Indian Journal of Chemical Technology

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VOLUME 14

NUMBER 6

NOVEMBER 2007

CODEN:ICHTEU

 

ISSN:0971-457X

 

CONTENTS

 

Papers

 

 

Optical resolution of racemic tryptophan through non-chiral membranes by ultrafiltration using chiral selector in solution

 

547

        IPC Code (s): C07B57/00, C12P41/00

 

        Kripal Singh & H C Bajaj

 

 

Improved conversion to ethyl acetate through removal of water of esterification by membrane pervaporation

 

552

        IPC Code (s): B01D17/00, B01D61/36

 

        Swatilekha Das, A K Banthia & Basudam Adhikari

 

 

Electrochemical reduction of ornidazole at a composite polymer membrane electrode

560

        IPC Code (s): C25C1/00, C25B11/00

 

        D C Tiwari, Rajeev Jain & Gaurav Sahu

 

 

Electrochemical reduction of 2-acetyl benzofuran and its derivatives at glassy carbon electrode

566

        IPC Code (s): C25B3/04, G01N

 

        G P Mamatha, B S Sherigara & K M Mahadevan

 

 

Preparation and characterization of an all solid supercapacitor based on polyaniline-Al2O3 layer on aluminium alloy-Al-2024

 

572

        IPC Code (s): H01G9/025

 

        M Selva Kumar & D Krishna Bhat

 

 

Some fatty acid oxadiazoles for corrosion inhibition of mild steel in HCl

576

        IPC Code (s): C23F11/00

 

        M Z A Rafiquee, Nidhi Saxena, Sadaf Khan & M A Quraishi

 

 

Inhibitory effects of some imines on the corrosion of mild steel in hydrochloric acid solution

584

        IPC Code (s): C23F11/00

 

        A V Shanbhag, R A Prabhu, G M Kulkarni, R G Kalkhambkar & T V Venkatesha

 

 

Recovery of cephalosporin C from aqueous solution using polymeric adsorbent

592

        IPC Code (s): B01D15/00

 

        Punita Mishra, Pradeep Srivastava, P K Mishra & Subir Kundu

 

 

Sorption of water soluble dyes from aqueous solutions on zirconium phosphate

597

        IPC Code (s): B01J39/02, C09B

 

        Amit Jayswal & Uma Chudasama

 

Desilication of agro based black liquor and green liquor using jet loop reactor

606

        IPC Code (s): D21C

 

        Sachin A Mandavgane, G D Paradkar, J Varu, R Pamar & D Subramanian

 

 

Sensitive spectrophotometric methods for the determination of pantoprazole sodium in pharmaceuticals using bromate-bromide, methyl orange and indigo carmine as reagents

 

611

        IPC Code (s): A61K, G01J3/00

 

        K Basavaiah & U R Anil kumar

 

 

Flotability of barite particles with different shape and roughness

616

        IPC Code (s): E21C50/00

 

        U Ulusoy & M Yekeler

 

 

Studies on effect of growth factor on morphological, chemical and pulp and paper making characteristics and its impact on fluff generation

 

626

        IPC Code (s): D21C3/00

 

        Dharm Dutt, C H Tyagi & R S Malik

 

 

Notes

 

 

Regeneration of carbonyl compounds from their oxime using Ce (IV) based phase-transfer oxidants

 

635

        IPC Code (s): C07C27/18, C07C251/32

 

        Anindita Dewan & Dilip Kumar Kakati

 

 

Estimation of thermal conductivity of binary liquid mixtures employing new approach

638

        IPC Code (s): G01N25/18

 

        J D Pandey, R Dey, N K Soni, Prakash Chandra & M K Yadav

 

 

An empirical correlation in predicting the viscosity of refined vegetable oils

642

        IPC Code (s): A23D, G01N

 

        Anupama Gupta, S K Sharma & Amrit Pal Toor

 

 

 

Acknowledgement to referees

 

647

Annual Author Index

 

649

Annual Keyword Index

 

652

Guidelines for Authors

655

 

  

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 547-551

 

Optical resolution of racemic tryptophan through non-chiral membranes by ultrafiltration using chiral selector in solution

 

Kripal Singh & H C Bajaj*

 

Optical resolution of racemic mixture of tryptophan has been performed by ultrafiltration in solution containing bovine serum albumin (BSA) as a chiral selector, using non chiral polysulfone (hydrophobic) and polyamide (hydrophilic) membranes. The effectiveness of optical resolution was characterized in terms of enantiomeric enrichment (%ee) in permeate. Solute flux and enantiomeric enrichment of two different membranes were compared. Effects of solute and bovine albumin (chiral selector) concentration in feed solution, pH of the feed and operating pressure were studied in detail to optimize the enantiomeric enrichment process. It has been observed that enantioselectivity of ultrafiltration process is strongly pH-dependent and reaches a maxima at feed pH 9.0–9.2. The solute flux (racemic tryptophan dissolved in the liquid) as well as permeate flux (solution consisting racemic tryptophan, BSA and buffer) decreases but %ee increases with permeation time, which indicates that concentration polarization effects the enantioselectivity of the process adversely. Enantioselectivity increases with the BSA content in the feed solution. Optical resolution of tryptophan racemic mixture upto 33 %ee in single pass, at a permeate flux of 9 l/m2-h was obtained.

Keywords: Enantioselectivity, Enantiomer enrichment, Ultrafiltration, Bovine serum albumin, Chiral selector

IPC Code (s): C07B57/00, C12P41/00

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 552-559

 

Improved conversion to ethyl acetate through removal of water of esterification by membrane pervaporation

 

Swatilekha Das, A K Banthia & Basudam Adhikari*

 

Crosslinked poly (vinyl alcohol) (PVA) membranes were prepared using maleic acid (MA) and citric acid (CA) as crosslinking agents. First the water separation ability of the crosslinked membranes from aqueous acetic acid (10-90% acetic acid) and ethanol (20-80% ethanol) solutions at 30 to 90°C was tested by pervaporation. The effects of temperature, feed concentration, crosslinker type on pervaporation characteristics were investigated. The PVAMA membrane showed separation factors of 1.9-16.2 and fluxes of 4.26-38.48 kg/m2 h and PVACA membrane showed separation factors of 3.8-33 and fluxes of 2.17-480.8 kg/m2 h for acetic acid-water separation. In case of ethanol-water separation, the PVAMA membrane showed separation factors of 0.7-17.9 and fluxes of 2.5-36.2 kg/m2 h and PVACA membrane showed separation factors of 1.4-41.9 and fluxes of 3.8-359.7 kg/m2 h. PVACA membrane has shown high separation efficiency of water than that of PVAMA membrane. Having high selectivity and good permeating ability for water both the membranes were then used to remove water of esterification from reaction of acetic acid with ethanol by a batch pervaporation. Compared to around 60% conversion in conventional esterification, up to 98% conversion to ethyl acetate was achieved from ethanol and acetic acid when water by product was removed by pervaporation using the prepared membranes at same temperature.

Keywords: Pervaporation, PVA membrane, Esterification, Flux

IPC Code (s): B01D17/00, B01D61/36

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 560-565

 

Electrochemical reduction of ornidazole at a composite polymer
membrane electrode

D C Tiwari, Rajeev Jain* & Gaurav Sahu

 

Composite polymer membrane has been fabricated on platinum foil using electrochemical deposition of pyrrole and aniline as monomers. The composite has been used as an electrode to analyse ornidazole. The results were comparable with the glassy carbon electrode. The mechanism of biological action of ornidazole is dependent upon the nitro group reduction process. In aprotic medium the reduction of the ornidazole occurs in two steps, the first involving one electron to form the nitro radical and the second step involving three electrons, resulting in the formation of the hydroxylamine derivative.

Keywords: Composite polymer membrane, Pyrrole, Aniline, Ornidazole, Glassy carbon electrode

IPC Code (s): C25C1/00, C25B11/00

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 566-571

 

Electrochemical reduction of 2-acetyl benzofuran and its derivatives at glassy carbon electrode

 

G P Mamatha, B S Sherigara* & K M Mahadevan

 

Electrochemical reduction of 2-acetylbenzo[b]furan and its derivatives namely 2-acetylbromobenzo[-b]furan, 2-acetylbromo-5-bromobenzo[b]furan and 2-acetyl naphtha[2,1-b] furan has been carried out in four different aqueous solvents namely DMSO, DMF, acetonitrile, ethanol using Britton Robinson buffer as supporting electrolyte at glassy carbon electrode employing cyclic voltametric techinque. Single irreversible wave was observed due to the reduction of >C=O moiety to secondary alcohol derivatives of benzofuran. Formation of pinacol due to dimerization of the intermediate radical was ruled out on steric consideration. The other data viz. the effect of sweep rate, concentration of the electroactive species, effect of temperature, effect of surfactant, effect of dielectric constant on cathodic peak potential (Epc), and cathodic peak current (ipc) has been found out. Diffusion coefficent (D0) and heterogeneous rate constant (k0) have been evaluated. The electrode process was shown to be diffusion controlled and irreversible. The electrolytic products are characterised/identified by controlled potential electrolysis. The results of the electroreduction are compared with that of the chemical reduction method.

Keywords: Voltammetry, 2-Acetyl benzo [-b] furan, Reduction, Glassy carbon electrode

IPC Code (s): C25B3/04, G01N

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 572-575

 

Preparation and characterization of an all solid supercapacitor based on polyaniline-Al2O3 layer on aluminium alloy-Al-2024

M Selva Kumar & D Krishna Bhat*

 

The characteristics of an all solid state supercapacitor based on polyaniline (Pani)-Al2O3 coating on aluminium alloy 2024 (Al-2024) surface prepared by the constant current method have been investigated. Three stages are observed in the potential- electrolysis time relation for the simultaneous preparation of the dielectric layer and the conducting polymer on the aluminium foil. The deposition of polyaniline film has been confirmed by cyclic voltammetry. The solid state capacitor has been studied by AC impedance spectroscopy and the capacitive behaviour of the cell is discussed in terms of Nyquist plots, complex capacitance and complex power. The study revealed that the capacitor has comparatively good capacitance, ranging from 450 to 600nF/cm2, a low time constant and also very low resistance. The normalized reactive power, |Q|/|S| and active power |P|/|S| versus frequency plot for the solid state capacitor allow an overview of the whole frequency behaviour of the supercapcitors, ranging from a pure resistance at high frequency to a pure capacitance at low frequency. When a capacitor is used as a source stiffening capacitor and is buffering the supply by delivering initial current, a lower RC time constant allows delivering significantly more current. So this type of solid-state capacitor can be used for the DC-DC converter modules.

Keywords: Supercapacitors, Electrochemical deposition, Polyaniline, Aluminium Alloy Al-2024, Solid electrolyte

IPC Code (s): H01G9/025

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 576-583

 

Some fatty acid oxadiazoles for corrosion inhibition of mild steel in HCl

M Z A Rafiquee, Nidhi Saxena*, Sadaf Khan & M A Quraishi

 

inhibition effect of some fatty acid oxadiazoles on the corrosion of mild steel (MS) in aqueous solution containing 1 N HCl was investigated by weight loss, potentiodynamic polarization technique, electrochemical impedance spectroscopy and scanning electron microscopy. The adsorption of these compounds was found to obey Langmuir adsorption isotherm. Various thermodynamic parameters were calculated to investigate the mechanism of corrosion inhibition. The effect of inhibitor concentration, solution temperature, immersion time and acid concentration on the corrosion of mild steel has also been investigated by weight loss technique. Scanning electron microscopy (SEM) is used to examine the surface morphology of the mild steel samples both in absence and presence of inhibitor at optimum concentration. Potentiodynamic polarization data showed that the compounds studied are cathodic type inhibitors in the acid solution. Electrochemical impedance spectroscopy was also used to investigate the mechanism of the corrosion inhibition.

Keywords: Mild steel, Oxadiazoles, Potentiodynamic polarization, Electrochemical impedance spectroscopy  (EIS), Scanning electron microscopy (SEM)

IPC Code (s): C23F11/00

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 584-591

 

Inhibitiory effects of some imines on the corrosion of mild steel in hydrochloric acid solution

 

A V Shanbhag, R A Prabhu, G M Kulkarni, R G Kalkhambkar & T V Venkatesha*

 

The inhibition effect of 4-[(E)-(phenylimino)methyl]phenol (PIP), 4-[(E)-(4-fluorophenylimino)methyl]phenol (FIP), 4-[(E)-(4-chlorophenylimino)methyl]phenol (CIP), 4-[(E)-(4-bromophenylimino)methyl]phenol(BIP) and 4-[(E)-(4-nitro-phenylimino) methyl]phenol (NIP) on the corrosion of mild steel in hydrochloric acid was investigated. The corrosion inhibiting action was studied through weight loss and electrochemical techniques. The corrosion parameters such as anodic and cathodic Tafel slopes (ba and bc), corrosion potential (Ecorr), corrosion current densities (Icorr), surface coverage (q) and corrosion inhibition efficiencies %IE were determined. The polarization measurements indicated that the inhibitors are of mixed type. The adsorption obeyed Langmuir adsorption isotherm. The inhibition efficiencies increased with increase in inhibitor concentration but decreased with increase in temperature and also with increase in acid concentration. The activation and thermodynamic parameters were calculated for different temperatures.

Keywords: Corrosion, Mild steel, Langmuir’s isotherm, Imines, Thermodynamic parameters

IPC Code(s): C23F11/00

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 592-596

 

Recovery of cephalosporin C from aqueous solution using polymeric adsorbent

 

Punita Mishra, Pradeep Srivastava*, P K Mishra & Subir Kundu

 

Commercially available neutral polymeric sorbents are used for recovery of beta lactam antibiotic cephalosporin C (CPC), from aqueous solution. The objective of this work is to evaluate the separation of CPC from fermentation broth during purification process. The neutral forms of CPC are preferentially adsorbed onto the neutral sorbents. Adsorption of CPC was higher onto the aromatic (XAD 4) as compared to aliphatic ester sorbent (XAD 8). The kinetics of CPC adsorption on aromatic polymeric adsorbent has been investigated. Isopropyl alcohol solution was used to desorb CPC.

Keywords: Adsorption, Desorption, Cephalosporin C, Polymeric adsorbents

IPC Code (s): B01D15/00

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 597-605

 

Sorption of water soluble dyes from aqueous solutions on zirconium phosphate

 

Amit Jayswal & Uma Chudasama*

 

Amorphous zirconium phosphate (ZP) an inorganic ion exchange material of the class of tetravalent metal acid (tma) salt has been synthesized by sol-gel method. The material has been characterized for elemental analysis (ICP-AES), thermal analysis (TGA, DSC), FT-IR and X-ray diffraction studies. Chemical resistivity of the material in various media has been assessed. The sorption behaviour of dyes methylene blue (MB), crystal violet (CV), methyl violet (MV) and janus green B (JGB) towards ZP has been studied at 313, 323 and 333 K and kinetic and thermodynamic parameters evaluated. Adsorption isotherms (Langmuir and Fruendlich), breakthrough capacity and elution behaviour of dyes have also been studied. Sorption affinity of dyes towards ZP is found to be MB > CV ≈ MV > JGB.

Keywords: Zr (IV) phosphate, Inorganic ion exchanger, Tetravalent metal acid salt, Waste treatment containing dyes

IPC Code (s): B01J39/02, C09B

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 606-610

 

Desilication of agro based black liquor and green liquor using jet loop reactor

 

Sachin A Mandavgane*, G D Paradkar, J Varu, R Pamar & D Subramanian

 

Non-wood fibers represent the largest resource of fibrous materials for many developing countries in the world. Attention is now being focused on cellulose bearing agricultural residues, which can be used as raw materials for production of paper. Though chemical pulping of these raw materials poses no problem, major difficulty arises in the recovery of heat and chemicals from the spent cooking chemical (black liquor). The presence of silica in black liquor obtained from agro based pulp and paper mill causes serious problems at filtration, washing, evaporation, burning, recausticizing and clarification levels of chemical recovery. It is, therefore, necessary to remove silica before the black liquor is concentrated to high solid content. The success of the desilication process by carbonation lies in accurate pH control otherwise lignin
co-precipitation occurs during desilication. In the present work, a high mass transfer efficient, compact Jet Loop Reactors (JLR) or some times called as Highly Compact Reactor (HCR) is used for desilication to obtain exact pH control. The experiments were carried out in a 15 L reactor at room temperature as well as at higher temperatures. The results obtained in JLR are compared with those obtained by Bubble Column Reactor (BCR). Desilication of green liquor in both the reactors at different temperatures is also studied. The results show that desilication in JLR is more efficient at higher temperatures.

Keywords: Black liquor, Green liquor, Desilication, Delignification, JLR, BCR, Carbonation

IPC Code (s): D21C

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 611-615

 

Sensitive spectrophotometric methods for the determination of pantoprazole sodium in pharmaceuticals using bromate-bromide, methyl orange and indigo carmine as reagents

 

K Basavaiah* & U R Anil kumar

Two new sensitive spectrophotometric methods are described for the determination of pantoprazole sodium sesqui hydrate (PNT) using bromate-bromide mixture and two dyes, methyl orange and indigocarmine, as reagents. The methods entail the addition of a known excess of bromate-bromide mixture to PNT in hydrochloric acid medium followed by determination of residual bromine by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (Method A) or indigo carmine and measuring the absorbance at 610 nm (Method B). In both methods, the amount of bromine reacted corresponds to the amount of PNT. The absorbance is found to increase linearly with concentration of PNT. Under the optimum conditions, PNT could be assayed in the concentration ranges 0.12-1.50 and 0.5-6.0 mg mL-1 by method A and method B, respectively. The apparent molar absorptivities are calculated to be 1.8x105 and 4.1x104 L mol-1cm-1 for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.002 and 0.011 µg cm-2. The limits of detection and quantification are also reported for both methods. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The methods were successfully applied to the assay of PNT in its tablet formulation and the results were compared with those of a reference method by calculating the Student’s t-value and F-value. No interference was observed from common tablet adjuvants. The accuracy and reliability of the methods were further ascertained by recovery experiments via standard-addition procedure.

Keywords: Pantoprazole sodium, Assay, Spectrophotometry, Bromate-bromide

IPC Code (s): A61K, G01J3/00

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 616-625

 

Floatability of barite particles with different shape and roughness

 

U Ulusoy & M Yekeler*

 

In this article, different mill (ball, rod and autogenous) products of barite mineral were characterized in terms of their shape, roughness and wettability. 2D shape parameters were measured by the particle projections using SEM and expressed by elongation and roundness. Surface roughness values were determined and stated as the parameters of Ra value on the surface of the compressed discs. The wettability characteristics (gc) of barite were determined by microflotation and contact angle measurement techniques. Finally, some correlations were established between the shape parameters, surface roughness values and the wettability characteristics. In conclusion, the degree of hydrophobicity was favoured with elongation, while it was not favoured with roundness and roughness regardless of the type of the mill used.

Keywords: Floatability, Shape, Roughness, Grinding, Barite

IPC Code (s): E21C50/00

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 626-634

 

Studies on effect of growth factor on morphological, chemical and pulp and paper making characteristics and its impact on fluff generation

Dharm Dutt*, C H Tyagi & R S Malik

 

The dearth of cellulosic fibers has compelled the paper technocrats to search for high yielding and fast growing trees. Leucaena leucocephala has solved the manifold purposes of both farmers as well as paper manufacturers. However, paper manufacturers face the serious problem of fluff in the drying section of paper machine with this furnish. L. leucocephala of the same species was cut after 2, 3 and 4 years and was analyzed for, morphological, chemical and pulp evaluation characteristics. The fibers of 2 and 3 years old of L. leucocephala are immature and consist of more non-fibrous elements i.e. vessels and parenchymatous cells. When such type of fibers are subjected to mechanical attrition for removal of primary wall, cause more fiber cuttings instead of fibrillation. The primary wall is permeable to water but does not participate in bond formation. These non-fibrous elements have larger surface area than fibers and their presence affects fiber bonding adversely. The loosely bonded fibers from the paper sheet adhere on press rolls or dryers during sheet making and contribute to fluff problem. L. leucocephala cut after 4 years of cultivation does not show fluff problem because of complete cellulose formation of fibers.

Keywords: Ageing effect, Proximate chemical analysis, Pulping, Black liquor, Fluff

IPC Code (s): D21C3/00

 

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 635-637

 

Regeneration of carbonyl compounds from their oximes using Ce(IV) based phase-transfer oxidants

 

Anindita Dewan & Dilip Kumar Kakati*

 

Regeneration of ketone and aldehyde from their oximes is an important reaction in synthetic organic chemistry. In the oxidative deoximation processes the use of inorganic reagents is restricted by the insolubility of inorganic reagents in organic solvents. However this problem can be alleviated by the use of oxidants, like tetra-alkyl ammonium salts in the form of phase-transfer reagents. In the present case two phase transfer oxidants cetyldimethyl benzyl ammonium cerium nitrate (CDBACN) and cetyltrimethyl ammonium cerium nitrate (CTACN) were used for oxidative deoximation of oximes of carbonyl compounds. The regenerated carbonyl compounds were characterized from their melting points and spectroscopic analysis.

Keywords: Phase-transfer oxidant, Cetyldimethyl benzyl ammonium cerium nitrate (CDBACN), Cetyltrimethyl ammonium cerium nitrate (CTACN)

IPC Code (s): C07C27/18, C07C251/32

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 638-641

 

Estimation of thermal conductivity of binary liquid mixtures employing new approach

 

J D Pandey*, R Dey, N K Soni, Prakash Chandra & M K Yadav

 

Thermal conductivity of four binary liquid mixtures of polyethers with n-dodecane have been computed using a new approach. Decent agreement has been found between the experimental and estimated values of thermal conductivity for all systems.

Keywords: Thermal conductivity, Binary liquid mixtures, Polyethers, New approach

IPC Code (s): G01N25/18

 

Indian Journal of Chemical Technology

Vol. 14, November 2007, pp. 642-645

 

An empirical correlation in predicting the viscosity of refined vegetable oils

Anupama Gupta, S K Sharma & Amrit Pal Toor*

 

Accurate knowledge of transport properties of oil is essential for mass and heat flow. Viscosity is one of the important properties of an oil which needs to be determined as it influences the ease of handling, transport and nature of storage. The effect of temperature on viscosity of six refined vegetable oils viz. palm oil, rice bran oil, cottonseed oil, mustard oil, sunflower oil and soybean oil has been studied. An empirical correlation between reduced viscosity and reduced temperature has been derived for the determination of viscosities of refined vegetable oils showing Arrhenius behaviour above 20°C (293 K). This correlation predicts the viscosity of refined vegetable oils at temperatures more than 40-60°C above 20°C (293 K). Consistency tests for viscosity data using reduced parameters have been reported. The viscosities calculated using proposed empirical correlation agree well with the reported experimental values.

        Keywords: Refined vegetable oils, Temperature, Viscosity

        IPC Code (s): A23D, G01N