title: Pentafluorobenzylation of the fungicide metabolite fenpropimorphic acid for GC/MS investigations of soil samples.
abstract: For the determination of fenpropimorphic acid in soil samples, a derivatization step with pentafluorobenzylbromide has been established in order to perform GC/MS with negative chemical ionization. In spite of forming the electrophilic pentafluorobenzyl ester, only the fenpropimophic acid anion was detected. Additional derivatization reactions with diazomethane and 2,2,2-trichloroethanol showed that the formation of this acid anion was depending on the leaving group. In comparison with the determination of the methyl ester with GC/MS and electron impact ionization, the detection limit was however improved from 10 microg/kg to 2 microg/kg dry soil and the analytical quality was ensured due to higher stability of the pentafluorobenzyl ester standards.
authors.affiliation: Institute of Ecological Chemistry and Waste Analysis, Technical University of Braunschweig, Hagenring 30, D-38106, Braunschweig, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Dieckmann
authors.forename: R
authors.initials: R
authors.lastname: Kreuzig
authors.forename: M
authors.initials: M
authors.lastname: Bahadir