RESUMO
Supercritical fluid extraction (SFE) was applied to extraction of pesticides from vegetables and fruits. Residues were extracted from homogenized samples mixed with water-absorbent polymer with supercritical carbon dioxide in a stainless steel tube, followed by elution with acetone. Co-extractives were removed by means of mini-column clean-up. Measurement was performed by GC-MS/MS. Calibration was achieved by preparing matrix-matched calibration standards to counteract matrix effects. With the Japanese method validation guideline as a reference, the method was assessed in 5 agricultural products spiked with 334 pesticides at 0.01 and 0.1 µg/g. Compounds at each level were extracted from 2 samples on 5 separate days. The trueness of the method for 189 pesticides in all samples was 70-120%, and the repeatability and within-run reproducibility were also consistent with the guideline. The trueness of the method for the other 71 pesticides was in the range of 50-70%, though the repeatability and within-run reproducibility were satisfactory. This method is available as a multiresidue analysis method for vegetables and fruits.
Assuntos
Frutas/química , Resíduos de Praguicidas/análise , Verduras/química , Cromatografia Gasosa , Cromatografia Gasosa-Espectrometria de Massas , Reprodutibilidade dos TestesRESUMO
Supercritical fluid extraction (SFE) was applied to extraction of pesticides from cereals and pulses. Residues were extracted from homogenized samples mixed with water-absorbent polymer and supercritical carbon dioxide in a stainless steel tube, followed by elution with acetonitrile. Co-extractives were removed by means of mini-column clean-up. Measurement was performed by GC-MS/MS. Calibration was achieved by preparing matrix-matched calibration standards to counteract matrix effects. With the Japanese method validation guideline for pesticide residues as a reference, the method was assessed in 5 agricultural products spiked with 334 pesticides at 0.01 and 0.1 µg/g. Compounds at each level were extracted from 2 samples on 5 separate days. The trueness of the method for 137 pesticides in all samples was 70-120%, and the repeatability and within-run reproducibility were also consistent with the guideline. The trueness of the method for the other 101 pesticides was in the range of 50-70%, though the repeatability and within-run reproducibility were satisfactory. This method is available as a multiresidue analysis method for cereals and pulses.