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1.
Environ Sci Pollut Res Int ; 30(17): 51099-51112, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36808039

RESUMO

In the present work, alginate magnetic graphene oxide biocomposite was synthesized for the removal and extraction of aromatic amines (aniline, p-chloroaniline (PCA), and p-nitroaniline (PNA)) from water samples. The biocomposite was investigated for its physiochemical characteristics such as surface morphology, functional groups, phase determination, and elemental composition. The results revealed that the functional groups of graphene oxide and alginate retained in biocomposite with magnetic properties. The biocomposite was applied to water samples for the removal and extraction of aniline, p-chloroaniline, and p-nitroaniline through adsorption process. The adsorption process was studied under various experimental conditions like time, pH, concentration, dose, and temperature, and all the parameters were optimized. The maximum adsorption capacities at room temperature have an optimum pH = 4 for aniline = 18.39 mg g-1, for PCA = 17.13 mg g-1, and for PNA = 15.24 mg g-1. Kinetic and isotherm models showed that the experimental data is best fitted to pseudo-second-order kinetic model and the Langmuir isotherm model. Thermodynamic study suggested that the adsorption process is exothermic and spontaneous. Ethanol was found to be the best eluent for the extraction of all the three analytes suggested by the extraction study. The maximum percent recoveries from spiked water samples were calculated for aniline = 98.82%, PCA = 96.65%, and PNA = 93.55% which showed that alginate magnetic graphene oxide biocomposite could be a useful and ecofriendly adsorbent for the removal of organic pollutants in water treatment processes.


Assuntos
Grafite , Poluentes Químicos da Água , Compostos de Anilina , Termodinâmica , Grafite/química , Adsorção , Fenômenos Magnéticos , Alginatos/química , Poluentes Químicos da Água/análise , Cinética , Concentração de Íons de Hidrogênio
2.
Scientifica (Cairo) ; 2022: 6729248, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072016

RESUMO

Food waste is a vast issue global, including in Malaysia. Food waste brings negative impacts, including increasing food production costs, impact on human health, and environmental degradation. Malaysian's animal- and plant-based diet preferences affected the desired food waste decomposition method as most of the methods only allow plant-based material to be utilized as food waste compost. The objectives of this study were to understand Malaysians' awareness of food waste behaviour and the food waste component for the decomposition. Malaysians usually produce more plant-based food waste than animal-based food waste. Most Malaysians have a high awareness of causes and impact of food waste, but they lack action on food waste reduction. Bio-compost is believed to be the most effective method to manage food waste, and most of them were willing to have it at home. However, some of them are unwilling to have a compost pile at home because there is no time to take care of it.

3.
Environ Sci Pollut Res Int ; 29(59): 88763-88778, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35838938

RESUMO

Scarcity in mining and geo-political direction diverts attention toward critical metal recycling. Gallium (Ga), indium (In) and germanium (Ge) are among the critical metals that consume approximately 80% of world mining in the innovative production of electrical and electronic equipment. The fast obsolescing rate generates a large amount of electronic waste, which is now seen as a secondary reservoir for critical metals. These metal resources need to be dealt with with effective recycling capabilities. Based on solid-phase extraction, magnetic nano-hydrometallurgy is opening a new area of metallic contents recovery in conventional hydrometallurgy. In the present work, polyacrylonitrile (PAN) based electrospun nanofibres were synthesized and carbonized at 800 °C in an inert environment. After surface oxidation, carbon nanofibres were decorated with magnetite particles through co-precipitation. The saturation magnetization value (Ms = 23.6 emu/g) confirms high loading of magnetite particles. The selected critical metal ions are freely present in an aqueous solution at pH 1 to 3; thus, highest removal efficiency was observed at pH 2. Pseudo-second-order kinetics confirm the chemical/charge interaction between sorbent and sorbate ions. Maximum sorption capacity calculated through Langmuir isotherm was 226, 191 and 171 mg/g for Ge(IV), Ga(III) and In(III) metal ions, respectively. The RL value (0 < RL < 1) indicates favourable sorption process. The sorbed target metal ions were collectively eluted using 1 mol/L hydrochloric acid. The preconcentration factor was calculated at 1080 for Ge(IV) and In(III) while 1260 for Ga(III). The method was validated with 5 µg/mL spiked multi-element standards and applied to multiple acid-leached electronic waste samples like PCBs, waste LCD panels and solar panels. Recoveries in the range of 96.2% for Ga(III), 95.6% for In(III) and 97.4% for Ge(IV) in the presence of diverse ions indicate the suitability of the proposed method for target metal ions even in a complex matrix.


Assuntos
Resíduo Eletrônico , Gálio , Nanofibras , Resíduo Eletrônico/análise , Óxido Ferroso-Férrico , Carbono , Índio , Íons , Concentração de Íons de Hidrogênio , Adsorção
4.
Ecotoxicol Environ Saf ; 190: 110099, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31923752

RESUMO

In the proposed method iron crosslinked alginate encapsulated magnetic graphene oxide beads were synthesized and used as an adsorbent for the microextraction of endocrine disrupting compounds from water samples and further analyzed by high performance liquid chromatography with ultraviolet detector. The beads were characterized using spectroscopic techniques, such as Fourier transform infra-red spectroscopy for the determination of different functional groups, Scanning electron microscopy for surface morphology, X-ray diffraction for phase determination and energy dispersive X ray spectroscopy for elemental composition. The results revealed that beads surface have functional groups of alginate and graphene oxide which are involved in π-π, n-πinteractions and hydrogen bonding for the bisphenol A and epichlorohydrin adsorption. The experimental conditions were studied for two endocrine disrupting compounds (Epichlorohydrin ad Bisphenol A) and at optimum conditions the adsorption capacity was 6.73 mgg-1 for epichlorohydrin and 7.01 mgg-1 for bisphenol A. The kinetic and equilibrium studies revealed that the adsorption process follow pseudo-second order kinetics and Langmuir equilibrium models. Analytical parameters were calculated for the microextraction of epichlorohydrin and bisphenol A. Limit of detection was 8.25 ngL-1 and 13.99 ngL-1 (n = 4) for epichlorohydrin and bisphenol A, respectively. Different solvents used for microextraction and maximum extraction of both endocrine disrupting compounds were obtained with methanol. The proposed method was applied to spiked samples and the recovery values were 97.17 ± 3.13% for epichlorohydrin and 99.46 ± 1.39% for bisphenol A. The magnetic graphene oxide encapsulated inside an alginate shows nontoxic green chemical with high extraction performance for toxic organic compounds in water treatment.


Assuntos
Disruptores Endócrinos/análise , Grafite/química , Microextração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Adsorção , Alginatos/química , Compostos Benzidrílicos , Cromatografia Líquida de Alta Pressão , Monitoramento Ambiental , Epicloroidrina , Limite de Detecção , Fenômenos Magnéticos , Magnetismo , Fenóis , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
5.
Environ Toxicol Chem ; 38(12): 2614-2620, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31499576

RESUMO

An accurate and sensitive method has been developed for determination of the herbicide isoproturon using the Quick Easy Cheap Effective Rugged Safe (QuEChERS) extraction-spectrofluorimetric technique. The method involves the reaction of 2-cyanoacetamide with isoproturon in basic medium (NH3 ; 15 mol/L). The resulting fluorescent product was found to show maximum emission at 378 nm and maximum excitation at 333 nm. Fluorescence intensity under the influence of different parameters was investigated. The linear range of analyte concentrations was found to be 0.5 to 15 µg/mL, with a limit of detection of 0.144 µg/mL, a limit of quantification of 0.437 µg/mL (signal to noise ratio = 3), and a regression coefficient of 0.9991, under optimized conditions. The proposed method was effectively applied for determination of isoproturon in different matrices; the percentage of recovery varied from 85.00 ± 1.2% to 96.00 ± 0.5%. The method was also applied for residue analysis of isoproturon in real soil samples collected from a pilot field. For extraction of isoproturon, the QuEChERS extraction approach was used, and the average residue in the soil samples was found to be 0.81 ± 0.07 µg/g. To show the potential of this approach, our results were compared with those of other methods reported in the literature. Environ Toxicol Chem 2019;38:2614-2620. © 2019 SETAC.


Assuntos
Fracionamento Químico/métodos , Herbicidas/análise , Herbicidas/isolamento & purificação , Compostos de Fenilureia/análise , Compostos de Fenilureia/isolamento & purificação , Espectrometria de Fluorescência/métodos , Poluentes do Solo/análise , Poluentes do Solo/isolamento & purificação
6.
Carbohydr Polym ; 199: 461-472, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30143151

RESUMO

Magnetic chitosan graphene oxide composite was successfully prepared and used as an adsorbent for the simultaneous removal and extraction of three phenylurea herbicides monuron, linuron and isoproturon and determined using high performance liquid chromatography with UV detector. The composition and morphology of the composite was studied through Fourier transformed infrared spectroscopy, Scanning electron microscopy, Energy dispersive X-ray and X-ray diffraction analysis. Several factors such as pH of solution, adsorption time, temperature, kinetics and isotherms were studied. The maximum adsorption capacity was 35.71 mg/g for monuron, 33.33 mg/g for linuron and 29.41 mg/g for isoproturon at room temperature and pH 5. The adsorption process best fitted to pseudo second order kinetics and Langmuir adsorption isotherm. Thermodynamic study suggested exothermic and spontaneous adsorption process. The % recoveries for linuron, monuron and isoproturon were 94.09%±2.68, 92.37%±1.14 and 90.32%±1.23 respectively. The proposed method was successfully applied to spiked samples of rice and river Kabul water.

7.
Water Sci Technol ; 75(5-6): 1410-1420, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28333056

RESUMO

In the present study, fuller's earth (FE) was modified with sodium dodecyl sulfate for removal of Acid Red 17 (AR 17) dye from aqueous solutions. The surfactant-modified FE and FE were characterized by a Fourier transform infrared spectrometer, thermogravimetric analyzer and scanning electron microscope. Batch adsorption experiments were carried out as a function of contact time, pH, initial concentration of AR 17 and adsorbent dosage. About 99.1% adsorption efficiency was achieved within 60 min at adsorbent dose of 0.1 g for initial dye concentration of 1,000 mg L-1 at pH 10. The adsorption data were well fitted with the Dubinin-Radushkevich isotherm model implying physisorption as the major phenomenon for adsorption. The kinetic data were analyzed using four kinetic equations: pseudo-first-order, pseudo-second-order, intraparticle diffusion and Elovich equations. The rates of adsorption confirmed the pseudo-second-order kinetics with good correlation value (R2 = 0.999). The results indicate that the modified adsorbent can effectively be used for the removal of AR 17 from wastewater with high absorption capacity of 2164.61 mg g-1.


Assuntos
Compostos de Alumínio/química , Compostos de Magnésio/química , Rodaminas/isolamento & purificação , Silicatos/química , Tensoativos/química , Adsorção , Difusão , Concentração de Íons de Hidrogênio , Cinética , Concentração Osmolar , Dodecilsulfato de Sódio/química , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Termogravimetria , Fatores de Tempo , Poluentes Químicos da Água/isolamento & purificação
8.
Artigo em Inglês | MEDLINE | ID: mdl-28157588

RESUMO

New experimental designs for the extraction of polyphenols from different seeds including Basil seed, Red seed, Sesame seeds and Ajwan seeds were investigated. Four variables the concentration and volume of methanol and NaOH solutions as well as the temperature and time of extraction were varied to see their effect on total phenol extraction. The temperature was varied in the range from 25°C to 200°C while the time in the range from 30 to 200minutes. Response surface methodology was used to optimize the extraction parameters. The estimation of polyphenols was measured through phenols reduction UV-Vis spectroscopic method of phosphotungstic-phosphomolybdic acids (Folin-Ciocalteu's reagent). Calibration curve was made by using tannic acid as a polyphenols standard in the concentration range from 0.1 to 10ppm. The regression line obtained shows the value of correlation coefficient i.e. R=0.930 and Root mean square error of cross validation (RMSEC) value of 0.0654. The Basil seeds were found containing the highest amount of total phenols i.e. 785.76mg/100g. While the Sesame seeds having the least amount i.e. 33.08mg/100g. The Ajwan seeds and the Red seeds are containing the medium amounts i.e. 379mg/100g and 220.54mg/100g respectively.


Assuntos
Apiaceae/química , Lepidium/química , Ocimum basilicum/química , Polifenóis/análise , Polifenóis/isolamento & purificação , Sementes/química , Sesamum/química , Espectrofotometria Ultravioleta/métodos , Análise de Variância , Calibragem , Padrões de Referência , Soluções
9.
Anal Sci ; 32(3): 313-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26960611

RESUMO

A spectrofluorimetric method for determination of triazine herbicides was developed. The method involves reaction of ammonical 2-cyanoacetamide with the herbicide. The net fluorescent intensity (FI) of the product was measured at 376 nm using 330 nm as excitation wavelength. A linear relationship between concentration and FI was found in the range of 0.3 - 10 µg mL(-1) for atrazine and 0.2 - 10 µg mL(-1) for terbutryn. The LOD and LOQ were found to be 0.07 ± 0.023 µg mL(-1) and 0.23 ± 0.023 µg mL(-1), respectively, with %RSD <12.1% for atrazine and 0.027 ± 0.009 µg mL(-1) and 0.091 ± 0.009 µg mL(-1), respectively, with %RSD <5% for terbutryn. The %recoveries of the subject triazines from soil and wheat grains were found in the range of 90.0 ± 0.14 to 96.0 ± 0.15% for atrazine and 95.0 ± 0.05 to 98 ± 0.02% for terbutryn.


Assuntos
Grão Comestível/química , Herbicidas/análise , Poluentes do Solo/análise , Espectrometria de Fluorescência/métodos , Triazinas/análise , Triticum/química , Nitrilas/química , Sensibilidade e Especificidade
10.
Talanta ; 146: 130-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26695244

RESUMO

Magnetic allylamine modified graphene oxide-poly(vinyl acetate-co-divinylbenzene) (MGO-DVB-VA) was synthesized and used for magnetic solid phase extraction of Pb(II), Cd(II), Cu(II), Ni(II) and Co(II) prior to their determination by flame atomic absorption spectroscopy. The adsorbent surface functional group was characterized by using FT-IR and Raman spectroscopy. XRD pattern was used to determine the layers of GO. Surface morphology and elemental composition of the adsorbent were evaluated by using SEM and EDX analysis. Various parameters, effecting adsorption efficiency like initial solution pH, adsorbent dose, type and volume of eluent, volume of sample and diverse ions effects were optimized. The preconcentration factor (PF) is 40 for all the metals and the limits of detection for Pb, Cd, Cu, Ni and Co are in the range of 0.37-2.39 µg L(-1) and relative standard deviation below 3.1%. The method was validated by using the method for certified reference materials (Tobacco Leaves (INCT-OBTL-5), Tomato Leaves (1573a), Certified Water (SPS-ww2) and Certified Water (TMDA 64-2)). The method was successfully applied for natural water and food samples.


Assuntos
Alilamina/química , Grafite/química , Metais Pesados/isolamento & purificação , Nanocompostos/química , Óxidos/química , Polímeros/química , Extração em Fase Sólida/métodos , Adsorção , Métodos Analíticos de Preparação de Amostras , Concentração de Íons de Hidrogênio , Imãs/química , Metais Pesados/química , Compostos de Vinila/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
11.
J Ayub Med Coll Abbottabad ; 27(1): 32-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26182732

RESUMO

BACKGROUND: Cerebro-vascular disease is a commonest long term complication of type-2 diabetes mellitus. The study was done to determine concentration of serum adiponectin and lipid profile in type-2 diabetic men with coronary heart disease (CHD) in the region of Khyber Pakhtunkhwa (KPK), and to find possible relationship between them. METHODS: This was a cross-sectional study comprising of randomly selected thirty six healthy adult males and thirty six type-2 diabetic males with coronary heart disease. Their fasting blood samples were analysed for serum adiponectin, fasting blood glucose, glycosylated haemoglobin and lipid profile which included total cholesterol (T-C), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). The relationship of adiponectin with other variables in type-2 diabetic men with coronary heart disease was determined with Pearson correlations coefficient (r). RESULTS: Type-2 diabetic males with coronary heart disease when compared to healthy males showed significantly low levels of serum adiponectin (p=<0.001) and HDL-C (p=<0.001) and significantly high level of FBG (p=<0.001), HbAlc (p=<0.001), TC (p=<0.05), TG (p=<0.05) and LDL-C (p=<0.05). Serum adiponectin level showed a significant negative correlation with FBG (r = -0.332; p= 0.04), HbAlc (r = -0.818; p=<0.01) and TG (r = -0.640; p=<0.01) in type-2 diabetic men with coronary heart disease. Adiponectin showed a significant positive association with HDL-C in controls (r = 0.948; p=<0.01) and patients of type-2 diabetes with CHD (r = 0.650; p=<0.01). CONCLUSION: Serum adiponectin concentration is markedly decreased in patients of type-2 diabetes with coronary heart disease. Hypoadiponectinemia is related with deranged lipid profile, i.e., high TG and low HDL-C levels in type-2 diabetic men with CHD. Moreover, adiponectin is associated positively with HDL-C and negatively with HbAlc and TG levels in the studied population.


Assuntos
Adiponectina/sangue , Doença das Coronárias/sangue , Diabetes Mellitus Tipo 2/sangue , Lipídeos/sangue , Biomarcadores/sangue , Doença das Coronárias/epidemiologia , Doença das Coronárias/etiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Ensaio de Imunoadsorção Enzimática , Hemoglobinas Glicadas/metabolismo , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Prognóstico
12.
Asian Pac J Cancer Prev ; 15(22): 10009-13, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25520061

RESUMO

BACKGROUND: Vitamin D receptor (VDR) gene has been a subject of extensive pharmacogenetic research recently. Association studies between different types of cancers including prostate cancer (PCa) and VDR gene polymorphism have also been conducted. The objective of this study was to find possible associations between PCa and VDR gene polymorphisms in the Pakistani population. MATERIALS AND METHODS: A total of 162 subjects, including prostate cancer patients and controls, were genotyped for Apa I, Taq I and Fok I polymorphisms in the VDR gene using allele specific PCR, PCR-RFLP and direct DNA sequencing. Allelic frequencies were tested for Hardy-Weinberg equilibrium and associations between the genetic markers and PCa were calculated using logistic regression. RESULTS: Apa I CC genotype was found to have strongest association with PCa risk, and "A" genotype was found to have protective effect. Fok I and Taq I did not have appreciable levels of association with PCa, although Taq I "TC" heterozygotes seemed to have some protective effect. Similarly the "C" allele of Fok I also seemed to have protective effect. CONCLUSIONS: To our knowledge, this is the first report showing association between VDR gene polymorphisms and PCa in Pakistan. Our findings may be somewhat skewed because of small sample size and tendency of consanguineous marriages in Pakistani society; nevertheless, it shows the trend of association and protective effects of certain VDR gene polymorphisms against PCa.


Assuntos
Polimorfismo Genético/genética , Neoplasias da Próstata/genética , Receptores de Calcitriol/genética , Estudos de Casos e Controles , Feminino , Seguimentos , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Paquistão/epidemiologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Prognóstico , Neoplasias da Próstata/epidemiologia , Fatores de Risco
13.
Luminescence ; 29(3): 266-74, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23754499

RESUMO

A simple and sensitive chemiluminescence (CL) method was developed for the determination of citalopram in pharmaceutical preparations and human plasma. The method is based on the enhancement of the weak CL signal of the luminol-H2 O2 system. It was found that the CL signal arising from the reaction between alkaline luminol and H2 O2 was greatly increased by the addition of silver nanoparticles in the presence of citalopram. Prepared silver nanoparticles (AgNPs) were characterized by UV-visible spectroscopy and transmission electron microscopy (TEM). Various experimental parameters affecting CL intensity were studied and optimized for the determination of citalopram. Under optimized experimental conditions, CL intensity was found to be proportional to the concentration of citalopram in the range 40-2500 ng/mL, with a correlation coefficient of 0.9997. The limit of detection (LOD) and limit of quantification (LOQ) of the devised method were 3.78 and 12.62 ng/mL, respectively. Furthermore, the developed method was found to have excellent reproducibility with a relative standard deviation (RSD) of 3.65% (n = 7). Potential interference by common excipients was also studied. The method was validated statistically using recovery studies and was successfully applied to the determination of citalopram in the pure form, in pharmaceutical preparations and in spiked human plasma samples. Percentage recoveries were found to range from 97.71 to 101.99% for the pure form, from 97.84 to 102.78% for pharmaceutical preparations and from 95.65 to 100.35% for spiked human plasma.


Assuntos
Antidepressivos de Segunda Geração/análise , Citalopram/análise , Medições Luminescentes/métodos , Nanopartículas/química , Preparações Farmacêuticas/análise , Prata/química , Antidepressivos de Segunda Geração/sangue , Citalopram/sangue , Humanos , Medições Luminescentes/instrumentação
14.
Pak J Pharm Sci ; 26(5): 921-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24035947

RESUMO

A simple, sensitive, selective and cost effective spectrofluorimetric method has been established for the quantification of sulpiride after their complete alkaline hydrolysis. The method is based on the condensation of the primary amino group of alkaline hydrolytic product of sulpiride with acetyl acetone and formaldehyde in acidic medium (0.25 M HCl) to form a fluorescent product. The reaction product formed shows maximum fluorescence intensity at 483 nm after excitation at 431 nm. The different reaction conditions influencing the condensation reaction were carefully optimized and a linear range of 0.1-3.5 µg mL-1 with good correlation coefficient between flourescent intensity and concentration of sulpiride was found at optimum parameters. The LOD and LOQ were found to be 11 and 39 ng mL-1 respectively. The proposed method was successfully used for the quantification of sulpiride in bulk powder and commercial formulations. The effect of common pharmaceutical excipients and co-administered drug was also studied and no interferences were observed. The validity of the method was tested by analyzing sulpiride in bulk powder, and pharmaceutical formulations through recovery studies. Recoveries (%) were obtained from 98.62 to 100.24% for bulk powder, and 97.09 to 100.57 % for commercial formulations. The results were validated statistically with those obtained by reference literature high performance liquid chromatographic method.


Assuntos
Espectrometria de Fluorescência , Sulpirida/análise , Tecnologia Farmacêutica/métodos , Calibragem , Química Farmacêutica , Excipientes/química , Formaldeído/química , Concentração de Íons de Hidrogênio , Pentanonas/química , Pós , Padrões de Referência , Reprodutibilidade dos Testes , Espectrometria de Fluorescência/normas , Tecnologia Farmacêutica/normas , Temperatura
15.
Luminescence ; 28(4): 516-22, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23436454

RESUMO

We describe the development and validation of a new, simple, sensitive and cost-effective method for the determination of ceftriaxone in commercial formulations and spiked human plasma. The method proposes the conversion of ceftriaxone into a fluorescent product by reacting with ortho-phthalaldehyde (OPA) in the presence of sulfite at room temperature. The reaction medium is buffered to pH 10 using borate buffer. The derivatized reaction product is highly fluorescent and exhibits maximum fluorescence intensity at λ(em) = 386 nm after excitation at λ(ex) = 324 nm. The experimental parameters affecting progress of the derivatization reaction were carefully studied and optimized. Under optimum experimental conditions, the method has an excellent correlation coefficient of 0.9984 with a broad linear range of 0.4-20 µg/mL. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.30 × 10(-3) and 3.90 × 10(-3) µg/mL, respectively. The interference effects of common excipients on the quantification of drug were investigated and no interference effect was observed. The proposed method has been successfully applied to the determination of ceftriaxone in pharmaceutical formulations and spiked human plasma samples. The method has been validated statistically through percent recovery studies using standard addition and by comparison with a reference HPLC method. The developed method exhibits excellent inter- and intraday precision.


Assuntos
Ceftriaxona/análise , Ceftriaxona/sangue , Preparações Farmacêuticas/química , Espectrometria de Fluorescência/métodos , Humanos , Estrutura Molecular , Espectrometria de Fluorescência/instrumentação
16.
Luminescence ; 28(6): 915-21, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23225777

RESUMO

A highly sensitive and simple method for identifying sulpiride in pharmaceutical formulations and biological fluids is presented. The method is based on increased chemiluminescence (CL) intensity of a luminol-H2O2 system in response to the addition of Cr (III) under alkaline conditions. The CL intensity of the luminol-H2O2-Cr (III) system was greatly enhanced by the addition of sulpiride and the CL intensity was proportional to the concentration of sulpiride in a sample solution. Various parameters affecting the CL intensity were systematically investigated and optimized for determination of the sulpiride in a sample. Under the optimum conditions, the CL intensity was proportional to the concentration of sulpiride in the range of 0.068-4.0 µg/mL, with a good correlation coefficient of 0.997. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 8.50 × 10(-6) µg/mL and 2.83 × 10(-5) µg/mL, respectively. The method presented here produced good reproducibility with a relative standard deviation (RSD) of 2.70% (n = 7). The effects of common excipients and metal ions were studied for their interference effect. The method was validated statistically through recovery studies and successfully applied for the determination of sulpiride in pure form, pharmaceutical preparations and spiked human plasma samples. The percentage recoveries were found to range from 99.10 to 100.05% for pure form, 98.12 to 100.18% for pharmaceutical preparations and 97.9 to 101.4% for spiked human plasma.


Assuntos
Líquidos Corporais/química , Cromo/química , Preparações Farmacêuticas/química , Sulpirida/análise , Humanos , Peróxido de Hidrogênio/química , Medições Luminescentes , Luminol/química
17.
J Fluoresc ; 23(1): 161-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23014772

RESUMO

A simple, sensitive, and accurate spectrofluorimetric method was developed for the determination of citalopram in bulk and pharmaceutical preparations. The method is based on the enhancement of the weak fluorescence signal (FL) of the Tb (III)-citalopram system in the presence of silver nanoparticles. Fluorescence intensities were measured at 555 nm after excitation at 281 nm. Prepared silver nanoparticles (AgNPs) were characterized by UV-Visible spectra and transmission electron microscopy (TEM). Various factors affecting the formation of citalopram-Tb (III)-AgNPs complexes were studied and optimized. The fluorescence intensity versus concentration plot was linear over the range 0.02-14 µg mL(-1), with an excellent correlation coefficient of 0.9978. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 7.15 × 10(-6) µg mL(-1) and 2.38 × 10(-5) µg mL(-1) respectively. The proposed method was found to have good reproducibility with a relative standard deviation of 3.66% (n = 6). The interference effects of common excipients found in pharmaceutical preparations were studied. The developed method was validated statistically by performing recoveries studies and successfully applied for the assay of citalopram in bulk powder and pharmaceutical preparations. Percent recoveries were found to range from 98.98% to 100.97% for bulk powder and from 96.57% to 101.77% for pharmaceutical preparations.


Assuntos
Citalopram/análise , Citalopram/química , Nanopartículas Metálicas/química , Compostos Organometálicos/química , Prata/química , Espectrometria de Fluorescência/métodos , Térbio/química , Soluções Tampão , Composição de Medicamentos , Concentração de Íons de Hidrogênio
18.
Luminescence ; 28(5): 719-25, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22987788

RESUMO

A sensitive and accurate spectrofluorimetric method has been developed for the determination of sulpiride in pharmaceutical preparations and human plasma. The developed method is based on the derivatization reaction of 2-cyanoacetamide with sulpiride in 30% ammonical solution. The fluorescent derivatized reaction product exhibited maximum fluorescence intensity at 379 nm after excitation at 330 nm. The optimum conditions for derivatization reactions were studied and the fluorescence intensity versus concentration plot was found to be linear over the concentration range 0.2-20.0 µg/mL with a correlation coefficient of 0.9985. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.82 and 2.73 ng/mL, respectively. The proposed method was validated according to ICH guidelines. The effects of common excipients and co-administered drugs were also studied. The accuracy of the method was checked using the standard addition method and percent recoveries were found to be in the range of 99.00-101.25% for pharmaceutical preparations and 97.00-97.80% for spiked human plasma. The method was successfully applied to commercial formulations and the results obtained for the proposed method were compared with a high-performance liquid chromatography reference method and statistically evaluated using the Student's t-test for accuracy and the variance ratio F-test for precision. A reaction pathway was also proposed.


Assuntos
Nitrilas/química , Preparações Farmacêuticas/química , Sulpirida/análise , Amônia/química , Humanos , Estrutura Molecular , Espectrometria de Fluorescência , Temperatura , Fatores de Tempo
19.
Pak J Pharm Sci ; 25(4): 823-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23010000

RESUMO

A simple and fast method for spectrophotometric determination of sparfloxacin using p-dimethyl-aminobenzaldehyde (DMAB) has been developed. A yellow coloured product formed from reaction between sparfloxacin and DMAB as a result of condensation reaction at room temperature. The maximum absorbance was found at 392 nm with molar absorptivity of 4.9 × 10(3) L mol(-1) cm(-1). All parameters for the reaction, as concentration of DMBA reagent, molarity of sulphuric acid, and reaction temperature were studied. Under the conditions studied, a linear relationship between absorbance of the condensation product and concentration of sparfloxacin in the range of 2.0-80.0 µg mL(-1) was found with good correlation coefficient (0.9997). The limits of detection (LOD) and quantification (LOQ) for the proposed method were found to be 0.22 and 0.75 µg mL(-1) respectively. The repeatability and accuracy (model) of the method was studied at three different concentrations of sparfloxacin and found with value of relative standard deviation less than 2.0%. The method was found selective for determination of sparfloxacin in the presence of commonly used excipients in dosage forms. The developed method was validated statistically and applied successfully to the analysis of the drug in pure form, pharmaceutical preparations, and spiked blood plasma and urine samples with good accuracy (real) and precision. The percentage recovery was found from 99.0-100.0% with relative standard deviation less than 1%. The results of the proposed method were compared statistically with the results of literature HPLC method.


Assuntos
Antituberculosos/análise , Fluoroquinolonas/análise , Espectrofotometria/métodos , Antituberculosos/sangue , Antituberculosos/urina , Benzaldeídos/química , Química Farmacêutica , Formas de Dosagem , Fluoroquinolonas/sangue , Fluoroquinolonas/urina , Concentração de Íons de Hidrogênio , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Espectrofotometria/normas , Temperatura
20.
Hypertens Pregnancy ; 31(2): 292-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-20860490

RESUMO

OBJECTIVES: To evaluate the levels of serum lipoproteins in women with pregnancy-induced hypertension and compare it with the corresponding levels in pregnant women having normal blood pressure. METHOD: This cross-sectional study was conducted in the three tertiary care hospitals of Peshawar, North West Frontier Province, Pakistan. A total of 206 pregnant women at gestational age of >20 weeks were registered in the study after taking informed consent. All relevant information was recorded on a predesigned questionnaire. Serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C) and triglyceride (TG) levels were measured in 151 women with pregnancy induced hypertension (PIH) and compared with the corresponding values for a control group of 55 normotensive pregnant women. RESULT: Cholesterol levels were not statistically different between the patient group and controls. Triglyceride levels were significantly higher in the patient group than in controls. Women who developed hypertension after 20 weeks of gestation had 6.7, 4.2, 40.5, and 39.7% higher concentrations of TC, LDL-C, VLDL-C, and TG, respectively, and 28, 22.4, and 67.6% higher ratios of TC : HDL-C, LDL-C : HDL-C, and TG : HDL-C, respectively, as compared to the control subjects. The mean difference of the concentrations of HDL-C, VLDL-C, and TG, and the ratios TC : HDL-C, LDL-C : HDL-C, TG : HDL-C, and HDL-C : VLDL-C between the patients and control group was statistically significant. CONCLUSION: The assessment of blood lipids may be helpful in the prevention of complications in PIH patients.


Assuntos
Hipertensão Induzida pela Gravidez/sangue , Lipoproteínas/sangue , Adulto , Fatores Etários , Estudos Transversais , Feminino , Humanos , Paquistão , Gravidez , Adulto Jovem
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