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1.
Electrophoresis ; 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38794968

RESUMO

This study introduces a novel method for the quantification of malachite green (MG), a pervasive cationic dye, in surface water by synergizing multiphase electroextraction (MPEE) with digital image analysis (DIA) and partial least square discriminant analysis. Aimed at addressing the limitations of conventional DIA methods in terms of quantitation limits and selectivity, this study achieves a significant breakthrough in the preconcentration of MG using magnesium silicate as a novel sorbent. Demonstrating exceptional processing efficiency, the method allows for the analysis of 10 samples within 20 min, exhibiting remarkable sensitivity and specificity (over 0.95 and 0.90, respectively) across 156 samples in both training and test sets. Notably, the method detects MG at low concentrations (0.2 µg L-1) in complex matrices, highlighting its potential for broader application in environmental monitoring. This approach not only underscores the method's cost-effectiveness and simplicity but also its precision, making it a valuable tool for the preliminary testing of MG in surface waters. This study underscores the synergy among MPEE, DIA, and chemometric tools, presenting a cost-efficient and reliable alternative for the sensitive detection of water contaminants.

2.
J Sep Sci ; 47(5): e2300865, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38471971

RESUMO

A novel coating for stir bar sorptive extraction was developed by growing a covalent organic framework, TpPa-1 (derived from phenylenediamine and 1,3,5-trimethylphloroglucinol), onto the surface of Ni-Al layered double hydroxide. Using a poly(ether ether ketone) tube as the supporting substrate, a TpPa-1/layered double hydroxide-coated stir bar was fabricated and demonstrated excellent extraction performance for Sudan dyes. Notably, its extraction efficiency significantly exceeded that of stir bars modified with only TpPa-1 or Ni-Al layered double hydroxide. Based on this innovative coating, a stir bar sorptive extraction-high performance liquid chromatography method was established. This method exhibited low limits of detection (0.04-0.08 ng/mL) for the analysis of Sudan dyes. It also featured a wide linear range (0.25-100 or 200 ng/mL) and demonstrated good repeatability with relative standard deviations ≤6.22%. The recoveries obtained for spiked lake water and chili powder samples were 93.5%-105.2% and 87.8%-100.6%, respectively, demonstrating the practical potential of the developed method for detecting trace Sudan dyes in real samples.

3.
Sensors (Basel) ; 24(2)2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38257570

RESUMO

Currently, it is necessary to maintain the quality of aquifers and water bodies, which means the need for sensors that detect molecules as emerging pollutants (EPs) at low concentrations in aqueous complex solutions. In this work, an electronic tongue (e-tongue) prototype was developed to detect 17ß-estradiol in tap water. To achieve such a prototype, an array of sensors was prepared. Each sensor consists of a solid support with interdigitated electrodes without or with thin films prepared with graphene oxide, nanotubes, and other polyelectrolytes molecules adsorbed on them. To collect data from each sensor, impedance spectroscopy was used to analyze the electrical characteristics of samples of estrogen solutions with different concentrations. To analyze the collected data from the sensors, principal components analysis (PCA) method was used to create a three-dimensional plane using the calculated principal components, namely PC1 and PC2, and the estrogen concentration values. Then, damped least squares (DLS) was used to find the optimal values for the hyperplane calibration, as the sensitivity of this e-tongue was not represented by a straight line but by a surface. For the collected data, from nanotubes and graphene oxide sensors, a calibration curve for concentration given by the 10PC1×0.492-PC2×0.14-14.5 surface was achieved. This e-tongue presented a detection limit of 10-16 M of 17ß-estradiol in tap water.


Assuntos
Grafite , Nanotubos de Carbono , Polieletrólitos , Estradiol , Estrogênios , Língua , Água
4.
J Environ Manage ; 368: 122211, 2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39182376

RESUMO

The crucial role of Rare Earth Elements (REEs) in the development of hi-tech in addition to their limited availability have urged countries to develop sustainable alternatives to their conventional primary sources (ore mining). Sorption technologies using magnetic materials such as spinel ferrite nanoparticles provide efficient removal of REEs from contaminated solutions and ease of separation through application of an external magnetic field. However, there is still limited knowledge available regarding the optimal operational conditions in which to use these materials, especially in complex aqueous mixtures with different REEs. In this study, we have used Surface Response Methodology (SRM) applied to MnFe2O4 nanosorbents to identify their ideal sorption conditions of pH (4-8), REEs concentration (1-5 µM) and sorbent mass (20-180 mg L-1) in a mixture of nine REEs in water samples of distinct salinity (NaCl: 0-30 g L-1). Our results indicated that high pH favored REEs sorption because of the material's surface charge, which promoted interactions with REEs ions at pH 6-8. Yttrium was the least removed element, but total removal was achieved for lowest REEs concentration using 151 mg L-1 of sorbent. High removals were also obtained for the concentration of 5 µM (100 % removal, except for Y and La). Salinity did not impair sorption significantly (<10 %), which was owed to the high sorbent mass used in those assays. An increase in sorbent mass and initial REEs concentration also promoted faster kinetics. The spinel type MnFe2O4 nanoparticles showed great promise in a realistic application, which is the next proposed step in this line of research.

5.
Molecules ; 29(14)2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-39064836

RESUMO

Genotoxic substances widely exist in the environment and the food supply, posing serious health risks due to their potential to induce DNA damage and cancer. Traditional genotoxicity assays, while valuable, are limited by insufficient sensitivity, specificity, and efficiency, particularly when applied to complex food matrices. This study introduces a multiparametric high-content analysis (HCA) for the detection of genotoxic substances in complex food matrices. The developed assay measures three genotoxic biomarkers, including γ-H2AX, p-H3, and RAD51, which enhances the sensitivity and accuracy of genotoxicity screening. Moreover, the assay effectively distinguishes genotoxic compounds with different modes of action, which not only offers a more comprehensive assessment of DNA damage and the cellular response to genotoxic stress but also provides new insights into the exploration of genotoxicity mechanisms. Notably, the five tested food matrices, including coffee, tea, pak choi, spinach, and tomato, were found not to interfere with the detection of these biomarkers under proper dilution ratios, validating the robustness and reliability of the assay for the screening of genotoxic compounds in the food industry. The integration of multiple biomarkers with HCA provides an efficient method for detecting and assessing genotoxic substances in the food supply, with potential applications in toxicology research and food safety.


Assuntos
Dano ao DNA , Testes de Mutagenicidade , Mutagênicos , Mutagênicos/análise , Mutagênicos/toxicidade , Testes de Mutagenicidade/métodos , Humanos , Análise de Alimentos/métodos , Chá/química , Biomarcadores , Solanum lycopersicum/química , Histonas/metabolismo , Histonas/análise , Café/química , Spinacia oleracea/química , Rad51 Recombinase/metabolismo
6.
J Nanobiotechnology ; 21(1): 97, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36941596

RESUMO

Assessing the antimicrobial activity of engineered nanomaterials (ENMs), especially in realistic scenarios, is of great significance for both basic research and applications. Multiple analytical methods are available for analysis via off-line or on-line measurements. Real-world samples are often complex with inorganic and organic components, which complicates the measurements of microbial viability and/or metabolic activity. This article highlights the recent advances achieved in analytical methods including typical applications and specifics regarding their accuracy, cost, efficiency, and user-friendliness. Methodological drawbacks, technique gaps, and future perspectives are also discussed. This review aims to help researchers select suitable methods for gaining insight into antimicrobial activities of targeted ENMs in artificial and natural complex matrices.


Assuntos
Anti-Infecciosos , Nanoestruturas , Nanoestruturas/análise , Anti-Infecciosos/farmacologia
7.
J Sep Sci ; 46(19): e2300205, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37525342

RESUMO

The development of novel sample preparation media plays a crucial role in pharmaceutical analysis. To facilitate the extraction and enrichment of pharmaceutical molecules in complex samples, various functionalized materials have been developed and prepared as adsorbents. Recently, some functionalized porous organic materials have become adsorbents for pharmaceutical analysis due to their unique properties of adsorption and recognition. These advanced porous organic materials, combined with consequent analytical techniques, have been successfully used for pharmaceutical analysis in complex samples such as environmental and biological samples. This review encapsulates the progress of advanced porous materials for pharmaceutical analysis including pesticides, antibiotics, chiral drugs, and other compounds in the past decade. In addition, we also address the limitations and future trends of these porous organic materials in pharmaceutical analysis.


Assuntos
Manejo de Espécimes , Porosidade , Adsorção , Preparações Farmacêuticas
8.
Mikrochim Acta ; 190(12): 476, 2023 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-37993653

RESUMO

There is an urgent need for the harmonization of critical parameters in single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) and they have been deeply studied and optimized in the present work using platinum nanoparticles (PtNPs) as a representative case of study. Special attention has been paid to data processing in order to achieve an adequate discrimination between signals. Thus, a comparison between four different algorithms has been performed and the method for transport efficiency calculation has also been thorougly evaluated (finding the use of a well-characterized solution of the same targeted analyte (30 nm PtNPs) as adequate). The best results have been obtained after the application of a deconvolution approach for the data processing and using 5 ms as dwell time and 40,000 data points for data acquisition. Under the optimized conditions, a correct discrimination between NP events and background signal up to 100 or 750 ng L-1 of added ionic Pt was reached for 30 and 50 nm PtNPs, respectively. The suitability of the developed method for the characterization of PtNPs in relevant environmental (water samples) and biological (cell culture media) matrices has also been demonstrated.


Assuntos
Nanopartículas Metálicas , Nanopartículas Metálicas/química , Espectrometria de Massas/métodos , Platina/química , Análise Espectral
9.
Anal Bioanal Chem ; 414(14): 4245-4254, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35426494

RESUMO

Lateral flow assays (LFAs) widely deployed for on-site diagnosis have predominantly utilized antibodies as recognition molecules. Antibodies with limited thermal stability deteriorate the performance of the LFA over time. Herein, we demonstrate a stable and robust LFA by utilizing thermally stable peptide-based 12-14 kDa affimers as recognition molecules, in lieu of conventional protein-based antibodies to analyze complex samples with a significantly improved shelf life at room temperature. The model system studied here is that of interleukin-8 (IL8) biomarker for validating the efficacy of the proposed approach, using a pair of affimer probes that demonstrates dual functionality of capturing and reporting. Affimers immobilized on the test zone of LFA serve as capture probes for IL8-affimer-MB complexes. Whereas affimers conjugated with the MBs that enable extraction of IL8 from the sample matrix serve as reporters for visual detection. The MB complexes captured at the test zone resulted in brownish test bands that enable concentration-dependent detection of IL8. The assay yielded sensitive visual detection of IL8 at ng/mL levels (~ 0.1 ng/mL and 1 ng/mL in buffer and human plasma, respectively), within 20 min, using sample volumes of ~ 100 µL. Importantly, the stability of affimer-incorporated LFA improved significantly in contrast to antibody-incorporated LFA over time, even when stored at 4 °C. Therefore, the proposed affimer-based LFA in conjunction with MBs offer stable and reliable detection of biomarkers at clinically relevant concentration ranges in complicated matrices, even without requiring cold storage, hence, offering a promising avenue for on-site diagnosis in resource-limited settings.


Assuntos
Bioensaio , Interleucina-8 , Anticorpos , Bioensaio/métodos , Biomarcadores , Humanos , Imunoensaio/métodos , Peptídeos
10.
J Sep Sci ; 45(13): 2273-2300, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35389521

RESUMO

Mycotoxin contamination is a globally concerned problem for food and agricultural products since it may directly or indirectly induce severe threats to human health. Sensitive and selective screening is an efficient strategy to prevent or reduce human and animal exposure to mycotoxins. However, enormous challenges exist in the determination of mycotoxins, arising from complex sample matrices, trace-level analytes, and the co-occurrence of diverse mycotoxins. Appropriate sample preparation is essential to isolate, purify, and enrich mycotoxins from complicated matrices, thus decreasing sample matrix effects and lowering detection limits. With the cross-disciplinary development, new solid-phase extraction strategies have been exploited and integrated with nanotechnology to meet the challenges of mycotoxin analysis. This review summarizes the advance and progress of solid-phase extraction techniques as the methodological solutions for mycotoxin analysis. Emphases are paid on nanomaterials fabricated as trapping media of solid-phase extraction techniques, including carbonaceous nanoparticles, metal/metal oxide-based nanoparticles, and nanoporous materials. Advantages and limitations are discussed, along with the potential prospects.


Assuntos
Micotoxinas , Nanoestruturas , Animais , Contaminação de Medicamentos , Alimentos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Humanos , Micotoxinas/análise , Nanoestruturas/análise , Extração em Fase Sólida
11.
Environ Sci Technol ; 55(13): 8753-8759, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34110808

RESUMO

Identification of nanoplastics in complex environmental matrices remains a challenge. Despite the increase in nanoplastics studies, there is a lack of studies dedicated to nanoplastics detection, partially explained by their carbon-based structure, their wide variety of composition, and their low environmental concentrations compared to the natural organic matter. Here, pyrolysis coupled to a GCMS instrumental setup provided a relevant analytical response for polypropylene and polystyrene nanoplastic suspensions. Specific pyrolysis markers and their indicative fragment ions were selected and validated. Possible interferences with environmental matrices were explored by spiking nanoplastics in various organic matter suspensions (i.e., algae, soil natural organic matter, and soil humic acid) and analyzing an environmental suspension of nanoplastics. While a rapid polypropylene nanoplastics identification was validated, polystyrene nanoplastics require preliminary treatment. The strategies presented herein open new possibilities for the detection/identification of nanoplastics in environmental matrices such as soil, dust, and biota.


Assuntos
Microplásticos , Poliestirenos , Substâncias Húmicas , Polipropilenos , Solo
12.
Anal Bioanal Chem ; 413(20): 5201-5213, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34228133

RESUMO

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was established for simultaneous quantification of eight pharmaceutical molecules (2-hydroxyibuprofen, diclofenac, ibuprofen, propranolol, ofloxacin, oxazepam, sulfamethoxazole, carbamazepine) and caffeine in environmental matrices. Analysis was performed by ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS-MS). Quantification was performed by using the 13C internal standard method for each molecule. Two methods were firstly optimized on freeze-dried waste activated sludge and then applied and validated on real complex matrices, which have contrasted physicochemical properties, i.e., clarified wastewater and primary sludge. The combination of acetate buffer with MgSO4 (protocol A) and citrate buffer with Na2SO4 (protocol B) was found necessary to recover the nine targeted compounds. Adding a higher salts quantity of Na2SO4 (protocol B) compared to MgSO4 (protocol A) is crucial to increase the ionic strength of the aqueous solution and to obtain comparable extraction recoveries of the targeted molecules. Adding two times solvent volume to the aqueous phase leads to increased absolute recovery for all molecules and both protocols. After demonstration of the final protocol's performance on the control matrix, its robustness was tested on the matrices of interest. As a result, the two proposed detection methods exhibit good reproducibility, high sensitivity, and high reliability.

13.
Molecules ; 26(11)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071301

RESUMO

The new screening method for rapid evaluation of major phenolic compounds in apples has been developed. Suitability of coupling HPLC/UHPLC separation with the diode-array detection and universal charged aerosol detection with respect to the presence of interfering substances was tested. Characteristics of both detection techniques were compared and method linearity, limits of detection and quantitation, and selectivity of them determined. Student t-test based on slopes of calibration plots was applied for the detailed comparison. The diode-array detection provided the best results regarding sensitivity and selectivity of the developed method in terms of evaluation of phenolics profiles. The response of the charged aerosol detector was negatively affected by co-eluting substances during rapid-screening analyses. Coulometric detection was used for advanced characterization of extracts in terms of antioxidant content and strength to obtain more complex information concerning sample composition. This detection also allowed evaluation of unidentified compounds with antioxidant activity. HPLC/UHPLC separation using a combination of diode-array and coulometric detectors thus represented the best approach enabling quick, yet complex characterization of bioactive compounds in apples.


Assuntos
Aerossóis/química , Cromatografia Líquida de Alta Pressão/métodos , Eletroquímica/métodos , Malus/metabolismo , Antioxidantes/química , Calibragem , Cromatografia/métodos , Tecnologia de Alimentos , Limite de Detecção , Fenol/química , Fenóis/análise , Reprodutibilidade dos Testes
14.
J Sep Sci ; 43(12): 2477-2486, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32233066

RESUMO

Arginase represents a promising therapeutic target for various pathologies including inflammatory, cardiovascular, and parasitic diseases or cancers. In the current work, we report, for the first time, about the development of a thin-layer chromatography-based bioautography which can be used to rapidly detect arginase inhibitors in complex matrices such as plant extracts. The assay is based on the detection of urea produced by arginase using the coloring reagent α-isonitrosopropiophenone, resulting in the formation of a pink background on thin-layer chromatography plates. The assay conditions were optimized in order to provide sufficient contrast between the pink colored thin-layer chromatography plate and the clearer zones generated by the presence of arginase inhibitors. Different parameters were tested, such as incubation time and temperature, atmospheric conditions, as well as substrate and enzyme concentrations. This technique makes it possible to detect 0.1 µg of a known arginase inhibitor, Nω -hydroxy-nor-Arginine, after it has been spotted, either pure or mixed with a Myrtus communis methanolic fruit extract, and the plate has been developed in an appropriate solvent. The newly developed method was used to reveal the presence of an inhibitor in hempseed cakes (Cannabis sativa L.).


Assuntos
Arginina/análogos & derivados , Automação Laboratorial , Inibidores Enzimáticos/análise , Extratos Vegetais/análise , Arginase/antagonistas & inibidores , Arginase/metabolismo , Arginina/análise , Arginina/farmacologia , Cannabis/enzimologia , Cromatografia em Camada Fina , Inibidores Enzimáticos/farmacologia , Frutas/química , Myrtus/química , Extratos Vegetais/farmacologia
15.
Anal Bioanal Chem ; 408(1): 23-33, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26670771

RESUMO

Where does flow injection analysis mass spectrometry (FIA-MS) stand relative to ambient mass spectrometry (MS) and chromatography-MS? Improvements in FIA-MS methods have resulted in fast-expanding uses of this technique. Key advantages of FIA-MS over chromatography-MS are fast analysis (typical run time <60 s) and method simplicity, and FIA-MS offers high-throughput without compromising sensitivity, precision and accuracy as much as ambient MS techniques. Consequently, FIA-MS is increasingly becoming recognized as a suitable technique for applications where quantitative screening of chemicals needs to be performed rapidly and reliably. The FIA-MS methods discussed herein have demonstrated quantitation of diverse analytes, including pharmaceuticals, pesticides, environmental contaminants, and endogenous compounds, at levels ranging from parts-per-billion (ppb) to parts-per-million (ppm) in very complex matrices (such as blood, urine, and a variety of foods of plant and animal origin), allowing successful applications of the technique in clinical diagnostics, metabolomics, environmental sciences, toxicology, and detection of adulterated/counterfeited goods. The recent boom in applications of FIA-MS for high-throughput quantitative analysis has been driven in part by (1) the continuous improvements in sensitivity and selectivity of MS instrumentation, (2) the introduction of novel sample preparation procedures compatible with standalone mass spectrometric analysis such as salting out assisted liquid-liquid extraction (SALLE) with volatile solutes and NH4(+) QuEChERS, and (3) the need to improve efficiency of laboratories to satisfy increasing analytical demand while lowering operational cost. The advantages and drawbacks of quantitative analysis by FIA-MS are discussed in comparison to chromatography-MS and ambient MS (e.g., DESI, LAESI, DART). Generally, FIA-MS sits 'in the middle' between ambient MS and chromatography-MS, offering a balance between analytical capability and sample analysis throughput suitable for broad applications in life sciences, agricultural chemistry, consumer safety, and beyond.


Assuntos
Análise de Injeção de Fluxo/tendências , Ensaios de Triagem em Larga Escala/tendências , Espectrometria de Massas/tendências , Análise de Injeção de Fluxo/métodos , Ensaios de Triagem em Larga Escala/métodos , Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Preparações Farmacêuticas/análise
16.
Angew Chem Int Ed Engl ; 53(52): 14503-7, 2014 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-25384839

RESUMO

Coated blade spray (CBS) is a technology based on solid-phase microextraction (SPME) that has been designed for the quick extraction/cleanup of analytes from complex matrices and direct desorption/ionization under ambient mass spectrometry conditions. The entire analytical process can be completed in less than 3 min and enables limits of quantitation in the low picogram-per-milliliter region to be reached.

17.
Toxins (Basel) ; 16(6)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38922132

RESUMO

Ricin and abrin are highly potent plant-derived toxins, categorized as type II ribosome-inactivating proteins. High toxicity, accessibility, and the lack of effective countermeasures make them potential agents in bioterrorism and biowarfare, posing significant threats to public safety. Despite the existence of many effective analytical strategies for detecting these two lethal toxins, current methods are often hindered by limitations such as insufficient sensitivity, complex sample preparation, and most importantly, the inability to distinguish between biologically active and inactive toxin. In this study, a cytotoxicity assay was developed to detect active ricin and abrin based on their potent cell-killing capability. Among nine human cell lines derived from various organs, HeLa cells exhibited exceptional sensitivity, with limits of detection reaching 0.3 ng/mL and 0.03 ng/mL for ricin and abrin, respectively. Subsequently, toxin-specific neutralizing monoclonal antibodies MIL50 and 10D8 were used to facilitate the precise identification and differentiation of ricin and abrin. The method provides straightforward and sensitive detection in complex matrices including milk, plasma, coffee, orange juice, and tea via a simple serial-dilution procedure without any complex purification and enrichment steps. Furthermore, this assay was successfully applied in the unambiguous identification of active ricin and abrin in samples from OPCW biotoxin exercises.


Assuntos
Abrina , Anticorpos Neutralizantes , Ricina , Ricina/imunologia , Ricina/toxicidade , Ricina/análise , Abrina/imunologia , Abrina/toxicidade , Humanos , Anticorpos Neutralizantes/imunologia , Anticorpos Monoclonais/imunologia , Animais
18.
J Pharm Anal ; 14(3): 416-426, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38618244

RESUMO

The comprehensive detection and identification of active ingredients in complex matrices is a crucial challenge. Liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) is the most prominent analytical platform for the exploration of novel active compounds from complex matrices. However, the LC-HRMS-based analysis workflow suffers from several bottleneck issues, such as trace content of target compounds, limited acquisition for fragment information, and uncertainty in interpreting relevant MS2 spectra. Lycibarbarspermidines are vital antioxidant active ingredients in Lycii Fructus, while the reported structures are merely focused on dicaffeoylspermidines due to their low content. To comprehensively detect the new structures of lycibarbarspermidine derivatives, a "depict" strategy was developed in this study. First, potential new lycibarbarspermidine derivatives were designed according to the biosynthetic pathway, and a comprehensive database was established, which enlarged the coverage of lycibarbarspermidine derivatives. Second, the polarity-oriented sample preparation of potential new compounds increased the concentration of the target compounds. Third, the construction of the molecular network based on the fragmentation pathway of lycibarbarspermidine derivatives broadened the comprehensiveness of identification. Finally, the weak response signals were captured by data-dependent scanning (DDA) followed by parallel reaction monitoring (PRM), and the efficiency of acquiring MS2 fragment ions of target compounds was significantly improved. Based on the integrated strategy above, 210 lycibarbarspermidine derivatives were detected and identified from Lycii Fructus, and in particular, 170 potential new compounds were structurally characterized. The integrated strategy improved the sensitivity of detection and the coverage of low-response components, and it is expected to be a promising pipeline for discovering new compounds.

19.
J Chromatogr A ; 1717: 464705, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38310702

RESUMO

This article presents the assembly and characterization of poly(diallyldimethylammonium chloride)/multi-walled carbon nanotubes (PDDA/MWCNTs) thin films on borosilicate bottles using a layer-by-layer (LBL) approach. The thin films, consisting of 10 bilayers of coating materials, were thoroughly characterized using UV-VIS spectroscopy, scanning electron microscopy (SEM), and zeta potential measurements. The modified bottles were then utilized for the extraction of analytes with diverse acid-base characteristics, including drugs, illicit drugs, and pesticides, from saliva, urine, and surface water samples. The studied analytes can be adsorbed on the surface of the LBL film mainly through hydrogen bonding and/or hydrophobic interactions. Remarkably high extraction percentages of up to 92 % were achieved, accompanied by an impressive enhancement in the analytical signal of up to 12 times when the sample volume was increased from 0.7 to 10 mL. These results highlight the outstanding extraction and sorption capabilities of the developed material. Additionally, the (PDDA/MWCNTs)10 films exhibited notable resistance to extraction and desorption processes, enabling their reuse for at least 5 cycles. The straightforward and cost-effective fabrication of these sorbent materials using the LBL technique, combined with the ability to extract target compounds during sample transportation and/or storage, renders this sample preparation method a promising alternative.


Assuntos
Nanopartículas em Multicamadas , Nanotubos de Carbono , Nanotubos de Carbono/química , Microscopia Eletrônica de Varredura
20.
J Trace Elem Med Biol ; 84: 127467, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38704916

RESUMO

BACKGROUND: Mercury (Hg) is a persistent pollutant occurring in the environment able to transition between different species. It can therefore be found in air, soil and water reservoirs becoming a present concern for the general population but also sensitive populations like pregnant women. Therefore, investigating organ-specific transfer mechanisms of Hg is mandatory for Hg toxicity testing. For this, an in vitro system using microporous inserts to monitor the transfer across an in vitro placental barrier has been used. However, due to the cytotoxicity of Hg only low concentrations (1.26 ×10-4 - 1.36 ×10-2 µg/µL Hg) can be applied, making Hg determination in cell culture medium using inductively coupled plasma-optical emission spectrometry challenging, especially when these trace amounts should be determined alongside other trace elements which are naturally occurring in cells and cell culture medium like the essential metals manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn). Additionally, Hg analysis on an ICP system holds also a number of challenges like a persistent memory effect and instability of Hg standard solutions. METHODS: The development of a rapid and sensitive ICP-OES method to determine Hg in different matrices like cell culture medium and cells has been performed on an Avio 220 Max ICP-OES (Perkin-Elmer) equipped with a cyclonic spray chamber and MicroMist® nebulizer. Cell lysates and cell culture medium were diluted in a mixture of 0.2 % L-cysteine, 2 % HNO3 and 0.1 % HCl and directly introduced into the ICP-OES system. Further method development included the suitability of the analysis of multiple elements like Mn, Fe, Cu, and Zn as well as the determination of the limit of detection and limit of quantification. RESULTS: The combination of 0.2 % L-cysteine, 2 % HNO3 and 0.1 % HCl is able to bind and stabilize Hg ions in standard solutions and in biological matrices over a wide dynamic concentration range (1 - 500 µg/L) also alongside other metals like Mn, Fe, Cu and Zn without losses of sensitivity. A short run time of 3 min enables high throughput analysis. Additionally, the high salt and carbon concentrations in the culture medium do not affect Hg sensitivity using the ICP-OES. CONCLUSION: This method is a useful tool for the quantification of Hg in a variety of complex matrices including cells and cell culture media (high salt and carbon-rich (∼1 % each)) with high sensitivity and minimal sample preparation allowing high throughput. Furthermore, not only Hg can be determined in biological matrices, but even multiple elemental analysis can be carried out to address the effect of Hg on other metals homeostasis.


Assuntos
Cisteína , Mercúrio , Mercúrio/análise , Cisteína/análise , Cisteína/química , Humanos , Calibragem
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