Heavy metal pollution is a serious environmental problem. The presence of such metals in different areas of an ecosystem subsequently leads to the contamination of consumable products such as dietary and processed materials. Accurate monitoring of metal concentrations in various samples is of importance in order to minimize health hazards resulting from exposure to such toxic substances. For this purpose, it is essential to have a general understanding of the basic principles for different methods of elemental analysis. This article provides an overview of the most sensitive techniques of elementalanalysis such as atomic absorption/emission spectrometry, mass spectrometry, x-ray fluorescence, voltametry, and nuclear techniques. In addition, the article addresses some applications in a range of sample matrices.

The purpose of current research work was to formulate and typify gelatin and poly(vinyl) alcohol (Gel/PVA) hydrogel which would be highly pH-responsive and can able to accomplish targeted delivery of methotrexate in order to treat the colo-rectal pathologies. The primed gel/pva hydrogel discs were subjected to various physicochemical techniques i.e. swelling, diffusion co-efficient, sol-gel analysis and porosity using three altered sorts of pH (1.2, 6.8 & 7.4) phosphate buffer solutions for assessment/evaluation, and their characterization was done through Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA). Shape alteration and controlled methotrexate of release of Gel/PVA hydrogel have been done using three type of pH (1.2, 6.8 & 7.4) phosphate buffer mediums. Methotrexate was loaded through in-situ drug loading method due to hydrophobicity. Different kinetic models (first order & zero order kinetic), Higuchi model and Krosmere peppas model/Power law were applied to manipulate the drug release data. Physicochemical evaluation tests and drug release profile results were found insignificant (p< 0.05) in various pH mediums and dependent upon polymers concentration pH of medium and cross-linker amount. Kinetic model disclosed that release of methotrexate from Gel/PVA hydrogel follow non-Fickian diffusion method. It became concluded from this research work that release of methotrexate Gel/PVA hydrogel in targeted colon area can be achieved for treating colo-rectal disorders.

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Introduction: A simple and reliable high performance liquid chromatographic method has been developed for quantitative determination of pregabalin in bulk and dosage form. Pregabalin, a γ amino butyric acid analogue has negligible sensitivity to UV or fluroscence detection. Hence, it has been derivetized by ninhydrin to form a chromophoric complex that could be quantified by UV detection. Materials and Methods: The concentration of ninhydrin was set to 5 mg/ml and phosphate buffer solution (pH 7.4) was used as solvent for reaction. The resultant complex was separated by HPLC and detected by UV detector at 569nm wavelength. Results: The developed method showed a linear response within 50 to 600 µg/mL of pregabalin. The method was accurate with mean recovery values within 100 ± 2%. The repeatability of the method was established by intra-day and inter-day precision study. Finally a commercial pregabalin capsule was assayed by the developed HPLC method including ninhydrin derivatization. The result of the mean assay was found to be 100.37 ±2.94 %. Conclusion: This is the first time we are reporting pregabalin analysis using ninhydrin derivatization for HPLC analysis. Therefore, the developed method can be considered as a significant improvement in pregabalin quantitation and it can be easily applied for routine quality control tests of pregabalin.

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