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1.
J Fluoresc ; 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38753257

RESUMO

The accurate and sensitive detection of prostate specific antigen (PSA) is vital for the early diagnosis and treatment of prostate cancer. To this end, an unlabeled fluorescent aptasensor was constructed by using a novel Compound B {1,1'-(1,4-phenylene) bis(3-ethyl-1H-imidazol-3-ium) iodide} with aggregation-induced emission (AIE) activity as a fluorescence signal and NH2-Fe3O4 particle as an adsorption platform. Compound B could combine with prostate specific antigen aptamers (PSA-Apt) to form a PSA-Apt/B complex, which further generated the AIE effect. Then, PSA was added to the PSA-Apt/B solution. PSA combined with PSA-Apt/B to form the PSA-Apt/B/PSA complex. Next, NH2-Fe3O4 magnetic particles were added to the solution. Given that PSA-Apt/B/PSA would no longer combine with NH2-Fe3O4 magnetic particles, the PSA-Apt/B/PSA complex remained in the supernate after magnet separation, and the supernate showed strong fluorescence (I). When no PSA was added to the PSA-Apt/B solution, PSA-Apt/B could combine with NH2-Fe3O4 magnetic particles and would be sucked into the bottom of the test tube by magnet, and the supernate would show weak fluorescence (I0). Result showed that the difference between the above-mentioned two fluorescence values (∆I = I - I0) had an excellent linear relationship with the PSA concentration within the concentration range of 0.01-10 ng/mL, and its limit of detection was 3 pg/mL (S/N = 3). In addition, the sensor has high accuracy and can be directly used to test PSA in actual serum samples.

2.
Anal Chim Acta ; 1311: 342714, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38816153

RESUMO

BACKGROUND: Antibiotics residues can accelerate the growth of drug-resistant bacteria and harm the ecological environment. Under the effect of enrichment and biomagnification, the emergence of drug-resistant pathogenic bacteria may eventually lead to humans being ineffective to drugs in the face of bacterial or fungal disease infections in the future. It is urgent to develop an efficient separation medium and analytical method for simultaneous extraction and determination of antibiotics in the water environment. RESULTS: This work doped 2,6-Di-O-methyl-ß-cyclodextrin, randomly methyl-ß-cyclodextrin, 2-hydroxypropyl-ß-cyclodextrin with thymol:fatty acid respectively to construct non-covalent interaction-dominated pH-responsive ternary supramolecular deep eutectic solvents (SUPRADESs), which can undergo a hydrophilic/hydrophobic transition with aqueous phase to achieve an efficient microextraction. Semi-empirical method illustrated that SUPRADESs have a wide range of hydrogen bond receptor sites. We developed a SUPRADES-based analytical method combined with liquid chromatography-triple quadrupole mass spectrometry for the extraction and determination of trace quinolones and sulfonamides in wastewater. The overall limits of detection of the method were 0.0021-0.0334 ng mL-1 and the limits of quantification were 0.0073-0.1114 ng mL-1. The linearity maintained good in the spiked level of 0.01-100 ng mL-1 (R2 > 0.99). The overall enrichment factors of the method were 157-201 with lower standard deviations (≤8.7). SIGNIFICANCE: The method gave an extraction recovery of 70.1-115.3 % for 28 antibiotics in livestock farming wastewater samples from Zhejiang, China, at trace levels (minimum 0.5 ng mL-1). The results demonstrated that inducing the phase transition between SUPRADES and aqueous phase by adjusting pH for extraction is a novel and efficient pretreatment strategy. To our knowledge, this is the first application of cyclodextrin-based ternary SUPRADESs with pH-responsive reversible hydrophobicity-hydrophilicity transition behavior in wastewater analysis.


Assuntos
Ciclodextrinas , Solventes Eutéticos Profundos , Quinolonas , Sulfonamidas , Águas Residuárias , Poluentes Químicos da Água , Águas Residuárias/química , Águas Residuárias/análise , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Sulfonamidas/química , Sulfonamidas/análise , Sulfonamidas/isolamento & purificação , Quinolonas/química , Quinolonas/isolamento & purificação , Quinolonas/análise , Ciclodextrinas/química , Solventes Eutéticos Profundos/química
3.
Artigo em Inglês | MEDLINE | ID: mdl-38623904

RESUMO

All-solid-state lithium batteries (ASSLBs) are attracting tremendous attention due to their improved safety and higher energy density. However, the use of a metallic lithium anode poses a major challenge due to its low stability and processability. Instead, the graphite anode exhibits high reversibility for the insertion/deinsertion of lithium ions, giving ASSLBs excellent cyclic stability but a lower energy density. To increase the energy density of ASSLBs with the graphite anode, it is necessary to lower the negative/positive (N/P) capacity ratio and to increase the charging voltage. These strategies bring new challenges to lithium metal plating and dendrite growth. Here, a nano-Ag-modified graphite composite electrode (Ag@Gr) is developed to overcome these shortcomings for Li5.5PS4.5Cl1.5-based ASSLBs. The Ag@Gr composite exhibits a strong ability to inhibit lithium metal plating and fast lithium-ion transport kinetics. Ag nanoparticles can accommodate excess Li, and the as-obtained Li-Ag alloy enhances the kinetics of the composite electrode. The ASSLB with the Li(Ni0.8Co0.1Mn0.1)O2 cathode and Ag@Gr anode achieves an energy density of 349 W h kg-1. The full cell using Ag@Gr with an N/P ratio of 0.6 also highlights the rate performance. This work provides a simple and effective method to regulate the charge transport kinetics of graphite anodes and improve the cyclic performance and energy density of ASSLBs.

4.
J Hazard Mater ; 471: 134260, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38678722

RESUMO

Pyrrolizidine alkaloids (PAs), released into the environment by donor plants, are absorbed by crops or transported by animals, posing a global food safety concern. Photolysis is an effective way to eliminate harmful substances in the environment or food. Photolysis happens as PAs move among plants, environment and crops. In this study, we first investigated the photolysis and hydrolysis of 15 PAs and identified their degradation products via ultra-high performance liquid chromatography and Q-Exactive Orbitrap mass spectrometry. PAs were degraded under UV radiation but minimally affected by visible light from a xenon lamp, and solvent pH had little impact on their photolysis. PAs were stable in neutral and acidic solutions but degraded by 50% within 24 h in alkaline conditions. The degradation products of PAs were mainly PAs/PANOs isomers and some minor byproducts. Cytotoxicity and computational analysis revealed isomers had similar toxicity, with minor products being less toxic. This study is a precursor for revealing the potential PAs degradation dynamics in the environment and food products, providing a reference for systematic evaluations of potential health and ecological risks of their degradation products.


Assuntos
Espectrometria de Massas , Fotólise , Alcaloides de Pirrolizidina , Alcaloides de Pirrolizidina/química , Alcaloides de Pirrolizidina/toxicidade , Cromatografia Líquida de Alta Pressão , Hidrólise , Raios Ultravioleta , Humanos
5.
Anal Sci ; 39(7): 1151-1161, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36947336

RESUMO

This work first proposed a novel green and efficient method based on Quick, Easy, Cheap, Efficient, Rugged, and Safe pretreatment (QuEChERS) combined with switchable hydrophilic solvent homogeneous liquid-liquid microextraction (SHS-HLLME) for trace determination of triazole fungicides (TFs) in agricultural products such as vegetables and fruits by gas chromatography-mass spectrometry (GC-MS). N,N-Dimethyl benzylamine was used for the synthesis of SHS. Box-Behnken design was applied for the optimization of extraction conditions and a mathematical model was obtained. Ultimately, 0.50 mL SHS, 1.0 mL 10 mol L-1 sodium hydroxide, and 45 s ultrasonic time were determined as optimal conditions for the SHS-HLLME method. The limit of detection and limit of quantification determined using the optimal method (SHS-HLLME/GC-MS) were 0.13-0.27 ng mL-1 and 0.43-0.90 ng mL-1, respectively. In addition, the SHS-HLLME method under optimal conditions was combined with the traditional QuEChERS method to realize the advancement of the SHS-HLLME method from simple to complex matrix analysis, and the QuEChERS-SHS-HLLME method was successfully applied to the analysis of TFs in cucumbers, tomatoes, watermelon and grapes in agricultural products. Matrix-matched calibration standards were used to improve the accuracy of TFs in spiked cucumber samples to obtain recovery results close to 100%. It was shown that the new method is green and rapid, enabling fast and inexpensive sample pretreatment with up to 100-fold enrichment factor and low detection limit compared with the original QuEChERS method.


Assuntos
Fungicidas Industriais , Microextração em Fase Líquida , Resíduos de Praguicidas , Praguicidas , Cromatografia Gasosa-Espectrometria de Massas/métodos , Praguicidas/análise , Solventes/química , Fungicidas Industriais/análise , Microextração em Fase Líquida/métodos , Resíduos de Praguicidas/análise
6.
Food Chem ; 411: 135486, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36682163

RESUMO

The existing QuEChERS-combined analytical pretreatment methods are limited by large reagent consumption, high environmental burden, and mediocre effects. To provide an efficient and green pretreatment method, this study developed pH-responsive switchable deep eutectic solvents (SDESs) to extract triazole fungicides (TFs) from fruit peel wastes, which could enhance the preconcentration effect of target compounds in food waste samples with complex matrices. The mechanisms of pH-induced phase transition and hydrophobicity-hydrophilicity conversion of pH-responsive SDESs were investigated by pH phase diagrams and chemical characterization techniques, respectively. We validated the established method by high-performance liquid chromatography-diode array detector (HPLC-DAD), and lower LOD (0.089-0.351 ng mL-1), LOQ (0.297-1.172 ng mL-1), RSD (≤8.8 %) and satisfactory recoveries (90.6 %-110.9 %) and preconcentration factors (389-512) were obtained in rotting grape peel, watermelon peel, and orange peel samples. Our findings highlight the potential of pH-responsive SDESs in the extraction and analysis of various natural food products.


Assuntos
Fungicidas Industriais , Microextração em Fase Líquida , Eliminação de Resíduos , Solventes Eutéticos Profundos , Triazóis , Alimentos , Solventes/química , Concentração de Íons de Hidrogênio , Microextração em Fase Líquida/métodos
7.
Mass Spectrom Rev ; 42(5): 1808-1827, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35638257

RESUMO

Traditional Chinese medicines (TCMs) have been widely used in clinical and healthcare applications around the world. The characterization of the phytochemical components in TCMs is very important for studying the therapeutic mechanism of TCMs. In the analysis process, sample preparation and instrument analysis are key steps to improve analysis performance and accuracy. In recent years, chromatography combined with mass spectrometry (MS) has been widely used for the separation and detection of trace components in complex TCM samples. This article reviews various sample preparation techniques and chromatography-MS techniques, including the application of gas chromatography-MS and liquid chromatography-MS and other MS techniques in the characterization of phytochemicals in TCM materials and Chinese medicine products. This article also describes a new ambient ionization MS method for rapid and high-throughput analysis of TCM components.

8.
Anal Methods ; 14(44): 4576-4582, 2022 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-36341556

RESUMO

Highly sensitive and specific detection of cancer markers (such as carcinoembryonic antigen) is very important for early diagnosis and treatment of cancer. Herein, we developed a label-free fluorescent aptamer biosensor based on the aggregation-induced emission (AIE) effect and hydroxycobalt oxide (CoOOH) platform, and used it to detect carcinoembryonic antigen (CEA) with high sensitivity and specificity. Fluorescent ionic liquid Compound B can combine with a CEA aptamer (CEA-Apt) through electrostatic attraction and hydrophobic interaction to form an ionic liquid/aptamer (CEA-Apt/B) complex and produce the AIE effect, thereby enhancing the fluorescence intensity of B. CEA-Apt/B was adsorbed on the surface of CoOOH when CoOOH was added to the buffer solution, and the fluorescence of B was quenched. After adding CEA to the solution, CEA-Apt/B bound to CEA and separated from the surface of CoOOH because CEA-Apt had stronger affinity for CEA, resulting in fluorescence recovery of B. In the level range of 0.67-10000 pg mL-1, the fluorescence recovery intensity of the sensor had an excellent linear relationship with the level of CEA, and its LOD was 0.2 pg mL-1 (S/N = 3). In addition, the sensor had good selectivity and can be directly used to detect CEA in human serum with high accuracy.


Assuntos
Aptâmeros de Nucleotídeos , Líquidos Iônicos , Humanos , Antígeno Carcinoembrionário/química , Aptâmeros de Nucleotídeos/química , Óxidos/química
9.
Toxins (Basel) ; 14(9)2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-36136571

RESUMO

Pyrrolizidine alkaloids (PAs) are common constituents of plants and have serious hepatotoxicity. Intermedine (Im) and lycopsamine (La) are two monoesters of PAs that frequently coexist in the PA-containing plants (e.g., comfrey and tea). The present study aimed to explore the combined hepatotoxicity and toxicity mechanism of the Im and La mixture. In vitro, the combined cytotoxicity of the Im and La mixture on human hepatocytes (HepD) was examined by CCK-8, colony formation, wound healing, and Annexin V/PI staining assays. The combination of Im and La inhibited the ability of HepD cells to proliferate, colonize, and migrate and induced hepatocytes apoptosis in a dose-dependent manner. In addition to significantly causing a burst of intracellular reactive oxygen species (ROS), mitochondrial apoptosis, and endoplasmic reticulum (ER) stress, the Im and La mixture can also cause an increase in intracellular Ca2+, triggering the PERK/eIF2α/ATF4/CHOP apoptosis pathway. This study provided the first direct evidence that the combined PAs induced hepatotoxicity through ER-mediated apoptosis. These results supplemented the basic toxicity data for the combined PAs and provided a new perspective for the risk assessment of combined PA toxicity.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Alcaloides de Pirrolizidina , Anexina A5 , Apoptose , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Estresse do Retículo Endoplasmático , Humanos , Alcaloides de Pirrolizidina/análise , Alcaloides de Pirrolizidina/toxicidade , Espécies Reativas de Oxigênio , Sincalida , Chá
10.
J Chromatogr A ; 1675: 463178, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35660318

RESUMO

A low matrix effect pretreatment method by Gas-liquid microextraction technique (GLME) combined with ultrasound assisted extraction (UAE-GLME) has been developed for fast analysis of 41 multi-class pesticides in different crop samples. Extraction and cleanup procedures were completed within 20 min, and the impact of matrix effects in potato, lentil, corn and soybean matrices were systematically evaluated. As high as 97.6% pesticides treated by UAE-GLME experienced low matrix effect, and up to 99% pesticides except parathion-methyl in lentil samples were categorized as medium matrix effect. Good trueness (recoveries of 61.3-115.8%) and precision (RSD≤20%) were demonstrated by the UAE-GLME method, with MLOQs ranged from 0.005 to 0.02 mg kg-1. This method detected 2-phenylphenol, pyrimethanil, triadimefon and tebuconazole in the range of 0.008-0.012 mg kg-1 in real food samples. The multiresidue analysis feature of GLME has been validated, which displays further potential for high-throughput determination of organic pollutants in foods with distinctive properties.


Assuntos
Poluentes Ambientais , Resíduos de Praguicidas , Praguicidas , Produtos Agrícolas/química , Poluentes Ambientais/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Praguicidas/análise , Extração em Fase Sólida/métodos
11.
Anal Methods ; 14(12): 1187-1193, 2022 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-35230360

RESUMO

A new method was developed for the determination of three triazole fungicides in environmental water samples by gas chromatography-mass spectrometry (GC-MS) based on ultrasonic assisted switchable hydrophilic solvent homogeneous liquid-liquid microextraction. As a switchable hydrophilic solvent, N,N-dimethylcyclohexylamine (DMCHA) does not require a dispersant or centrifugation. Ultrasound assistance is helpful to speed up the extraction of target compounds and can reduce the pretreatment time. The entire pretreatment process of this method only takes 5 minutes. Using the Box-Behnken design as the means of optimization, optimal extraction conditions were obtained through a mathematical model. Good linearity was obtained in the range of 5-500 µg L-1, and the correlation coefficient of target compounds was greater than 0.999. The matrix spiked recoveries were between 81.3% and 111.1% and the detection limit was between 0.46 and 0.99 µg L-1. Intraday relative standard deviation (n = 3) was 13.0-13.9% at 100 µg L-1. Finally, it was concluded that the method is a rapid, efficient and simple method for the analysis of triazole fungicides in water.


Assuntos
Fungicidas Industriais , Microextração em Fase Líquida , Fungicidas Industriais/análise , Cromatografia Gasosa-Espectrometria de Massas , Microextração em Fase Líquida/métodos , Solventes/química , Triazóis/análise , Água/análise
12.
Food Chem ; 373(Pt B): 131512, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-34772573

RESUMO

A novel composite material consisting of zirconiumbiphenyldicarboxylate metal-organic framework, graphite oxide and ferroferric oxide was fabricated by a facile one-step method and served as a magnetic solid phase extraction sorbent for the simultaneous determination of nitroimidazoles and benzimidazoles in honey. The amount of graphite oxide for the synthesis of composite material and analysis parameters were optimized. The optimum parameters were: dipotassium hydrogen phosphate buffer solution (pH 6) as diluent solvent, adsorption time 10 min, desorption time 5 min, methanol/acetonitrile (1:1, V/V) as desorption solvent. The targets were detected by ultra-high performance liquid chromatography tandem mass spectrometry. The recoveries of twelve analytes ranged in 70.5%-103.4% with relative standard deviations lower than 12.9% (n = 3). The quantification limits were 0.2-0.6 µg/kg. Using the composite material as sorbent, a simple, rapid and environmental-friendly method based on magnetic solid phase extraction was successfully developed for determination of seven nitroimidazoles and five benzimidazoles in honey.


Assuntos
Mel , Estruturas Metalorgânicas , Nitroimidazóis , Benzimidazóis , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Mel/análise , Fenômenos Magnéticos , Nitroimidazóis/análise , Extração em Fase Sólida , Espectrometria de Massas em Tandem
13.
Food Chem ; 368: 130771, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34438181

RESUMO

The stable isotope and photosynthesis response of tea (Camellia sinensis) is determined under different light and temperature conditions. The results showed that isotopes of young tea leaves were more enriched with increasing light intensity (31 ~ 411 µmol m-2∙s-1). However, the value of δ13C and δ15N seemed depleted, while δ2H and δ18O became enriched as temperature increasing from 15 to 35 °C. Significant isotope differences were found in tea leaves harvested between early growth (0 ~ 10 days) and later growth (10 ~ 21 days) periods (p < 0.05). Pearson's correlation showed a negative correlation between isotopes (δ13C, δ15N and δ2H) and photosynthetic parameters (EVAP and CI) ranging from 0.497 to 0.872, under 25 °C/203 µmol m-2∙s-1. But δ18O had a weak correlation with all photosynthetic parameters under the same conditions. These distinctive correlations between isotopes and photosynthetic parameters provide new insights which could be used to predict tea isotope responses arising from subtle seasonal or climate change conditions.


Assuntos
Camellia sinensis , Fotossíntese , Isótopos de Carbono/análise , Isótopos , Folhas de Planta/química , Chá , Temperatura
14.
J Oleo Sci ; 70(10): 1481-1494, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34497174

RESUMO

In the past decade, natural deep eutectic solvents (NADESs) as green and sustainable extraction solvents with great potential for the efficient extraction of bioactive compounds from the plants are emerging. In this study, a microwave-assisted technology is used to prepare natural deep eutectic solvents. And natural deep eutectic solvents as pretreatment solvents coupled with microwave-assisted hydrodistillation (MAHD) for isolating essential oil (EO) derived from turmeric (Curcuma longa L.) is investigated. To improve the essential oil yield of turmeric (Curcuma longa L.) as a target, various factors affecting extraction efficiency including the type and amount of natural deep eutectic solvents, pretreatment time, pretreatment temperature and hydrodistillation (HD) time are discussed and optimized through central composite design (CCD) of the response surface methodology (RSM). The optimal conditions are as follows: natural deep eutectic solvent composed of choline chloride and oxalic acid (molar ratio with 1:1) as a pretreatment solvent, an amount of 60 g, a pretreatment time of 5 min, a pretreatment temperature of 84 ºC, a hydrodistillation time of 76 min. Under the optimum conditions, the highest essential oil yield of 0.85% is achieved. Additionally, the essential oil is analyzed by using gas chromatography-mass spectrometry (GC-MS), with a total of 49 compounds being identified. Through combining natural deep eutectic solvents with a microwave-assisted hydrodistillation technique, this work provides an eco-friendly extraction way of isolating essential oil, which boosts development in the monitoring other spice quality field.


Assuntos
Curcuma/química , Solventes Eutéticos Profundos/química , Destilação/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Extração Líquido-Líquido/métodos , Micro-Ondas , Óleos Voláteis/análise , Colina/química , Óleos Voláteis/isolamento & purificação , Ácido Oxálico/química , Temperatura , Fatores de Tempo
15.
J Chromatogr A ; 1651: 462338, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34153735

RESUMO

ß-Cyclodextrin can be functionalized by derivation of reactive hydroxyl on the ring due to its special chiral environment and structural characteristics, which can be used to identify or separate a variety of chiral substance. In this manuscript, a series of excellent chiral stationary phases for high-performance liquid chromatography were developed for enantioseparation by using anhydride modified ß-cyclodextrin bearing chiral (R/S)-α-phenethylamine or (S)-(+)-2-amino-1-propanol. They were characterized by elemental analysis, Fourier transform infrared spectra (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and BET. These chiral stationary phases presented good resolution and repeatability, about 17 kinds of enantiomers were effectively separated. And most of enantiomers were separated better than those reported in the literature in the same both normal and reversed phase modes. The RSD values of Rs for repeatability and column-to-column were below 0.44% and 2.83%, respectively. All results revealed that these new CSPs show great prospect for chiral separation in actual applications.


Assuntos
Anidridos/química , Cromatografia Líquida/métodos , beta-Ciclodextrinas/química , Cromatografia Líquida de Alta Pressão/métodos , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo
16.
Food Chem ; 353: 129429, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33714121

RESUMO

The mechanistic insights into the oral pungency of capsaicin-related dietary components have been elucidated from the spatial structural perspectives by establishing statistically significant and highly predictive three-dimensional quantitative structure-property relationship models. Our results visualized the possible favorable and unfavorable steric and electrostatic interactions with the pungent receptors with the assistance of pharmacophore models, and revealed the suitable electronegative/positive or bulky substitutions in the vanillyl group, amide moiety, linear alkyl chain and their adjacent structural area of capsaicin required for the desired pungency, which was not only complementary to the viewpoints proposed in our previous structure-pungency correlations, but also was applied to clearly clarify the pungent differences in compounds, and well predict the pungency of 21 capsaicin analogs though with ambiguous experimental data on pungency. Hopefully, this work would benefit the overall understanding of the pungent mechanism and facile discovery/design of analogs with desired pungency to expand their applications in foods.


Assuntos
Capsaicina/química , Análise de Alimentos/métodos , Capsaicina/análise , Dieta , Humanos , Relação Quantitativa Estrutura-Atividade , Eletricidade Estática
17.
Talanta ; 225: 121987, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592735

RESUMO

Separation and identification of chiral enantiomers play an increasingly important role in many fields like pharmaceutical production, preparation of chemical intermediates and biochemistry. Although there are multiple methods for obtaining a single enantiomer, chiral chromatographic separation is still considered to be one of the most efficient methods. Among the numerous chiral separation materials, cellulose and its derivatives, with strong chiral recognition ability, large loading capacity and easy to functionalization, have been presented excellent enantioseparation performance, which reveals their great prospect in chiral separation. In this review, the types of cellulose derivatives, preparation of cellulose-functionalized chiral stationary phases and their application in chiral chromatographic separation in recent years were systematically summarized, and we hope to provide a useful reference for researchers working in chiral separation and inspire new discoveries in the field of cellulose-functionalized chiral separation materials.


Assuntos
Celulose , Cromatografia Líquida de Alta Pressão , Estereoisomerismo
18.
Food Chem ; 346: 128920, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33387836

RESUMO

A high-throughput method using a new ZIF-8@GO thin-film microextraction coating was established for determining macrolides and lincosamides in honey. The coating preparation parameters (ZIF-8@GO synthesis conditions, coating material proportions, dipping time) and analysis parameters (sample diluent solvent, adsorption and desorption conditions using the ZIF-8@GO coating) were optimized. The optimized parameters were: diluent solvent sodium carbonate/sodium bicarbonate buffer solution (pH 9), adsorption time 45 min, desorption time 5 min, desorption solvent 45:40:15 v/v/v methanol/acetonitrile/water. The extracted targets were determined by ultra-high performance liquid chromatography tandem mass spectrometry. The recoveries of 10 analytes were 67.5-107.2% and the detection and quantification limits were 0.1-0.4 and 0.4-1.4 µg/kg, respectively. The method could analyze 96 samples per run. The minimal manual time and effort is required since the bulk of the sample processing is fully automated. It was a useful and efficient method for monitoring drug residues and was successfully used to analyze real samples.


Assuntos
Antibacterianos/análise , Mel/análise , Lincosamidas/análise , Microextração em Fase Líquida/métodos , Macrolídeos/análise , Acetonitrilas , Cromatografia Líquida de Alta Pressão/métodos , Limite de Detecção , Espectrometria de Massas em Tandem/métodos
19.
Sci Total Environ ; 752: 141924, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32898803

RESUMO

E-waste recycling is well known for releasing halogenated organic compounds (HOCs) and heavy metals. This study investigated the occurrence and distribution of traditional and novel classes of contaminants, including chlorinated, brominated, and mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and polyhalogenated carbazoles (PHCZs), in soil from an e-waste disposal site in Hangzhou. PBDEs were the most abundant, at 343-69306 ng kg-1, followed by PHCZs (896-41,362 ng kg-1), PCDD/Fs (349-19,396 ng kg-1), PCBs (51.3-1834 ng kg-1), PBDD/Fs (2.99-524 ng kg-1) and PXDD/Fs (0.104-21.2 ng kg-1). The detected target compound concentrations were generally lower than those reported in the literature for informal e-waste sites. Nevertheless, they can serve as a basis of information for evaluation and subsequent control. The toxic equivalent (TEQ) contributions from these contaminants (except PBDEs) decreased as follows: PCDD/Fs > PXDD/Fs > PHCZs > PCBs > PBDD/Fs. ΣDioxins (PCDD/Fs + PBDD/Fs + PXDD/Fs) accounted for 47.7%-97.2% of the total TEQs in the soil. OCDD, 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from combustion and transport because of their low saturated vapor pressure. PXDFs were more abundant than PXDDs, and homologue profiles suggested a similar formation mechanism for PXDFs and PBDFs involving successive Br-to-Cl exchange. PHCZs were reported in soil from an e-waste disposal area for the first time, and their concentrations were several orders of magnitude higher than those of the other contaminants. Although the risk of human exposure in this study was estimated to be lower than the values recommended by the WHO (1-4 pg TEQ/kg bw/day), health implications still exist, and further investigations are necessary.

20.
J Mater Chem B ; 8(41): 9555-9565, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33001126

RESUMO

Aminated poly(glycidyl methacrylate)s-based polymers for gene delivery not only can reduce toxicity and improve solubility, but can improve gene transfection efficiency and reduce protein aggregation. In this study, we first prepared poly(glycidyl methacrylate) (PGMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization, and then the obtained PGMA homopolymer was post-modified with ethanol amine (EA), 1-amino-2-propanol (AP), 3-(dibutylamino)propylamine (DA) and N-(2-hydroxyethyl)ethylenediamine (HA), respectively, to yield four kinds of PGMA-based gene vectors containing hydroxyl groups (abbreviated as PGEA, PGAP, PGDA and PGHA). The effects of the different side chains and hydroxyl groups on the biological properties of these four cationic polymers were investigated. We found that the transfection efficiency of the PGHA/p53 complex was higher than those of the other three polymer/gene complexes through MTT assay and laser scanning confocal microscopy. Hence, we chose HA for further post-modification to fabricate a cationic copolymer, PCL-ss-P(PEGMA-co-GHA) (abbreviated as PGHAP), via a combination of ring opening polymerization (ROP) and RAFT copolymerization. The PCL-ss-P(PEGMA-co-GHA) amphiphilic copolymer could self-assemble into nanoparticles, which could be used to encapsulate anticancer drug doxorubicin (DOX) and compress the p53 gene to form the DOX-loaded PCL-ss-P(PEGMA-co-GHA)/p53 complex (abbreviated as DPGHAP/p53). The gel retardation assay showed that p53 gene could be well immobilized and remained stable under the electronegative conditions. MTT assay showed that the DPGHAP/p53 complex had a significant antitumor effect on A549 cells and H1299 cells compared with free DOX or/and p53 gene therapy alone. Furthermore, the test results from live cell imaging systems revealed that the DPGHAP/p53 complexes could effectively deliver DOX and the p53 gene into A549 cells. Therefore, the constructed cationic polymer PCL-ss-P(PEGMA-co-GHA) has potential application prospects as a co-vector of anticancer drugs and genes.


Assuntos
Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Portadores de Fármacos/química , Técnicas de Transferência de Genes , Ácidos Polimetacrílicos/química , Proteína Supressora de Tumor p53/genética , Células A549 , Aminação , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Genes p53 , Terapia Genética , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/terapia , Transfecção/métodos
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