VOLUME 39, NO6, DEC-2017
123
 
Bioavailability of Aluminum from Black Shale Using Acidic Metabolites of Heterotrophs

Fozia Anjum, Shazia Anwer Bukhari, Tajnees Pirzada, Mir Munsif Ali Talpur, Mahmood-ur Rahman and Shahzad Ahmad Shahid Chatha

Aluminum was bioextracted from black shale using Aspergillus niger and Penicillium notatum as acidophiles. Wet chemical and electron dispersive X-ray analysis (EDX) showed the presence of iron, silicon, aluminum, titanium, copper, sulphur, phosphorus, chlorine, potassium, sodium, calcium, carbon and oxygen in the original shale. A detailed investigation of the leaching process with these microorganisms was conducted. Microbes were tested for acid production and leaching capabilities of aluminum from black shale. Different organic wastes were evaluated as substrates by microbes. Moreover, citric acid generated by fungi could be an important leaching agent acting in the dissolution of aluminum. Aluminum dissolution with A. niger was better than those with P. notatum. Maximum recovery of aluminum (65.71%) was found in an A. niger medium containing acidified mango peel substrate at 28oC after 36days of leaching at 120 rpm. The results obtained with chemical leaching when using different concentrations of organic acids showed that dissolution of aluminum was much higher in citric and oxalic acid than other acids. Besides acidic metabolites production, microbiological activities play an important role in contribution of metals extraction. In future scenario, these discarded ores might be a potential source of metals.
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Utilization of Carbon dioxide (CO2) for the Production of Ethanol

Hizba Waheed and Arshad Hussain

Concentration of CO2 is increasing tremendously in earth’s atmosphere which is leading to disastrous impacts like increasing earth’s average temperature, melting of polar ice, rising of sea levels and other climatic effects that will result in massive drought, water shortage, agricultural losses and food shortage. Utilizing CO2 as a feed stock for various chemicals is an advantageous solution towards this problem. New CO2 based Fuels is developing an innovative and breakthrough technology providing a revolutionary, cost-effective solution to two global concerns: CO2 emissions and diminishing liquid fuel reserves. CO2 can be converted to alternate fuel by first reacting it with freshly prepared methyl magnesium bromide, CH3MgBr (Grignard’s reagent) and then reducing the resultant product into Ethanol (C2H5OH) by using Sodium Borohydride (NaBH4) along with other electrophiles. The process produces 72% product yield. The product formed was characterized by using HPLC and FTIR techniques. The process can be carried out at mild conditions of temperature and pressure but keeping the moisture content minimum. The described progression will result in lessening of CO2 and providing another option for renewable energy source.
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Optimization of Ethanol Production from Garcinia Cambogia Residues and the Effects of its Medicinal Component on Production Yield

Hongzhi Ma, Fengying Zhang, Miao Yu, Qipeng Liu, Qunhui Wang

Garcinia cambogia, a Chinese herbal medicine, was popular due to its effect for weight loss. The main medical component inside was determined to be hydroxycitric acid (HCA). To realize the resource technology of garcinia cambogia residue, Optimum ethanol production from residues was investigated, and the effects of remaining HCA on the ethanol yield were investigated. A Plackett-Burman experimental design was used to screen the significance of several influencing factors, and cellulase, yeast extract, and KH2PO4 were observed to exert important effects. The optimum ethanol fermentation conditions were determined through an orthogonal design to include a cellulase concentration of 100 U/g, a yeast extract concentration of 15 g/L, and a KH2PO4 concentration of 1.0 g/L. The ethanol concentration obtained under optimal conditions was 4.0 g/L. The remained HCA in the residues showed minimal influences on ethanol fermentation and could even increase ethanol yield at low concentrations.
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Impact of Egg White Protein on the Quality and Stability of Corn Oil-in-Water Emulsion

Shahid Iqbal, Javeria Batool, Mahvish Ajaz, Nida Ambreen, Muhammad Akhlaq

The effect of egg albumin has been examined on the texture and stability of O/W emulsion. The corn oil was used as dispersed phase while the aqueous phase as continuous phase of the emulsion. The aqueous phase was designed with the protein contents (0.5- 4 wt. %) at pH 7. The different oil phase (10-40 wt. %) were homogenized in aqueous phase (90-60 wt. %). It was observed that the viscosity and turbidity of the emulsion were increased with the increase of protein concentration and oil phase contents. Flow profile showed that shear stress was increased with increase of shear rate but it decreased at higher shear rate (100 s-1) in heated emulsion. On the other hand the emulsion viscosity was decreased with the increase of shear rate showing non- Newtonian behavior. This work may be useful in the formulation and physicochemical properties of food products i.e. sauces, mayonnaise etc.
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Synthesis of Zeolite-Zeolite (MFI-FAU) Composite Catalysts for the Isomerization of n-Hexane

Awais Sattar Ghouri and Muhammad Rashid Usman

In this research work, the aim is to produce a relatively novel zeolite-zeolite (MFI-FAU) composite catalyst having better potential of catalyzing isomerization of lighter hydrocarbons such as light naphtha, n-pentane, n-hexane, n-heptane and mixture thereof. A series of zeolite-zeolite (MFI-FAU) composite catalysts have been synthesized by incorporating previous practices and techniques. The catalytic performance of as-synthesized zeolite-zeolite (MFI-FAU) composite catalysts have been investigated by isomerizing 95% pure n-hexane in conventional fixed bed flow micro-reactor at temperature 200-240 ºC under atmospheric pressure. In order to explore chemical and physical features of zeolite-zeolite (MFI-FAU) composite catalysts, they are examined and characterized using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectrometry (EDX), N2 adsorption-desorption measurements (BET, BJH, t-plot measurements) and Fourier transform infrared (FTIR) spectroscopy equipped with attenuated total reflectance (ATR) arrangements.
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Fluoride Concentration in Toothpastes Marketed in Pakistan

Tahir Rafique, Faisal Soomro, Sajid Iqbal, Muhammad Afzal and Khaula Shirin

Efficacy of fluoride as a cariostatic agent is a well-established fact. Last few decades have seen a dramatic decline in dental decay throughout the world. As a systematic approach, fluoride is added to the drinking water to prevent dental decay but topical application using toothpaste has been more effective against dental caries, therefore fluoride is added to toothpaste in the form of sodium fluoride and sodium monofluorophosphate. Based on the fact that excessive exposure to fluoride causes dental fluorosis and lower amount makes toothpaste ineffective against dental caries, so the amount of fluoride in the toothpaste must be regulated. Therefore, in the present study, toothpastes including local and imported brands sold in Karachi have been collected and analyzed for their fluoride contents. In a total of 55 samples, amount of fluoride ranged from 10 to 1,674 ppm in local samples and in imported brands it ranged from 426 to 1,444 ppm. Eighty-two percent of the local brands fell short of 1,000 ppm fluoride which is the lower limit of fluoride in toothpaste as recommended by WHO. A large amount of variations has been observed in acclaimed fluoride levels and analyzed fluoride level; furthermore, 70% of the local samples have not even mentioned the content of fluoride in their brands. In the context of increasing number of cases of dental decay in Karachi, these results provide baseline data to the authorities concerned to regulate the fluoride levels in toothpaste.
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Liquid Chromatography Method Development and Optimization for Valsartan: Pharmacokinetics of Oral Hydrogels in Rabbits

Muhammad Sohail, Mahmood Ahmad, Muhammad Usman Minhas, Abubakar Munir, Ikrima Khalid and Haroon Rashid

A simple, rapid, precise, accurate high performance liquid chromatography method has been developed and subsequently validated for determination of valsartan in rabbit plasma. The method was developed employing mixture of mobile phase consisting of 0.02 M potassium dihydrogen phosphate buffer and acetonitrile (45:55), pH was adjusted to 2.7 using 50% orthophosphoric acid and pumped thorough chromatographic system at a flow rate of 1 ml/min. An isocratic elution mode was carried out at HPLC system (Agilent Technologies, 1200 series, USA) fitted with variable wavelength detector and data processing software ChemStation. For sample analysis, 20µl sample was injected and eluate was monitored at 225nm wavelength. Pharmacokinetic evaluation was performed in rabbits after the oral administration of valsartan loaded PVA-co-poly(AA) hydrogels. The mean Cmax of valsartan was 408.439ng/ml, Tmax was 12h and half life (t1/2) was 8.812h. The extraction procedure was simple with good response even at very low drug concentration, thereby making this method suitable for pharmacokinetic application. It is concluded that developed method is simple, fast, cost effective, and reproducible for the analysis of pharmacokinetic parameters in the rabbit plasma.
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Study on Electrochemical Fingerprints of Radix Paeoniae Alba

Jian Zhong Jin and Chao Shen

The electrochemical fingerprints of Radix Paeoniae Alba were studied by chemical oscillation system of H+-Mn2+-CH3COCH3-BrO3-. Influences of variety of Radix Paeoniae Alba for the chemical oscillation system were studied. Finally, 43 ℃ temperature, 500 rpm stirring rate, 1000 mg Radix Paeoniae Alba, 2.0 mol•L- 1 hydrogen ion concentration, 0.084 g MnSO4, 0.835 g KBrO3, 1mL acetone and 100 mL total volume were chosen as the optimal experimental conditions. The results indicated that the electrochemical fingerprints of Radix Paeoniae Alba from different regions showed significantly different characteristics, so the electrochemical fingerprint is a efficacious method to identify the regions and variety of Radix Paeoniae Alba.
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Application of Fourier-Transform Infrared (FT-IR) Spectroscopy for Determination of Total Phenolics of Freeze Dried Lemon Juices

Syed Tufail Hussain Sherazi, Aijaz Ahmed Bhutto, Sarfaraz Ahmed Mahesar and Muhammad Iqbal Bhanger

A cost effective and environmentally safe analytical method for rapid assessment of total phenolic content (TPC) in freeze dried lemon juice samples was developed using transmission Fourier-transform infrared spectroscopy (FT-IR) in conjunction with chemometric techniques. Two types of calibrations i.e. simple Beer’s law and partial least square (PLS) were applied to investigate most accurate calibration model based on region from1420 to 1330 cm−1. The better analytical performance was obtained by PLS technique coefficient of determination (R2), root mean square error of calibration (RMSEC) with the value of 0.999 and 0.00864, respectively. The results of TPC in freeze dried lemon juice samples obtained by transmission FT-IR were compared with TPC observed by Folin-Ciocalteu (FC) assay and found to be comparable. Outcomes of the present study indicate that transmission FT-IR spectroscopic approach could be used as an alternative approach in place of Folin-Ciocalteu (FC) assay which is expensive and time-consuming conventional chemical methods for determination of the total phenolic content of lemon fruits.
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Development and Validation of Spectrophotometric Method for Assay Determination and In Vitro Dissolution Studies of Sofosbuvir Tablets

Bakht Zaman, Waseem Hassan, Asghar Khan and Hamsa Noreen

In vitro dissolution of sofosbuvir 400 mg tablets dosage form was performed, using USP dissolution apparatus type-II (paddle type), at 75rpm ± 4 %, and 900mL ± 1%, 0.05 M phosphate buffer pH 6.8 ± 0.05 equilibrated at 37.0 ± 0.5ºC as dissolution medium. Percentage of dissolved sofosbuvir as a function of time was determined using the straight line equation and linear regression using zero order and first order ANOVA based kinetics model. Comparative dissolution studies on two different generic brands A and B was performed comparing the drug release profile with innovator brand Sovaldi 400 mg tablets. The comparison of dissolution profiles was evaluated using model independent approach. The values of similarity factor f2 were (4 and 3) and the difference factor f1 were (64 and 50) for both generic products A and B respectively. A simple and precise spectrophotometric method was developed for estimation of sofosbuvir in dissolution medium based on spectrophotometric detection at wavelength 262 nm. The specific absorbance (A = 1%) of sofosbuvir was 178.5 ± 4% and Beer’s law was obeyed in the concentration ranges 4µg mL−1 to 48µg mL−1. The method was validated appropriately for accuracy, precision, linearity, and specificity, according the guidelines of United State Pharmacopoeia and International Conference on Harmonization. The calibration curve was linear with correlation coefficient (r > 0.9999) and there was no spectral interference from excipients present in the tablets dosage form. This method is precise, rapid and specific for determination of sofosbuvir in tablets dosage form and successfully applied for assay determination and in vitro dissolution studies.
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