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1.
Int J Mol Sci ; 24(8)2023 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-37108587

RESUMEN

A new synthetic material, namely, (3-(((4-((5-(((S)-hydroxyhydrophosphoryl)oxy)-2-nitrobenzylidene) amino) phenyl) imino) methyl)-4-nitrophenyl hydrogen (R)-phosphonate)), was subjected to a quaternary ammonium salt and named (HNAP/QA). Several characterizations, such as FTIR spectrometry, 1H-NMR analysis, 13C-NMR analysis, 31P-NMR Analysis, TGA analysis, and GC-MS analysis, were performed to ensure its felicitous preparation. HNAP/QA is capable of the selective adsorption of W(VI) ions from its solutions and from its rock leachate. The optimum factors controlling the adsorption of W(VI) ions on the new adsorbent were studied in detail. Furthermore, kinetics and thermodynamics were studied. The adsorption reaction fits the Langmuir model. The sorption process of the W(VI) ions is spontaneous due to the negative value of ∆G° calculated for all temperatures, while the positive value of ∆H° proves that the adsorption of the W(VI) ions adsorption on HNAP/QA is endothermic. The positive value of ∆S° suggests that the adsorption occurs randomly. Ultimately, the recovery of W(IV) from wolframite ore was conducted successfully.


Asunto(s)
Cromo , Contaminantes Químicos del Agua , Cromo/química , Bases de Schiff/química , Termodinámica , Temperatura , Iones , Adsorción , Cinética , Concentración de Iones de Hidrógeno
2.
Int J Mol Sci ; 23(15)2022 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-35955812

RESUMEN

Spent Ni-Cd batteries are now considered an important source for many valuable metals. The recovery of cadmium, cobalt, and nickel from spent Ni-Cd Batteries has been performed in this study. The optimum leaching process was achieved using 20% H2SO4, solid/liquid (S/L) 1/5 at 80 °C for 6 h. The leaching efficiency of Fe, Cd, and Co was nearly 100%, whereas the leaching efficiency of Ni was 95%. The recovery of the concerned elements was attained using successive different separation techniques. Cd(II) ions were extracted by a solvent, namely, Adogen® 464, and precipitated as CdS with 0.5% Na2S solution at pH of 1.25 and room temperature. The extraction process corresponded to pseudo-2nd-order. The prepared PTU-MS silica was applied for adsorption of Co(II) ions from aqueous solution, while the desorption process was performed using 0.3 M H2SO4. Cobalt was precipitated at pH 9.0 as Co(OH)2 using NH4OH. The kinetic and thermodynamic parameters were also investigated. Nickel was directly precipitated at pH 8.25 using a 10% NaOH solution at ambient temperature. FTIR, SEM, and EDX confirm the structure of the products.


Asunto(s)
Cadmio , Níquel , Cadmio/química , Cobalto , Suministros de Energía Eléctrica , Níquel/química , Dióxido de Silicio
3.
Molecules ; 27(16)2022 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-36014341

RESUMEN

Tannery industries are one of the extensive industrial activities which are the major source of chromium contamination in the environment. Chromium contamination has been an increasing threat to the environment and human health. Therefore, the removal of chromium ions is necessary to save human society. This study is oriented toward the preparation of a new triazole Schiff base derivatives for the remediation of chromium ions. 4,4'-((1E)-1,2-bis ((1H-1,2,4-triazol-3-yl) imino)ethane-1,2-diyl) diphenol was prepared by the interaction between 3-Amino-1H-1,2,4-triazole and 4,4'-Dihydroxybenzil. Then, the produced Schiff base underwent a phosphorylation reaction to produce the adsorbent (TIHP), which confirmed its structure via the different tools FTIR, TGA, 1HNMR, 13CNMR, GC-MS, and Phosphorus-31 nuclear magnetic resonance (31P-NMR). The newly synthesized adsorbent (TIHP) was used to remove chromium oxyanions (Cr(VI)) from an aqueous solution. The batch technique was used to test many controlling factors, including the pH of the working aqueous solution, the amount of adsorbent dose, the initial concentration of Cr(VI), the interaction time, and the temperature. The desorption behaviour of Cr(VI) changes when it is exposed to the suggested foreign ions. The maximum adsorption capacity for Cr(VI) adsorption on the new adsorbent was 307.07 mg/g at room temperature. Freundlich's isotherm model fits the adsorption isotherms perfectly. The kinetic results were well-constrained by the pseudo-second-order equation. The thermodynamic studies establish that the adsorption type was exothermic and naturally spontaneous.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Cromo/química , Humanos , Concentración de Iones de Hidrógeno , Iones , Cinética , Bases de Schiff , Triazoles , Aguas Residuales , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos
4.
Acta Odontol Scand ; 76(1): 39-47, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28952824

RESUMEN

PURPOSE: The aim of this study was to evaluate available bone quality and quantity after performing sinus augmentation using simvastatin/ß-TCP combination versus ß-TCP alone. MATERIALS AND METHODS: This study included eight sinus lift procedures conducted on six patients. The sinuses were divided into two equal groups. The patients were recalled one, two weeks two, five, nine months post-operatively for post-operative evaluation. Radiographic evaluation involved cone beam computed tomography (CBCT) radiographs taken for every patient one week and nine months post-operatively to evaluate the changes in bone height, while histomorphometric evaluation involved transcortical bone biopsies taken after nine months during the second-stage surgery for implant placement. RESULTS: The histomorphometric results showed that the amount of newly formed bone was higher in the simvastatin group when compared to the ß-TCP group nine months after the surgery; the difference between the two groups was statistically significant. On the other hand, the radiographic evaluation showed that the rate of resorption of the simvastatin group was found to be higher than the control group; however, the difference between both groups was statistically insignificant. CONCLUSION: These results showed that Simvastatin is safe to be used in sinus lift with promising osteoinductive capacity, yet further studies using larger sample size is needed.


Asunto(s)
Sustitutos de Huesos/uso terapéutico , Fosfatos de Calcio/uso terapéutico , Simvastatina/uso terapéutico , Elevación del Piso del Seno Maxilar/métodos , Adulto , Anciano , Tomografía Computarizada de Haz Cónico , Quimioterapia Combinada , Femenino , Humanos , Masculino , Maxilar/patología , Seno Maxilar/diagnóstico por imagen , Persona de Mediana Edad , Proyectos Piloto
5.
Int J Biol Macromol ; 258(Pt 1): 128890, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38134996

RESUMEN

The release of harmful organic dyes from different industries besides its degradation products is a major contributor to environmental contamination. The catalytic reduction of these organic pollutants using nanocomposites based on polymeric material presents potential advantages for the environment. In this study, novel nanocomposite based on cellulose acetate (CA)-derived from discharged cigarette butts and zinc oxide nanoparticles (ZnO NPs) was prepared utilizing a very simple and low-cost solution blending method and used as support for silver nanoparticles (Ag NPs). A simple reduction method was used to anchor different percentages of Ag NPs on the ZnO@CA nanocomposite surface via utilizing sodium borohydride as a reducing agent. The Ag-ZnO@CA nanocomposite was characterized using X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The TEM analysis showed spherical Ag NPs, with an average diameter of ∼17.6 nm, were uniformly anchored on the ZnO@CA nanocomposite surface. The prepared nanocomposites were evaluated as catalysts for the reduction of organic dyes in water. It was found that 10 % Ag-ZnO@CA nanocomposite showed a remarkable reduction of Rhodamine B (RhB), Rhodamine 6G (Rh6G), Methylene Blue (MB), and Sunset Yellow (SY) dyes in short time. In the presence of this nanocomposite, the rate constant, kapp values for RhB, Rh6G, MB, and SY were 0.3498 min-1, 1.51 min-1, 0.2292 min-1, and 0.733 min-1, respectively. This nanocomposite was recovered and reused in five successive cycles, with a negligible loss of its activity. Furthermore, the nanocomposites demonstrated moderate antibacterial activity toward Staphylococcus aureus and Escherichia coli. Thus, this study directed attention on recycling of waste material to a valuable nanocomposite and its applications in environmental protection.


Asunto(s)
Celulosa/análogos & derivados , Nanopartículas del Metal , Nanocompuestos , Óxido de Zinc , Óxido de Zinc/química , Plata/química , Nanopartículas del Metal/química , Antibacterianos/química , Escherichia coli , Nanocompuestos/química , Colorantes
6.
Maxillofac Plast Reconstr Surg ; 44(1): 30, 2022 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-36136180

RESUMEN

PURPOSE: Surgical removal of intra-bony calcific benign lesions is technically challenging regarding its accessibility, proximity to vital structures, and deteriorating effect on the remaining bony structures. METHODS: Computer-guided buccal cortical plate separation was performed for ten patients using patient-specific osteotomy locating guides and pre-bent plates. The guide was designed to outline the osteotomy, the buccal cortical plate was separated, the lesion was removed, and finally, the pre-bent plates were used to fix the separated cortex. RESULTS: Surgical procedures were uneventful for all patients, operation time was 39.5 ± 13.01 min, postoperative pain decreased within the follow-up time intervals, and there was a statistical significant difference between the time intervals (P value < 0.001). Edema and trismus were acceptable. One case showed nerve affection which resolved after 4 weeks. CONCLUSION: Computer-guided buccal cortical plate separation for removal of intra-bony calcified benign lesions provides a promising approach, especially for inexperienced surgeons. TRIAL REGISTRATION: ClinicalTrials.gov NCT05329974 . Registered on 6 April 2022-retrospectively registered.

7.
Nanomaterials (Basel) ; 12(13)2022 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-35808142

RESUMEN

Considering how important rare earth elements (REEs) are for many different industries, it is important to separate them from other elements. An extractant that binds to REEs inexpensively and selectively even in the presence of interfering ions can be used to develop a useful separation method. This work was designed to recover REEs from spent nickel-metal hydride batteries using ammonium sulfate. The chemical composition of the Ni-MH batteries was examined. The operating leaching conditions of REE extraction from black powder were experimentally optimized. The optimal conditions for the dissolution of approximately 99.98% of REEs and almost all zinc were attained through use of a 300 g/L (NH4)2SO4 concentration after 180 min of leaching time and a 1:3 solid/liquid phase ratio at 120 °C. The kinetic data fit the chemical control model. The separation of total REEs and zinc was conducted under traditional conditions to produce both metal values in marketable forms. The work then shifted to separate cerium as an individual REE through acid baking with HCl, thus leaving pure cerium behind.

8.
Luminescence ; 26(6): 510-7, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22162453

RESUMEN

A new highly sensitive and specific spectrofluorimetric method has been developed to determine a sympathomimetic drug pseudoephedrine hydrochloride. The present method was based on derivatization with 4-chloro-7-nitrobenzofurazan in phosphate buffer at pH 7.8 to produce a highly fluorescent product which was measured at 532 nm (excitation at 475 nm). Under the optimized conditions a linear relationship and good correlation was found between the fluorescence intensity and pseudoephedrine hydrochloride concentration in the range of 0.5-5 µg mL(-1). The proposed method was successfully applied to the assay of pseudoephedrine hydrochloride in commercial pharmaceutical formulations with good accuracy and precision and without interferences from common additives. Statistical comparison of the results with a well-established method showed excellent agreement and proved that there was no significant difference in the accuracy and precision. The stoichiometry of the reaction was determined and the reaction pathway was postulated.


Asunto(s)
4-Cloro-7-nitrobenzofurazano/química , Preparaciones Farmacéuticas/química , Seudoefedrina/análisis , Espectrometría de Fluorescencia/métodos , Estándares de Referencia
9.
ACS Omega ; 5(11): 5629-5637, 2020 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-32226838

RESUMEN

We developed a novel, simple, sensitive, accurate, and precise method for the determination of calcitonin in different serum samples with medullar thyroid carcinoma. The designed flower-like thin film gold nanoparticles doped in a sol-gel/polyethylene glycol mold are used as an optical biosensor for the efficient determination of calcitonin. The sensor was characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray microanalysis, and Fourier-transform infrared spectroscopy. The efficiency of the considered bio-sensor is done using the quencher calcitonin of the emission band at 360 nm of biomarker obtained at λex = 333 nm in acetonitrile solvent. The sensing mechanism was based on fluorescence resonance energy transfer. The remarkable quenching of the fluorescence intensity at 360 nm of optical sensor by various concentrations of calcitonin was successfully used as an optical biosensor for the assessment of calcitonin for different serum samples of patients with medullar thyroid carcinoma. The calibration plot was prepared for the concentration range 0.01-1000 pg/mL of calcitonin with a correlation coefficient of 0.99 and a detection limit of 0.707 pg/mL. The suggested method augments the sensitivity of calcitonin as a useful biomarker for the early diagnosis of medullar thyroid carcinoma. This method is considered as a gateway for the construction of a new prototype for the follow-up of thyroid cancer in the spinal cord during and after treatment.

10.
Front Chem ; 8: 561052, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33324607

RESUMEN

A low-cost, simple, and highly selective method was used for the assessment of total prostate specific antigen (tPSA) in the serum of prostate cancer patients. This method is based on quenching the intensity of luminescence displayed by the optical sensor Eu (TTA)3 phen/poly methylmethacrylate (PMMA) thin membrane or film upon adding different concentrations of tPSA. The luminescent optical sensor was synthesized and characterized through absorption, emission, scanning electron microscopy (SEM), and x-ray diffraction (XRD), and is tailored to present red luminescence at 614 nm upon excitation at 395 nm in water. The fabricated sensor fluorescence intensity is quenched in the presence of tPSA in aqueous media. The fluorescence resonance energy transfer (FRET) is the main mechanism by which the sensor performs. The sensor was successfully utilized to estimate tPSA in the serum of patients suffering prostate cancer in a time and cost effective way. The statistical results of the method were satisfactory with 0.0469 ng mL-1 as a detection limit and 0.99 as a correlation coefficient.

11.
Artículo en Inglés | MEDLINE | ID: mdl-17553739

RESUMEN

Two rapid, simple and sensitive extractive specrophotometric methods has been developed for the determination of three histamine H1-antagonists drugs, e.g., chlorphenoxamine hydrochloride (CPX), diphenhydramine hydrochloride (DPH) and clemastine (CMT) in bulk and in their pharmaceutical formulations. The first method depend upon the reaction of molybdenum(V) thiocyanate ions (Method A) with the cited drugs to form stable ion-pair complexes which extractable with methylene chloride, the orange red color complex was determined colorimetrically at lambda(max) 470nm. The second method is based on the formation of an ion-association complex with alizarin red S as chromogenic reagents in acidic medium (Method B), which is extracted into chloroform. The complexes have a maximum absorbance at 425 and 426nm for (DPH or CMT) and CPX, respectively. Regression analysis of Beer-Lambert plots showed a good correlation in the concentration ranges of 5.0-40 and 5-70microgmL(-1) for molybdenum(V) thiocyanate (Method A) and alizarin red S (Method B), respectively. For more accurate analysis, Ringbom optimum concentration ranges were calculated. The molar absorptivity, Sandell sensitivity, detection and quantification limits were calculated. Applications of the procedure to the analysis of various pharmaceutical preparations gave reproducible and accurate results. Further, the validity of the procedure was confirmed by applying the standard addition technique and the results obtained in good agreement well with those obtained by the official method.


Asunto(s)
Antagonistas de los Receptores Histamínicos H1/análisis , Preparaciones Farmacéuticas/química , Antraquinonas/química , Clemastina/análisis , Clemastina/química , Clemastina/aislamiento & purificación , Difenhidramina/análisis , Difenhidramina/química , Difenhidramina/aislamiento & purificación , Formas de Dosificación , Etilaminas/análisis , Etilaminas/química , Etilaminas/aislamiento & purificación , Antagonistas de los Receptores Histamínicos H1/química , Antagonistas de los Receptores Histamínicos H1/aislamiento & purificación , Concentración de Iones de Hidrógeno , Cinética , Reproducibilidad de los Resultados , Solventes/química , Espectrofotometría , Temperatura , Factores de Tiempo
12.
Artículo en Inglés | MEDLINE | ID: mdl-17964849

RESUMEN

A simple, rapid, and extractive spectrophotometric method was developed for the determination of hyoscine butylbromide (HBB) and famciclovir (FCV) in pure and pharmaceutical formulations. These methods are based on the formation of yellow ion-pair complexes between the basic nitrogen of the drug and four sulphonphthalein acid dyes, namely; bromocresol green (BCG), bromothymol blue (BTB), bromocresol purple (BCP) and bromophenol blue (BPB) in phthalate buffer of pH range (3.0-3.5). The formed complexes were extracted with chloroform and measured at 420, 412, 409 and 415nm for HBB and at 418, 412, 407 and 414nm for FCV using BCG, BTB, BCP and BPB, respectively. The analytical parameters and their effects on the reported systems are investigated. Beer's law was obeyed in the range 1.0-20microgmL(-1) with correlation coefficient (n=6)> or =0.9997. The molar absorptivity, Sandell sensitivity, detection and quantification limits were also calculated. The composition of the ion pairs was found 1:1 by Job's method in all cases and the conditional stability constant (Kf) of the complexes have been calculated. The free energy changes (DeltaG) were determined for all complexes formed. The proposed methods have been applied successfully for the analysis of the studied drugs in pure and pharmaceutical formulations with percentage recoveries ranges from 99.84 to 100.26. The results were in good agreement with those obtained by the official methods.


Asunto(s)
2-Aminopurina/análogos & derivados , Bromuro de Butilescopolamonio/química , 2-Aminopurina/química , Química Farmacéutica , Famciclovir , Concentración de Iones de Hidrógeno , Iones/química , Estructura Molecular , Sensibilidad y Especificidad , Solventes , Espectrofotometría , Temperatura , Factores de Tiempo
13.
J AOAC Int ; 90(3): 686-92, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17580620

RESUMEN

Three simple, sensitive, and reproducible spectrophotometric methods (A-C) for the determination of pipazethate hydrochloride (PiCl) in pure form and in pharmaceutical formulations are described. The first and second methods, A and B, are based on the oxidation of the drug by Fe3+ in the presence of o-phenanthroline (o-phen) or bipyridyl (bipy). The formation of tris-complex upon reactions with Fe3+-o-phen and/or Fe3+-bipy mixture in an acetate buffer solution of the optimum pH values was demonstrated at 510 and 522 nm, respectively, with o-phen and bipy. The third method, C, is based on the reduction of Fe(III) by PiCl in acid medium and subsequent interaction of Fe(II) with ferricyanide to form Prussian blue, which exhibits an absorption maximum at 750 nm. The concentration ranges are from 0.5 to 8, 2 to 16, and 3 to 15 microg/mL for Methods A-C, respectively. For more accurate analysis, Ringbom optimum concentration ranges were calculated. The molar absorptivity, Sandell sensitivity, and detection and quantitation limits were calculated. The developed methods were successfully applied to the determination of PiCl in bulk and pharmaceutical formulations without any interference from common excipients. The relative standard deviations were < or =0.83% with recoveries of 98.9-101.15%.


Asunto(s)
Benzotiadiazinas/análisis , Benzotiadiazinas/química , Química Farmacéutica/métodos , 2,2'-Dipiridil/química , Acetatos/química , Tampones (Química) , Ferricianuros/química , Ferrocianuros/farmacología , Concentración de Iones de Hidrógeno , Modelos Químicos , Preparaciones Farmacéuticas/química , Fenantrolinas/química , Reproducibilidad de los Resultados , Espectrofotometría , Comprimidos , Temperatura
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 66(4-5): 1279-87, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17142094

RESUMEN

Two rapid, simple and sensitive extractive specrophotometric methods has been developed for the determination of anti-tussive drugs, e.g., dextromethorphan hydrobromide (DEX) and pipazethate hydrochloride (PiCl) and anti-spasmodic drugs, e.g., drotaverine hydrochloride (DvCl) and trimebutine maleate (TM) in bulk and in their pharmaceutical formulations. The proposed methods depend upon the reaction of cobalt(II)-thiocyanate (method A) and molybdenum(V)-thiocyanate ions (method B) with the cited drugs to form stable ion-pair complexes which extractable with an n-butnol-dichloromethane solvent mixture (3.5:6.5) and methylene chloride for methods A and B, respectively. The blue and orange red color complexes are determined either colorimetrically at lambdamax 625 nm (using method A) and 467 or 470 nm for (DEX and PiCl) or (DvCl and TM), respectively (using method B). The concentration range is 20-400 and 2.5-50 microg mL-1 for methods A and B, respectively. The proposed method was successfully applied for the determination of the studied drugs in pure and in pharmaceutical formulations applying the standard additions technique and the results obtained in good agreement well with those obtained by the official method.


Asunto(s)
Antitusígenos/análisis , Cobalto/química , Molibdeno/química , Parasimpatolíticos/análisis , Tiocianatos/química , 1-Butanol/química , Antitusígenos/aislamiento & purificación , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Parasimpatolíticos/aislamiento & purificación , Preparaciones Farmacéuticas/química , Reproducibilidad de los Resultados , Solventes , Espectrofotometría Ultravioleta
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 67(3-4): 1088-93, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17092767

RESUMEN

A simple, accurate and highly sensitive spectrophotometric method is proposed for the rapid determination of pipazethate hydrochloride, dextromethorphan hydrobromide and drotaverine hydrochloride using chromotrope 2B (C2B) and chromotrope 2R (C2R). The method consists of extracting the formed ion-associates into chloroform in the case of pipazethate HCl and dextromethorphan HBr or into methylene chloride in the case of drotaverine HCl. The ion-associates exhibit absorption maxima at 528, 540 and 532 nm with C2B and at 526, 517 and 522 nm with C2R for pipazethate HCl, dextromethorphan HBr and drotaverine HCl, respectively. The calibration curves resulting from the measurements of absorbance-concentration relations (at the optimum reaction conditions) of the extracted ion-pairs are linear over the concentration range 4.36-52.32 microg mL(-1) for pipazethate, 3.7-48.15 microg mL(-1) for dextromethorphan and 4.34-60.76 microg mL(-1) for drotaverine, respectively. The effect of acidity, reagent concentration, time, solvent and stoichiometric ratio of the ion-associates were estimated. The molar absorptivity and Sandell sensitivity of the reaction products were calculated. Statistical treatment of the results reflects that the procedure is precise, accurate and easily applied for the determination of the drugs under investigation in pure form and in their pharmaceutical preparations.


Asunto(s)
Antitusígenos/análisis , Benzotiadiazinas/análisis , Dextrometorfano/análisis , Papaverina/análogos & derivados , Preparaciones Farmacéuticas/análisis , Antitusígenos/química , Benzotiadiazinas/química , Calibración , Cloroformo/química , Dextrometorfano/química , Relación Dosis-Respuesta a Droga , Cloruro de Metileno/química , Estructura Molecular , Naftalenosulfonatos/química , Papaverina/análisis , Papaverina/química , Preparaciones Farmacéuticas/química , Sensibilidad y Especificidad , Solventes/química , Espectrofotometría Ultravioleta , Factores de Tiempo , Agua/química
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 67(5): 1306-12, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17113819

RESUMEN

Simple, rapid, and extractive spectrophotometric methods were developed for the determination of gatifloxacin (GT) in bulk and pharmaceutical dosage form. These methods are based on the formation of yellow ion-pair complexes between the basic nitrogen of the drug and three sulphonphthalein acid dyes, namely; bromocresol green (BCG), bromocresol purple (BCP), bromophenol blue (BPB) and bromothymol blue (BTB) in phthalate buffer pH 3.0, 3.4 and 3.2, using BCG, BCP and (BPB or BTB), respectively. The formed complexes were extracted with chloroform and measured at 415, 417, 412 and 414 nm for BCG, BPB, BCP and BTB, respectively. The analytical parameters and their effects on the reported systems are investigated. The reactions were extremely rapid at room temperature and the absorbance values remains unchanged at 48 h for all reactions. Beer's law was obeyed in the ranges 2.0-20, 2.0-14 and 2.0-16 microg mL(-1) for BCG, BCP and (BPB or BTB), respectively. The composition of the ion pairs was found 1:1 by Job's method. Beer's law validation, accuracy, precision, limits of detection, limits of quantification. The proposed methods have been applied successfully for the analysis of the drug bulk form and its dosage form. The results were in good agreement with those obtained by the official and reported methods.


Asunto(s)
Fluoroquinolonas/análisis , Preparaciones Farmacéuticas/análisis , Espectrofotometría/métodos , Tampones (Química) , Calibración , Fluoroquinolonas/química , Gatifloxacina , Concentración de Iones de Hidrógeno , Cinética , Reproducibilidad de los Resultados , Solventes , Temperatura , Factores de Tiempo , Tolueno/química
17.
Open Access Maced J Med Sci ; 5(1): 72-78, 2017 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-28293321

RESUMEN

AIM: This study was established to evaluate the amount of bone height changes in the posterior mandibular area of edentulous patients receiving screw-retained prostheses versus removable telescopic implant overdentures. MATERIAL AND METHODS: Every patient received four inter-foraminal implants regarding the mandibular arch and four anterior implants for the maxillary arch, computer guided surgical guides were planned for the insertion of the implants accurately with a flapless technique. Panoramic radiographs were made immediately, six months and twelve months after the prostheses` use proportional area and vertical measurements were applied to determine changes in the bone height of the posterior mandibular edentulous area. RESULTS: After twelve months, a statistically non-significant amount of bone resorption was reported for both groups. CONCLUSION: Up to the limitations of this study both treatment options the screw retained and telescopic overdenture can be used for rehabilitation of completely edentulous patients. These cases must be followed for a longer period to have a definite answer regarding their efficiency in the long run.

18.
Talanta ; 146: 435-41, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26695287

RESUMEN

A new simple and sensitive preconcentration, separation and environmentally friendly method based on carrier element free coprecipitation (CEFC) was developed using 4-(2-hydroxybenzylideneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one (APSAL) as a new organic co-precipitant to precipitate Cr(3+), Cu(2+), Fe(3+), Pb(2+) and Zn(2+) ions from water and food samples. The levels of the studied elements were detected by flame atomic absorption spectrometry (FAAS). The impact of several analytical parameters, such as pH, sample volume and coprecipitant amount as well as centrifugation rate and time was investigated to recover the examined metal ions. The influence of matrix ions was also tested, and no interferences were observed. The recovery values of the analyte ions were calculated and found to be in the range of 95-101%. The detection limits, corresponding to three times the standard deviation of the blank (N=10), were found to be in the range of 0.2-1.2 µg L(-1). The relative standard deviation (RSD) was calculated to evaluate the precision of the proposed method and was found to be ≤5.0%. The calculated preconcentration factor was 100. The proposed method was successfully applied to separate and preconcentrate trace amounts of ions in several water and food samples. To confirm the accuracy and validate the proposed method, certified reference materials were analyzed with satisfactory results.


Asunto(s)
Métodos Analíticos de la Preparación de la Muestra/métodos , Precipitación Química , Análisis de los Alimentos/métodos , Límite de Detección , Metales Pesados/análisis , Metales Pesados/aislamiento & purificación , Agua/química , Centrifugación , Concentración de Iones de Hidrógeno , Pirazoles/química , Factores de Tiempo , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/aislamiento & purificación
19.
Food Chem ; 202: 409-16, 2016 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-26920312

RESUMEN

A new, sensitive and simple solid phase extraction (SPE), separation and preconcentration method of some heavy metal ions, Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II) at trace levels using multiwalled carbon nanotubes (MWCNTs) impregnated with 2-(2-benzothiazolylazo)orcinol (BTAO) from food and water samples were investigated. The effect of analytical parameters was examined. The metals retained on the nanotubes at pH 7.0 were eluted by 5.0mL HNO3 (2.0molL(-1)). The influence of matrix ions on the proposed method was evaluated. The preconcentration factor was calculated and found to be 100. The detection limits (LODs) for Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II) were found at 0.70, 1.2, 0.80, 2.6 and 2.2µgL(-1), respectively. The relative standard deviation (RSD) and the recoveries of the standard addition method were lower than 5.0% and 95-102%, respectively. The new procedure was successfully applied to the determination of trace amounts of the studied metal ions in various food and water samples and validated using certified reference materials SRM 1570A (spinach leaves) with satisfactory and compatible results.


Asunto(s)
Análisis de los Alimentos/métodos , Metales Pesados/análisis , Nanotubos de Carbono/química , Extracción en Fase Sólida/métodos , Contaminantes Químicos del Agua/análisis , Concentración de Iones de Hidrógeno , Límite de Detección , Espectroscopía de Resonancia Magnética
20.
Acta Pharm ; 66(1): 109-18, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26959547

RESUMEN

A novel, simple and robust high-performance liquid chromatography (HPLC) method was developed and validated for simultaneous determination of xipamide (XIP), triamterene (TRI) and hydrochlorothiazide (HCT) in their bulk powders and dosage forms. Chromatographic separation was carried out in less than two minutes. The separation was performed on a RP C-18 stationary phase with an isocratic elution system consisting of 0.03 mol L(-1) orthophosphoric acid (pH 2.3) and acetonitrile (ACN) as the mobile phase in the ratio of 50:50, at 2.0 mL min(-1) flow rate at room temperature. Detection was performed at 220 nm. Validation was performed concerning system suitability, limits of detection and quantitation, accuracy, precision, linearity and robustness. Calibration curves were rectilinear over the range of 0.195-100 µg mL(-1) for all the drugs studied. Recovery values were 99.9, 99.6 and 99.0 % for XIP, TRI and HCT, respectively. The method was applied to simultaneous determination of the studied analytes in their pharmaceutical dosage forms.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Hidroclorotiazida/química , Polvos/análisis , Polvos/química , Triantereno/química , Xipamida/química , Calibración , Reproducibilidad de los Resultados
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