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1.
Math Biosci Eng ; 21(2): 2050-2083, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38454674

RESUMEN

The influence of short-range interactions between a multi-phase, multi-component mixture and a solid wall in confined geometries is crucial in life sciences and engineering. In this work, we extend the Cahn-Hilliard model with dynamic boundary conditions from a binary to a ternary mixture, employing the Onsager principle, which accounts for the cross-coupling between forces and fluxes in both the bulk and surface. Moreover, we have developed a linear, second-order and unconditionally energy-stable numerical scheme for solving the governing equations by utilizing the invariant energy quadratization method. This efficient solver allows us to explore the impacts of wall-mixture interactions and dynamic boundary conditions on phenomena like spontaneous phase separation, coarsening processes and the wettability of droplets on surfaces. We observe that wall-mixture interactions influence not only surface phenomena, such as droplet contact angles, but also patterns deep within the bulk. Additionally, the relaxation rates control the droplet spreading on surfaces. Furthermore, the cross-coupling relaxation rates in the bulk significantly affect coarsening patterns. Our work establishes a comprehensive framework for studying multi-component mixtures in confined geometries.

2.
Molecules ; 29(1)2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38202829

RESUMEN

Following previous studies, the ternary mixture of methanol/formamide/acetonitrile (MeOH/Formamide/MeCN) was studied using the UV-Vis absorption spectra at 298.15 K with a set of five probes, 4-nitroaniline, 4-nitroanisole, 4-nitrophenol, N,N-dimethyl-4-nitroaniline and 2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridinio)phenolate (Reichardt betaine dye), for a total of 22 mole ternary fractions. In addition, nine mole fractions of the underling binary mixtures, MeOH/Formamide and Formamide/MeCN were also tested. Spectroscopic results were used to model the preferential solvation order for each probe in the mixtures. The Kamlet-Taft solvatochromic solvent parameters, α, ß, and π*, were also computed through the use of the solvatochromic shifts of the five probe indicators. Moreover, discrepancies in the spectroscopic behavior of 4-nitrophenol in formamide-rich mixtures were observed and analyzed.

3.
Artículo en Inglés | MEDLINE | ID: mdl-37591457

RESUMEN

Metal oxide nanoparticles (NPs) are considered among the most prevalent engineered nanomaterials. To have a deeper understanding of the mode of action of multiple metal oxide nanoparticles in mixtures, we have used a unicellular freshwater microalga Scenedesmus obliquus as a model organism. The toxicity of silicon dioxide (SiO2), iron oxide (Fe3O4), and zinc oxide (ZnO) NPs was studied individually as well as in their binary (SiO2 + Fe3O4, Fe3O4 + ZnO, and ZnO + SiO2) and ternary (SiO2 + Fe3O4 + ZnO) combinations. The effects of metal ions from ZnO and Fe3O4 were investigated as well. The results observed from the study, showed that a significant amount of toxicity was contributed by the dissolved ions in the mixtures of the nanoparticles. Decreases in the cell viability, ROS generation, lipid peroxidation, antioxidant enzyme activity, and photosynthetic efficiency were analyzed. Among all the individual particles, ZnO NPs showed the maximum effects and increased the toxicities of the binary mixtures. The binary and ternary mixtures of the NPs clearly showed increased toxic effects in comparison with the individual entities. However, the ternary combination had lesser toxic effects than the binary combination of Fe3O4 + ZnO. The decline in cell viability and photosynthetic efficiency were strongly correlated with various oxidative stress biomarkers emphasizing the crucial role of reactive oxygen species in inducing the toxic effects. The findings from this study highlight the importance of evaluating the combinatorial effects of various metal oxide NPs as part of a comprehensive ecotoxicity assessment in freshwater microalgae.


Asunto(s)
Nanopartículas del Metal , Microalgas , Scenedesmus , Óxido de Zinc , Óxido de Zinc/toxicidad , Dióxido de Silicio/toxicidad , Óxidos , Nanopartículas del Metal/toxicidad , Antioxidantes , Agua Dulce , Iones
4.
Membranes (Basel) ; 12(11)2022 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-36363589

RESUMEN

Aquivion® E87-12S Perfluorosulfonated acid ionomer material (PFSA) has been studied as a membrane technology for natural gas sweetening from CO2, H2S due to its interesting chemical and mechanical stability and good separation performance for polar compounds in humid environments. In the present work, permeation of the H2S/CO2/CH4 ternary mixture in this short-side PFSA chain was investigated at pressures up to 10 bar, temperatures up to 50 °C, and in a range of relative humidity (RH) from 20% to 90%. The results obtained confirm the strong dependence of Aquivion® on water activity and temperature, and its ability to separate gases based on their water solubility without substantial differences between pure and mixed gas experiments. Indeed, even when tested in ternary mixture, the permeation behavior remains similar to that observed for pure components and binary mixtures. In particular, the permeability of H2S is higher than that of CO2 and methane CH4, reaching values of 500 Barrer at 50 °C and 80% RH, against 450 and 23 Barrer for the other two gases respectively. Additionally, when tested at higher pressures of up to 10 bar under humid conditions, the membrane properties remained largely unchanged, thus confirming the overall stability and durability of Aquivion® E87-12S in acid environments.

5.
J Pharm Sci ; 111(10): 2758-2764, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35908653

RESUMEN

Mesalazine is a low-permeable and low-soluble drug, which makes it a class IV drug in the Biopharmaceutics Classification System. Hence, its solubilization can be helpful for various stages of formulation development. The purpose of this study was to investigate the solubilization manner and thermodynamics of mesalazine in ternary solvent combinations of {ethanol (1) + propylene glycol (2) + water (3)} using the shake-flask technique at (298.2-313.2) K. In the following, the mathematical representation of the acquired solubility data using some popular models was evaluated. The accuracies of the applied models were described by percentages of mean relative deviation (MRD%). Based on obtained results (MRD% < 10.0), it can be concluded that the trained models can adequately predict the solubility of mesalazine in the investigated ternary solvent combinations. The findings also revealed that the solution composition and temperatures greatly influence the solubility of mesalazine. In addition, the thermodynamic characteristics of the mesalazine dissolution process indicate that the mesalazine dissolution process is endothermic and entropy-driven. The generating data in the current work also expands the available solubility database for mesalazine in the solvent mixtures.


Asunto(s)
Etanol , Agua , Mesalamina , Propilenglicol , Solubilidad , Solventes , Temperatura , Termodinámica
6.
Meat Sci ; 188: 108785, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35278974

RESUMEN

This study aims to optimize the preparation of thyme essential oil nanoemulsion using a ternary mixture design based on the following three components: chitosan, gum Arabic and median-chain triacyglycerols (MCT). The results showed that the formulation which contained 40% chitosan, 40% gum Arabicand 20% of MCT led to a stable nanoemulsion within 30 days of storage at 4 °C. Indeed, the observed mean diameter (d[4,3]) and the polydispersity index (PDI) are the lowest with a ζ-potential value greater than +30 mV. Moreover, the amount of thyme essential oil dissolved in MCT was optimized and the 2% (w/w) was selected to prepare O/W nanoemulsion for preserving meat products. Besides, the obtained data of the chemical characteristics of meat products demonstrated that the pH, TVNB, TBARS, shear strength increased slightly and insignificantly with storage time at 4 °C.However, there was a difference between control and sample treated with nanoemulsionsin terms of physicochemical characteristics.


Asunto(s)
Quitosano , Aceites Volátiles , Thymus (Planta) , Emulsiones , Carne
7.
Environ Sci Pollut Res Int ; 29(33): 49908-49924, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35220522

RESUMEN

The present article analyses the refrigerant safety parameters flammability, global warming potential (GWP) and coefficient of performance (COP) for twenty-seven combinations that contain two flammable and one non-flammable (dilutant) component. The flammability of the flammable refrigerants R290, R600, R600a, R152a and R161 were investigated with different dilutants such as R245fa, R13I1 and R134a. To determine the minimum inerting concentration (which decides the flammable zone), two methods were used: thermal balance method (TBM) and the modified thermal balanced method (MTBM). The MICs estimated with both the methods are compared against the 50 experimental data points available in the literature (for different ternary mixtures). It was found that for all the ternary mixtures, majority of the MIC values estimated with MTBM are within ± 8% while with TBM are within ± 30%. Fifty-five ternary mixture compositions were identified (from the proposed twenty-seven mixture combinations) using the MICs predicted by MTBM. The COPs of the identified mixtures M1-M6, M8-M12, M14-M24, M26-M30, M34-M39 and M53-M54 are estimated to be less than 10% of the COP of R134a (at the same operating conditions). It is also estimated that the corresponding GWP value of the mixtures (M1 to M6, M8 to M12, M14 to M24, M26 to M30, M34 to M39, M53 and M54) are reduced by 91 to 99% when compared to R134a (GWP = 1300).


Asunto(s)
Gases , Calentamiento Global
8.
Food Chem ; 377: 132005, 2022 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-34998152

RESUMEN

This study investigated the effect of whey protein isolate (WPI) and phenolic copigments on the color and anthocyanin stability of mulberry anthocyanin extract (MAE) subjected to heat treatment (80℃/120 min) at pH 3.6. Results showed that four phenolic compounds, including gallic acid, ferulic acid, (-)-epigallocatechin gallate (EGCG), and rutin, significantly affected the color enhancement of MAE solution, among which the strongest copigmentation effect on MAE was observed for rutin at 0.08-0.8 mg/ml. WPI (0.16 mg/ml) and rutin (0.8 mg/ml) reduced the thermal degradation rate of total anthocyanins by 27.1% and 50%, respectively. WPI-MAE-rutin ternary mixtures improved the color stability of MAE solution and decreased the anthocyanin's thermal degradation rate by 18.1% and 10.6%, respectively, compared with the corresponding binary systems (MAE-WPI and MAE-rutin). The results implied the MAE-WPI-rutin had a better protective effect on the thermal stability of MAE than the binary systems.


Asunto(s)
Antocianinas , Morus , Fenoles/química , Extractos Vegetales , Proteína de Suero de Leche , Antocianinas/química , Concentración de Iones de Hidrógeno , Morus/química , Extractos Vegetales/química , Proteína de Suero de Leche/química
9.
Heliyon ; 7(8): e07858, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34485737

RESUMEN

This study aims to improve the fuel properties limitations of biodiesel which affect the engine performance characteristics in diesel engines. A ternary mixture simplex axial design model was used to determine the fuel properties of ternary blend mixture of waste distilled engine oil, waste cooking oil biodiesel, and petroleum diesel, and comparing it with existing physical properties models. The fuel properties namely: heating value, flash point, cetane number, density, and viscosity were determined by changing the composition in the ternary mixture design. Furthermore, the experimental data of the mixture model was fitted with existing viscosity, density, heating value, and flash point models. The viscosities were fitted with the Cragoe, Bingham, Arrhenius, and Kendall-Monroe viscosity models at 40 °C respectively. The best fit of the experimental data occurred in the following descending order: Arrhenius, Kendall-Monroe, Bingham, and Cragoe with R2 values of 0.9771, 0.9529, 0.9508, and 0.6096, respectively. The density at 20 °C, heating value, flash point, and cetane number were fitted with Kay's model based on the mixing empirical equation. The results showed that these properties were well predicted by Kay's model mixing rule empirical model due to high values of R2 of 0.9880, 0.978, 0.9929, and 0.961 respectively. The viscosity, density, heating value, and flash point of the ternary blend mixtures are within the American Society for Testing and Materials (ASTM) D 6751 and ASTM D 975 specifications range.

10.
Spectrochim Acta A Mol Biomol Spectrosc ; 263: 120137, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34273891

RESUMEN

Five simple, selective and accurate spectrophotometric methods have been applied and developed for first time for simultaneous determination of amlodipine besylate (AML) and celecoxib (CEL) in presence of one harmful impurity, 4-methylacetophenone (MAP), in their ternary mixture without prior separation. Those spectrophotometric methods were developed and called: dual wave length in ratio spectra (DWRS), successive ratio-derivative spectra (SDR), modified absorption factor method (MAFM), modified amplitude center method (MACM) and first derivative -zero crossing coupled with amplitude factor method (FDAF). These methods include various steps using zero /or ratio /or derivative spectra and some mathematical techniques. Linear calibration curves were constructed over the concentration range of 2-100, 10-200 and 0.5-20 µg/mL for AML, CEL and MAP, respectively. High sensitivity with low LOD values 0.583, 3.118 and 0.147 for AML, CEL and MAP, respectively were obtained. Moreover, validation of the proposed methods was achieved according to ICH guidelines and satisfactory results were obtained indicating that the developed methods can be used for quality control analysis of AML and CEL concerning its impurity. No significant difference was observed when the obtained results of the developed methods were statistically compared with the reported HPLC method.


Asunto(s)
Amlodipino , Celecoxib , Espectrofotometría
11.
Carbohydr Polym ; 245: 116437, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32718594

RESUMEN

This contribution falls within the context of sustainable functional materials. We report on the production of fruit leathers based chiefly on peach pulp, but combined with hydroxypropyl methylcellulose (HPMC) as binding agent and cellulose micro/nanofibrils (CMNF) as fillers. Increased permeability to moisture (from 0.9 to 5.6 g mm kPa-1 h-1m-2) and extensibility (from 10 to 17%) but reduced mechanical resistance (67-2 MPa) and stiffness (1.8 GPa-18 MPa) evidenced the plasticizing effect of peach pulp in HPMC matrix, which was reinforced by CMNF. A ternary mixture design allowed building response surfaces and optimizing leather composition. The laboratory-scale leather production via bench casting was extended to a pilot-scale through continuous casting. The effect of scaling up on the nutritional and sensory features of the peach leather was also depicted. The herein established composition-processing-property correlations are useful to support the large-scale production of peach leather towards applications both as packaging materials and as nutritional leathers.


Asunto(s)
Antioxidantes/química , Películas Comestibles , Frutas/química , Derivados de la Hipromelosa/química , Prunus persica/química , Humedad , Microfibrillas/química , Peso Molecular , Permeabilidad , Proyectos Piloto , Plastificantes/química
12.
J Pharm Biomed Anal ; 177: 112821, 2020 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-31491660

RESUMEN

Two high performance chromatographic methods were developed and validated for the simultaneous determination of Ambroxol, Guaifenesin and Theophylline in pharmaceutical dosage forms and in the presence of Guaiacol and Caffeine as the officially stated impurities. These were a reversed phase liquid and a thin layer chromatographic methods. The liquid chromatographic separation was achieved using Inertsil ODS-3 C18 column (4.6 mm × 250 mm, 5 µm). Gradient elution was performed using a mixture of solvent A (0.05 M ammonium acetate, pH 3, adjusted with glacial acetic acid) and solvent B (methanol), at a flow rate of 1.0 mL/min. The separated peaks were detected at 260.0 nm. The thin layer chromatography was performed using HPTLC 60 F254 silica gel plates, mobile phase was consisting of ethyl acetate: methanol: acetic acid (10:0.5:1, v/v/v) and detection was performed at 254.0 nm. Validation of the developed methods was achieved according to International Conference on Harmonization (ICH) guidelines. The proposed methods were fast, accurate, precise, and sensitive. Hence, they could be employed for routine quality control of the ternary mixture in capsule and syrup dosage forms.


Asunto(s)
Contaminación de Medicamentos/prevención & control , Control de Calidad , Fármacos del Sistema Respiratorio/análisis , Ambroxol/análisis , Ambroxol/química , Cafeína/análisis , Cápsulas , Cromatografía Líquida de Alta Presión/métodos , Combinación de Medicamentos , Guayacol/análisis , Indoles/análisis , Indoles/química , Límite de Detección , Quinolizinas/análisis , Quinolizinas/química , Reproducibilidad de los Resultados , Fármacos del Sistema Respiratorio/química , Fármacos del Sistema Respiratorio/normas , Teofilina/análisis , Teofilina/química
13.
Heliyon ; 5(8): e02203, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31453394

RESUMEN

Ultrasonic velocity (U), density (ρ), viscosity (ƞ) for the ternary mixture of benzene + chloroform + cyclohexane in the whole range of composition has been carried out at various temperatures 303.15, 308.15 and 313.15K. From the measured parameters U, ρ and ƞ, some derived parameters ß, L f , V f , π i , Z, R,W with molar enthalpy (H m ) and apparent molar volume (ɸ v ) are also estimated. The decreasing trend of ƞ, R,W, H m , and ɸ v with concentrations and other parameters are in increasing trend were observed. The trend of acoustical and physico-chemical parameters confirm the dynamics of molecules at higher temperature and the magnitude of intermolecular interactions among the constituents of the mixtures always reflects the nature of substance. The role of enthalpy and apparent molar volume has been used to determine their thermal response. The sign and magnitude of these properties are evident for the nature of interactions between component molecules.

14.
Sensors (Basel) ; 19(10)2019 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-31121987

RESUMEN

We discuss an effective tool for the detection and identification of substances in ternary mixtures with similar spectral properties using a broadband reflected THz signal. Nowadays, this is an urgent problem; its effective solution is still far off. Two ternary mixtures of the explosives (RDX+TNT+HMX and RDX+TNT+PETN) were used as the examples for demonstration of the efficiency of the method proposed. The identification is based on the pulsed THz spectroscopy. We follow the spectral intensities together with the use of integral correlation criteria. They use the spectral line dynamics of the THz pulse reflected from the substance under investigation and that of the standard THz signal from database. In order to increase the accuracy and reliability of the identification, we analyze the partial non-overlapping time intervals, containing the main pulse of the reflected THz signal and the sequential sub-pulses. The main pulse is shown to contain information about high absorption frequencies (ν > 2.6 THz) of the mixture components. In the sub-pulses, the absorption frequencies of the components are detected in the range of low (ν < 2.6 THz) and high (ν > 2.6 THz) frequencies. The opportunity of distinguishing the mixtures with similar spectral properties is also shown.

15.
J Chromatogr A ; 1562: 47-58, 2018 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-29859683

RESUMEN

An intermittent simulated moving bed (3F-ISMB) operation scheme, the extension of the 3W-ISMB to the non-linear adsorption region, has been introduced for separation of glucose, lactic acid and acetic acid ternary-mixture. This work focuses on exploring the feasibility of the proposed process theoretically and experimentally. Firstly, the real 3F-ISMB model coupled with the transport dispersive model (TDM) and the Modified-Langmuir isotherm was established to build up the separation parameter plane. Subsequently, three operating conditions were selected from the plane to run the 3F-ISMB unit. The experimental results were used to verify the model. Afterwards, the influences of the various flow rates on the separation performances were investigated systematically by means of the validated 3F-ISMB model. The intermittent-retained component lactic acid was finally obtained with the purity of 98.5%, recovery of 95.5% and the average concentration of 38 g/L. The proposed 3F-ISMB process can efficiently separate the mixture with low selectivity into three fractions.


Asunto(s)
Técnicas de Química Analítica/métodos , Ácido Láctico/aislamiento & purificación , Ácido Acético/aislamiento & purificación , Adsorción , Técnicas de Química Analítica/instrumentación , Glucosa/aislamiento & purificación
16.
Bioresour Technol ; 241: 593-602, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28601777

RESUMEN

An innovative benign process for recovery lactic acid from its fermentation broth is proposed using a novel hyper-cross-linked meso-micropore resin and water as eluent. This work focuses on modeling the competitive adsorption behaviors of glucose, lactic acid and acetic acid ternary mixture and explosion of the adsorption mechanism. The characterization results showed the resin had a large BET surface area and specific pore structure with hydrophobic properties. By analysis of the physicochemical properties of the solutes and the resin, the mechanism of the separation is proposed as hydrophobic effect and size-exclusion. Subsequently three chromatographic models were applied to predict the competitive breakthrough curves of the ternary mixture under different operating conditions. The pore diffusion was the major limiting factor for the adsorption process, which was consistent with the BET results. The novel HD-06 resin can be a good potential adsorbent for the future SMB continuous separation process.


Asunto(s)
Fermentación , Ácido Láctico , Ácido Acético , Adsorción , Difusión
17.
J Chromatogr A ; 1453: 19-33, 2016 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-27260199

RESUMEN

An 8-zone simulated moving bed chromatography with internal recycle (8ZSMB-IR) has been designed for center-cut separation, that is, for isolating an intermediately adsorbed component out of a multicomponent mixture. The system consists of two integrated subunits and operates in a fully continuous manner. In the first subunit the feed mixture is split into two fractions containing either a single component or a binary mixture. The binary mixture is recycled through the internal raffinate or extract port into the second subunit, where the target product is isolated. Additionally, the solvent is also recycled internally. For a case study, the separation of a ternary mixture of cycloketones as a model system under weakly non-linear isotherm conditions has been investigated. A few novel configurations of the 8ZSMB-IR unit including the arrangement of the internal recycle of extract, raffinate and solvent streams between two subunits have been examined with respect to various performance indicators for the process realization. The unit performed best with the developed configuration when the internal raffinate stream was recycled and the solvent recycling loop was closed between the last and the first zone of the first subunit. That configuration has further been analyzed experimentally and numerically. On the basis of the results a strategy for determining reliable operating conditions for the 8ZSMB-IR process has been developed. The procedure exploited a model of the process dynamics, which was implemented to refine the isotherm coefficients and to quantify the mixing effect of the liquid stream inside the recycling loops. The upgraded model with the adjusted parameters has been validated based on experimental data and successfully applied for optimizing the operating conditions of the separation.


Asunto(s)
Cromatografía/métodos , Adsorción , Cetonas/aislamiento & purificación , Modelos Teóricos , Solventes/química
18.
Artículo en Inglés | MEDLINE | ID: mdl-27314226

RESUMEN

Avocado oil is a high-value and nutraceutical oil whose authentication is very important since the addition of low-cost oils could lower its beneficial properties. Mid-FTIR spectroscopy combined with chemometrics was used to detect and quantify adulteration of avocado oil with sunflower and soybean oils in a ternary mixture. Thirty-seven laboratory-prepared adulterated samples and 20 pure avocado oil samples were evaluated. The adulterated oil amount ranged from 2% to 50% (w/w) in avocado oil. A soft independent modelling class analogy (SIMCA) model was developed to discriminate between pure and adulterated samples. The model showed recognition and rejection rate of 100% and proper classification in external validation. A partial least square (PLS) algorithm was used to estimate the percentage of adulteration. The PLS model showed values of R(2) > 0.9961, standard errors of calibration (SEC) in the range of 0.3963-0.7881, standard errors of prediction (SEP estimated) between 0.6483 and 0.9707, and good prediction performances in external validation. The results showed that mid-FTIR spectroscopy could be an accurate and reliable technique for qualitative and quantitative analysis of avocado oil in ternary mixtures.


Asunto(s)
Contaminación de Alimentos/análisis , Aceites de Plantas/análisis , Aceite de Soja/análisis , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Algoritmos , Calibración , Humanos , Análisis de los Mínimos Cuadrados , Persea/química , Análisis de Componente Principal , Espectroscopía Infrarroja por Transformada de Fourier/normas , Aceite de Girasol
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 153: 321-32, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26322842

RESUMEN

A comparative study of smart spectrophotometric techniques for the simultaneous determination of Omeprazole (OMP), Tinidazole (TIN) and Doxycycline (DOX) without prior separation steps is developed. These techniques consist of several consecutive steps utilizing zero/or ratio/or derivative spectra. The proposed techniques adopt nine simple different methods, namely direct spectrophotometry, dual wavelength, first derivative-zero crossing, amplitude factor, spectrum subtraction, ratio subtraction, derivative ratio-zero crossing, constant center, and successive derivative ratio method. The calibration graphs are linear over the concentration range of 1-20 µg/mL, 5-40 µg/mL and 2-30 µg/mL for OMP, TIN and DOX, respectively. These methods are tested by analyzing synthetic mixtures of the above drugs and successfully applied to commercial pharmaceutical preparation. The methods that are validated according to the ICH guidelines, accuracy, precision, and repeatability, were found to be within the acceptable limits.


Asunto(s)
Doxiciclina/análisis , Omeprazol/análisis , Espectrofotometría/métodos , Tinidazol/análisis , Formas de Dosificación , Doxiciclina/química , Omeprazol/química , Estándares de Referencia , Reproducibilidad de los Resultados , Tinidazol/química
20.
Mar Pollut Bull ; 102(1): 30-5, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26705576

RESUMEN

The aims of the present study were to optimize and validate methods for esterase activity (EA), total oxidant status (TOS) and total antioxidant capacity (TAC) determination in mussel' gills, and to establish the relationships between these biomarkers and Pb, Cd and Cu pollution, in single form and ternary mixture. Two different buffers for sample homogenization, the need of ultracentrifugation, and analytical validation were evaluated. Coefficients of variation, when buffer without additives and ultracentrifugation were used, were <15%, and recovery were 97%-109% in all cases. The EA response tends to decrease with treatments, TOS decreased significantly in Cd and ternary groups, while TAC tended to increase in treatments with Pb, Cd and ternary groups. In conclusion, the methods for EA, TOS and TAC measurements in gills of mussel were precise and accurate and could be interesting resources in biomonitoring programmes.


Asunto(s)
Antioxidantes/metabolismo , Esterasas/metabolismo , Metales Pesados/toxicidad , Mytilus/metabolismo , Oxidantes/metabolismo , Contaminantes Químicos del Agua/toxicidad , Animales , Biomarcadores , Monitoreo del Ambiente/métodos , Branquias/efectos de los fármacos , Branquias/metabolismo , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis
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