Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 512
Filtrar
1.
Food Chem ; 319: 126539, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32193060

RESUMO

Two molecularly imprinted microspheres and two fluorescent tracers for benzimidazoles and pyrethroids were synthesized respectively. The two types of microspheres were coated in the wells of conventional microplate simultaneously. Then the sample extracts and the two traces were added for differential competition. The fluorescence intensities at two different emission wavelengths were excited and recorded for quantification of the two classes of drugs respectively. The optimized multiplexed fluorescence method could be used to determine 8 benzimidazoles and 10 pyrethroids in mutton and beef samples simultaneously. The limits of detection of the method for the 18 drugs were in the range of 5.2-17 ng/mL, and the recoveries from the standards fortified blank samples were in the range of 67.7%-109%. From the analysis of 60 real mutton and beef samples, this method could be used for multi-screening the residues of benzimidazoles and pyrethroids in meat samples.


Assuntos
Benzimidazóis/análise , Piretrinas/análise , Carne Vermelha/análise , Animais , Benzimidazóis/química , Fluorescência , Microesferas , Impressão Molecular , Estrutura Molecular , Piretrinas/química
2.
Artigo em Inglês | MEDLINE | ID: mdl-32004940

RESUMO

Flibanserin (FLB) is the first FDA approved drug showed to have significant activity against sexual desire disorder of premenopausal and postmenopausal women. Unfortunately, FLB is used as an adulterant in dietary supplement products as a performance enhancer in sports. Identification of FLB and its metabolites in the biological samples requires an authenticated analytical technique. The aim of this study was to identify N-oxide metabolite of FLB in microsomal and S9 human liver enzyme fractions, rat urine and feces. There are several N-oxide reported as genotoxic impurity or reactive metabolites based on position of N-oxide in piperazine ring. This study also describes the strategy to utilize degradation chemistry for isolation of N-oxide and its step-wise characterization. An LC-MS method has been developed and employed for identifying the N-oxide metabolite of FLB. The targeted N-oxide metabolite in the extracted ion chromatogram of the in vitro and in vivo samples has been confirmed by analyzing the changes in observed mass at m/z 407.1693. Major distinguished abundant ions at m/z 243.1104, 190.0974, 161.0705, 119.0601 confirmed the structure of the metabolite. This study will help to understand the oxidative potential of FLB in toxicokinetic study. The developed method can be useful to identify FLB or its N-oxide metabolite in dope testing in future. This is the first time to report a strategy to utilize degradation chemistry for N-oxide metabolite characterization. In this study, isolated N-oxidative degradation product was used to confirm N-oxide metabolite which was characterized by LC-MS through H/D exchange and structure was ensured by NMR spectroscopy (1H, COSY).


Assuntos
Benzimidazóis , Medição da Troca de Deutério/métodos , Fezes/química , Espectrometria de Massas em Tandem/métodos , Administração Oral , Animais , Benzimidazóis/administração & dosagem , Benzimidazóis/análise , Benzimidazóis/química , Benzimidazóis/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Espectroscopia de Ressonância Magnética , Masculino , Oxirredução , Ratos , Ratos Sprague-Dawley
3.
J Chromatogr A ; 1618: 460847, 2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31928768

RESUMO

The functionalization of covalent organic frameworks (COFs) enhances chemical properties and expands future applications. Herein, a facile strategy for sulfoacid-functionalized COF is presented through post-modification of covalent triazine frameworks (CTFs) platform. The magnetic solid phase extraction (MSPE) material is obtained by anchoring in situ Ni particles on CTF support (Ni/CTF-SO3H) possessing a dual retention mechanism combining hydrophilic-lipophilic-balance (HLB) and cation-exchange interaction. We established the (Ni/CTF-SO3H)-MSPE method for selectively enriching carbendazim (CBZ) and thiabendazole (TBZ) from food samples and reducing matrix effect simultaneously. The method detection limit is 1.23-7.05 µg kg-1 for CBZ and TBZ in vegetable, fruit and juice samples, determined by high-performance liquid chromatography-ultraviolet detector. The recoveries of spiked CBZ and TBZ in the samples are 80.2-115.1% and RSDs 6.0-11.4%, depending on both analytes and samples. Our work provides a unique perspective in the development of functionalized COFs as a versatile HLB/cation-exchange mixed-mode SPE sorbent for extraction of basic analytes in complex matrix.


Assuntos
Benzimidazóis/análise , Bebidas/análise , Frutas/química , Fungicidas Industriais/análise , Interações Hidrofóbicas e Hidrofílicas , Estruturas Metalorgânicas/química , Ácidos Sulfônicos/química , Triazinas/química , Verduras/química , Adsorção , Cátions , Limite de Detecção , Reprodutibilidade dos Testes , Extração em Fase Sólida , Ácidos Sulfônicos/síntese química
4.
J Chromatogr Sci ; 57(10): 910-919, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31644804

RESUMO

A new ultra-high-performance liquid chromatography method for the simultaneous quantification of sofosbuvir, daclatasvir and ledipasvir was developed. Two combinations of these direct-acting antivirals are used in hepatitis C virus infection therapy and show high efficacy and safety. Fractional factorial design was used for screening the most influential factors on separation and time analysis. These significant factors were optimized using a central composite design. The optimum resolution was carried out by using a Waters XBridge C18 column (150 mm, 4.6 mm ID, 5 µm) at a temperature of 35°C ± 2°C and acetonitrile/sodium perchlorate buffer (10 mM, pH = 3.2) (40: 60 v/v) as mobile phase at a flow rate of 1.5 mL min-1. UV detection was set at λ = 210 nm. A short chromatographic separation time was achieved. The developed method was validated according to the accuracy profile approach and was found specific, precise, faithful and accurate. The detection limits were between 0.07 and 0.13 µg mL-1. Hence, this novel method can be employed for the routine quality control analysis and in dissolution profile studies of generics containing these products.


Assuntos
Benzimidazóis/análise , Cromatografia Líquida de Alta Pressão/métodos , Fluorenos/análise , Imidazóis/análise , Sofosbuvir/análise , Benzimidazóis/química , Fluorenos/química , Imidazóis/química , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Sofosbuvir/química , Comprimidos
5.
Food Chem ; 309: 125756, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31776048

RESUMO

In this work, a selective sorbent for carbendazim was prepared by the thermal immobilization of the poly(glycidoxypropylmethyl-co-dimethylsiloxane), PGDMS, on silica. The lab-made Si(PGDMS) sorbent was physicochemically and morphologically characterized and was used into the pipette tip for the disposable pipette extraction (DPX) of carbendazim residues of orange juice. The DPX method was optimized from a central composite design and validated according to the SANTE/11813/2017 document recommended by the European Union. The proposed method presented recoveries between 93 and 110% with RSD <16% and the limit of quantification below the MRL for carbendazim in citrus. The whole sample preparation process was carried out at less than 3 min, with good accuracy and precision without the need of any cleanup step or electrical equipment, allowing its portability for the extraction of carbendazim residues in orange juice.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Cromatografia Líquida de Alta Pressão/métodos , Citrus/química , Sucos de Frutas e Vegetais/análise , Citrus/metabolismo , Limite de Detecção , Polímeros/química , Dióxido de Silício/química , Extração em Fase Sólida/instrumentação , Extração em Fase Sólida/métodos , Temperatura
6.
Se Pu ; 37(10): 1112-1117, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642291

RESUMO

A method was developed for the simultaneous determination of 11 benzimildazoles residue markers in chicken meat, liver and kidney samples by high performance liquid chromatography (HPLC). The chicken tissue sample was extracted with acetonitrile, defatted with n-hexane, and purified with an MCX solid-phase extraction cartridge. Chromatographic separation was performed on an Atlantis T3 column with the gradient elution of methyl alcohol-1% (v/v) acetic acid aqueous solution as the mobile phases at a flow rate of 1.0 mL/min. The detection wavelength was set at 292 nm. Analytes were quantified by the external standard method. The linearities of the calibration curves were well in the range of 25-1000 µg/L, and the limit of quantification was 50 µg/kg. The recoveries at different spiked levels in all the three matrices ranged from 70.91% to 103.21%, and the relative standard deviations (RSDs) were between 1.48% and 10.08% (n=6). The developed method is characterized by an excellent purification effect, sensitivity and accuracy, and can be used for the determination of benzimidazoles residue markers in chicken tissue samples.


Assuntos
Benzimidazóis/análise , Contaminação de Alimentos/análise , Carne/análise , Animais , Galinhas , Cromatografia Líquida de Alta Pressão , Extração em Fase Sólida
7.
Obstet Gynecol ; 134(3): 481-484, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31403599

RESUMO

BACKGROUND: There are currently no data regarding the transfer of candesartan into human milk. This report provides data on this transfer, an estimation of the amount breastfed infants receive, and plasma concentrations from two breastfed infants. CASES: Three breastfeeding mothers, all stabilized on candesartan (8-32 mg/d), provided milk and plasma samples over one dosing interval (24 hours). Two infant plasma samples were obtained. The amount the infants ingested was estimated to be 0.09% (95% CI 0.07-0.11) of the maternal dose (weight-adjusted). Candesartan was undetectable (less than 0.2 micrograms/L) in infant plasma samples. CONCLUSION: A relative infant dose of 0.09% suggests that maternal benefit from candesartan at standard therapeutic doses may outweigh risk in breastfeeding healthy, term infants.


Assuntos
Anti-Hipertensivos/análise , Benzimidazóis/análise , Leite Humano/química , Tetrazóis/análise , Adulto , Anti-Hipertensivos/sangue , Benzimidazóis/sangue , Aleitamento Materno , Feminino , Humanos , Lactente , Recém-Nascido , Tetrazóis/sangue
8.
Sci Total Environ ; 695: 133790, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31422335

RESUMO

Neonicotinoid insecticides (NNIs) are a relatively new class of insecticides, and carbendazim (CBDZ) is a representative antifungal biocide. The occurrence of them in indoor dust was not documented in China. In this study, 336 indoor dust samples were collected from 3 cities, including Taiyuan (October 2016), Wuhan (October 2016 and 2018), and Shenzhen (February 2019), located in North, Central, and South China, for determination of the residues of six NNIs, two of their metabolites, and CBDZ. Acetamiprid (ACE), imidacloprid (IMI), and CBDZ were found to be the major target analytes in dust samples from all selected cities with detection frequencies of 98.8%, 99.7%, and 95.2%, respectively. At least one target NNI was detected for all of the dust samples, with the median concentration of 25.8 ng/g for the imidacloprid-equivalent total neonicotinoids (IMIeq: generated by the relative potency factor method), and the median for CBDZ was 35.8 ng/g. Higher levels of several NNIs and CBDZ were found in urban areas of Taiyuan and Wuhan than those in rural areas. A significant increase of the NNI residues was observed in dust of Wuhan from 2016 to 2018 (while not significant for CBDZ). Finally, the estimated daily intake (EDI) of IMIeq and CBDZ for infants and toddlers were higher than that found in other age groups through dust ingestion, which indicated that infants and toddlers may be susceptible to current residue of NNIs and CBDZ in indoor dust, and dust ingestion of NNIs might be <1% of that reported for dietary intakes in China. This is the first study to report the residue levels of NNIs and CBDZ in dust samples from indoor environment in China.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Benzimidazóis/análise , Carbamatos/análise , Poeira/análise , Monitoramento Ambiental , Neonicotinoides/análise , Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , China
9.
Biosens Bioelectron ; 142: 111491, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31326864

RESUMO

A novel electrochemical sensor based on nitrogen and sulfur doped hollow Mo2C/C spheres (N, S-Mo2C) and molecularly imprinted polymer (MIP) was proposed for carbendazim (CBD) determination. The N, S-Mo2C were prepared by first nitrogen and sulfur doping via one-pot method and subsequent carbonization at high temperature. A film of MIP was then fabricated in situ on the N, S-Mo2C surface by electropolymerization, with CBD acting as template molecule and o-phenylenediamine as functional monomer. The N, S-Mo2C were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and electrochemical behaviors of CBD on differently modified electrodes were explored by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimal conditions, a calibration curve of current shift versus the logarithm of CBD concentration was obtained in the range of 1×10-12 ∼ 8×10-9 M with a detection limit of 6.7×10-13 M (S/N=3). Moreover, the proposed sensor exhibited favorable stability and selectivity, and was applied to analyze pesticide residues in fruits and vegetables with decent accuracy.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Técnicas Eletroquímicas/métodos , Molibdênio/química , Praguicidas/análise , Polímeros/química , Técnicas Biossensoriais/métodos , Espectroscopia Dielétrica/métodos , Eletrodos , Frutas/química , Limite de Detecção , Impressão Molecular/métodos , Nitrogênio/química , Fenilenodiaminas/química , Enxofre/química , Verduras/química
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 220: 117088, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31158606

RESUMO

A novel fluorescence application for simultaneous determination of two common fungicide pesticides (carbendazim and chlorothalonil) in peanut oil is presented. Using the strategy of combining excitation-emission matrix (EEM) fluorescence with three-way calibration methods, the proposed approach successfully achieved quantitative analysis of carbendazim and chlorothalonil pesticide residues in peanut oil, even with highly overlapped spectra. It needs little preparation, using "mathematical separation" instead of "analytical separation" to achieve concentration prediction of target analytes in complex systems. Each analyte was performed using fluorescence spectroscopy after instrument spectral correction and scatter removal. Then the data were modeled with two three-way calibration algorithms, including alternating trilinear decomposition (ATLD) and alternating penalty trilinear decomposition (APTLD). The results indicated that APTLD performed slightly better than ATLD for this system. The carbendazim and chlorothalonil can be recognized simultaneously with the correlation coefficients all above 0.96 between resolved spectra and actual spectra. Satisfactory results have been achieved with the average recoveries (mean ±â€¯standard deviation) of carbendazim and chlorothalonil being 100.2 ±â€¯6.7% and 99.7 ±â€¯6.7%, respectively. Moreover, as for carbendazim and chlorothalonil, the sensitivity (SENs) are 1.50 × 102 and 3.80 × 102 mL ng-1, the limits of detection (LODs) are 11 ng mL-1 and 4.3 ng mL-1, the limit of quantitation (LOQ) are 33.33 ng mL-1 and 13.03 ng mL-1, respectively. The above results demonstrated that the proposed method is sensitive, fast and accurate for direct quantitative analysis of multiple pesticide residues in complex matrix such as that of peanut oil.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Contaminação de Alimentos/análise , Nitrilos/análise , Óleo de Amendoim/análise , Espectrometria de Fluorescência/métodos , Algoritmos , Calibragem , Análise de Alimentos/métodos , Limite de Detecção , Resíduos de Praguicidas/análise , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador
11.
Food Chem ; 293: 271-277, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151611

RESUMO

The contamination of pesticide residues in Oolong tea has raised much concern in recent years. The objective of this study was to synthesize gold nanoparticles (AuNPs) and develop surface-enhanced Raman spectroscopy (SERS) methods for detection and quantification of pesticides in Oolong tea. Facile synthesis of spherical and monodispersed AuNPs with an average diameter of 15 nm was achieved, which induced strong electromagnetic fields in SERS analysis. AuNP substrates were employed for rapid detection and quantification of carbendazim in Tieguanyin Oolong tea. Partial least squares (PLS) analysis and leave-one-out cross validation were utilized in spectral data analysis. The PLS results for Oolong tea samples were obtained: R value = 0.964; the detection limit = 100 µg/kg. These results demonstrate that SERS coupled with gold nanoparticle substrate is a simple, rapid, and sensitive analytical tool for measurement and quantification of carbendazim residues in Oolong tea.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Ouro/química , Nanopartículas Metálicas/química , Resíduos de Praguicidas/análise , Praguicidas/análise , Análise Espectral Raman/métodos , Chá/química , Cor , Limite de Detecção
12.
Anal Bioanal Chem ; 411(20): 5331-5345, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31209549

RESUMO

A novel method was developed and validated for the quantification of the three approved CDK4/6 inhibitors (abemaciclib, palbociclib, and ribociclib) in both human and mouse plasma and mouse tissue homogenates (liver, kidney, spleen, brain, and small intestine) using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). For all matrices, pretreatment was performed using 50 µL of sample by protein precipitation with acetonitrile, followed by dilution of the supernatant. Chromatographic separation of the analytes was done on a C18 column using gradient elution. A full validation was performed for human plasma, while a partial validation was executed for mouse plasma and mouse tissue homogenates. The method was linear in the calibration range from 2 to 200 ng/mL, with a correlation coefficient (r) ≥0.996 for each analyte. For both human and mouse plasma, the accuracy and precision were within ±15% and ≤15%, respectively, for all concentrations, except for the lower limit of quantification, where they were within ±20% and ≤20%, respectively. A fit-for-purpose strategy was followed for tissue homogenates, and the accuracy and precision were within ±20% and ≤20%, respectively, for all concentrations. Stability of all analytes in all matrices at different processing and storage conditions was tested; ribociclib and palbociclib were unstable in most tissue homogenates and conditions were modified to increase the stability. The method was successfully applied for the analysis of mouse samples from preclinical studies. A new ribociclib metabolite was detected in mouse plasma samples with the same m/z transition as the parent drug.


Assuntos
Aminopiridinas/análise , Benzimidazóis/análise , Cromatografia Líquida/métodos , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Piperazinas/análise , Inibidores de Proteínas Quinases/análise , Purinas/análise , Piridinas/análise , Espectrometria de Massas em Tandem/métodos , Aminopiridinas/farmacologia , Animais , Benzimidazóis/farmacologia , Humanos , Camundongos , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Purinas/farmacologia , Piridinas/farmacologia
13.
J Environ Sci Health B ; 54(8): 702-708, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31112093

RESUMO

Benomyl is a benzimidazol fungicide used against various crop pathogens. Although banned in many countries, it is still widely used worldwide and is listed in different monitoring programs among the substances to be monitored to assess human exposure to pesticide residues. The assessment of benomyl is mainly based on the analysis of the residues of its most important metabolite, carbendazim. Existing methods often lack of selectivity and display a limited performance because of the presence of co-extracted compounds. Molecularly imprinted polymers (MIPs) offer an alternative methodology, adsorbing preferentially those target molecules for which the polymers are specifically prepared. In this study, we optimized the synthesis of a polymer imprinted with benomyl. Tests of specificity recognition showed a good performance for carbendazim compared with other similar pesticides. The mean recovery of benomyl (measured as carbendazim) from water samples was estimated to be 90% for MIPs while with real soil samples collected in Morocco the recovery efficiency was 62%. Preliminary tests also suggest that this MIP can implement traditional SPE techniques for assessing benomyl residual concentrations in environmental samples.


Assuntos
Benomilo/análise , Polímeros/química , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Adsorção , Benzimidazóis/análise , Carbamatos/análise , Fungicidas Industriais/análise , Impressão Molecular , Marrocos , Polímeros/síntese química , Extração em Fase Sólida/métodos
14.
J Colloid Interface Sci ; 546: 92-100, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30904688

RESUMO

We reported a carbon nanohorns/gold nanoparticles composites-based impedimetric aptasensor for carbendazim (CBZ) detection in lettuce and orange juice at picogram levels. The increased electron-transfer resistance, resulting from the formation of CBZ-aptamer complex, was recorded by electrochemical impedance spectroscopy as the aptasensor response for CBZ. Under the optimal conditions, the proposed aptasensor displayed a linear response for CBZ ranging from 1 to 1000 pg mL-1 with a detection limit of 0.5 pg mL-1. Noteworthy, the as-developed aptasensor displayed the lowest detection limit for CBZ among the previously reported methods. Common pesticides (atrazine, thiamethoxam, etc.) with 100-fold concentration did not interfere the CBZ detection. For CBZ detection in lettuce and orange juice, satisfactory recoveries were obtained with standard addition method. Statistics demonstrated that no significant differences were found between the data provided by standard HPLC-MS reference method and developed aptasensing method in term of accuracy and precision. We believe that the proposed aptasensor possesses a potential application for CBZ monitoring in agricultural product and food.


Assuntos
Aptâmeros de Nucleotídeos/química , Benzimidazóis/análise , Carbamatos/análise , Carbono/química , Ouro/química , Nanopartículas/química , Técnicas Biossensoriais , Impedância Elétrica , Técnicas Eletroquímicas , Tamanho da Partícula , Propriedades de Superfície
15.
Biosens Bioelectron ; 132: 375-381, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30901727

RESUMO

A highly sensitive diagnostic system for determining low-density infections that are missed by conventional methods is necessary to detect the carriers of Plasmodium falciparum. A fluorescent blue-ray optical system with a polycarbonate scan disc was developed to detect P. falciparum-infected red blood cells (Pf-iRBCs), and nine samples could be analyzed simultaneously. The cultured P. falciparum strain 3D7 was used to examine the potential of the system for diagnosing malaria. After an RBC suspension had been applied to the disc, the cells were dispersed on the disc by rotation. During the 10 min standing period to allow the RBCs to settle on the disc surface, the cells were simultaneously stained with nuclear fluorescence staining dye Hoechst 34580, which was previously adsorbed on the disc surface. RBCs were arranged on the disc surface as a monolayer by removing excess cells through momentary rotation. Over 1.1 million RBCs remained on the disc for fluorescence analysis. A portable, battery-driven fluorescence image reader was employed to detect fluorescence-positive RBCs for approximately 40 min. A good correlation between examination of Giemsa-stained RBCs by light microscopy and the developed system was demonstrated in the parasitemia range of 0.0001-1.0% by linear regression analysis (R2 = 0.99993). The limit of detection of 0.00020% and good reproducibility for parasitemia determination were observed. The ability of the developed system to detect sub-microscopic low-density Pf-iRBCs and provide accurate quantitative evaluation with easy operation was demonstrated.


Assuntos
Técnicas Biossensoriais/instrumentação , Eritrócitos/parasitologia , Malária Falciparum/parasitologia , Dispositivos Ópticos , Imagem Óptica/instrumentação , Plasmodium falciparum/isolamento & purificação , Benzimidazóis/análise , Desenho de Equipamento , Corantes Fluorescentes/análise , Humanos , Limite de Detecção , Malária Falciparum/diagnóstico , Parasitemia/diagnóstico , Parasitemia/parasitologia , Reprodutibilidade dos Testes
16.
Chemosphere ; 224: 562-571, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30836251

RESUMO

Herein, a method for the simultaneous determination of the currently prescribed sartan drugs (eprosartan, EPR; olmesartan, OLM; losartan, LOS; candesartan, CAN; telmisartan, TEL; irbesartan, IRB; and valsartan, VAL), and the biodegradation product valsartan acid (VALA), in water samples (raw and treated wastewater, river and tap water) was developed. Solid-phase extraction (SPE) and ultra-performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) were employed as concentration and determination techniques, respectively. Different sorbents and elution solvents were tested for sample preparation. Under optimized conditions, samples at neutral pH (6-8 units) were concentrated using mixed-mode (reversed-phase and anionic exchange) cartridges. Thereafter, the sorbent was washed with 5 mL of a methanol: water (1:1) solution, dried under a nitrogen stream and compounds were eluted with 2 mL of methanol: NH3 (98:2). The accuracy of the method (accounting for SPE efficiency and matrix effects during electrospray ionization) was investigated using solvent-based calibration standards. Global recoveries, obtained for different water matrices (tap, river, treated and raw wastewater), ranged from 82% to 134%, with standard deviations between 2 and 18%. LOQs varied from 2 to 50 ng L-1. Analysis of un-spiked samples confirmed: (1) the incomplete removal of sartans at sewage treatment plants (STPs), (2) the formation of VALA during municipal water treatment, and (3) the presence of VALA in the processed tap water samples. Additional findings of the current study are the detection of hydroxylated derivatives of the sartan drugs IRB and LOS in wastewater, and the E-Z isomerization of EPR in environmental water samples.


Assuntos
Anti-Hipertensivos/análise , Cromatografia Líquida/métodos , Monitoramento Ambiental/métodos , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Anti-Hipertensivos/isolamento & purificação , Benzimidazóis/análise , Tetrazóis/análise , Valsartana/análise , Purificação da Água
17.
Food Chem ; 280: 103-109, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30642474

RESUMO

In this study, a molecularly imprinted polymer capable of recognizing 8 benzimidazoles was first synthesized. The computation simulation showed that the shape and size of used template were the main factors influencing its recognition ability. Then the polymer was used as recognition reagent to prepare a chemiluminescence sensor on conventional 96-well microplate. The sample solution and a HRP-labeled hapten were added into the microplate wells to perform competitive binding, and the light signal was initiated with 4-(imidazol-1-yl)phenol enhanced luminol-H2O2 system. The optimized sensor was used to determine the residues of 8 benzimidazoles in mutton and beef. Result showed that the sensor achieved ultrahigh sensitivity (limits of detection of 1.5-21 pg/mL), rapid assay process (18 min) and satisfactory recovery (65.8%-91.2%). Furthermore, this sensor could be reused for 4 times. Therefore, this sensor could be used as a rapid, simple, sensitive and durable tool for screening the residual benzimidazoles in meat.


Assuntos
Benzimidazóis/análise , Análise de Alimentos/métodos , Medições Luminescentes/métodos , Carne/análise , Análise de Alimentos/instrumentação , Contaminação de Alimentos/análise , Peróxido de Hidrogênio/química , Medições Luminescentes/instrumentação , Luminol/química , Mebendazol/análise , Impressão Molecular , Polímeros/química
18.
J Pharm Biomed Anal ; 166: 20-29, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30599278

RESUMO

Lifirafenib (BGB-283), a dual inhibitor trageting BRAF kinase and EGFR, showed favorable efficacy and safety in treating patients with different cancer types harboring mutations in BRAF, KRAS and NRAS. In order to support the clinical pharmacokinetic study, a sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and validated to quantify lifirafenib concentration in human plasma and urine. Plasma samples were purified using protein precipitation. Urine samples were pre-treated by adding tween 80 with the purpose of preventing non-specific adsorption, then extracted by centrifugation. Chromatographic separation was achieved on Phenomenex Luna C18 column with a gradient elution. The mass detection was performed using electrospray ionization (ESI) source under multiple reaction monitoring (MRM) in positive ionization mode. The method was fully validated, and the result of inter-assay and intra-assay precisions were less than 15% and the accuracy within the scope of ±15%. The linear range for plasma and urine covered from 10 to 10,000 ng/mL and 1 to 200 ng/mL, respectively, with correlation coefficients of 0.99. The validation for matrix effect, recovery, stability and carryover were met the acceptance criteria. The method showed robust and sensitive, it successfully fulfilled the requirement of clinical pharmacokinetic study of lifirafenib in Chinese patients with locally advanced or metastatic solid tumors.


Assuntos
Benzimidazóis/análise , Cromatografia Líquida de Alta Pressão/métodos , Naftiridinas/análise , Espectrometria de Massas em Tandem/métodos , Benzimidazóis/sangue , Benzimidazóis/farmacocinética , Benzimidazóis/urina , Confiabilidade dos Dados , Humanos , Naftiridinas/sangue , Naftiridinas/farmacocinética , Naftiridinas/urina , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray
19.
Biomed Chromatogr ; 33(2): e4394, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30248717

RESUMO

As one of the main fungicides for the apple leaf disease control, thiophanate-methyl (TM) mainly exerts its fungicidal activity in the form of its metabolite carbendazim (MBC), whose dissipation kinetics is very distinct from that of its parent but has been paid little attention. The aim of this work was to investigate the dissipation kinetics of TM and its active metabolite MBC in apple leaves using a modified QuEChERS-UPLC-MS/MS method. The results showed that TM and MBC could be quickly extracted by this modified QuEChERS procedure with recoveries of 81.7-96.5%. The method linearity was in the range of 0.01-50.0 mg kg-1 with the quantification limit of 0.01 mg kg-1 . Then this method was applied to the analysis of fungicide dissipation kinetics in apple leaves. The results showed that the dissipation kinetics of TM for the test in 3 months can be described by a first-order kinetics model with a DT50 (dissipation half-life) range of 5.23-6.03 days and the kinetics for MBC can be described by a first-order absorption-dissipation model with the Tmax (time needed to reach peak concentration) range of 4.78-7.09 days. These models can scientifically describe the behavior of TM and MBC in apple leaves, which provides necessary data for scientific application.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Malus/química , Resíduos de Praguicidas/análise , Tiofanato/análise , Adsorção , Benzimidazóis/química , Benzimidazóis/farmacocinética , Carbamatos/química , Carbamatos/farmacocinética , Cromatografia Líquida de Alta Pressão/métodos , Modelos Lineares , Resíduos de Praguicidas/química , Resíduos de Praguicidas/farmacocinética , Folhas de Planta/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas em Tandem/métodos , Tiofanato/química , Tiofanato/farmacocinética
20.
J Chromatogr Sci ; 57(3): 213-219, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30395199

RESUMO

Azilsartan Medoxomil (AZL) angiotensin II receptor blocker and chlorthalidone (CLT) were determined by ultraperformance liquid chromatography (UPLC) method in their combined dosage form, they were both subjected to forced degradation studies under extensive stress conditions. The method is a stability indicating by resolving the investigated drugs from their degradation products. Moreover, the degradation products for both drugs obtained from forced degradation were subjected to LC-MS for structure elucidation. The UPLC technique depends on the measurement of spectra for AZL and CLT at 254 nm. Linearity, accuracy and intermediate precision were acceptable over the concentration range of 67.2-268.8 and 40-160 µg/mL for AZL and CLT, respectively. The method was applied for the determination of the studied drugs in their dosage forms. The UPLC method is inexpensive, simple and considered as green chemistry method for the routine analysis and quality control of both drugs in their combined dosage form.


Assuntos
Benzimidazóis/análise , Benzimidazóis/química , Clortalidona/análise , Clortalidona/química , Cromatografia Líquida de Alta Pressão/métodos , Oxidiazóis/análise , Oxidiazóis/química , Estabilidade de Medicamentos , Modelos Lineares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Comprimidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA