RESUMEN
A method was developed to determine the combined amounts of residual, free 3-phenoxybenzyl alcohol (permethrin alcohol) and its acetone-extractable glucosides in representative fruits and vegetables after application of pyrethyroid insecticides such as permethrin or cypermethrin. 3-Phenoxybenzyl glucoside was synthesized and used to spike food samples. Conditions were developed for extraction, enzymatic hydrolysis, derivatization with heptafluorobutyric anhydride, and cleanup prior to detection and quantitation by gas chromatography with electron capture detection. Limits of detection in various foods were < or = 0.01 ppm. In addition, 2 sets of field trial samples that were sprayed with permethrin and collected at intervals were also analyzed. In general, the amounts of total permethrin alcohol in foods were small.
Asunto(s)
Análisis de los Alimentos , Insecticidas/análisis , Piretrinas/análisis , Aerosoles , Calibración , Cromatografía de Gases , Cromatografía en Gel , Contaminación de Alimentos/análisis , Frutas/química , Glucosa/metabolismo , Glucósidos/síntesis química , Glucósidos/química , Hidrólisis , Permetrina , Residuos de Plaguicidas/análisis , Estándares de Referencia , Verduras/químicaRESUMEN
A gas chromatographic method with electron capture detection (GC-ECD) has been developed to quantitate the sum of free acids of pyrethroid metabolites, their glucosides, and their other base-cleavable conjugates that are extracted from tea leaves when a tea infusion is prepared. Four representative glucoside conjugates were synthesized; hydrolytic conditions were established; and extraction, derivatization and GC conditions were developed for analysis of these pyrethroid acid metabolites at > or = 0.01 ppm on dry tea. GC/mass spectrometry was used to confirm assignment of residues found in some tea samples.