Determination of pesticides residues in quinoa (Chenopodium quinoa Willd) using QuEChERS and LC-MS/MS

Franz Zirena Vilca; Graziela Cristina Rossi Moura Andrade; Walter Alejandro. Zamalloa Cuba; Valdemar Luiz. Tornisielo

doi:10.9755/ejfa.2018.v30.i5.1683

Authors

Franz Zirena Vilca Escuela de Posgrado de la Universidad Nacional del Altiplano, Av Floral 1153 Puno-Perú
Graziela Cristina Rossi Moura Andrade Centro de Energia Nuclear na Agricultura, Laboratorio de Ecotoxicologia, Avenida Centenario 303, 13416-903 Piracicaba, SP, Brazil
Walter Alejandro. Zamalloa Cuba Escuela Profesional de Ingeniería Quimica de la Universidad Nacional del Altiplano, Av Floral S/N Puno-Peru
Valdemar Luiz. Tornisielo Centro de Energia Nuclear na Agricultura, Laboratorio de Ecotoxicologia, Avenida Centenario 303, 13416-903 Piracicaba, SP, Brazil

DOI:

https://doi.org/10.9755/ejfa.2018.v30.i5.1683

Abstract

The QuEChERS method was optimized and validated for the determination of 40 pesticides in 37 samples of quinoa from the harvest 2010-2011 in Puno - Peru. The method involves extraction with 1% acetic acid acetonitrile with CH₃COONa anhydrous and MgSO₄ followed by dispersive solid-phase extraction with PSA and C18. Analyses were performed with LC-MS/MS using C18 column 150 mm x 2.1 x 3.5 µm, water and acetonitrile 0.1% formic acid used as mobile phase. Spiked quinoa blank at 0.01 and 0.1 mg kg^-1 was employed to evaluate recovery ranging from the 31.6 and 125.1% with RSD ≤ 23. The method showed linearity r2 ≥ 0.99 and limits of quantification ranged from 0.001 and 0.01 mg kg^-1, and was not observed a matrix effects. No pesticides residues were observed in the analyzed samples.