[en] Present work is carried out to synthesize nano hydroxyapatite ceramic particles using the self assembling properties of surfactants. To implement the self assembling behavior as templates, different surfactants are selected on the basis of different charged head groups and chain lengths to compare the morphological aspects of the synthesized nano particles. The factors which affecting the morphology of the particles i.e. the packing parameters of the amphiphilic surfactant molecules are investigated theoretically and by some means co-relate with the experimental values. It is observe that pH, temperature, stirring rate, surfactant concentration and the counter ions affect the morphology of the particles. The precipitation route is used to produce the nano particles and is characterized for molecular composition, phase analysis and morphology by FTIR, XRD and SEM respectively. (author)

[en] Solid state pH electrodes were prepared with copper wire and graphite fibers as internal references. Different materials were used for adhesion purposes. Electrodes behavior was compared with commercial pH glass electrode. One commercially available pH glass electrode was converted to solid state electrode and data obtained was compared to original data. Slope of 58 mV/ pH was obtained for standard buffer solutions. (author)

[en] The complexation study provides stability constant data of metal complexes. The knowledge of stability constants of metal complexes is important in view of finding the best complexing agent for extraction and separation of metal ions. In the present work, the mathematical treatment of complexation equilibria was discussed to get insight on the methodology for finding the stability constants. The cyclic voltammetry and pH analysis methods were used to evaluate the stability constants of uranyl acetate complexes. The stability constants of uranyl acetate complexes obtained from cyclic voltammetry and pH analysis methods were in close agreement with the reported data in literature. (author)

[en] The third chemistry conference 2011 on recent trends in chemistry was held from October 17-19, 2001 at Islamabad, Pakistan. More than 65 papers and oral presentation. The scope of the conference was wide open and provides and opportunity for participation of broad spectrum of chemists. This forum provided a platform for the dissemination of the latest research followed by discussion pertaining to new trends in chemistry. This con fence covered different aspects of subjects including analytical chemistry, environmental chemistry, polymer chemistry, industrial chemistry, biochemistry and nano chemistry etc. (A.B.)

[en] The science of chemical taxonomy is used for the classification of plants on the basis of their chemical constituents which are deeply concerned with the molecular characteristics. Five locally available plant taxa of Solanum nigrum Complex viz.: S. americanum Mill., S. chenopodioides Lam., S. nigrum L., S. retroflexum Dunal and S. villosum Mill. were investigated to resolve the international taxonomic controversy about these plants. Comparative qualitative and quantitative analyses of these plant samples were undertaken keeping Alkaloids, Flavonoids and Epicuticular wax as potential characters. The glycosides of alkaloids and flavonoids were determined by HPLC whereas their aglycones and epicuticular waxes were analysed using GC-MS. HPLC and GC-MS analyses of these constituents from S. nigrum Complex had not been reported previously. Statistical analyses of results grouped taxa into different clusters on the basis of similarity index and Euclidean distance. (author)

[en] Analytical techniques are widely used for verification and accountancy of nuclear materials. Nuclear Material (NM) inventories are based on sampling followed by Destructive Analysis. Destructive Analyses range from traditional chemical techniques to recent implementations of radiometric methods. These techniques are performed to quantify the amount of nuclear material (elemental assay and isotopic composition) present in a specific item, container, or in some cases facility and resolving shipper-receiver differences. Analytical techniques used for the MC and A of nuclear material normally require more attention than that for process control because the largest contribution to Material Unaccounted For is in measurement uncertainty. Therefore analytical techniques selected for material control and accountability are highly precise and they comply with accepted 'International Target Values 2010'. (author)

[en] Nanofiltration (NF) is a treatment technology which is suitable for selective removal of solutes from solvents in process industries. Its application is increasing worldwide due to certain advantages associated to this technique such as low operation pressure, high flux, high retention of multivalent ion salts and low maintenance costs. Recently this technique has been successfully applied for removal of uranium from drinking water. Experiments were conducted for separation of 'U' contents from waste stream of Uranium Refining Plant at CPC Project. A spiral wound polypiprazine amide nano filtration membrane with an effective surface area of 2.60 m2 was used for this experimentation. The experiments were carried out with concentration mode. The results of this study show 'U' content retention of greater than 99% whereas 'U' contents were found to be less than 3 ppm in the permeate stream. The results further reveal that the pH of the feed solution had significant influence on retention efficiency of the membrane. The membrane retention efficiency was reduced to 85% when feed with a pH of 1.0 was processed whereas maximum retention was found to be at neutral pH value. (author)

[en] Herbicides are chemical substance used to kill weed in agriculture field to improve crop yield.The use of herbicides is steadily on the increase world wide and also in Pakistan due to the shift from traditional practices of weed elimination. These substances are either acidic, basic or ester. Due to their solubility in water, they can find their way into different water sources through run off or leaching and thus can pose serious health threat. For the public health safety it is therefore important to monitor these herbicides in potable water supplies and food products. A variety of methods have been developed over the last ten years for the determination of different classes of herbicides and have been applied to samples of environmental will be importance. These details of these methods and their potential application will be discussed. (author)

[en] A wavelength dispersive X-ray fluorescence spectrometer, Pan Analytical (Philips) model. Magix was purchased in 2002 for chemical analysis of nuclear related materials. The required analytical work could not be done in open atmosphere due to active nature of the samples. The Glove box adapted models of these instruments are banned for our country. Therefore modification and Glove box (GB) adaptation was required. It was very innovative and time consuming assignment as only sample handling part of the instrument had to be placed inside GB, leaving rest of the instrument available for later repair/maintenance work. Different options were considered for adaptation point of view, keeping in mind the isolation and negative pressure inside the GB. One of such option was finalized which involved placing a tray in between the spectrometer and top shield plate. An intricate and complex geometrical shaped tray was designed which extended outward in the shape of a glove box. In this way originality of the instrument was maintained as well as the required objectives were achieved. (author)

[en] Synthetic antithyroid agents act through inhibition of enzyme or by making stable charge transfer (CT) complex with iodine. Iodine acts as s-acceptor and the synthetic compound as n-donor. Study of CT complexation of various drugs with iodine using UV/visible spectroscopy has revealed a positive correlation between the formation constant (Kc) and in vivo an activity. Some alkyl derivatives of 9H-purine-6-thiol were synthesized and evaluated in vitro as well as in vivo for potential antithyroid effects. The compounds exhibited 1:1 charge transfer complexation with iodine and have quite high values of formation constants. The blood assays of rats treated with these compounds and histological study of the thyroid tissues indicated the hyperactivity of gland. These compounds are expected to have lesser side effects as the sulfa group, a cause of toxicity in many medicines, is blocked. Phenyl derivative proved to be the most potent antithyroid agent comparable with methimazole. (author)