A miniaturized QuEChERS and UPLC–MS/MS method for the determination of mycotoxins in cashew nuts

This study aimed to develop and validate a multi-mycotoxin analysis method applied to cashew nuts by employing a miniaturized QuEChERS method followed by determination by ultra-performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS). Satisfactory recoveries for the concentrations 1, 10 and 30 ng g⁻¹, ranging from 66% (fumonisin B₁) to 110% (ochratoxin A) and relative standard deviations lower than 9% (fumonisin B₂) were obtained for the target compounds. Limits of quantification ranged from 0.004 ng g⁻¹ (sterigmatocystin) to 0.59 ng g⁻¹ (alternariol). The applicability of the analytical method was verified by analyzing 30 cashew nut samples from the city of Rio de Janeiro, RJ, southeastern Brazil. Aflatoxins M1, G2, G1, B2, B1, ochratoxin A and sterigmatocystin were detected, respectively, in 27%, 10%, 17%, 30%, 30%, 30% and 50% of the analyzed samples, at maximum concentrations of 0.56, 0.67, 1.43, 2.02, 4.93, 4.81, and 0.35 ng g⁻¹. The maximum limit established by Brazilian legislation for aflatoxins was not exceeded by any of the analyzed samples.