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Variations in sulphur and nitrogen foliar concentration of deciduous and conifers vegetation in Slovakia
1997
Mankovska, B. (Forest Research Inst., Zvolen (Slovak Republic).)
Influence of a mycorrhizal fungus and/or rhizobium on growth and biomass partitioning of subterranean clover exposed to ozone
1997
Miller, J.E. (North Carolina State Univ., Raleigh, NC (USA). Dept. of Forestry) | Shafer, S.R. | Schoeneberger, M.M. | Pursley, W.A. | Horton, S.J. | Davey, C.B.
Fish contamination and human exposure to mercury in Tartarugalzinho River, Amapa State, Northern Amazon, Brazil: a screening approach
1997
Bidone, E.D. (Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. Geoquimica) | Castilhos, Z.C. | Santos, T.J.S. | Souza, T.M.C. | Lacerda, L.D.
Pollution prevention in the paints and coatings industry
1997
Joseph, Ron
Analyzing nonpoint source water pollution problems
1997
Favero, Philip
Water pollution IV
1997
Rajar, R (Rudi) | Brebbia, C. A.
Himalayan microbial diversity
1997
Sati, S. C. | Saxena, J. (Jitendra) | Dubey, R. C.
The description, assessment and meaning of vertical fluxes of matter within ecotypes - a systematic consideration Full text
1997
Dämmgen, Ulrich | Grünhage, Ludger | Jäger, Hans-Jürgen
The interactions between sediments and water
1997
Evans, R. Douglas | Wisniewski, Joe | Wisniewski, Jan R.
Direct aqueous derivation and gas chromatographic analysis of halogenated lower carboxylates in environmental samples
1997
Ozawa, H. (Nagano-ken. Research Inst. for Health and Pollution (Japan))
Analytical method for hydrophilic polar environmental pollutants was studied. Among these pollutants, the halogenated lower carboxylates were the target compounds of this investigation. A novel but simple derivatization method necessary for sample preparation for instrumental analysis was developed. The new derivatization method for the carboxylates is not a conventional chemical reaction in non-aqueous solvent following isolation from the environmental samples but rather, a direct aqueous reaction ; direct conversion of the carboxylates to amides using a carbodiimide in dilute aqueous solution. Halogenoanilines were selectively used with dicyclohexylcarbodiimide (DCC) under acidic conditions at room temperature to form the anilide derivatives. Moreover, this reaction proceeds while mixing the sample water, DCC, a halogenoaniline, and small volume of extracting solvent. Thus, for the first time, simultaneous derivatization of the carboxylates and extraction of the products into solvent was achieved. Based on the results, simple and practical determination methods by gas chromatography were developed for traces of these carboxylates in environmental samples and the proposed methods were applied to some real samples. Such analytical derivatization methods for carboxylates are useful and noteworthy because they can form C-N bonds in aqueous media under mild conditions with carbodiimides and N atoms of amino and other compounds.
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