Herein, a QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure together with liquid chromatography and tandem mass spectrometry was applied to the multi-residue analysis of 203 pesticides in strawberries. To reduce the amount of co-eluents, we compared several dispersive solidphase extraction cleanup procedures and found that cleanup using octadecylsilane provided the best recoveries. Spiked-sample recoveries of 70-120% with relative standard deviations of <20% were obtained for all tested pesticides except for quinmerac. Matrix-matched calibration curves exhibited good linearities (R 2 > 0.99), and the limits of quantification (LOQs) were lower than the maximum residue limits recommended by the European Commission and Korea Food and Drug Administration. The developed method was applied to real samples, revealing that their pesticide contents exceeded the corresponding LOQs. The obtained results demonstrate that octadecylsilane-based dispersive solid-phase extraction is a rapid and high-throughput cleanup procedure for the multi-residue analysis of pesticides in strawberries. Análisis de residuos múltiples de 203 pesticidas detectados en fresas empleando cromatografía líquida de espectrometría de masas en tándem en combinación con el método QuEChERS RESUMEN El presente estudio aplicó un procedimiento QuEChERS [acrónimo en inglés de rápido, fácil, barato, efectivo, resistente y seguro] junto con cromatografía líquida y espectrometría de masas en tándem para analizar residuos múltiples de 203 pesticidas detectados en fresas. Con el propósito de reducir la cantidad de coeluyentes, se compararon varios procedimientos de limpieza de extracción en fase sólida dispersiva, constatándose que la limpieza con octadecilsilano proporcionó las mejores recuperaciones. Así, se obtuvieron recuperaciones de muestras con picos de 70-120% y desviaciones estándar relativas <20% para todos los pesticidas analizados, excepto quinmerac. Las curvas de calibración de matriz coincidente exhibieron buenas linealidades (R 2 > 0.99), mientras que los límites de cuantificación (LOQ) fueron inferiores a los límites máximos de residuos (LMR) recomendados por la Comisión Europea y la Administración de Alimentos y Medicamentos de Corea. El método desarrollado se aplicó a muestras reales, revelando que los contenidos de pesticidas de éstas excedían los LOQ correspondientes. Los resultados obtenidos demuestran que la extracción dispersiva en fase sólida basada en octadecilsilano es un procedimiento de limpieza rápido y de alto rendimiento para analizar residuos múltiples de pesticidas en fresas.

Agricultural water is closely linked to surface and ground water as well as soil; hence, ensuring its safety is an important endeavor. We used the “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) method to analyze multi-residue pesticides in agricultural water by using a combined-sorbent-based clean-up procedure. Among the various sorbents examined, clean-up using ENVI-Carb combined with a primary secondary amine sorbent delivered the highest recovery of multi-residue pesticides (>93.9%). While the developed method showed satisfactory linearity (R2 > 0.9991), precision, and specificity, recovery was low for pyrazolate (29.1%) and thidiazuron (59.2%). The limits of detection and quantification for the 55 pesticides targeted in this study were in 0.02–3.0 μg L−1 and 0.1–9.9 μg L−1, respectively. The developed method was used to identify and quantify multi-residue pesticides during sample analysis. The results suggest that the QuEChERS method employing a combination of ENVI-Carb and another sorbent can be applied for the effective analysis of multi-residue pesticides in agricultural water.