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A gas chromatography — mass spectrometric method for determination of unsymdimethylhydrazine (UDMH) in soil and water has been developed. The method is based on derivatization of UDMH with 2-nitrobenzaldehyde, 4-nitrobenzaldehyde, 4-chlorobenzaldeyhde, 4-cyanobenzaldehyde, 4-dimethyaminobenzaldehyde, benzaldehyde and furfuraldehyde, followed by analysis of the derivative using gas chromatography — mass spectrometry. The effect of ambient air and antioxidants (pyrogallol and TiCl3) to absorb dissolved oxygen from the reagents has been investigated. The method proves to be useful for UDMH analysis in soil and water, and has been used for environmental site assessment at a former missile base in Ukraine. On a mis au point une methode spectrometrique de masse par chromatographie gazeuse pour la determination d'unsymdimethylhydrazine (UDMH) dans la terre et l'eau. La methode s'appuie sur la derivation d'UDMH avec le 2-nitrobenzaldehyde, 4-nitrobenzaldehyde, 4-chlorobenzaldehyde, 4-cyanobenzaldehyde, 4-dimethyaminobenzaldehyde, benzaldehyde et furfuraldehyde, suivie de l'analyse des derives au moyen de la spectrometrie de masse par chromatographie gazeuse. On a etudie l'effet de l'air ambiant et des antioxydants (pyrogallol et TiCl3) pour absorber l'oxygene dissous des reactifs. La methode s'avere utile pour l'analyse d'UDMH dans l'eau et dans l'air, et elle a ete utilisee a des fins d'evaluation environnementale dans une ancienne base de missiles en Ukraine.

A hybrid method incorporating selective polymeric binding and membrane separation was used for the removal of arsenic from contaminated groundwater. Two types of polymers, polyethylenimine (PEI) and poly-diallyl dimethyl ammonium chloride (DADMAC) and an ultrafiltration membrane were used at various concentrations and pH. Bench-scale tests demonstrated a high degree of arsenic removal. The retention of arsenic was also determined in the presence of various background salts such as NaCl, NaNO3, Na2SO4, Na2CO3. Retention was found to depend on the concentration and type of anion present in solution.