VOLUME 28, NO2, APR 2006

Determination of 4-Hydroxybiphenyl with N-bromosuccinimide

A potentiometric titration method has been used for the determination of 4-Hydroxybiphenyl with N-bromosuccinimide (NBS). The organic compound like 4-Hydroxybiphenyl is less soluble in aqueous media, while platinum indicator requires aqueous medium for potential measurements. Therefore, a mixed organic-aqueous medium has been used to dissolve 4-Hydroxybiphenyl for its determination with N-bromosuccinimide. A linear curve is obtained by plotting peak height (cm) vs. concentration (mg) of 4-Hydroxybiphenyl determined. The method is simple, as it requires only readily available laboratory equipment. At moderate concentration of the analyte, the error is within the range +0.1 to -0.4. However, at lower concentration, typically a few mg of the analyte, the error range is -3.3 to -3.6. read more

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INAM UL HAQUE ,A KHAN ,S A HUSSAIN ,

Effect of Gamma irradiation on Tensile Strength and Pyrolysis Behavior of Polyvinyl Chloride

Pyrolysis-Gas chromatoghraphy (py.GC) technique has been used for the rapid characterization of polyvinyl chloride (PVC) start as soon as the sample is inserted in the hot zone. The carrier gas rapidly swept the primary products from hot zone to the chromatographic column. So the secondary decomposition is largely eliminated and the prolysis products give accurate information about the nature, composition and structure of the polymeric material. The productions of hydrocarbons from PVC are monitored. The effect of the variation of temperature (600-800oC). Sample size (0.5-3) mg, pyrolysis atmosphere Nitrogen and Helium, residence time (0.365-1.827) seconds and gamma irradiation on tensile strength was also studied. The observed products from PVC were Ehatne/Ethene. Propane/propone 1,3-Buadiene, 1-butene, benzene and toluene. The yield of these products showed an increase with an increase in temperature from 600-800oC. Gamma irradiation of PVC at doze rate higher than 1 KGry was to decrease the tensile strength and the yield of Ethane/ethane propane/propene. 1.3 Butadiene. And 1-butene decrease. While the yield  of Benzene and toluene remains constant.    read more

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A F K IFRIHIM ,Z H FAROOQUI ,M IQBAL ,I A AWAN ,

Comparative study of Limestone Resources from Different Areas of N.W.F.P for Industrial Utilization

Good quality of huge limestone beds is found in many parts of N.W.F.P, Pakistan, particularly in Khyber Agency, Kohat and cherat areas. Limestone samples were collected from different localities of these areas for chemicals analysis. The chemical composition was determined and compared to standard values for the industrials utilization. The chemical composition of the deposits of all the three areas indicate that these deposits could be utilized for production of cement, refining of sugar, glass, ceramic, paper and chemical industries.read more

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M A FARRUKH ,F HAMID ,S NOOR ,

Effect of Deep Fat Frying on Physico-Chemical properties of Silybum Marianum and Sunflower Seed Oils.

The crude Silybum Marianum oil and sunflower oil were used for repeated deep fat frying of potato-fillet (French fries) for 5 consecutive days @ 20 minutes per day at 180-190oC and then allowed to cool for 18 hours at 25oC. The test oils were evaluated for physical and chemical deterioration. The quality indicates peroxide value (POV), anisidine value (AV), iodine value (IV), free fatty acid (FFA) and color (O.D at 420nm) of the samples were measured. It was found that all the quality parameters significantly increased as frying time was advanced, while the reverse trends regarding IV was observed in all the test oil. The highest average POV (38.1meq/kg), FFA (15.9%) and AV (9) were observed in Silybum Marianum oil while IV (97.1g/100g) in sunflower oil. The maximum change in color (discoloration) was observed in sunflower oil.read more

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H KHATTAK ,F K BANGASH ,

Accumulation of Heavy Metals in Tarry Deposit on Leaves at Various Locations of Karachi

In this study metal accumulation heavy metals accumulation in the tarry deposits on the leaves of tress growing along the busy road of Karachi city has been estimated. Samples of the tarry deposits on leaves were collected from various intersections on the busy roads of Karachi. In this study total average concentration of lead, copper, manganese, zinc nickel and cadmium were found in the range of 0.014-2.547, 0.026-1.8, 0.285-4.984, 0.472-7.173, 0.014-7.173, 0.014-0.265 and 0.002-0.027 mg/g respectively. The result shows that almost all the pollution is being generated by automobile exhaust in the urban areas of Karachi.read more

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G H SHAIKH ,D R HASHMI ,S I SIDDQUI ,

Contamination Arsenic in Public Water Supply Schemes of Larkhana and Mirpurkhas Districts of Sind

Arsenic (As) contamination of drinking water is now a global issue and is present, all over the world. In response to the growing concerns about this poisonous carcinogen and awareness of the dangers of As in drinking water, an exclusive study was carried out on the occurrence and distribution of arsenic in drinking water samples, collected from ten (10) villages of District Larkana, and seven (07) villages of District Mirpurkhas, in Sind province. The samples were collected from different public water supply schemes, where the drinking water quality is known to have been deteriorated. In all the study areas of Mirpurkhas, arsenic concentration was found below the maximum permissible limit as recommended by World Health Organization (WHO). An average concentration of 2.04 ppb was observed in water samples of Mirpurkhas with a narrow variation in the range of 0.40-20.02 ppb. Altogether 10% of the water samples of district Larkhana exceeded the WHO guideline of 10 ppb. As compared to Mirpurkhas, District Larkhana has appeared as a more problematic zone from the point of view of arsenic contamination in the particular study area.read more

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F PERVEEN ,I SIDDIQUI ,S K ALVI ,F A KHAN ,U ASGHAR ,T H USMANI ,

Pollution of Phulali Canal Water in the City Premises of Hyderabad: Metal Monitoring

Phulali canals passes through Hyderabad city with a population of about 2 million. Most of the municipal and city industrials effluent is added to canal water during of 14km and has direct impact on the health of human beings, crops and cattle life. The levels of trace and toxic elements are found higher in the order > Mg (249.53mg/l)> Ca(83.446mg/l)> Na(45.778 mg/l)> K(11.697 mg/l)> Al(1.592mgf/l)> Fe(1.451mg/l)> Mn(0.596mg/l)> Ba(0.576mg/l)> Zn(0.167mg/l)> Co(0.151mg/l)> Cr(0.0082mg/l)> Pb(0.2026mg/l)> Cu(0.063mg/l)> Cd(0.004mg/l)>Ni(0.005mg/l). strong positive correlation also exists for certain pair of elements like Mg-Cu(r=0.963), Na-Ni(r=0.932), Ba-Zn(r=0.929), Al-Mn(r=0.941), Cd-Ba(r=0.448), Cr-co(r=0.366), Pb-Cu(r=0.238), Zn-Fe(r=0.212) and Fe-Co(r=0.154). the results have been compared with NEQs, drinking water upper limits for human beings and livestock, irrigation water limits and aquatic life protection limits. The levels of manganese, iron and cobalt are found higher than the irrigation water restriction values and overall water is poorly unsuitable for drinking of livestock, aquatic life and for irrigation purposes in the long run.read more

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J I IQBAL ,M H S WATTOO ,M I BHANGER ,S A TIRMIZI ,F H WATTOO ,T G KAZI ,

A Comparative Characterization of Different Non-Conventional Oilseeds found in Pakistan

Hexane-extracted oil contents of rice bran of variety super kernel (Oryza saliva) muskmelon (Cucumis melo), watermelon (cirllus vulgaris) and mango kernel (Mangofera indica) ranged from 10 to 45%. Other physical and chemical parameters of the extracted oils were follow: Iodine value 117, 106, 83 and 50; refractive index (40oC) 1.446, 1.467, 1.468 and 1.461; density (40oC) 0.919, 0.926, 0.902 and 0.974; saponification value 183.0, 174, 205 and 189, unsaponifiable matter 5.64, 4.18, 0.68 and 1.00, respectively. The investigated oils were found to contain a high levels of oleic acid (C18:3 Omega-9) ranged 23-83% followed by Iinoleic acid (C18:3 Omega-6) 1-59%. Linolenic acid (C18:3 Omega-3) was only found in super kernel variety (2.4%). Many parameters of the investigated oils were quite comparable with those different conventional oils.read more

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M I BHANGER ,R SHAHAID ,S IQBAL ,M KHAN ,T ANWER ,F ANWAR ,

Effect of Metal Chlorides on the Spectral Behavior of poly (Vinylpyrrolodone) in Aqueous Solution

Electronic spectral behavior of poly (Vinylpyrrolodone) in Aqueous Solution i.e. PVP, was determined in aqueous solution including a variety of metalchloride (MgCl2, KCl and BaCl2). The n®p* excitations shifted to longer wavelength depending on the nature and the salt concentration of different cation. The order of effectiveness of cation is K1+ > Ca2+> Mg2+ > Ba2+ for poly (Vinylpyrrolodone) Solution. Change observed in lmax by the salt were correlated with the polymer solvent interactions. These changed were attributed to attraction of PVP molecules with co solute molecules. As the concentration of the co solute increased, a red shift in the peaks was observed indicating an increase in interaction between PVP and co solutes.    read more

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M S KHAN ,K GUL ,

Thermal Treatment of Aluminum Trihydroxide and its Effect on the Reactivity

Aluminum trihydroxide Al (OH)3 was heat treated at temperatures 250,350 and 550oC and the ultimate effect of water of crystallization on its reactivity was studied. The reactivity was found reduced to half on heating. The process described thermal transformation of crystalline phase from gibbsite to boehmite and to alumina.  read more

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M L MIRZA ,W A SHAH ,F SHAHEEN ,M P I QAZI ,