potentially resulting from dietary supplementation.

15.
Front Biosci (Landmark Ed) ; 28(1): 3, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36722277

RESUMO

BACKGROUND: Brewer's spent grain (BSG) is one of the main by-products of beer industry, little used because of its high moisture making it difficult to transport and store. Mainly used as animal feed and for energy production, the agro-industrial waste have recently attracted attention as source of bioactive compounds, with potential applications in many sectors as food, nutraceutical, pharmaceutical, cosmetic, food packaging. The present work focuses on BSG as potential source of valuable small-size bioactive compounds. METHODS: Laboratory-made BSG was obtained by using four base malts for mashing. After drying, BSG was eco-friendly extracted with water and the extracts analyzed by untargeted ElectroSpray Ionization (ESI)-Mass Spectrometry (MS)/Mass Spectrometry (MS) (ESI-MS/MS) infusion experiments and by targeted High Performance Liquid Chromatography-PhotoDiodeArray-ElectroSpray Ionization-Mass Spectrometry (HPLC-PDA-ESI-MS) in Selected Ion Recording (SIR) mode analysis, to investigate the metabolic profile, the phenolic profile, the individual phenolic content, and tryptophan content. Aqueous extracts of malts and wort samples were also analyzed for a comparison. Data were statistically analyzed by ANOVA test. An explorative analysis based on Principal Component Analysis (PCA) was also carried out on malts, wort and threshes, in order to study correlation among samples and between samples and variables. RESULTS: The untargeted ESI-MS/MS infusion experiments provided the mass spectral fingerprint of BSG, evidencing amino acids (γ-aminobutyric acid, proline, valine, threonine, leucine/isoleucine, lysine, histidine, phenylalanine and arginine) and organic and inorganic acids (pyruvic, lactic, phosphoric, valerianic, malonic, 2-furoic, malic, citric and gluconic acids), besides sugars. γ-Aminobutyric acid and lactic acid resulted predominant among the others. The targeted HPLC-PDA-ESI-MS in SIR mode analysis provided the phenolic profile of the polar fraction of BSG, evidenced tryptophan as the main residual metabolite in BSG (62.33-75.35 µg/g dry BSG), and catechin (1.13-4.24 µg/g dry BSG) as the representative phenolic antioxidant of not pre-treated BSG samples. The chemometric analysis of the individual compounds content in BSG, malt and wort evidenced similarities and differences among the samples. CONCLUSIONS: As main goal, the phytochemical characterization of BSG from base malts highlighted BSG as a potential source of small biomolecules, as tryptophan and catechin, besides γ-aminobutyric acid and lactic acid, opening to new perspectives of application for BSG. Strategies for their recovery are a future challenge. Moreover, ESI-MS/MS analysis was confirmed as a powerful tool for fast characterization of complex matrix. Last, results obtained by chemometric elaboration of data demonstrated the possibility to monitor a small number of molecules to ensure the quality of a final product.


Assuntos
Catequina , Espectrometria de Massas em Tandem , Animais , Triptofano , Cromatografia Líquida , Espectrometria de Massas por Ionização por Electrospray
16.
Front Mol Biosci ; 9: 1108896, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36699704

RESUMO

The rheological properties of blood play an important role in regulating blood flow in micro and macro circulation. In thalassemia syndromes red blood cells exhibit altered hemodynamic properties that facilitate microcirculatory diseases: increased aggregation and reduced deformability, as well as a marked increase in adherence to the vascular endothelial cells. A personalized approach to treating thalassemia patients (transfusions, iron chelation, and splenectomy), has increased patients' life expectancy, however they generally present many complications and several studies have demonstrated the presence of high incidence of thromboembolic events. In this study the hemorheological profiles of thalassemia patients have been characterized to point out new indices of vascular impairment in thalassemia. Plasma viscosity, blood viscosities at low and high shear rates (η1 and η200, respectively), erythrocyte aggregation index (η1/η200), and the erythrocyte viscoelastic profile (elastic modulus G', and viscous modulus G") have been studied in transfusion-dependent and non-transfusion-dependent thalassemia patients. Moreover, the levels of inflammation biomarkers in thalassemia have been evaluated to investigate a relationship between the biomarkers, the disease severity and the rheological parameters. The biomarkers studied are the main components of the immune and endothelial systems or are related to vascular inflammation: cytokines (IL-2, IL-6, IL-10, IL-17A, TNF-alpha), chemokines (IL-8, MIP-1alpha), adipocytokines (leptin and adiponectin), growth factors (VEGF, angiopoietin-1), adhesion molecules (ICAM-1, VCAM-1, E-selectin, L-selectin), and a monocyte/macrophage activation marker (CD163). This study shows that transfusion-dependent thalassemia patients, both major and intermedia, have blood viscosities comparable to those of healthy subjects. Non-transfusion-dependent thalassemia intermedia patients show high blood viscosities at low shear rates (η1), corresponding to the flow conditions of the microcirculation, an increase in erythrocyte aggregation, and high values of the elastic G' and viscous G" modules that reflect a reduced erythrocyte deformability and an increase in blood viscosity. Levels of cytokines, chemokines and adhesion molecules are different in transfusion- and non-transfusion dependent patients and positive correlations between η1 or η1/η200 and the cytokines IL-6 and IL-10 have been observed. The evaluation of the hemorheological profiles in thalassemia can provide new indicators of vascular impairment and disease severity in thalassemia in order to prevent the onset of thromboembolic events.

17.
Diagnostics (Basel) ; 11(1)2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33466645

RESUMO

Chronothanatology has always been a challenge in forensic sciences. Therefore, the importance of a multidisciplinary approach for the characterization of matrices (organs, tissues, or fluids) that respond linearly to the postmortem interval (PMI) is emerging increasingly. The vitreous humor is particularly suitable for studies aimed at assessing time-related modifications because it is topographically isolated and well-protected. In this work, a novel approach based on thermogravimetry and chemometrics was used to estimate the time since death in the vitreous humor and to collect a databank of samples derived from postmortem examinations after medico-legal evaluation. In this study, contaminated and uncontaminated specimens with tissue fragments were included in order to develop a classification model to predict time of death based on partial least squares discriminant analysis (PLS-DA) that was as robust as possible. Results demonstrate the possibility to correctly predict the PMI even in contaminated samples, with an accuracy not lower than 70%. In addition, the correlation coefficient of the measured versus predicted outcomes was found to be 0.9978, confirming the ability of the model to extend its feasibility even to such situations involving contaminated vitreous humor.

18.
Biomolecules ; 11(9)2021 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-34572525

RESUMO

The interactions of dopamine [2-(3,4-Dihydroxyphenyl)ethylamine, (Dop-)] with methylmercury(II) (CH3Hg+), magnesium(II), calcium(II), and tin(II) were studied in NaCl(aq) at different ionic strengths and temperatures. Different speciation models were obtained, mainly characterized by mononuclear species. Only for Sn2+ we observed the formation of binuclear complexes (M2L2 and M2LOH (charge omitted for simplicity); M = Sn2+, L = Dop-). For CH3Hg+, the speciation model reported the ternary MLCl (M = CH3Hg+) complex. The dependence on the ionic strength of complex formation constants was modeled by using both an extended Debye-Hückel equation that included the Van't Hoff term for the calculation of enthalpy change values of the formation and the Specific Ion Interaction Theory (SIT). The results highlighted that, in general, the entropy is the driving force of the process. The sequestering ability of dopamine towards the investigated cations was evaluated using the calculation of pL0.5 parameter. The sequestering ability trend resulted to be: Sn2+ > CH3Hg+ > Ca2+ > Mg2+. For example, at I = 0.15 mol dm-3, T = 298.15 K and pH = 7.4, pL0.5 = 3.46, 2.63, 1.15, and 2.27 for Sn2+, CH3Hg+, Ca2+ and Mg2+ (pH = 9.5 for Mg2+), respectively. For the Ca2+/Dop- system, the precipitates collected at the end of the potentiometric titrations were analyzed by thermogravimetry (TGA). The thermogravimetric calculations highlighted the formation of solid with stoichiometry dependent on the different metal:ligand ratios and concentrations of the starting solutions.


Assuntos
Cátions Bivalentes/química , Dopamina/química , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Modelos Moleculares , Concentração Osmolar , Soluções , Temperatura , Termodinâmica , Termogravimetria
19.
RSC Adv ; 10(71): 43394-43399, 2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-35519692

RESUMO

In this work, an innovative screening platform is developed and validated for the on site detection of cannabinoids in hemp seed oil, for food safety control of commercial products. The novelty of this completely automated tool consists of a miniaturized NIR spectrometer operating in a wireless mode that permits processing samples in a rapid and accurate way and to obtain in a single click the early detection of a residual amount of cannabinoids in oil, including cannabidiol (CBD), the psychoactive Δ9-tetrahydrocannabinol (THC) and the Δ9-tetrahydrocannabinolic acid (THCA). Simulated samples were realized to instruct the platform and prediction models were developed by chemometric analysis of the NIR spectra using partial least square regression algorithms. Once calibrated, the platform was used to predict samples acquired in the market and on websites. Validation of the system was achieved by comparing results with those obtained from GC-MS analyses and a good correlation was observed.

20.
Talanta ; 211: 120672, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32070595

RESUMO

Cannabinoids in hemp plant are strictly located in the inflorescence, in particular in top side of the plant while a lower amount may be found in the leaves. As a consequence, the lower amount of cannabinoids which can be recovered in the hemp flours is obtained from seeds, thus from contamination during harvesting procedures. To this aim, a screening test for the real time detection of cannabinoids in hemp flour was developed by a miniaturized analytical platform based on the MicroNIR spectrometer. Chemometrics was used to develop models of prediction to identify the cannabinoids and simultaneously to quantify the residual amounts in order to accomplish specific regulatory legislation according to the country. In particular, Partial Least Square-Discriminant Analysis (PLS-DA) and Partial Least Square regression (PLSr) were applied and results demonstrated that MicroNIR/Chemometric platform permit to differentiate hemp flours according to the presence of CBD, THC and CBG. In addition, for each cannabinoid, a quantification method was developed in the range 0.001-0.1 %ww, and their performances were evaluated by comparing results to those obtained by the reference procedures. Processing of the real samples provided a suitable correlation and confirmed the capabilities of this innovative platform to be used for the monitoring of the residual content of cannabinoids in hemp flours.


Assuntos
Canabinoides/análise , Farinha/análise , Cannabis , Contaminação de Alimentos/análise , Miniaturização , Espectroscopia de Luz Próxima ao Infravermelho
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