Investigation on the chemical structure of nonextractable residues of the fungicide cyprodinil in spring wheat using 13C-C1-phenyl-cyprodinil on 13C-depleted plants-an alternative approach to investigate nonextractable residues.
13C-labelled cyprodinil was applied on 13C-depleted wheat plants with 27-fold field application rate. A control experiment applying same amounts of 14C-cyprodinil showed that main portions of the residues were detected in the cellulose (15% NER), hemicellulose (28.3% NER), and lignin fraction (23.3% NER). 16.7% were detected in water soluble polymers, 6% in both, pectin and protein fraction, and 4% in the starch containing fraction. Free cyprodinil was detectable by TLC in all fractions except lignin. A direct characterization of the residues in vivo by CP-MAS was not successful. Cell wall fractions were further analysed by liquid state NMR to determine the structure of the mobilized highly polymer/polar residues: Within lignin, where most of the residues were located at field application rate, neither intact cyprodinil nor its metabolites could not be detected. The 13C-label introduced was probably incorporated in the polymer as natural lignin monomers and thus are not considered as bound residues according to IUPAC definition.
Ertunç
Tanya
T
Department of Biology V-Environmental Chemistry, Technical University of Aachen, Aachen, Germany. t.ertunc@nercrcl.gla.ac.uk
Schmidt
Burkhard
B
Kühn
Holger
H
Bertmer
Marco
M
Schäffer
Andreas
A
D002247:Carbon Isotopes / Q000032:analysis; D002473:Cell Wall; D005506:Food Contamination; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry; D011743:Pyrimidines / Q000032:analysis* / Q000737:chemistry; D014908:Triticum / Q000737:chemistry*
D002247:Carbon Isotopes; D010573:Pesticide Residues; D011743:Pyrimidines; C108338:cyprodinil