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1.
New Phytol ; 243(4): 1424-1439, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38922886

RESUMO

Acyl-CoA-Binding Proteins (ACBPs) bind acyl-CoA esters and function in lipid metabolism. Although acbp3-1, the ACBP3 mutant in Arabidopsis thaliana ecotype Col-0, displays normal floral development, the acbp3-2 mutant from ecotype Ler-0 characterized herein exhibits defective adaxial anther lobes and improper sporocyte formation. To understand these differences and identify the role of ERECTA in ACBP3 function, the acbp3 mutants and acbp3-erecta (er) lines were analyzed by microscopy for anther morphology and high-performance liquid chromatography for lipid composition. Defects in Landsberg anther development were related to the ERECTA-mediated pathway because the progenies of acbp3-2 × La-0 and acbp3-1 × er-1 in Col-0 showed normal anthers, contrasting to that of acbp3-2 in Ler-0. Polymorphism in the regulatory region of ACBP3 enabled its function in anther development in Ler-0 but not Col-0 which harbored an AT-repeat insertion. ACBP3 expression and anther development in acbp3-2 were restored using ACBP3pro (Ler)::ACBP3 not ACBP3pro (Col)::ACBP3. SPOROCYTELESS (SPL), a sporocyte formation regulator activated ACBP3 transcription in Ler-0 but not Col-0. For anther development, the ERECTA-related role of ACBP3 is required in Ler-0, but not Col-0. The disrupted promoter regulatory region for SPL binding in Col-0 eliminates the role of ACBP3 in anther development.


Assuntos
Alelos , Proteínas de Arabidopsis , Arabidopsis , Flores , Regulação da Expressão Gênica de Plantas , Regiões Promotoras Genéticas , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Inibidor da Ligação a Diazepam/metabolismo , Inibidor da Ligação a Diazepam/genética , Ecótipo , Flores/genética , Flores/crescimento & desenvolvimento , Mutação/genética , Fenótipo , Polimorfismo Genético , Regiões Promotoras Genéticas/genética
2.
Nat Prod Res ; : 1-9, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37322870

RESUMO

Preventing aging signs is a vast cosmetic quest hence; the authors felt the necessity to focus on emerging new plant extracts by the evaluation of anti-aging potential of eight plants cultivated in Egypt. Total phenolics (TPC), total flavonoids content (TFC) and collagenase assay were performed; only four plants were subjected to (ORAC) assay, ferrozine iron metal chelation assay and (HPLC) analysis against polyphenolic standard; validation method according to ICH guidelines for ellagic acid content in C. oliviforme by HPLC-DAD was performed, molecular docking simulation was implemented by (MOE) module. C. oliviforme exhibited the highest anti-collagenase with the lowest (IC50), (TPC = 299.70 ± 16.97 mg/GAE), method of validation of C. oliviforme extract following the ICH guidelines of ellagic acid content (147.446 ± 0.00041 mg/g); C. oliviforme was the most potent extract and was standardized to be reproducible for the industrial scale.

3.
MethodsX ; 10: 102061, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36879763

RESUMO

Highly hydrophilic compounds such as nicotinamide metabolites are very difficult to separate via high-performance liquid chromatography (HPLC) using octadecyl (C18) columns. In general, for the separation of hydrophilic compounds, hydrophilic interaction liquid chromatography (HILIC) columns are used instead of reversed phase chromatography using C18 columns. However, HILIC columns generally obey complex separation mechanisms because ionic interactions are involved in the retention process, which hinders the optimization of the separation conditions. Additionally, the resulting peak shapes are disturbed when large amounts of aqueous samples are injected. This study demonstrates that COSMOSIL PBr columns, in which both hydrophobic and dispersive interactions occur, show high retention for various hydrophilic compounds under similar separation conditions as those used with C18 columns. Specifically, using a COSMOSIL PBr column, 11 nicotinamide metabolites could be separated under simpler conditions than those used previously with C18 columns, affording better peak shape for each compound. The applicability of the method was evaluated using a tomato sample, from which the nicotinamide metabolites were successfully separated. The results show that the COSMOSIL PBr column is a good alternative to the C18 column for a good separation of all the peaks, including impurity peaks.

4.
J Food Sci ; 88(1): 175-192, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36524784

RESUMO

Despite the global preference for green extraction methods in the recovery of plant bioactives, Tetrapleura tetraptera fruit polyphenols (TTP) are yet to receive considerable attention. For the first time, pressurized hot water extraction (PHWE) of TTP was optimized for total phenol content (TPC) and antioxidant activity (AA) using the Box Behnken design of response surface methodology. Predictor variables were time, temperature, and liquid-to-solid ratio. An optimum solution with a desirability of 0.805 was selected and parameters were 43 min, 220°C, and 60 ml g-1 liquid-to-solid ratio, yielding TPC of 8.92 mg gallic acid equivalent per gram of sample on dry weight basis (GAE g-1  dw-1 ) and AA of 70.35%. Purified, optimized TTP were characterized and quantified using HPLC/LC-MS. PHWE mainly extracted rutin (379.04 µg g-1 ), cyanidin-3-O-glucoside (chloride) (299.55 µg g-1 ), naringenin 7-O-glucoside (240.11 µg g-1 ), p-coumaric acid (177.28 µg g-1 ), isorientin (150.43 µg g-1 ), and gallic acid (118.06 µg g-1 ) whereas cyanidin-3-O-glucoside (chloride) (83.27 µg g-1 ), protocatechuic acid (61.37 µg g-1 ), rutin (28.03 µg g-1 ), and gallic acid (22.62 µg g-1 ) were mainly extracted by hot water extraction, which was a control. PHWE-obtained TTP showed higher cellular antioxidant activity, cytotoxicity in human liver cancer cell lines (HepG2), and antimicrobial property against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis than control. The potential mechanisms underlying the biological activities of some of the major polyphenols extracted were briefly discussed. Considering the wide use of the T. tetraptera (TT) fruit in Africa in foods and medicine, the use of more efficient green extraction methods such as PHWE is recommended. PRACTICAL APPLICATION: This study serves as a baseline for optimizing pressurized hot water extraction, purification, identification, and quantification of Tetrapleura tetraptera polyphenols (TTP) and their biological activities, being the first of its kind. The varied biological effects shown can be exploited further for applications of TTP as nutraceutical agents and preservatives in foods in different forms. Also, the high amounts of gallic acid and other phenolic acids and flavonoids confirmed in this study make TTP good candidates for the development of metal-phenol network nanoparticles to enhance adequate solubility and distribution in food systems in light of the above proposed applications.


Assuntos
Antioxidantes , Tetrapleura , Humanos , Antioxidantes/análise , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Frutas/química , Cloretos , Espectrometria de Massas em Tandem , Extratos Vegetais/farmacologia , Fenóis/análise , Água , Polifenóis/farmacologia , Ácido Gálico , Rutina
5.
Rev. Univ. Ind. Santander, Salud ; 52(3): 261-284, Julio 8, 2020. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1155626

RESUMO

Resumen Introducción: la consulta de un particular que trajo un producto fitoterapéutico a base de caléndula cuyo consumo le causó fuertes reacciones adversas, originó esta investigación sobre la composición de este producto. Objetivo: caracterizar la composición química de muestras de lotes diferentes de un producto comercial denominado fitoterapéutico a base de caléndula (Calendula officinalis) (PFC) comercializado en Colombia. Metodología: se analizaron tabletas de ocho cajas del PFC de cuatro lotes diferentes de producción (2017 y 2018). Se llevó a cabo el análisis de espacio de cabeza (HS) de tabletas por microextracción en fase sólida (SPME), con una fibra PDMS/DVB (65 µm), expuesta al HS de la muestra durante 30 min a 50 °C. Las fracciones volátiles se analizaron por cromatografía de gases acoplada a espectrometría de masas (GC/MS). Los extractos de tabletas obtenidos con mezcla de metanol:agua (1:1, v/v) se analizaron por cromatografía líquida (LC) de alta (HPLC) y ultra-alta eficiencia (UHPLC), con detectores de arreglo de diodos (DAD) y espectrometría de masas de alta resolución (HRMS), respectivamente; la cuantificación de diclofenaco se hizo por calibración con patrón externo y por adición de estándar. Los espectros de masas de baja y alta resolución y patrones de fragmentación de las sustancias detectadas se estudiaron, usando GC/HRMS y LC/HRMS-Orbitrap. Resultados: en tabletas analizadas por HSSPME, se encontraron monoterpenoides y sesquiterpenoides de origen vegetal, ftalatos, residuos de solventes (2-cloroetanol, etilenglicol) y sustancias químicas intermediarias en la síntesis de diclofenaco (2,6-dicloroanilina y 2,6-cloro-N-fenil-bencenamina). En los cromatogramas, obtenidos por GC/MS de los extractos de tabletas obtenidos con diclorometano, se detectaron diclofenaco, sus impurezas A, B y C, los ésteres de diclofenaco y algunas otras impurezas. Diclofenaco en cantidad ca. 40 mg (7-8%) se cuantificó por HPLC en tabletas (> 70 analizadas) escogidas al azar de ocho cajas del PFC, adquirido en el mercado local de Bucaramanga (Colombia). Conclusión: en cada tableta analizada se determinaron alrededor de 40 mg del compuesto sintético diclofenaco (sustancia no declarada en la etiqueta del producto) y en ninguna se detectaron ésteres de los triterpenoides oleanano o faradiol, constituyentes del extracto de caléndula que poseen actividad antiinflamatoria; se encontraron algunos flavonoides comunes a muchas plantas, en cantidades mil veces menores que la de diclofenaco.


Abstract Introduction: The consultation of a person who brought a marigold-based phytotherapeutic product whose consumption caused strong adverse reactions, originated this investigation of the composition of this product. Objective: to characterize the chemical composition of samples of different lots of a commercial product called calendula-based phytotherapeutic product (Calendula officinalis) (PFC) commercialized in Colombia. Methodology: Tablets of eight packs of the phytotherapeutic product from four different production batches (2017 and 2018) were analyzed. Headspace analysis (HS) of tablets by solid phase microextraction (SPME) was carried out with a PDMS/ DVB fiber (65 µm), exposed to the HS of the sample for 30 min at 50 °C. Volatile fractions were analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Tablet extracts obtained with methanol:water mixture (1:1, v / v) were analyzed by liquid chromatography (LC) of high (HPLC) and ultra-high performance (UHPLC) with diode array (DAD) and high-resolution mass spectrometric (HRMS) detectors, respectively; diclofenac was quantified by external calibration and standard addition. Low- and high-resolution mass spectra (MS, HRMS) and fragmentation patterns of detected substances were studied, using GC/HRTOF-MS and LC/HRMS-Orbitrap. Results: in tablets analyzed by HS-SPME, monoterpenoids and sesquiterpenoids of plant origin, phthalates, solvent residues (2-chloroethanol, ethylene glycol) and intermediary chemicals in diclofenac synthesis (2,6-dichloroaniline and 2,6- chloro-N-phenyl-benzenamine) were found. In the chromatograms (GC/MS) of the extracts of tablets obtained with organic solvent (dichloromethane), diclofenac, its impurities A, B and C, diclofenac esters, and some other compounds were detected; diclofenac quantification by HPLC found amounts of ca. 40 mg (7 - 8%) in tablets (> 70 analyzed) chosen at random from eight packs of the calendula-based phytotherapeutic product, purchased in the local market in Bucaramanga (Colombia). Conclusion: each analyzed tablet contained around 40 mg of the synthetic compound diclofenac (substance not declared in the product's label) and no tablet contained detectable amounts of esters of the triterpenoids oleanane or faradiol, which are calendula extract constituents that possess antiinflammatory activity; a few flavonoids that are common to many plants were found in amounts a thousand times smaller than that of diclofenac.


Assuntos
Humanos , Diclofenaco , Calendula , Medicamento Fitoterápico , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Colômbia , Cromatografia Gasosa-Espectrometria de Massas
6.
Chemosphere ; 209: 137-146, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29929119

RESUMO

In this pilot study three fractions of particulate matter (PM0.25, PM2.5-0.25, and PM10-2.5) were collected in three environments (classroom, home, and outdoors) in a village located nearby an industrial complex. Time-activity pattern of 20 students attending the classroom was obtained, and the dose of particles reaching the children's lungs under actual environmental conditions (i.e. real dose) was calculated via dosimetry model. The highest PM concentrations were reached in the classroom. Simulations showed that heavy intensity outdoor activities played a major role in PM deposition, especially in the upper part of the respiratory tract. The mass of PM10-2.5 reaching the alveoli was minor, while PM2.5-0.25 and PM0.25 apportion for most of the PM mass retained in the lungs. Consequently, PM2.5-0.25 and PM0.25 were the only fractions used in two subsequent toxicity assays onto alveolar cells (A549). First, a cytotoxicity dose-response assay was performed, and doses corresponding to 5% mortality (LC5) were estimated. Afterwards, two LC-MS metabolomic assays were conducted: one applying LC5, and another applying real dose. A lower estimated LC5 value was obtained for PM0.25 than PM2.5-0.25 (8.08 and 73.7 ng/mL respectively). The number of altered features after LC5 exposure was similar for both fractions (39 and 38 for PM0.25 and PM2.5-0.25 respectively), while after real dose exposure these numbers differed (10 and 5 for PM0.25 and PM2.5-0.25 respectively). The most metabolic changes were related to membrane and lung surfactant lipids. This study highlights the capacity of PM to alter metabolic profile of lung cells at conventional environmental levels.


Assuntos
Monitoramento Ambiental , Metabolômica , Material Particulado/toxicidade , Poluição do Ar em Ambientes Fechados/análise , Criança , Humanos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Tamanho da Partícula , Material Particulado/análise , Projetos Piloto , Sistema Respiratório/efeitos dos fármacos
7.
FASEB J ; 32(6): 3108-3118, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29401599

RESUMO

Although thioredoxin-interacting protein (TXNIP) is involved in a variety of biologic functions, the contribution of endothelial TXNIP has not been well defined. To investigate the endothelial function of TXNIP, we generated a TXNIP knockout mouse on the Cdh5-cre background (TXNIPfl/fl cdh5cre). Control (TXNIPfl/fl) and TXNIPfl/fl cdh5cre mice were fed a high protein-low carbohydrate (HP-LC) diet for 3 mo to induce metabolic stress. We found that TXNIPfl/fl and TXNIPfl/fl cdh5cre mice on an HP-LC diet displayed impaired glucose tolerance and dyslipidemia concretizing the metabolic stress induced. We evaluated the impact of this metabolic stress on mice with reduced endothelial TXNIP expression with regard to arterial structure and function. TXNIPfl/fl cdh5cre mice on an HP-LC diet exhibited less endothelial dysfunction than littermate mice on an HP-LC diet. These mice were protected from decreased aortic medial cell content, impaired aortic distensibility, and increased plasminogen activator inhibitor 1 secretion. This protective effect came with lower oxidative stress and lower inflammation, with a reduced NLRP3 inflammasome expression, leading to a decrease in cleaved IL-1ß. We also show the major role of TXNIP in inflammation with a knockdown model, using a TXNIP-specific, small interfering RNA included in a lipoplex. These findings demonstrate a key role for endothelial TXNIP in arterial impairments induced by metabolic stress, making endothelial TXNIP a potential therapeutic target.-Bedarida, T., Domingues, A., Baron, S., Ferreira, C., Vibert, F., Cottart, C.-H., Paul, J.-L., Escriou, V., Bigey, P., Gaussem, P., Leguillier, T., Nivet-Antoine, V. Reduced endothelial thioredoxin-interacting protein protects arteries from damage induced by metabolic stress in vivo.


Assuntos
Aorta/metabolismo , Proteínas de Transporte/metabolismo , Dislipidemias/metabolismo , Intolerância à Glucose/metabolismo , Estresse Fisiológico , Tiorredoxinas/metabolismo , Animais , Aorta/patologia , Proteínas de Transporte/genética , Dieta com Restrição de Carboidratos/efeitos adversos , Proteínas Alimentares/efeitos adversos , Proteínas Alimentares/farmacologia , Dislipidemias/induzido quimicamente , Dislipidemias/genética , Dislipidemias/patologia , Intolerância à Glucose/induzido quimicamente , Intolerância à Glucose/genética , Intolerância à Glucose/patologia , Inflamassomos/genética , Inflamassomos/metabolismo , Camundongos , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/biossíntese , Serpina E2/biossíntese , Tiorredoxinas/genética
8.
Pharm Biol ; 54(12): 3113-3120, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27558975

RESUMO

CONTEXT: The rising problem of atherosclerosis and ischemic heart disease emphasizes the need to look for new antithrombotic components with effective modes of action. Corydalis yanhusuo (Y.H. Chou & Chun C. Hsu) W.T. Wang ex Z.Y. Su & C.Y. Wu (Papaveraceae) (Rhizoma Corydalis) has been used in the traditional medicines for the treatment of cardiovascular disease. OBJECTIVE: The antiplatelet aggregation compounds in Rhizoma Corydalis were screened to validate its traditional medicinal use. MATERIAL AND METHODS: Total alkaloid extract (TAE) of Rhizoma Corydalis was obtained by refluxing 100 g Rhizoma Corydalis powder with 600 mL 70% ethanol, and purified by acidification (20% HCl) and alkalization (5 M NaOH) process. Potential antiplatelet aggregation compounds in TAE were screened by a method involving platelet bio-specific extraction and HPLC-DAD/LC-MS analysis. Further in vitro antiplatelet aggregation activity confirmation of TAE and seven main alkaloids were achieved by turbidimetry method within 3 h after blood collection from rabbit carotid artery, and all the test drugs were at the concentration range of 25-350 µg/mL. Finally, HPLC-DAD was employed for the quantitative determination of seven main components in TAE. RESULTS: Five alkaloids, identified as glaucine, dehydrocorydaline, canadine, tetrahydrocoptisine and corydaline, can be specifically extracted with platelets. The results indicated that all these five alkaloids can inhibit thrombin-induced platelet aggregation in a low dose (IC50 of glaucine, dehydrocorydaline, canadine, tetrahydrocoptisine and corydaline were 49.057, 34.914, 33.547, 84.261 and 54.164 µg/mL, respectively) as compared to TAE (IC50 = 175.426 µg/mL) and aspirin (IC50 = 300.340 µg/mL), while the unbound compounds (palmatine and tetrahydropalmatine) had a very weak antiplatelet effect (IC50 > 200 µg/mL). DISCUSSION AND CONCLUSION: This study is the first reported work for antiplatelet components screening in Rhizoma Corydalis. Seven compounds were detected and identified by HPLC-DAD/LC-MS, of which five platelet-targeted compounds were discovered.


Assuntos
Alcaloides/análise , Corydalis , Extratos Vegetais/análise , Inibidores da Agregação Plaquetária/análise , Agregação Plaquetária/efeitos dos fármacos , Rizoma , Alcaloides/farmacologia , Animais , Extratos Vegetais/farmacologia , Agregação Plaquetária/fisiologia , Inibidores da Agregação Plaquetária/farmacologia , Coelhos
9.
Anal Biochem ; 470: 71-7, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25449302

RESUMO

An analytical chemical method has been developed for determination of ß-hydroxymyristic acid (ß-HMA), a component of lipopolysaccharides (LPSs/endotoxins) in dialysis water. In our investigation, the ß-HMA component was used as a chemical marker for endotoxin presence in dialysis water because it is available in the molecular subunit (lipid A) and responsible for toxicity. It is the most abundant saturated fatty acid in that subunit. The developed method is based on fluorescence derivatization with 4-nitro-7-piperazino-2,1,3-benzoxadiazole (NBD-PZ). A high-performance liquid chromatographic separation of the ß-HMA derivative was achieved using an octadecyl silica column in gradient elution. A wide dynamic range of ß-HMA was tested and a calibration curve was constructed with accuracy of 90% and variability of less than 10%. The limits of detection and quantification obtained were 2 and 5µM, respectively. The developed method was applied to detect endotoxins in dialysis water by alkaline hydrolysis of LPS using NaOH (0.25M) at 60°C for 2h. After hydrolysis, free acid was detected as its NBD-PZ derivative using high-performance liquid chromatography/mass spectrometry (HPLC/MS). Good recovery rates ranging from 98 to 105% were obtained for ß-HMA in dialysis water.


Assuntos
Técnicas de Química Analítica/métodos , Lipopolissacarídeos/análise , Ácidos Mirísticos/análise , Diálise Renal , Água/química , Calibragem , Hidrólise , Lipopolissacarídeos/química , Ácidos Mirísticos/química
10.
Redox Biol ; 2: 610-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25114837

RESUMO

Dihomo-γ-linolenic acid (DGLA) and its downstream fatty acid arachidonic acid (AA) are both nutritionally important ω-6 polyunsaturated fatty acids (ω-6s). Evidence shows that, via COX-mediated peroxidation, DGLA and its metabolites (1-series prostaglandins) are associated with anti-tumor activity, while AA and its metabolites (2-series prostaglandins) could be tightly implicated in various cancer diseases. However, it still remains a mystery why DGLA and AA possess contrasting bioactivities. Our previous studies showed that DGLA could go through an exclusive C-8 oxygenation pathway during COX-catalyzed lipid peroxidation in addition to a C-15 oxygenation pathway shared by both DGLA and AA, and that the exclusive C-8 oxygenation could lead to the production of distinct DGLA׳s free radical derivatives that may be correlated with DGLA׳s anti-proliferation activity. In the present work, we further investigate the anti-cancer effect of DGLA׳s free radical derivatives and their associated molecular mechanisms. Our study shows that the exclusive DGLA׳s free radical derivatives from C-8 oxygenation lead to cell growth inhibition, cell cycle arrest and apoptosis in the human colon cancer cell line HCA-7 colony 29, probably by up-regulating the cancer suppressor p53 and the cell cycle inhibitor p27. In addition, these exclusive radical derivatives were also able to enhance the efficacy of 5-Fluorouracil (5-FU), a widely used chemo-drug for colon cancer. For the first time, we show how DGLA׳s radical pathway and metabolites are associated with DGLA׳s anti-cancer activities and able to sensitize colon cancer cells to chemo-drugs such as 5-FU. Our findings could be used to guide future development of a combined chemotherapy and dietary care strategy for colon cancer treatment.


Assuntos
Ácido 8,11,14-Eicosatrienoico/metabolismo , Antineoplásicos/farmacologia , Neoplasias do Colo/patologia , Fluoruracila/farmacologia , Radicais Livres/metabolismo , Peroxidação de Lipídeos , Prostaglandina-Endoperóxido Sintases/metabolismo , Ácido 8,11,14-Eicosatrienoico/química , Apoptose/efeitos dos fármacos , Biocatálise , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Radicais Livres/química , Humanos , Relação Estrutura-Atividade
11.
Artigo em Inglês | MEDLINE | ID: mdl-24999616

RESUMO

In this study, magnetic single-walled carbon nanotubes (MSWCNTs) were prepared by impregnating magnetic Fe3O4 nanoparticles onto the surfaces of carboxylic single-walled carbon nanotubes based on electrostatic interactions. The prepared MSWCNTs were used as the adsorbent for the dispersive solid-phase extraction (DSPE) of paraquat from human urine. After adsorption, the paraquat was quantitatively desorbed with 5%TFA in acetonitrile and determined by HPLC-MS. Extraction parameters such as the type of CNT adsorbent, extraction time, sample volume, wash solvent, and the type and volume of desorption solvent were optimized to obtain high DSPE recoveries and extraction efficiencies. Under the optimized conditions, the calibration curve was linear in the range 3.75-375.0 µg/L with a correlation coefficient of 0.999 45. The LOD (S/N=3) and LOQ (S/N=10) were 0.94 and 2.82 µg/L, respectively. The recoveries ranged from 92.89 to 108.9% for spiked real urine samples with RSDs below 3.21%. Finally, the new method was successfully used to determine paraquat in urine samples of suspected paraquat poisoning patients. The MSWCNTs exhibited suitable properties and a high adsorption capacity for the extraction of paraquat.


Assuntos
Cromatografia Líquida/métodos , Nanopartículas de Magnetita/química , Nanotubos de Carbono/química , Paraquat/urina , Extração em Fase Sólida/métodos , Humanos , Limite de Detecção , Modelos Lineares , Paraquat/química , Paraquat/isolamento & purificação , Paraquat/intoxicação , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos
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