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Welcome to Journal of The Chemical Society Of Pakistan

Journal of the Chemical Society of Pakistan (JCSP) is a bimonthly Journal which publishes results of original, unpublished research work and review articles in all fields of Chemistry.

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Evaluation of Thermal Stability of Some Organically Modified Clays

MOHAMMAD SHAKIRULLAH, IMTIAZ AHMAD, MUHAMMAD ISHAQ AND HAMEED ULLAH

The paper is focused on the influence of some organic modifiers on the thermal stability of the clay-organic intercalates. The organic modifiers used were rubber, coal, thermosetting plastic, polystyrene and polyvinyl chloride Melt intercalation procedure was used. Modification with organic modifiers was performed at 400 oC. TG-DTA study was performed to evaluate the thermal stability of the resultant intercalates. Thermal properties were improved significantly in case of organically modified clay samples. Among the modifiers used, poly styrene proved very effective in case of crude clay while in case of pre baked clay, intercalation with rubber caused significant improvement in thermal stability. Thus, such intercalations are suggested to be effective if the clays under study are to be used at elevated temperature.
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Initially Approximated Quasi Equilibrium Manifold

Muhammad Shahzad, Muhammad Sajid, Muhammad Gulistan, Hina Arif

Most commonly, kinetics model reduction techniques are based on exploiting time scale separation into fast and slow reaction processes. Then, a researcher approximates the system dynamically with dimension reduction for slow ones eliminating the fast modes. The main idea behind the construction of the lower dimension manifold is based on finding its initial approximation using Quasi Equilibrium Manifold (QEM). Here, we provide an efficient numerical method, which allow us to calculate low dimensional manifolds of chemical reaction systems. This computation technique is not restricted to our specific complex problem, but it can also be applied to other reacting flows or dynamic systems provided with the condition that a large number of extra (decaying) components can be eliminated from the system. Through computational approach, we approximate low dimensional manifold for a mechanism of six chemical species to simplify complex chemical kinetics. A reduced descriptive form of slow invariant manifold is obtained from dissipative system. This method is applicable for higher dimensions and is applied over an oxidation of CO/Pt.
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Synthesis and Characterization of 1,2-Benzenedimethyloxy Substituted Novel Ball-Type and Mononuclear Metallo Phthalocyanines

Ayşegül Yazici, Nida Dalbul, Bekir Salih

The phthalodinitrile derivative 1 was prepared by the reaction of 1,2-benzenedimethanol and 4-nitrophthalonitrile in dry DMF in the presence of K2CO3 by the common method of nucleophilic substitution of an activated nitro group in an aromatic ring. The template reaction of 1 with the corresponding metal salts gave the novel mono-nuclear ZnPc 2 and ball-type metallophthalocyanine LuPc2 3. In this study, we have used the ‘‘heating of the solid phase’’method for the synthesis of novel ball-type LuPc2 3 phthalocyanines. Mono-nuclear ZnPc 2 phthalocyanine was prepared by reflax in solvent. Mono and ball-type phthalocyanines were characterized by elemental analyses, FT-IR, 1H NMR, 13C NMR, UV–vis and MALDI-TOF MS spectral data.
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Organophosphate Pesticide Residues in Okra and Brinjal Grown in Peri-Urban Environment of Big Cities of Punjab

Muhammad Atif Randhawa, Muhammad Zaman, Faqir Muhammad Anjum, Ali Asghar. Muhammad Wasim Sajid

Peri urban farming system is main supplier of vegetables to urban population and organophosphate pesticides exposure due to consumption of okra and brinjal to urban population has been estimated in this study. Okra and brinjal samples (90 samples for each vegetable) were collected from peri-urban farming area of Faisalabad, Multan and Gujranwala and were analysed by GC-ECD for quantification of chlorpyrifos, profenophos and triazophos residues. Data were statistically analyzed to calculate, mean and standard deviation. Quantification of pesticides residues revealed that 85 (47.22%) samples were contaminated and 15 (8.33 % of total samples and 17.64% of contaminated) samples showed residues value higher than MRL’S. Out of 85 contaminated samples 27 (31.76%) samples were contaminated with chlorpyrifos, 30 (35.29%) samples with profenofos and 29 (34.11) were contaminated with triazophos. The mean concentration of chlorpyrifos in okra was 0.192 mg Kg-1 and brinjal 0.197 mg Kg-1. The mean concentration for profenofos in okra was 0.02 mg Kg-1 and brinjal 0.035 mg Kg-1. Similarly mean concentration for triazophos in okra was 0.009 mg Kg-1 and brinjal 0.01 mg Kg-1. Overall, 6.67% samples of okra and 6.66% samples of brinjal contaminated with chlorpyrifos exceeded EU MRL of 0.05 mg kg-1. Okra samples were found contaminated at frequency of 4.44% and brinjal samples at frequency of 5.56% with higher profenofos residues level than MRL of 0.05 mg kg-1. Approximately, 6.67% samples of okra and 5.6% samples of brinjal had profenofos residue level above MRL of 0.01 mg kg-1. This study may be helpful for building database regarding regional exposure of urban population and facilitate in estimation of possible risk to their health in our daily life
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The Study of Composite Carrier Based on Organic and Inorganic Polymers

BATES MALIKOVNA KUDAIBERGENOVA, MARAT KIANOVICH BEISEBEKOV, SHYNAR NURLANOVNA ZHUMAGALIEVA, MADIAR MARATOVICH BEISEBEKOV, ZHARYLKASYN ABDUACHITOVICH. ABILOV, MUHAMMAD.IQBAL CHAUDHARY

In this work has been investigated the possibility of obtaining of composites on the basis of polyvinyl alcohol and bentonite clay Manrak deposit. The interaction of polyvinyl alcohol with bentonite clay has been studied by employing methods such as equilibrium swelling, sedimentation, electrophoresis, viscometer, and scanning electron microscopy. It was established that the interaction of polyvinyl alcohol and bentonite clay are due to the hydrogen bonding between them. The composite gels with the improved structural-mechanical and prolonged effect have been formed on a base both of polyvinyl alcohol and clay.
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A Thermodynamic Study on Lysozyme with Sodium Dodecyl Sulfate in Different Temperatures and PHs

GHOLAMREZA REZAEI BEHBEHENI

The interaction of Sodium Dodecyl Sulfate (SDS) with hen egg lysozyme have been investigated at 298, 303 and 308 K in phosphate buffer at two different pH values (5 and 7), by isothermal titration calorimetry. The calorimetric data analysis allows the measurement of the complete set of thermodynamic parameters. The negative SDS ion binds to positive residues, neutralizes the protein surface charges and leads to precipitation and turbidity of the solution. At low concentrations of SDS, the binding is mainly electrostatic, with some simultaneous interaction of the hydrophobic tail with nearby hydrophobic patches on the lysozyme. The enthalpies of denaturation at pH 7 are 180.47, 198.51 and 216.56 kJmol−1 for 298, 303 and 308 K respectively
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Analytical Data: Reliability and Presentation

NAILA SIDDIQUE, SHAHIDA WAHEED

Chemical analysis whether it is used to determine the composition of a sample or to devise a procedure for testing or preparation of another sample requires systematic experiment design and implementation. In order to determine and verify the validity of results various methods are employed to evaluate the data obtained. This process enables the analyst not only to understand the results but to find possible reasons for differences and similarities between samples. A simple scheme for carrying out analysis in order to obtain valid and reliable results is outlined in this paper. Moreover the importance of using reference and quality control materials to obtain quantitative results is also highlighted. To evaluate the performance and capability of a laboratory or an analytical procedure, parameters such as relative bias, z-scores, u-test, tests for accuracy and precision etc can be used. The use and significance of these parameters is explained using examples in this manuscript. Uncertainties and errors in measurement as well as the limits of detection (LOD) of an experimental procedure can also provide vital information about the data obtained. Simple calculations are used to explain how these can be obtained and what their magnitudes imply
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The Nucleation Effect and Thermal Behavior of Poly

YAN-HUA CAI

The nucleation effect and thermal behavior of bisamides compound(N, N'-Bis(benzoyl) tridecanedioic acid dihydrazide(NA)) as nucleating agent for poly(L-lactic acid) (PLLA) was evaluated by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and wide angle X-ray diffraction (WAXD). Compared to the neat PLLA, NA could increase the overall crystallization rate of PLLA. Upon the addition of 0.8% NA, the crystallization peak temperature increased from 96.28℃ to 113.58℃, and the crystallization enthalpy increased from 1.379 J•g-1 to 30.51 J•g-1. POM showed that the spherulite number of PLLA increased and the spherulite size reduced significantly with the presence of NA. The results of melting behavior at different conditions showed that the melting behavior of PLLA/NA samples was affected significantly by crystallization time, crystllization temperature and cooling rate. And there existed double-melting peaks resulting from melting-recrystallization at low crystallization temperature.
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Chelating Impact Assessment of Biological and Chemical Chelates on Metal Extraction from Contaminated Soils

SANA MUNAWAR, SHAZIA IRAM

Soil contamination is the result of uncontrolled waste dumping and poor practices by human. Of all the pollutants heavy metals are of particular concern due to their atmospheric deposition, leaching capacity and non-biodegradability. Heavy metal containing effluent is discharged into the agricultural fields and water bodies. This results in the accumulation of heavy metals in soil and the crops grown on the soil. Studies have revealed detrimental impacts on soil fertility and the poor health of animals and humans. Phytoextraction is a widely researched for remediation of heavy metal contaminated soil. To enhance the effect of phytoextraction heavy metals have to be available to the plants in soluble form. In this study the potential of different chelating agents was assessed in solubilizing the heavy metals making easy for plants to uptake them. For this purpose efficient chemical and biological chelating agent had to be identified. Along with that an optimum dose and application time for chemical chelating agent was determined. Ethylenediamine tetraacetic acid (EDTA), Diethylene triamine pentaacetic acid (DTPA), Nitriloacetic acid (NTA) were applied to the soil, containing Pb, Cr, Cu and Cd, at different concentrations and application time. Aspergillus niger and Aspergillus flavus were incubated in soil for different time periods. In correspondence with findings of the study, Pb and Cr were best solubilized by 5mM EDTA. For Cd and Cu 5mM DTPA carried out efficient chelation. NTA showed relatively inadequate solubilisation, although for Cr it performed equal to EDTA. A. niger and A. flavus instead of solubilizing adsorbed the metals in their biomass. Adsorption was mainly carried out by A. niger
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Input of Isosteric and Bioisosteric Approach in Drug Design

GOWHAR ALI, FAZAL SUBHAN, NAZAR UL ISLAM, INAMULLAH KHAN, KHALID RAUF, SAMIULLAH, MUZAFFAR ABBAS, ABDUR RAUF

Bioisosterism has unique relevance in the field of pharmaceutical sciences and is conducted to curtail side effects or to alter the biological activity of a lead molecule. In the biomedical field, the aim of exchanging one bioisostere for another is to boost the preferred pharmacological, biological or physical qualities of a substance without making substantial changes in the chemical skeleton. A vital feature of medicinal chemistry has been to ascertain a correlation between chemical skeleton of drugs and their physicochemical properties and in turn such properties modify the pharmacological properties and consequently the therapeutic response of drugs. Drugs with analogous structures often are liable to have comparable pharmacological properties. The present review highlights the vital role of bioisosterism as a special approach of structural modification and optimization process in drug design programme with clear 2D and 3D structural drawings.
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