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1.
Mikrochim Acta ; 191(5): 251, 2024 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-38589663

RESUMO

Nanocomposite microbeads (average diameter = 10-100 µm) were prepared by a microemulsion-solidification method and applied to the magnetic solid-phase extraction (m-SPE) of fourteen analytes, among pesticides, drugs, and hormones, from human urine samples. The microbeads, perfectly spherical in shape to maximize the surface contact with the analytes, were composed of magnetic nanoparticles dispersed in a polylactic acid (PLA) solid bulk, decorated with multi-walled carbon nanotubes (mPLA@MWCNTs). In particular, PLA was recovered from filters of smoked electronic cigarettes after an adequate cleaning protocol. A complete morphological characterization of the microbeads was performed via Fourier-transform infrared (FTIR) spectroscopy, UV-Vis spectroscopy, thermogravimetric and differential scanning calorimetry analysis (TGA and DSC), scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The recovery study of the m-SPE procedure showed yields ≥ 64%, with the exception of 4-chloro-2-methylphenol (57%) at the lowest spike level (3 µg L-1). The method was validated according to the main FDA guidelines for the validation of bioanalytical methods. Using liquid chromatography-tandem mass spectrometry, precision and accuracy were below 11% and 15%, respectively, and detection limits of 0.1-1.8 µg L-1. Linearity was studied in the range of interest 1-15 µg L-1 with determination coefficients greater than 0.99. In light of the obtained results, the nanocomposite microbeads have proved to be a valid and sustainable alternative to traditional sorbents, offering good analytical standards and being synthetized from recycled plastic material. One of the main objectives of the current work is to provide an innovative and optimized procedure for the recycling of a plastic waste, to obtain a regular and reliable microstructure, whose application is here presented in the field of analytical chemistry. The simplicity and greenness of the method endows the procedure with a versatile applicability in different research and industrial fields.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Nanocompostos , Nanotubos de Carbono , Humanos , Nanotubos de Carbono/química , Xenobióticos , Microesferas , Poliésteres , Extração em Fase Sólida/métodos , Nanocompostos/química , Fenômenos Magnéticos
2.
Sci Total Environ ; 929: 172677, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38663594

RESUMO

Cigarette butts, one of the most common forms of litter in the world, represent a source of chemical and plastic pollution releasing thousands of toxic compounds and microfibers of cellulose acetate (CA). Besides the correct waste management, the recovery of CA from cigarette filters is a way to cushion their negative effects on the environment. Thus far, recycling strategies have been limited to industrial applications, while not many solutions have designed for water remediation. This work describes a strategy to valorize this harmful waste and to reverse its environmental impact, proposing a simple and effective procedure of reclamation of CA and its reuse to prepare a composite sorbent for the treatment of polluted water. The first step entails the washing of filters with hot water (T = 90 °C) and hot ethanol (T = 58-68 °C) to remove the impurities produced during cigarette burning, as verified by means of UV and attenuated total reflection-Fourier-transform infrared (ATR-FTIR) spectroscopy, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). The second step involves the use of the regenerated CA to prepare porous cylinder-shaped cryogels (15 mm × 10 mm) whose sorption properties are enhanced by the combination with AC (15 % w/w). The synthesis takes advantage of the sol-gel transition of the polymer dispersion (5 % w/V) in a solution acetone/water 5 mM in NH3 (60/40, v/v). After characterization by dynamic mechanical analysis (DMA), TGA, FT-IR, and scanning electron microscopy (SEM), the adsorption capability of the physical cryogel was studied in terms of treated environmental water volume, contact time and concentration of the selected pollutants. The results have shown that the proposed strategy is a low-cost way to recycle CA from cigarette butts and that the designed sorbent is a promising material for water treatment, allowing quick removal times and yields >79.6 %.

3.
J Chromatogr A ; 1717: 464690, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38309188

RESUMO

The extensive use of pesticides to control pest infestations has led to the development of analytical methods to determine pesticide residues in food matrices to prevent food exposure. However, most developed analytical methods do not consider impact on the environment in terms of the toxicity of the chemicals used and the amount of waste produced. An environmentally-friendly method, based on a miniaturized matrix solid-phase dispersion followed by high-performance liquid chromatography-tandem mass spectrometry, for the analysis of fourteen pesticides in tomatoes, was exploited. For the recovery of pesticides from tomato samples, a low transition temperature mixture (LTTM), containing choline chloride and sesamol 1:3 molar ratio, was employed. Extraction parameters like sample-to-dispersant ratio, extraction solvent volume and LTTM volume were optimized through a Box-Behnken design. The 1:4 sample-to-dispersant ratio, 900 µL of ethanol as extraction solvent and 50 µL of LTTM ensured the best result considering the pesticides' peak areas. The optimized analytical method was validated obtaining the following results: linearity range was between LOQ and 5 mg kg-1 with a minimum R2 of 0.9944 for tebufenozide, values in the range of 0.001-0.023 and 0.004-0.076 mg kg-1 were obtained for LOD and LOQ respectively, while peak areas intra-day and inter-day repeatability were maximum of 10.19 and 9.15 %, respectively. The analytical method was then applied to real samples studying whole, pulp and peel tomato pool. The analysis of whole and tomato pulp revealed the presence of seven and eight of the fourteen investigated pesticides, respectively. However, their concentration was lower than the limit of quantification. In tomato peel, five pesticides, namely dimethomorph, methoxyfenozide, pyraclostrobin, pyriproxyfen, and spiromesifen were quantified and their concentrations were below maximum residue levels.


Assuntos
Resíduos de Praguicidas , Praguicidas , Solanum lycopersicum , Praguicidas/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Temperatura de Transição , Resíduos de Praguicidas/análise , Solventes/química , Extração em Fase Sólida/métodos
4.
Anal Bioanal Chem ; 416(5): 1127-1137, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38108844

RESUMO

Many agrochemicals are chiral molecules, and most of them are marketed as racemates or diastereomeric mixtures. Stereoisomers that are not the active enantiomer have little or no pesticidal activity and can exert serious toxic effects towards non-target organisms. Thus, investigating the possible exposure to different isomers of chiral pesticides is an urgent need. The present work was aimed at developing a new enantioselective high-performance liquid chromatography-mass spectrometry method for the simultaneous determination of nine chiral pesticides in urine. Two solid-phase extraction (SPE) procedures, based on different carbon-based sorbents (graphitized carbon black (GCB) and buckypaper (BP)), were developed and compared. By using GCB, all analytes were recovered with yields ranging from 60 to 97%, while BP allowed recoveries greater than 54% for all pesticides except those with acid characteristics. Baseline separation was achieved for the enantiomers of all target agrochemicals on a Lux Cellulose-2 column within 24 min under reversed-phase mode. The developed method was then validated according to the FDA guidelines for bioanalytical methods. Besides recovery, the other evaluated parameters were precision (7-15%), limits of detection (0.26-2.21 µg/L), lower limits of quantitation (0.43-3.68 µg/L), linear dynamic range, and sensitivity. Finally, the validated method was applied to verify the occurrence of the pesticide enantiomers in urine samples from occupationally exposed workers.


Assuntos
Agroquímicos , Praguicidas , Humanos , Agroquímicos/análise , Estereoisomerismo , Fuligem , Espectrometria de Massa com Cromatografia Líquida , Espectrometria de Massas em Tandem/métodos , Praguicidas/análise , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão/métodos
5.
Molecules ; 28(8)2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37110752

RESUMO

The use of efficient solar ovens can be a way for progressing ecofriendly technologies in the field of food preparation. In most performing direct solar ovens, the sun rays reach the foods directly, therefore, it becomes essential to check whether, in these conditions, foods can retain theirnutraceutical properties (antioxidants, vitamins and carotenoids). In the present research work, to investigate this issue, several foods (vegetables, meats, and a fish sample) were analyzed before and after cooking (traditional oven, solar oven, and solar oven with a UV filter). The content of lipophilic vitamins and carotenoids (analyzed via HPLC-MS) and the variation of total phenolic content (TPC), and antioxidant capacity (via Folin-Ciocalteu and DPPH assays) have evidenced that cooking with the direct solar oven allows to preserve some nutrients (i.e., tocopherols) and, sometimes, to enhance nutraceutical properties of vegetables (for example, solar oven-cooked eggplants showed 38% higher TPC compared to electric oven cooked sample) and meats. The specific isomerization of all-trans-ß-carotene to 9-cis was also detected. The use of a UV filter is advisable to avoid UV drawbacks (for instance, a significant carotenoid degradation) without losing the beneficial effects of the other radiations.


Assuntos
Antioxidantes , Carotenoides , Animais , Antioxidantes/análise , Carotenoides/química , Vitaminas , Tocoferóis , beta Caroteno , Vitamina A , Verduras/química , Culinária , Fenóis/análise
6.
J Pharm Biomed Anal ; 223: 115150, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36410131

RESUMO

The protection of the health and safety of workers in the agricultural sector requires the assessment of human exposure to pesticides through biomonitoring programs. In doing this, the health and safety of laboratory analysts should be also protected through the use of analytical procedures as safe as possible. According to Green Analytical Chemistry and Green Sample Preparation principles, the use of miniaturized extraction techniques such as dispersive liquid-liquid microextraction (DLLME) should be encouraged, with the aim of limiting the consumption of chemicals (solvents and reagents) and energy, as well as the production of wastes. Moreover, safer and more environmentally friendly alternatives to petroleum-derived solvents must be found. In this regard, the effort of researchers is focused on the development/identification of sustainable solvents, some of which have been ranked according to their disposal, environmental, safety, and health features. Here, we introduce the alternative use of isoamyl acetate ("banana oil") as sustainable extraction solvent. Compared with the trendy class of eutectic solvents (ESs), isoamyl acetate is advantageous because it is already in the liquid state, which fasters operations, and because it can be evaporated to dryness and reconstituted in a solvent compatible with the mobile chromatographic phase, which is not an option for ESs. The applicability of isoamyl acetate has been here evaluated for the first time to extract 12 pesticides of different polarities from urine matrix, by using a DLLME approach. The HPLC/MS validated method has proven to possess the sensitivity, precision and accuracy required to reliable bioanalytical methods. Its cheapness, simplicity and quickness make it an ideal sustainable choice for the screening of large numbers of samples in health monitoring programs involving people occupationally-exposed to pesticides.


Assuntos
Microextração em Fase Líquida , Praguicidas , Humanos , Solventes/química , Monitoramento Biológico , Microextração em Fase Líquida/métodos
7.
J Chromatogr A ; 1685: 463595, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36323104

RESUMO

As many as 40% of all plant protection products currently used contain chiral active ingredients. Enantiomers of the same pesticide have identical physicochemical properties in an isotropic medium, but they may display different activity and toxicity because of their interaction with enzymes or other naturally occurring asymmetric molecules. This difference may also lead to variations in biotic degradation rates, making one enantiomer more persistent than the other in natural and agricultural environments. In terms of methodological aspects, this critical review describes the most used chiral stationary phases for HPLC enantioseparations of chiral pesticides, pinpointing their strengths and weaknesses. As far as their applicability is concerned, most research has been carried out by means of columns based on derivatized amylose/cellulose due to their rather universal analyte coverage. The chromatographic compatibility with sensitive detection techniques, such as mass spectrometry, has allowed the trace analysis of stereoisomers, revealing ubiquitous occurrence of some chiral pesticides in surface waters, sediments, plants, agricultural soils, roots, fruit and vegetables. The study of their distribution and degradation in various environmental compartments and agricultural soil-plant systems has highlighted the enrichment with one enantiomer over the other in certain matrices following the enantioselective dissipation catalysed by microorganisms or plant enzymes as well as the phenomenon of chiral inversion in some cases. Irrespective of the reliability of a chiral method, such investigations are often hindered by the lack of pure standards of single enantiomers, which makes it difficult to identify their stereochemical configuration and requires precise strategies of quantification. Surely, the research in this field has been grown over the last few years due to the necessity of assessing and limiting risks related to exposure to chiral pesticides, which can be considered emerging contaminants in all aspects.


Assuntos
Praguicidas , Poluentes do Solo , Praguicidas/análise , Solo/química , Cromatografia Líquida de Alta Pressão/métodos , Estereoisomerismo , Poluentes do Solo/análise , Água/análise , Reprodutibilidade dos Testes
8.
Antibiotics (Basel) ; 11(11)2022 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-36358113

RESUMO

The present Phase I study investigated, for the first time, fosfomycin pharmacokinetics in humans after two 3 g doses of fosfomycin trometamol administered 27 h apart, according to the dose regimen recommended for the prophylactic indication for transrectal prostate biopsy in adult men. Plasma, urine and seminal plasma concentrations were measured after one and two consecutive doses in 24 healthy men, representative of the target population of the prophylactic indication. Prostate and seminal vesicle concentrations were estimated based on seminal plasma concentrations using a one-step regression method. The exposure to fosfomycin was very similar in rate (Cmax, tmax) after one and two doses. The AUC showed a minimal increment. On average, the apparent volume of distribution was high (>100 L), and the mean clearance had an intermediate value. The total amount and dose fraction of fosfomycin excreted in urine showed a small increment after two doses. The renal clearance was about 5 L/h. The fosfomycin concentration in the prostate and seminal vesicles showed that the antibiotic increased on average after two consecutive doses. This result confirmed the ability of fosfomycin to distribute into the prostate and into seminal vesicles after one single dose and that a two consecutive dose regimen increases the antibiotic availability inside these peripheral tissues.

9.
Molecules ; 27(3)2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35164176

RESUMO

A green solvent-based DLLME/HPLC-MS method for the determination of 19 pesticides in wine samples has been developed. The extractant solvent is a hydrophobic eutectic mixture composed of L-menthol and butylated hydroxytoluene in a molar ratio of 3:1. The endogenous ethanol of wine has been used as dispersive solvent, in order to avoid the solidification of the extracts under 19 °C. The mobile phase composition, the elution gradient and the sample injection volume were optimized in order to make this hydrophobic mixture compatible with conventional reversed phase chromatography and electrospray ionization. The method was validated in matrix, using a wine free from the target compounds. Average recovery as high as 80%, precision between 3 and 14%, and limits of detection and quantification much lower than the maximum residue levels (MRLs) for grapes and wines fixed by the EU regulation, make this multiresidue method fitted for the purpose, with the further advantages of being quick, cheap and in compliance with the green analytical chemistry. From the analysis of 11 commercial wines it was found that just in a bio sample the target compounds were not detectable or lower than quantification limit; as for the other samples, the most widespread and abundant pesticides were methoxyfenozide and boscalid, but their levels were much lower than the relative MRLs.

10.
Int J Mol Sci ; 22(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34445079

RESUMO

Solid-phase extraction (SPE) coupled to LC/MS/MS analysis is a valid approach for the determination of organic micropollutants (OMPs) in liquid samples. To remove the greatest number of OMPs from environmental matrices, the development of innovative sorbent materials is crucial. Recently, much attention has been paid to inorganic nanosystems such as graphite-derived materials. Graphene oxide has been employed in water-purification processes, including the removal of several micropollutants such as dyes, flame retardants, or pharmaceutical products. Polysaccharides have also been widely used as convenient media for the dispersion of sorbent materials, thanks to their unique properties such as biodegradability, biocompatibility, nontoxicity, and low cost. In this work, chitosan-graphene oxide (CS_GO) composite membranes containing different amounts of GO were prepared and used as sorbents for the SPE of pesticides. To improve their dimensional stability in aqueous medium, the CS_GO membranes were surface crosslinked with glutaraldehyde. The composite systems were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, swelling degree, contact angle, and mechanical measurements. As the GO content increased, a decrease in surface homogeneity, an improvement of mechanical properties, and a reduction of thermal stability of the CS-based membranes were observed. The increased dimensional stability in water, together with the presence of high GO amounts, made the prepared composite membranes more efficacious than the ones based just on CS in isolating and preconcentrating different hydrophilic/hydrophobic pollutants.


Assuntos
Quitosana/química , Grafite/química , Membranas Artificiais , Praguicidas/isolamento & purificação , Extração em Fase Sólida/instrumentação , Poluentes Químicos da Água/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Praguicidas/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem , Água/análise , Poluentes Químicos da Água/análise
11.
J Pharm Anal ; 11(3): 292-298, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34277117

RESUMO

In the present work, dispersive liquid-liquid microextraction (DLLME) was used to extract six synthetic cannabinoids (JWH-018, JWH-019, JWH-073, JWH-200, or WIN 55,225, JWH-250, and AM-694) from oral fluids. A rapid baseline separation of the analytes was achieved on a bidentate octadecyl silica hydride phase (Cogent Bidentate C18; 4.6 mm × 250 mm, 4 µm) maintained at 37 °C, by eluting in isocratic conditions (water:acetonitrile (25:75, V/V)). Detection was performed using positive electrospray ionization-tandem mass spectrometry. The parameters affecting DLLME (pH and ionic strength of the aqueous phase, type and volume of the extractant and dispersive solvent, vortex and centrifugation time) were optimized for maximizing yields. In particular, using 0.5 mL of oral fluid, acetonitrile (1 mL), was identified as the best option, both as a solvent to precipitate proteins and as a dispersing solvent in the DLLME procedure. To select an extraction solvent, a low transition temperature mixture (LTTM; composed of sesamol and chlorine chloride with a molar ratio of 1:3) and dichloromethane were compared; the latter (100 µL) was proved to be a better extractant, with recoveries ranging from 73% to 101 % by vortexing for 2 min. The method was validated according to the guidelines of Food and Drug Administration bioanalytical methods: intra-day and inter-day precisions ranged between 4 % and 18 % depending on the spike level and analyte; limits of detection spanned from 2 to 18 ng/mL; matrix-matched calibration curves were characterized by determination coefficients greater than 0.9914. Finally, the extraction procedure was compared with previous methods and with innovative techniques, presenting superior reliability, rapidity, simplicity, inexpensiveness, and efficiency.

12.
Biomolecules ; 11(3)2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33802543

RESUMO

In this paper, the first phytochemical analysis of the ethanolic extract of Daphne sericea Vahl flowering aerial parts collected in Italy and its biological activities were reported. Eleven compounds were identified i.e., α-linolenic acid (1), tri-linoleoyl-sn-glycerol (2), pheophorbide a ethyl ester (3), pilloin (4), sinensetin (5), yuanhuanin (6), rutamontine (7), syringin (8), p-coumaric acid (9), p-anisic acid (10) and caffeic acid (11). To the best of our knowledge, compounds (1-4, 7-8 and 10) were isolated from D. sericea for the first time during this work, whereas sinensetin (5) represents a newly identified component of the entire Thymelaeaceae family. The extract was found to possess radical scavenging against both DPPH• and 2,2'-azino-bis(3-thylbenzothiazoline-6-sulfonic acid (ABTS•+) radicals, with at least a 40-fold higher potency against the latter. Moreover, chelating abilities against both ferrous and ferric ions have been highlighted, thus suggesting a possible indirect antioxidant power of the extract. Although the precise bioactive compounds remain to be discovered, the polyphenolic constituents, including phenolic acids, tannins and flavonoids, seem to contribute to the antioxidant power of the phytocomplex. In addition, the extract produced cytotoxic effects in MDA-MB-231 and U87-MG cancer cell lines, especially at the concentration of 625 µg/mL and after 48-72 h. Further studies are required to clarify the contribution of the identified compounds in the bioactivities of the extract and to support possible future applications.


Assuntos
Daphne/química , Etanol/química , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Antioxidantes/química , Itália , Thymelaeaceae/química
13.
J Chromatogr A ; 1642: 462036, 2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33714770

RESUMO

Biomonitoring is a potent tool to control the health risk of people occupationally and non-occupationally exposed. The latest trend in bioanalytical chemistry is to develop quick, cheap, easy, safe and reliable green analytical procedures to analyse a large number of chemicals in easily accessible biomatrices such as urine. In this paper, a new dispersive liquid-liquid microextraction (DLLME) procedure, conceived to treat urine samples and based on the use of a low transition temperature mixture (LTTM), was developed and validated to analyse twenty pesticides commonly used in farm practises. The LTTM was composed of choline chloride and sesamol in molar ratio 1:3 (ChCl:Ses 1:3); its characterization via differential scanning calorimetry identified it as an LTTM and not as a deep eutectic solvent due to the occurrence of a glass transition at -71 °C. The prepared mixture was used as the extraction solvent in the DLLME procedure, while ethyl acetate as the dispersing solvent. The salting out effect (50 mg mL-1 of NaCl in a diluted urine sample) improved the separation phase and the analyte transfer to the extractant. Due to the high ionic strength and despite the density of ChCl:Ses 1:3 (1.25 g mL-1), the LTTM layer floated on the top of the sample solution after centrifugation. All extracts were analysed by high-performance liquid chromatography coupled to mass spectrometry. After optimization and validation of the whole method, lower limits of quantitation were in the range of 0.02 - 0.76 µg  L-1. Extraction recoveries spanned from 50 to 101 % depending on the spike level and analytes. Precision and accuracy ranges were 3-18% and 5-20%, respectively. The extraction procedure was also compared with other methods, showing to be advantageous for rapidity, simplicity, efficiency, and low cost. Finally, urine samples from ten volunteers were effectively analysed using the developed method.


Assuntos
Cromatografia Líquida de Alta Pressão , Temperatura Baixa , Microextração em Fase Líquida/métodos , Espectrometria de Massas , Praguicidas/urina , Temperatura de Transição , Adulto , Varredura Diferencial de Calorimetria , Feminino , Humanos , Limite de Detecção , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Solventes/química , Fatores de Tempo , Adulto Jovem
14.
J Pharm Biomed Anal ; 189: 113421, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32590275

RESUMO

Coffee beans contain several compounds which have shown nutraceutial properties; among them chlorogenic acids (CGAs) are the most studied, have shown nutraceutical properties. These molecules are also present in the waste by-product known as spent coffee grounds (SCG). SCG are generated during the production of coffee drink, whereby roasted, ground coffee beans are heat or steam treated. A HPLC-PDA/ESI-MS method has been developed for the analysis of the most representative CGAs in SCG samples using a green extraction approach based on deep eutectic solvents (DESs). We examined fifteen different DESs based on choline chloride and betaine as hydrogen bond acceptor in combination with different hydrogen bond donors being seven alcohols, two organic acids, one sugar and urea. Fifteen CGAs were detected, identified and quantified for the evaluation of extraction efficiency. A betaine-based DES with triethylene glycol (molar ratio 1:2) was the most effective one at extracting CGAs from SCG also compared to a conventional organic solvent. Thirty percent of water added to DES and sample to solvent ratio 1:15 (g/mL) were selected as the best extraction conditions. The chromatographic method was validated studying LOD, LOQ, retention time and peak area precision, and linearity range. Retention time and peak area repeatability were determined obtaining RSDs values below 0.63 % and 8.51 %, respectively. Inter-day precision was determined obtaining RSDs value below 0.58 % and 8.80 % for retention time and peak area, respectively.


Assuntos
Betaína , Café , Cloretos , Colina , Suplementos Nutricionais , Solventes
15.
Electrophoresis ; 41(20): 1752-1759, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32106331

RESUMO

A HPLC-DAD/ESI-MS method has been developed and validated for the analysis of the most representative phenolic compounds in extra-virgin olive oil (EVOO) samples using a green extraction approach based on deep eutectic solvents (DESs) at room temperature. We examined ten DESs based on choline chloride and betaine in combination with different hydrogen bond donors comprising six alcohols, two organic acids, and one urea. Five phenolic compounds, belonging to the classes of secoiridoids and phenolic alcohols, were selected for the evaluation of extraction efficiency. A betaine-based DES with glycerol (molar ratio 1:2) was found to be the most effective for extracting phenolic compounds as compared to a conventional solvent. The optimization of the extraction method involved the study of the quantity of water to be added to the DES and evaluation of the sample-to-solvent ratio optimal condition. Thirty percent of water added to DES and sample to solvent ratio 1:1 (w/v) were selected as the best conditions. The chromatographic method was validated by studying LOD, LOQ, intraday and interday retention time precision, and linearity range. Recovery values obtained spiking seed oil sample aliquots with standard compounds at 5 and 100 µg/g concentration were in the range between 75.2% and 98.7%.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Azeite de Oliva/química , Fenóis , Extratos Vegetais/química , Solventes/química , Química Verde , Limite de Detecção , Modelos Lineares , Espectrometria de Massas , Fenóis/análise , Fenóis/química , Fenóis/isolamento & purificação , Reprodutibilidade dos Testes
16.
Sci Rep ; 10(1): 1920, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024866

RESUMO

Contaminated water with hexavalent chromium Cr(VI) is a serious environmental problem. This study aimed to evaluate the Cr(VI) removal by zero valent iron nanoparticles (nZVI) reduction process and the impact of Cr(VI), nZVI and combined treatment with nZVI and Cr(VI) on tomato growth performance. To evaluate the Cr(VI) toxic effect on germination capability, seeds were exposed to increasing Cr(VI) concentrations up to 1000 mg L-1. The inhibition of seed germination and the decrease of hypocotyl and root length started from Cr(VI) 5 mg L-1. Under treatment with Cr(VI) + nZVI 5 mg L-1, seed germination, hypocotyl and root length resulted significantly higher compared to Cr(VI) 5 mg L-1 treatment. The impact of only nZVI was investigated on chlorophyll and carotenoid in leaves; iron levels in leaves, roots, fruits and soil; carotenoid, fat-soluble vitamin and nicotianamine in mature fruits. A significant increase of leaf chlorophyll and carotenoids was observed after nZVI 5 mg L-1 treatment compared to controls. No significant variations were observed in carotenoids, fat-soluble vitamins and nicotianamine levels after treatment with nZVI 5 mg L-1 in mature fruits. For their ability to reduce Cr(VI) and to stimulate tomato growth, nZVI might to be considered as alternative for remediation purposes.


Assuntos
Cromo/isolamento & purificação , Recuperação e Remediação Ambiental/métodos , Ferro/química , Solanum lycopersicum/efeitos dos fármacos , Poluentes Químicos da Água/isolamento & purificação , Cromo/toxicidade , Água Subterrânea/análise , Água Subterrânea/química , Ferro/farmacologia , Nanopartículas/química , Desenvolvimento Vegetal/efeitos dos fármacos , Solo/química , Poluentes do Solo/isolamento & purificação , Poluentes do Solo/toxicidade , Poluentes Químicos da Água/toxicidade
17.
Int J Vitam Nutr Res ; 90(3-4): 295-301, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30829139

RESUMO

Previous studies showed a high prevalence of micronutrient deficiencies in obese subjects, with low folate and vitamin B12 serum levels and intakes. Correlations between vitamins and lipids have been investigated both in animal and human studies. The aim of our study is to evaluate the influence of dietetic and serum levels of folate and vitamin B12 on lipid pattern in morbidly obese subjects. We also analysed the relationship between serum concentrations and dietary intake of these micronutrients, and compared the intakes to the Recommended Levels of Nutrients and Energy Intakes (LARN). In 122 morbidly obese patients, mean BMI 45 ± 7 kg/m2, we evaluated anthropometric parameters, hepatic, glyco/lipid profile, total folate and vitamin B12, blood pressure, and finally nutritional intakes in a subgroup of 68 patients using a food frequency questionnaire about the frequency of food consumption and daily water intake. These values were determined in obese patients before and one year after sleeve gastrectomy. Both before and after surgery, levels of vitamins and minerals remained in normal range compared to LARN. According to univariate analysis, at baseline folate showed a significantly positive correlation with high-density lipoprotein cholesterol (p = 0.028, ρ = 0.204), apolipoprotein A-I (p = 0.006, ρ = 0.268) and vitamin B12 (p = 0.040, ρ = 0.192), and a significantly negative correlation with triglycerides (p = 0.049, ρ = -0.184). Folate and vitamin B12 levels do not correlate with their nutritional intakes, which remain within recommended range after surgery. In conclusion the correlation between folate and anti-atherogenic lipid profile is confirmed also in a large group of morbid obese patients.


Assuntos
Ácido Fólico/metabolismo , Lipídeos/química , Obesidade Mórbida , Vitamina B 12 , Vitaminas/química , Ácido Fólico/química , Humanos , Vitamina B 12/metabolismo , Vitaminas/metabolismo
18.
J Chromatogr A ; 1605: 360329, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31331655

RESUMO

This paper illustrates the development of a procedure based on the use of a low transition temperature mixture (LTTM) for the dispersive liquid-liquid microextraction (DLLME) of fungicides, insecticides and acaricides from surface waters. The LTTM preparation involves the heat-mixing of choline chloride and acetylsalicylic acid in a molar ratio 1:2 (ChCl(ASA)2). The resulting mixture appears as a clear viscous liquid at room-temperature, denser than water (1.20 ±â€¯0.01 g mL-1). For its characterization, differential scanning calorimetry (DSC) provided crucial evidence to classify it as a LTTM rather than as a deep eutectic solvent (DES) since it revealed an intense glass transition at -37 °C. Large-angle X-ray scattering (LAXS) confirmed the lack of any long-distance order. Due to the LTTM immiscibility with water, an evaluation study was carried out to test ChCl(ASA)2 as an effective alternative to the conventional chlorinated solvents for DLLME. To this end, 24 pesticides were used as model compounds, extracted from surface water samples (5 mL) and analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The definitive procedure required the optimization of some key parameters such as volume of extracting solvent, type and volume of dispersing solvent, volume of the aqueous sample, LTTM dispersion procedure, and extraction time. Depending on pKa and logP values, recoveries ranged from 18 (for very polar compounds) to 96%, revealing that the ideal candidates for the extraction with ChCl(ASA)2 are neutral compounds with logP >2. After complete validation, the method was applied to analyze water samples from the River Tiber where dodine and dimetomorph were found at low µg L-1 concentration levels.


Assuntos
Monitoramento Ambiental/métodos , Microextração em Fase Líquida , Praguicidas/isolamento & purificação , Temperatura de Transição , Poluentes Químicos da Água/isolamento & purificação , Água/química , Cromatografia Líquida de Alta Pressão , Hormônios Juvenis , Praguicidas/análise , Solventes/química , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise
19.
J Chromatogr A ; 1586: 30-39, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30563692

RESUMO

This paper describes the development of an original micro-solid phase extraction device and its evaluation for the isolation of F2-isoprostanes (F2-IsoPs) from cord and maternal plasma samples. The unit is very simple and consists in a rotating disc (1.8 cm diameter) of oxidized buckypaper (BP), enwrapped in a polypropylene mesh pouch. Even if the selected F2-IsoPs have logP and pKa values that make them suitable candidates for their sorption on BP, several parameters were optimized to maximize recoveries: time of adsorption and desorption; stirring speed; volume, pH and ionic strength of the sample; type, volume, and fractions of the elution solvent; oxidation grade of BP. Among all, the last one was crucial in affecting extraction yields because of the analyte interactions with polar functionalities, introduced by a preliminary oxidative acid treatment. The investigation established the optimal oxidation time and highlighted the pros and cons of the acid activation step. All extracts were analyzed by means of liquid chromatography-tandem mass spectrometry (LC-MS/MS). Validation was performed according to the main FDA guidelines for bioanalytical methods. Depending on the spike level and analyte, recoveries ranged between 30 and 120% with precision and accuracy values lower than 20%. Quantitative analysis was accomplished by matrix-matched calibration curves whose determination coefficients were higher than 0.95. Lower limit of quantitation (LLOQ) spanned the range 2.45-6.77 µg L-1. The validated method was applied to the analysis of eight pairs of mother/child plasma samples, revealing the presence of 8-iso-15-keto-PGF2α and 8-iso-PGE2 at a concentration of about 10 µg L-1 in most cord plasma samples of preterm newborns.


Assuntos
F2-Isoprostanos/análise , F2-Isoprostanos/isolamento & purificação , Sangue Fetal/metabolismo , Nanotubos de Carbono/química , Papel , Extração em Fase Sólida/métodos , Adsorção , Feminino , Humanos , Recém-Nascido , Limite de Detecção , Gravidez , Solventes , Espectrometria de Massas em Tandem/métodos
20.
Anal Chem ; 90(11): 6827-6834, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29706074

RESUMO

This paper describes, for the first time, the use of oxidized buckypaper (BP) as a sorbent membrane of a stir-disc solid phase extraction module. The original device, consisting of a BP disc ( d = 34 mm) enveloped in a polypropylene mesh pouch, was designed to extract organic micropollutants (OMPs) from environmental water samples in dynamic mode. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to analyze the extracts. Several classes of pesticides and pharmaceuticals were chosen as model compounds to evaluate key parameters affecting the recovery rates. To this end, the effects of adsorption time, desorption time, stirring speed, type and volume of solvent, and sample volume were thoroughly examined. After optimization, a novel and in-depth study was conducted to find a correlation between physicochemical properties of the analytes and extraction yields. Recoveries were mainly governed by a combination of log P and p Ka values. As indicated, hydrophilic compounds with log P < 1 showed poor affinity for the oxidized BP, compounds having log P > 1 exhibited recoveries ranging between 50% and 100% depending on their p Ka, while compounds with p Ka between 6 and 7.5 gave low yields irrespective of their log P. The analytical method was also validated and tested as large scale screening method of OMPs in surface waters. The analysis of real samples revealed the presence of some nonsteroidal anti-inflammatory drugs, sulfonamides, and pesticides at low ng L-1 concentration levels with relative standard deviations lower than 8%.


Assuntos
Papel , Praguicidas/análise , Extração em Fase Sólida , Sulfonamidas/análise , Poluentes Químicos da Água/análise , Oxirredução
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