خيارات البحث
النتائج 1 - 6 من 6
[Tracing of the source of nickel in groundwater in Roskilde and Storstroems County]
1997
Knudsen, C.
[Pesticide analyses in groundwater: State of the art]
1997
Hansen, N.
Protocols for evaluating the natural attenuation of fuel hydrocarbons and chlorinated aliphatic hydrocarbons in groundwater
1997
Wiedemeier, T.H.
[Detection of degradation products using chemical and biological methods [intrinsic bioremediation]]
1997
Dyreborg, S.
Speciation of lead in contaminated soils
1997
Sauve, S. | McBride, M.B. | Hendershot, W.H. (Cornell University, SCAS Department, Bradfield Hall 908, Ithaca, New York, 14853 (USA))
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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