RP-HPLC method for simultaneous estimation of Metformin HCl and Pioglitazone in tablet dosage form

Keni S. and Ambadekar S.

The present work describes a validated reverse phase high performance liquid chromatographic method for simultaneous estimation of Metformin HCl and Pioglitazone in tablet formulation. Chromatography was performed on a Zorbax Eclipse C18 (5 cm×2.1 mm I.D) column from agilent in isocratic mode with mobile phase containing acetonitrile: buffer pH 3.0 (20:80). The flow rate was 0.5 ml/min and the eluent was monitored at 218 nm. The selected chromatographic conditions were found to effectively separate Metformin HCl (RT- 0.928 min) and Pioglitazone (RT- 5.81 min). Linearity for Metformin HCl and Pioglitazone was found in the range of 800-1200 µg/ml and 24-36 µg/ml respectively. The proposed method was found to be accurate, precise, reproducible and specific and can be used for simultaneous analysis of these drugs in tablet formulation.

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Bio-sorption Analysis of Aqueous solution of Cu(II) by Zea Maize Cob Powder

Kumari Sharda, Virvadiya Chandresh and Gupta Vikal

An attempt has been made to study bio-sorption of copper(II) ions from aqueous solution by Zea Maize Cob powder using batch adsorption technique. Zea Maize plant is locally available in sub-humid southern plane and Arawali hills zone of Rajasthan. The effect of various parameters like adsorption mass, pH, particle size, contact time and copper ion concentration on bio-sorption process has also been studied. The bio-sorption process of Cu(II) has been tested with Langmuir and Freundlich models. The maximum removal efficiency of Cu(II) by Zea maize cob powder has been found 70% at pH 4.

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Manufacture of acid resistant fly ash geopolymer brick under atmospheric curing

Muduli Surabhi Dipali, Nayak Bansidhar and Mishra Barada kanta

Geopolymers are aluminosilicate based binder manufactured by activation of a solid aluminosilicate source material at high alkaline pH. In this research work fly ash, rich in silica and alumina has been used as a source material for manufacture of building brick through geopolymerization technology in presence of alkaline base chemicals consisting of anions of O2-, [OH]1-, Cl1- and [SO4]2- in different concentrations and sodium silicate solution under atmospheric curing. Then study has been conducted to assess the acid resistance property of fly ash geopolymer brick. This work consists in the immersion of fly ash geopolymer brick in solutions of 1% sulfuric acid and 1% hydrochloric acid up to a period of 12 months and evaluation of its resistance in terms of surface corrosion and compressive strength at 3 months intervals. The geopolymer fly ash brick immersed in 1% H2SO4 solution has no remarkable change whereas in 1% HCl solution, there was no change in appearance of the brick and did not show any noticeable change in colour and remained structurally intact though the exposed surface turned slightly softer in 1% sulphuric acid solution for long duration of exposure.

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Comparison between Conventional and Microwave-assisted Hydrodistillation Methods towards Extraction of Essential Oils from Murraya koenigii (Curry Leaves)

Azid M.Z, Sukari M.A., Ng R.C. and Ali N.A.

Study on the extraction of essential oils from leaves of Murraya koenigii had been carried out by conventional hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) methods. Time of the first oil droplet, percentage yield of the extracted oils and the chemical components of the extracted essential oils from both methods were compared. The running time for MAHD was set at one and half hour while running time for HD was 5 hours. The major components from the essential oils obtained from HD method were β-copaene (41.5%), α-selinene (10.0%) and α-humulene (8.4%). Meanwhile, major chemical components extracted from MAHD method were β-caryophyllene (19.5%), terpine-4-ol (17.6%) and linalool (9.8%). A total of 79.6% of chemical components were identified from essential oil extracted through HD method while MAHD method was 75.7%. The first oil droplet for HD method was found to be at 34 minutes and 20 minutes for MAHD method. MAHD is more preferable method for extracting essential oils from Murraya koenigii as it provides high extraction efficiency with less time taken.

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Environment friendly sol-gel pre-treatments for corrosion protection of aluminium alloys

Chawada G. and Dholakiya B. Z.

In this paper, corrosion resistance and adhesion of environmental friendly silane pre-treatment on aluminium substrate was studied. Coating solution (Sol) was formulated by using epoxy bis-silane precursor via acid hydrolysis and condensation reaction at constant solid content, fixed water ethanol ratio. Two different formulations (Sol 1 and Sol 2) were developed on the basis of epoxy/silane ratio. The organic-inorganic hybrid films were deposited on aluminium panels by dip-coating technique, by immersion of sample panels into the sol and their withdrawal at controlled rate to facilitate desired and uniform film. Films were subsequently cured at room temperature. Corrosion resistance of the coating was evaluated by electrochemical impedance spectroscopy (EIS), DC polarisation techniques and neutral salt spray test. The adhesion behaviour of the coating was investigated by cross hatch test. Results showed that Sol 2 showed significant improvement in the corrosion resistance and adhesion of the coating. Silane pr-treatment has excellent adhesion with substrate and commercial grade epoxy top coat.

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QSAR Model Study on the Fish Concentration Factors

Fan Deling, Liu Jining, Wang Lei and Shi Lili

The aim was to develop a reliable and practical quantitative structure-activity relationship (QSAR) model validated by strict conditions for predicting bio-concentration factors (BCF). We built up three QSAR models starting from 25 chemicals based on linear heuristic method (HM), radial basis function neural network (RBFNN) and support vector machine (SVM) methods. The selected six descriptors are the most important physical chemistry properties for the construction of QSAR model. In the HM method, the value of square of the correlation coefficient r2 is 0.8479, s2 is 0.0474; in the SVM method, the value of the r2 is 0.9351 and s2 is 0.0233 whereas in the BP method, the r2 is 0.7539, s2 is 0.154. The SVM model may be used for prediction of toxicity, safety and risk assessment of chemicals to achieve better ecotoxicological management.

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Anti-bacterial activity of tomato glycosides

Li Jian-Guang and Zhang Lu

Glycosides were extracted from green tomatoes with ethanol as the solvent. The extracted glycosides were purified by an HPD macroporous resin and a silica gel column, crystallised and then recrystallised to yield white powder. The minimal inhibitory concentration (MIC) of the extracted tomato glycosides against Escherichia coli was determined to be 3.54 mg/mL through agar diffusion test. The effects of pH, temperature and reaction time on the anti-bacterial activity of the tomato glycosides were investigated. The bacteriostatic effect of the tomato glycosides was stronger than that of 1.5% sodium benzoate. The tomato glycosides exhibited the strongest anti-bacterial effect at pH 7.

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Mineralogy and bioavailability of Selected Heavy Metals in Agricultural Soils

Ngole Veronica Mpode and Ekosse Georges-Ivo

Contamination of soils with heavy metals from agrochemicals presents a threat to food security and safety in communities depending on these soils for subsistence. Knowledge of the various factors and properties dictating metal behavior in agricultural soils is of paramount importance in the management of such contamination. This study considered the relationship between soil properties and metal mobility in three agricultural soil types from Botswana and appraised the role of clay mineralogy in heavy metal (HM) mobility in these soils. The mobility factor (MF) of metals in the three soils was determined from results of sequential extraction of HM in the soils. Mean concentrations of Cr, Co, Cu, Mn, Pb and Zn were highest in the vertisol with values of 127.7 mg/kg, 45.3 mg/kg, 119.4 mg/kg, 476.9 mg/kg, 52.2 mg/kg and 113.0 mg/kg respectively. Though the concentrations of HM in the vertisol were highest, the availability of these HM as indicated by values for MF of the different metals in the vertisol was lowest (0.02 – 1.13) whereas the arenosol with the lowest concentration of HM had the highest values for MF of most of the metals (0.54 – 13.38). These MF values were higher than those obtained for the luvisol which ranged from 0.05 to 1.07. The trends in MF did not match the trends observed in metal uptake by spinach grown on these soils. The observed patterns in HM mobility in the soils were attributed to the clay content and mineralogical assemblage the soils.

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Application of Taguchi Optimization Approach for the Removal of Cr (VI) from Aqueous Solution using Husk of Cajanus cajan

Kaushik A., Chauhan B. S. and Singh A. K.

The present study investigates the use of Husk of Cajanus cajan (HCC) as a suitable adsorbent for Cr(VI) from aqueous solutions. This study includes the Taguchi’s Optimization Technique for process parameter optimization. Taguchi’s approach helps to create a robust design of experiment which is a systematic methodology to obtain the results that are least affected by the variations (noise) of the system. In this method, we used statistical tools like signal-to-noise(S/N) ratio, analysis of variance (ANOVA). The study reveals that optimum response for the removal of Cr(VI) is obtained at the pH value 1.0, adsorbent dose 0.7 gm/50 ml and 15.5mg/L metal ion concentration. The results of the study also show that the pH of the solution is the most influential parameter for the adsorption of Cr(VI). Confirmation experiment was conducted to investigate the successful implementation of optimum process parameters.

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Separation and quantification of impurities of Desvenlafaxine Succinate from active pharmaceutical ingredient (API) using reverse phase liquid chromatography

Harlikar Jayvant Narayan and Amlani Arun Mahendra

High performance reverse phase liquid chromatography (HPLC) method was developed for quantification of impurities of Desvenlafaxine Succinate from active pharmaceutical ingredient (API). Desvenlafaxine Succinate and its impurities were separated using reverse phase gradient HPLC method. The experimental procedure involved variable wavelength detector (at 225nm), the mobile phases consisting of mobile phase A of phosphate buffer and mobile phase B of acetonitrile and water (98:2V/V) used with gradient program. The flow rate of the mobile phase was adjusted to 1.0mL per minute on an Inertsil ODS 3V, C-8 (250mm x 4.6mm, 5µ size) column. A calibration curve showed good linearity within the LOQ to 0.2% of the test range (i.e. 0.2 ppm to 2 ppm). The recovery at LOQ level ranged from 100% to 109% and the recoveries at 50% to 200% level ranged from 98% to 106%. The % RSD for repeatability was ≤ 1.5. The solution stability is established till 24 hours. The HPLC method is capable of detecting all process related impurities which may be present in the API. The method was validated and from the results obtained it can be concluded that the method is suitable for the intended purpose of separation and quantification.

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Fluoride Removal Efficiencies of Some Nano and Bulk Materials

Dutta P.

The removal efficiencies of fluoride by nano and bulk material of activated charcoal, silica gel and rice husk were studied with four different fluoride concentrations viz 5.8, 6.5, 7.7 and 8.6 ppm. It has been observed that the removal efficiency of fluoride by bulk activated charcoal after 1h was found to be 55.1, 50.7, 46.7 and 40.5 percent for initial fluoride concentrations 5.8, 6.5, 7.7 and 8.6 ppm respectively and the removal efficiency decreases as the initial concentration increases. Similarly removal efficiency of bulk silica gel and rice husk after 1h was found to be 38.2, 37.7, 37 and 36.5 percent for silica gel and 20.7, 19.8, 19.0 and 18.4 percent for rice husk for same initial concentration 5.8, 6.5, 7.7 and 8.6 ppm respectively and the removal efficiency decreases as the initial concentration increases. The extent to which fluorides were removed by nano materials viz. activated charcoal, silica gel and rice husk were higher than that of respective bulk materials. The higher adsorption capacity of nano materials than bulk materials may be due to increase in surface area at nano level. The adsorption data of rice husk was tested for Freundlich adsorption isotherm and Langmuir isotherm model as rice husk is an eco-friendly and cost effective material.

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Effect of organic manure and mineral fertilizers on passive pool of soil organic matter in a long-term experiment

Verma Gayatri

Soil organic carbon (SOC) is the most important indicator of soil quality because of its impact on other physical, chemical and biological indicators of soil quality. To sustain agricultural productivity and environmental quality it is important to maintain and improve soil quality in continuous cropping systems. Long-term studies have consistently shown the benefit of manures, adequate fertilization on maintaining agronomic productivity by increasing C inputs into the soil. To understand this phenomenon, passive pool of soil organic matter was studied in Inceptisol in a long term field experiment established in 1997 under maize-wheat cropping system at Instructional farm, Rajasthan College of Agriculture, Udaipur under All India Co-ordinated Research Project. The study involved various doses of N, NP, NPK with FYM, Zn, S and Azotobacter. Continuous application of organic manure alone and in combination with inorganic fertilizers enriched the soil with organic carbon, humic acid, fulvic acid and humin content. However, sole application of fertilizers led to lower organic carbon content. A significant correlation of passive fractions of organic matter was obtained with soil properties which revealed that these help in nutrient recycling and transformation.

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Spectroscopic Investigations on Structural Characterization of Borate Glass Specimen doped with Transition Metal Ions

Thirumaran S. and Sathish K.

Infra-Red spectroscopy is an effective tool for resolving the structure of local arrangement in glasses. Infrared investigations reveal structural changes and observed changes in infrared spectra due to irradiation and can be interpreted by assuming that irradiation of glass leads to formation of induced defects which led to decrease of the intensity of the main characteristic mid absorption bands. Structural changes after irradiation have been investigated by using FTIR spectroscopic studies. According to IR analysis, there is a depolymerization of the borate network and conversion of BO3 or BO4 units with the formation of non-bridging oxygen. The FTIR spectral studies confirm the presence of various functional groups of the sample. FTIR spectrum of sample exhibits broad absorption bands indicating the wide distribution of borate structural units. The effect of Na2CO3 and V2O5 and MnO2 contents on the structures of borate glass is evaluated from the FTIR spectra.

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Biodegradation of polyethylene (HDPE) by Pseudomonas sp. NCIM 2303

Gaikwad Bhaskar G. and Varma Rita J.

Cultures from NCIM culture collection (National Chemical Laboratory, Pune, India) were screened for biodegradation polyethylene carry bags. A strain of Pseudomonas sp. NCIM 2303 was found to be most effective. A film of polyethylene bag put in the supernatant of cell culture broth showed 4.16 % degradation in 5 days as determined by weight loss. Studies were carried out to enhance the biodegradability of the enzyme in the supernatant. It was assumed that after 5 days the enzyme in the broth is deactivated and hence no further degradation occurs. Thus after 5 days the film was removed, its weight loss noted and then once again suspended in fresh culture broth for 5 days, this was repeated until no further degradation was observed. After 7 cycles a total loss of 23.52 % was achieved.

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