Alginate magnetic graphene oxide biocomposite synthesis for removal of aromatic amines from aqueous samples.

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.

Eco-friendly alginate encapsulated magnetic graphene oxide beads for solid phase microextraction of endocrine disrupting compounds from water samples.

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.

Magnetic chitosan graphene oxide composite for solid phase extraction of phenylurea herbicides.

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.

Prevalence of hepatitis-C virus genotypes and potential transmission risks in Malakand Khyber Pakhtunkhwa, Pakistan.

BACKGROUND: Hepatitis C virus (HCV) is a leading cause of chronic liver disease and frequently progresses towards liver cirrhosis and Hepatocellular Carcinoma (HCC). This study aimed to determine the prevalence of HCV genotypes and their association with possible transmission risks in the general population of Malakand Division. METHODOLOGY: Sum of 570 serum samples were collected during March 2011 to January 2012 from suspected patients visited to different hospitals of Malakand. The suspected sera were tested using qualitative PCR and were then subjected to molecular genotype specific assay. Quantitative PCR was also performed for determination of pre-treatment viral load in confirmed positive patients. RESULTS: Out of 570 serum samples 316 sera were seen positive while 254 sera were found negative using qualitative PCR. The positive samples were then subjected to genotyping assay out of 316, type-specific PCR fragments were seen in 271 sera while 45 samples were found untypable genotypes. Genotype 3a was seen as a predominant genotype (63.3%) with a standard error of ±2.7%. Cramer's V statistic and Liklihood-Ratio statistical procedures are used to measure the strength and to test the association, respectively, between the dependent variable, genotype, and explanatory variables (e.g. gender, risk, age and area/districts). The dependent variable, genotype, is observed statistically significant association with variable risk factors. This implies that the genotype is highly dependent on how the patient was infected. In contrast, the other covariates, for example, gender, age, and district (area) no statistical significant association are observed. The association between gender-age indicates that the mean age of female was older by 10.5 ± 2.3 years with 95% confidence level using t-statistic. CONCLUSION: It was concluded from the present study that the predominant genotype was 3a in the infected population of Malakand. This study also highlights the high prevalence rate of untypable genotypes which an important issue of health care setup in Malakand and create complications in therapy of infected patients. Major mode of HCV transmission is multiple uses and re-uses of needles/injections. TRIAL REGISTRATION: ISRCTN ISRCTN73824458. Registered: 28 September 2014.

Kinetic and equilibrium profile of the adsorptive removal of Acid Red 17 dye by surfactant-modified fuller's earth.

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.

Preparation and characterization of magnetic allylamine modified graphene oxide-poly(vinyl acetate-co-divinylbenzene) nanocomposite for vortex assisted magnetic solid phase extraction of some metal ions.

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.

Investigation of repressive and enhancive effects of fruit extracts on the activity of glucose-6-phophatase.

Glucose-6-phosphatase is a key enzyme of glucose metabolic pathways. Deficiency of this enzyme leads to glycogen storage disease. This enzyme also plays a negative role in diabetes mellitus disorder in which the catalytic activity of this enzyme increases. Thus there is need for activators to enhance the activity of glucose-6-phosphatase in glycogen storage disease of type 1b while in diabetes mellitus repressors are needed to reduce its activity. Crude extracts of apricot, fig, mulberry and apple fruits were investigated for their repressive/enhancive effects on glucose-6-phosphatase in vivo. Albino mice were used as experimental animal. All the selected extracts showed depressive effects on glucose-6-phosphatase, which shows that all these extracts can be used as antidiabetic supplement of food. The inhibitory pattern was competitive one, which was evident from the effect of increasing dose from 1g/Kg body weight to 3g/Kg body weight for all the selected fruit extracts. However fig and apple fruit extracts showed high repressive effects for high doses as compared to apricot and mulberry fruit extracts. None of these selected fruit extracts showed enhancive effect on glucose-6-phosphatase activity. All these fruits or their extracts can be used as antidiabetic dietary supplement for diabetes mellitus.

RELATIONSHIP OF ADIPONECTIN LEVEL WITH LIPID PROFILE IN TYPE-2 DIABETIC MEN WITH CORONARY HEART DISEASE.

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.

A validated silver-nanoparticle-enhanced chemiluminescence method for the determination of citalopram in pharmaceutical preparations and human plasma.

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.

Validated spectrofluorimetric method for determination of sulpiride in commercial formulations using Hantzsch condensation reaction.

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.

Determination of sulpiride in pharmaceutical preparations and biological fluids using a Cr (III) enhanced chemiluminescence method.

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.

A validated spectrofluorimetric method for the determination of citalopram in bulk and pharmaceutical preparations based on the measurement of the silver nanoparticles-enhanced fluorescence of citalopram/terbium complexes.

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.

Quantification of sparfloxacin in pharmaceutical dosages and biological samples.

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.

Plastic catalytic pyrolysis to fuels as tertiary polymer recycling method: effect of process conditions.

This paper presents results regarding the effect of various process conditions on the performance of a zeolite catalyst in pyrolysis of high density polyethylene. The results show that polymer catalytic degradation can be operated at relatively low catalyst content reducing the cost of a potential industrial process. As the polymer to catalyst mass ratio increases, the system becomes less active, but high temperatures compensate for this activity loss resulting in high conversion values at usual batch times and even higher yields of liquid products due to less overcracking. The results also show that high flow rate of carrier gas causes evaporation of liquid products falsifying results, as it was obvious from liquid yield results at different reaction times as well as the corresponding boiling point distributions. Furthermore, results are presented regarding temperature effects on liquid selectivity. Similar values resulted from different final reactor temperatures, which are attributed to the batch operation of the experimental equipment. Since polymer and catalyst both undergo the same temperature profile, which is the same up to a specific time independent of the final temperature. Obviously, this common temperature step determines the selectivity to specific products. However, selectivity to specific products is affected by the temperature, as shown in the corresponding boiling point distributions, with higher temperatures showing an increased selectivity to middle boiling point components (C(8)-C(9)) and lower temperatures increased selectivity to heavy components (C(14)-C(18)).