A simple and efficient method employing solid-liquid extraction with low-temperature partitioning for the determination/monitoring of pesticide residues in strawberries by GC/ECD

摘要

The indiscriminate use of pesticides in strawberries can often make this crop unfit for consumption. In this study, the method of solid-liquid extraction with low-temperature partitioning (SLE/LTP) coupled with gas chromatography with electron capture detection (GC/ECD) was optimized. The proposed analytical method was validated by the analysis of spiked blank matrix samples. Limits of detection (LOD) varied between 4 and 16 μg kg-1, whereas limits of quantification (LOQ) ranged from 13 to 47 μg kg-1. Good recoveries (79-111%) and precision values (< 15%) were obtained for all compounds in the target matrix. This method has been successfully applied to the analysis of residues of pesticides found in strawberries collected from seven farms in the High Jequitinhonha Valley (MG, Brazil). The results revealed the presence of azoxystrobin, chlorothalonil, difenoconazole and iprodione in the strawberry samples.