React. Polym.17 (1992)115-139
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Determination of iodine content using ion exchange chromatography J. C s a p 6 a n d I. S a r u d i
Faculty of Animal Science, PANNON Agricultural University, P.O. Box 16, H-7400 Kaposvdr, Hungary A chromatographic method using an ion exchange column has been developed for the determination of the iodine content in biological materials, foods, fodders and mineral premixes. The method is based on the reaction between iodine and tyrosine resulting in the formation of 3-iodotyrosine and 3,5-diiodotyrosine. The reaction can be influenced with increasing the tyrosine concentration to form 3-iodotyrosine rather than the diiodo compound. The increased concentration of tyrosine results in a 3,5-diiodotyrosine concentration below the detection limit. The relative standard deviation of the analysis is 5% and the limit of determination is 0.1 mg/kg.
Ion exchange treatment of rinse water from heavy metal plating using weakly dissociating ion-exchangers L . A . D u k h o v a , L.V. S h e p e t y u k , O . V . K r j u c h k o v a a n d A . I . K a l i n i t c h e v
Institute of Phys. Chem., Lenin Avenue 31, Moscow 117915, USSR The ion exchange method of waste water treatment is widely used in metal plating plants. The ion exchange column system provides the recycling of the constituents of rinse water. Preparative ion exchange chromatography is suitable for effective selective removal of heavy metals from the effluents. This report deals with the experimental studies of wastewater treatment by weakly basic and complex-forming resins in chromatographic columns. The advantage of these resins consists in the possibility to realize selectivity that favours the uptake of ions from input solution both in sorption and regeneration stages of the process. Under definite conditions the formation of weakly dissociating complexes leads to sharpening of the sorption front and to the enhancement of intraparticle ion diffusion. Experimental investigations of ion exchange statics, kinetics and dynamics of metal ions removal from wastewater with ion concentrations 10-100 m g / l have been performed. In comparison with the strong dissociating resins, the weakly dissociating one gives much better results for removing metals from the effluent, the concentration of the recovered solution (15 g / l for Ni 2+ ions and 100-120 g / l for Cr 6+ ions) being high. These concentrations allow metal to be recycled. Short time of metal desorption and high flow rate of wastewater (40-100 cm/min) are obtained due to the employment of the ion exchange column with weakly dissociating resins.
Chemical fixation of 5-nitrofuran derivatives on macroporous styrene-divinylbenzene copolymers L. F e i s t e l
1, G .
S c h w a c h u l a 1, N. M o s z n e r 2 a n d H . B e r g m a n n 2
1Department of Ion Exchange, Chemie AG Bitterfeld-Wolfen, Germany 2 Department of Chemistry, Friedrich-Schiller-Universitiit Jena, Jena, Germany 5-Nitrofuran derivatives have been immobilized on macroporous styrene-divinylbenzene copolymers to get effective antimicrobial substances. It was tried to immobilize 5-nitrofuran using carboxylic, aminomethyl or sulfonamido groups being attached to the macroporous copolymers. These new products have been characterized by elemental analysis and IR spectroscopy. Furthermore, the hydrolytic stability was investigated. Reference:
J. Macromol. Sci. Chem. (1991).