Dissipation of difenoconazole in apples used for production of baby food.
Dissipation of fungicide difenoconazole (3-chloro-4-[(2RS,4RS;2RS,4SR)-4-methyl-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-2-yl]phenyl 4-chlorophenyl ether) was studied following its application on apples intended for production of baby food. The apples (varieties: Jonagold Decosta, Gala and Idared) were sprayed with the formulation to control pathogens causing fungal diseases: powdery mildew (Podosphaera leucotricha ELL et Ev./Salm.) and apple scab (Venturia inaequalis Cooke/Aderh.). A validated gas chromatography-based method with simultaneous electron capture and nitrogen phosphorus detection (GC-ECD/NPD) was used for the residue analysis. The analytical performance of the method was highly satisfactory, with expanded uncertainties ≤ 19% (a coverage factor, k = 2, and a confidence level of 95%). The dissipation of difenoconazole was studied in pseudo-first-order kinetic models (for which the coefficients of determination, R2, ranged between 0.880 and 0.977). The half-life of difenoconazole was 12-21 days in experiments conducted on three apple varieties. In these experiments, the initial residue levels declined gradually and reached the level of 0.01 mg kg-1in 50-79 days. For the residue levels to remain below 0.01 mg kg-1(the maximum acceptable concentration for baby foods), difenoconazole must be applied approximately 3 months before harvest, at a dose of 0.2 L ha-1(50 g of an active ingredient per ha).
a Laboratory of Pesticide Residue Analysis, Regional Experimental Station, Institute of Plant Protection - National Research Institute , Rzeszów , Poland.
Ewa
E
Szpyrka
b Department of Pesticide Residue Research , Institute of Plant Protection - National Research Institute , Poznań , Poland.
Stanisław
S
Walorczyk
D002849:Chromatography, Gas / Q000379:methods; D004148:Dioxolanes / Q000032:analysis / Q000737:chemistry* / Q000494:pharmacology; D005506:Food Contamination / Q000032:analysis*; D005638:Fruit / Q000737:chemistry; D005659:Fungicides, Industrial / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D006207:Half-Life; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000032:analysis*; D027845:Malus / Q000737:chemistry* / Q000187:drug effects; D010573:Pesticide Residues / Q000032:analysis / Q000737:chemistry; D011044:Poland; D015203:Reproducibility of Results; D014230:Triazoles / Q000032:analysis / Q000737:chemistry* / Q000494:pharmacology
D004148:Dioxolanes; D005659:Fungicides, Industrial; D010573:Pesticide Residues; D014230:Triazoles; C115058:difenoconazole
Difenoconazole; apple; baby food; dissipation; gas chromatography; residue