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The paper presents a comprehensive study on the removal efficiency for different concentrations of Cr(VI) aqueous solutions, using alginate gel beads with and without polyaniline constituent. Synthesized polyaniline was entrapped in calcium alginate particles and further characterized with optical/spectroscopic techniques. The influences of contact time, pH, adsorbent type and initial chromium concentration on the adsorption process have been investigated. In good agreement with similar studies, the mixed sorbent with polymeric composition (PANI-Alg) showed a good efficiency for hexa-valent Cr removal from aqueous solution under acidic conditions (pH 2). Modeling of experimental data was achieved using Langmuir and Freundlich equations. Our study suggests that the proposed material (polyaniline-alginate beads) could be used for the removal of Cr from contaminated waters, through a cost-effective and environmentally friendly process. [ABSTRACT FROM AUTHOR]

Impurities in pharmaceutical products require particular notice due to their associated risks for human health and their impact on environmental contamination. Inter- national Guidelines, European directives, Pharmacopoeias and other regulatory documents specify how to classify and control different categories of impurities which could be present at one time in a drug substance or product. If the classification is more or less complete (for instance one category of the residual solvents is represented by those for which no adequate toxicological data was found), the control strategies need to be defined and implemented. Various analytical techniques are applicable for the detection of impurities in the entire production flow - starting from active pharmaceutical ingredients, excipients, intermediates, to the finite drug product. Control strategies are completed and improved with highly efficient detection methods (such as Ultra Performance Liquid Chromatography and other process analytical technology-related techniques) and shall comply with specific environmental legislation, especially in connection to marketing restrictions and use of certain dangerous substances and preparations or ambient emissions. [ABSTRACT FROM AUTHOR]