Determination of cutin-bound residues of chlorothalonil by immunoassay.
An indirect competitive enzyme-linked immunosorbent assay (ELISA) was used to determine photochemically cutin-bound residues of chlorothalonil in enzymatically isolated tomato and apple fruit cuticles. The samples were spiked, irradiated, exhaustively extracted, and depolymerized with boron trifluoride complex resulting in a soluble depolymerisate. With this procedure, the ELISA could be calibrated with free target molecules for the quantification of originally bound chlorothalonil residues. In fruit cuticles that were irradiated for 8 h by simulated sunlight, 0.030 and 0.068 mg/g photoinduced cutin-bound residues of wax-free cuticles (calculated as chlorothalonil) were determined for tomatoes and apples, respectively. For the used antibody mAb chl. 4/11, cross-reactivities with derivatives of chlorothalonil simulating different types of cuticle-bound residues are given and discussed.
Jahn
C
C
Institut für Lebensmittelchemie (170), Universität Hohenheim, Garbenstrasse 28, D-70593 Stuttgart, Germany.
Schwack
W
W
D003429:Cross Reactions; D004350:Drug Residues / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005638:Fruit / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000032:analysis*; D018551:Solanum lycopersicum / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry*; D009570:Nitriles / Q000032:analysis*; D019685:Rosales
D005659:Fungicides, Industrial; D008563:Membrane Lipids; D009570:Nitriles; C000521:cutin; C005806:tetrachloroisophthalonitrile